218results about How to "Overcome volume" patented technology

The invention relates to an aerogel composite material, in particular to a glass fiber reinforced silicon dioxide aerogel composite material and a preparation method thereof. The excellent properties of aerogel are maintained, the mechanical properties of the aerogel are reinforced, and the glass fiber reinforced silicon dioxide aerogel composite material has good integrity and certain strength. The glass fiber reinforced silicon dioxide aerogel composite material is prepared by compounding glass fiber and silicon dioxide aerogel, wherein the glass fiber is a reinforcement, and the content ofthe glass fiber accounts for 1-15% total mass of a sample; the silicon dioxide aerogel is a matrix, tetraethoxysilane is a silicon source material, and methyltrimethoxysilane or methyltriethoxysilaneis used as a silicon source co-precursor. The preparation method comprises the following steps of: firstly, pretreating the glass fiber; then, preparing glass fiber reinforced silicon dioxide composite wet gel; and finally, aging, secondarily modifying and drying the silicon dioxide composite wet gel.

The invention relates to a photovoltaic high-frequency isolation boost soft switch DC / DC converter and a control method thereof, which is used for solving the problems of difficult current conversion of leading leg in idle load or light load and low efficiency in full load, improving the efficiency of the converter and realizing full-power converter. The photovoltaic high-frequency isolation boost soft switch DC / DC converter comprises a high-frequency transformer, wherein the primary side of the high-frequency transformer is provided with a phase shift PWM (pulse-width modulation) control converter; the high-frequency transformer is provided with three secondary sides; two secondary sides are formed by connecting bridge type diode rectification circuits in series for outputting high voltages, the output ends of the secondary sides are connected with output voltage and current sampling circuits, and the output voltage and current sampling circuits are connected with a controller; the third secondary side is formed by connecting a voltage dropping winding with a current converting inductor and a switch in series; the primary side of the transformer is provided with a blocking capacitor Cb and a saturation inductor LS which are connected in series; output filtering capacitors Lfl and Lf2 are coupling capacitors and share one magnetic core; output ends Df1-R1-Cf1 and Df2-R2-Cf2 form a crossed clamping buffer circuit; and the asymmetrical phase shift PWM controller controls power switching devices VT1 to VT4 and a switch K0.

The invention relates to a preparation method of a carbon-coated metal oxide-graphene composite electrode material. The preparation method comprises the steps of preparing a suspension graphite oxide liquid, carrying out ultrasonic dispersion, preparing a metal oxide precursor solution and a carbon source pecursor solution, carrying out the ultrasonic dispersion and mixing so as to obtain a dispersed solution, transferring the dispersed solution into a hydrothermal reaction kettle for reaction, cooling naturally, washing centrifugally, freezing, drying to obtain dried powder, and calcining the dried powder in a protective atmosphere to obtain the carbon-coated metal oxide-graphene composite electrode material. A one-step hydrothermal method is adopted for constructing a carbon-coated-graphene double protection composite structure, while the nanoscale metal oxide is prepared, a carbon coating manner and grapheme are compounded, the double protection composite structure can effectively overcome the volume effect and the severe polarization phenomenon in the charging and discharging process of metal oxide and can greatly improve the capacity and the cycling stability of a battery. The preparation method is simple, easy to implement, and suitable for large-scale industrial promotion.

A preparation method of a zinc oxide / graphene composite material for a lithium ion battery is as follows: first, taking graphite oxide to add into a solvent for ultrasonic treatment to obtain a graphene oxide dispersion liquid; then taking a zinc salt to add into the graphene oxide dispersion liquid, performing pH adjustment to make the mixed solution alkaline; then transferring the mixed solution to a hydrothermal reactor for reaction, cooling to room temperature when the reaction is finished, respectively washing for 3 times with water and ethanol, performing vacuum drying treatment to obtain a partly reduced graphene-zinc oxide composite material; finally, calcining the partly reduced graphene-zinc oxide composite material under inert atmosphere, cooling to room temperature when the calcining is finished to obtain the zinc oxide / graphene composite material. The zinc oxide / graphene composite material prepared by the method can be used as a negative electrode material for lithium ion batteries, can overcome the problems of poor conductivity and serious volume expansion effect of zinc oxide, has the characteristics of strong cyclic stability and strong conductivity; and the method has characteristics of simple operation, high repeatability and low cost.

The invention relates to a multi-micronano detector networking joint demonstration verification system based on an intelligent mobile robot, comprising a ground synergic control workstation, a synergic control model library, a satellite wireless communication equipment simulator, an intelligent mobile robot, a GPS (Global Positioning System) receiver, video navigation equipment and a display terminal, wherein the ground synergic control workstation controls the synergetic work and the formation transform and maintenance of the whole system; the synergic control model library provides a control algorithm and a control model for the ground synergic control workstation; the satellite wireless communication equipment simulator provides a communication link between satellites and the workstation; the intelligent mobile robot as a carrier of the GPS receiver and the satellite wireless communication equipment simulator is controlled by the control workstation to move and used for simulating the relative position change among the satellites; the GPS receiver and the video navigation equipment realize the relative navigation among the satellites; and the display terminal displays a networking joint verification result in real time. The invention can effectively decrease the test cost of a multi-micronano detector networking detection system, shortens a research and development period and has important engineering application values.

The invention discloses a gait-based wearable flexible knee joint robot exoskeleton facility which comprises a power and control system (4), a left knee joint airbag executing component (5), a right knee joint airbag executing component (6), a left foot pressure switch component (7), a right foot pressure switch component (8), a left foot posture sensor (9), a right foot posture sensor (10) and an air tube component (11), wherein a control circuit system (205) is used for controlling the output flow of a micro air pump A (203) and a micro air pump B (204) in real time, positive pressure and negative pressure are provided for the left knee joint airbag executing component (5) and the right knee joint airbag executing component (6) according to rules of gaits, and torque for assisting knee joints to bend and stretch in accordance with the gaits is provided for left and right legs in the walking process.

The invention discloses a lifting pillar support. The lifting pillar support is characterized by comprising a base, a lifting mechanism and a driving mechanism. The lifting mechanism and the driving mechanism are installed on the base. The driving mechanism can drive the lifting mechanism to move up and down. The driving mechanism comprises a motor, a reducer and a screw rod. The motor drives the screw rod through the reducer. The driving mechanism further comprises a top frame. The top frame is installed on the upper side of the lifting mechanism and the top frame can move up and down along with the lifting mechanism. The lifting pillar support has the advantages that the lifting pillar support which is easy to arrange and convenient to store and deliver is provided. Application range and efficiency are improved. On one hand, the problems that an original hydraulic driving lifting mechanism (a lifting platform and a lifting pillar) is big in self weight, large in size, slow in response speed and aging in oil leakage are solved. On the other hand, the lifting pillar support is convenient to deploy in advertising, media display, exhibition show, and sale promotion road show activities. The lifting pillar support is quiet, neat, energy-saving, environment-friendly and reusable.

The invention discloses a kind of array sensor for gas and the preparing method. The sensor uses the aurum, platinum or argentum as electrode; the RuO2, MoSi2, W or Pt is as heating membrane material; the random one or several kinds of the ZnO, SnO2 or Fe2O, or ZnO, SnO2 or Fe2O3 and Pt0.1wt%-3wt%, Pd0.1wt%-3wt%, Ni1wt%-30wt%, TiO21wt%-30wt%, WO31wt%-40wt%, Co2O3 1wt%-15wt%, V2O51wt%-30wt%, Al2O31wt%-20wt%, MnO21wt%-30wt% is as the sensing layer material. It gets the gas sensing array on the alumina, aluminium nitride or silicon base sheet with anti high temperature, electric insulating and heat conducting by the screen printing technology. The gas sensing array is fixed on the basal seat by the axis to form the gas sensing array sensor by ultrasonic hot press welding electrode leg wire. The sensor has the low production cost, low power cost, good mechanism stability. Each unit has the good gas sensing character and the process is proper for the big batch production.

The invention provides a BD, GPS and MEMS based integrated navigation system and method on account of defects f prior navigation systems. The system comprises an MEMS-IMU module, a GNSS module, a magnetometer module and an integrated navigation computer. The MEMS-IMU module, THE GNSS module and the magnetometer module are connected with the integrated navigation system respectively. By the aid of the navigation method, corrected position values, speed values and corrected attitude angle values can be output. The system and the method have the advantages of being anti-overloading, miniaturized, low in power consumption and cost, provided with high impact resistance and particularly applicable to various war environments. By the aid of the navigation method, drifting of gyroscopes, accelerometer and magnetometers can be suppressed, and the stability and the accuracy of the system are improved.

The invention relates to a box-type foldable electric bicycle, which consists of a handlebar assembly, a front wheel assembly, a rear wheel assembly, a frame assembly, a power drive mechanism, a seat assembling and a conventional traffic indicating lamp assembly, wherein a handlebar folder, a straight pipe folder and a front fork folder are arranged on the handlebar assembly; a rear fork folder is arranged on the rear wheel assembly, the frame assembly comprises a frame, a frame inner liner, a frame outer cover and a folding and locking mechanism; and the conventional traffic indicating lamp assembly comprises a headlamp, steering lamps and a brake lamp. When the box-type foldable electric bicycle is in a folded state, a left handlebar and a right handlebar are folded obliquely and lean against a straight handlebar pipe; the straight handlebar pipe is obliquely folded towards a front fork, is limited by the folding and locking mechanism together with the front wheel assembly and the rear wheel assembly which are folded and pull each other, and is collected in the cavity of the frame inner liner; and the external side of the frame is covered by the frame outer cover. The assembliesare reasonably foldable. Since the front wheel assembly and the rear wheel assembly are crosswise arranged in the folded state, the box-type foldable electric bicycle has the characteristics of scientific structure, reasonable layout, convenience and rapidness in folding and unfolding, regular shape, attractive appearance, smooth surface, small volume, convenience in storage, carrying and use andvery high practicability.

The invention discloses a graphene composite material, in particular a CoO and graphene composite material. The invention also relates to a preparation method of the graphene composite material and application of the graphene composite material in a lithium-ion battery. The preparation method comprises the steps of performing low-temperature recrystallization on cobalt acetate tetrahydrate, compositing the recrystallized cobalt acetate tetrahydrate and graphene oxide to obtain a precursor, and performing low-temperature annealing on the precursor under a high vacuum environment to obtain two-dimensional nano crystalline CoO-graphene composite material, wherein single-layer graphene with the thickness of 1-50 micrometers is taken as a carrier frame, and CoO nanocrystals with the average particle diameter of 2-20 nm are uniformly embedded in the upper and lower surfaces of the single-layer graphene. The prepared nano crystalline CoO-graphene composite material can be used as the negative electrode of a lithium-ion battery to effectively improve the capacitance of the lithium-ion battery; the preparation method is simple, the preparation period is short, the preparation efficiency is high, no toxic effect exists, the environment pollution is avoided, and the potential safety hazard is reduced.

The invention discloses an active vibration isolation control platform. The active vibration isolation control platform comprises an active vibration isolation device and an active vibration isolation controller; the active vibration isolation device comprises a lower platform, a midbody and an upper platform; a voice coil motor actuator is arranged between the midbody and the lower platform; a linear variable differential transformer type displacement sensor is arranged between the upper platform and the midbody; and two three-freedom-degree acceleration sensors are arranged on the upper platform and the lower platform respectively. The vibration isolation controller is designed according to a master-slave open type control structure and consists of an upper control computer and a lower execution controller, wherein the upper control computer is a mainframe of an embedded type industrial control computer PC / 104; and the lower execution controller is an open-type controller. The active vibration isolation control platform is quite effective on low-frequency vibration isolation and is applicable to precise manufacture, precise measurement, aerospace application and other vibration isolation fields with special requirement on vibration environment.

The invention is concerned with a kind of process equipment for produce production, especially a kind of wire feeding welding machine with fuse for fusible core. The worktable fixed on the frame has turning plate frame with at least four tasks and the task has movable clamp extended among the radial direction, and at the corresponding position to each task, there are tube push framework, wire feeding welding upper cap framework, welding down cap framework, location framework and stuff-accepting framework on the surface of worktable. Except the stuff-accepting framework, each of the aforesaid framework drives by each cam and drive pole under the worktable. The tube push framework connects with tube feeding equipment, and the wire feeding welding upper cap framework connects with upper cap feeding equipment, the welding down cap framework connects with down cap feeding equipment. The worktable and / or turning plate has equipment that keeps clamp moving. The drive axis drives by motor, the feeding equipment, heating equipment and motor of the tube, upper cap and down cap monitors by power control equipment.

The invention discloses a nutrient solution matrix-free seedling raising and cultivating system and a seedling raising method. The system comprises a nutrient solution seedling raising tank, a seedling grid plate, seeding paper and covering paper, wherein the nutrient solution seedling raising tank is filled with water or nutrient solution; the seedling raising grid plate is arranged on the nutrient solution seedling raising tank, and water through holes are formed on the side faces of the grid plate holes of the seedling raising grid plate; the seeding paper is laid on the seedling raising grid plate; and after seeding, the covering paper is covered on the seeding paper bearing seeds. The method comprises: sowing seeds on the seeding paper, covering the covering paper with high water absorbing performance and breathability and covering the perlite or vermiculite on the covering paper; and after the seeds germinate, the roots of the seedlings penetrate the seeding paper to grow downward to absorb water and nutrients from the nutrient solution below. When the system is used, a matrix which is adopted by the conventional industrial seeding raising technique is not used, the overall accurate control over the temperature, water, nutrient and oxygen required by plants for growth in the whole seedling raising process is realized, the industrialization of the seedling raising processis realized, and the uniformity, strong seedling rate and robust degree of the seedlings are improved.

The invention relates to animal muscle diagnosis and human body bioelectricity acquisition and recognition. The invention relates to electrode conductors for collecting surface electromyography signals, a functional buffer stage circuit, a preposing differential amplifying circuit, a filter circuit, a double T trap circuit and a back-stage amplifying circuit; the preposing differential amplifying circuit comprises a preceding stage differential amplifying circuit and a secondary differential amplifying circuit; the output end of the preceding stage differential amplifying circuit is also connected with a voltage follower circuit and an inverse amplifying feedback circuit which is communicated with the voltage follower circuit; the output of the inverse amplifying feedback circuit is communicated with the root of the electrode conductor; the filter circuit is the fifth-order Butterworth filter circuit; the electrode conductors are two silver electrodes which are pasted on the surface of skin; and the distance between the two silver electrodes is 8-12mm. The active double electrode surface electromyography sensor has good fixed mode, stable collected signals and strong signal filtering function, causes the capability of the circuit resisting the interfering of the power frequency to be increased and overcomes the defects of the high noise brought about by the electrode wiring, larger whole volume of the sensor and the like.

The invention relates to a preparation method of an ultra-high density cobaltosic oxide / porous graphene nano-composite anode material for a lithium ion battery and brings forward a novel low-cost in-situ growth method. According to the method, evenly distributed in plane defect sites are manufactured on the surface of oxidized graphene by means of strong oxidization of a chemical reagent; and then through a low-temperature hydrothermal reaction, in-situ growth of ultra-high density cobaltosic oxide nano-particles happens on porous graphene with the defect active sites. Cobaltosic oxide accounts for more than 92% of the compound, and adverse effects such as the drop in first coulombic efficiency and tilt of a charging / discharging platform due to addition of overmuch graphene can remarkably be improved. In the cobaltosic oxide / porous graphene nano-composite material, graphene can effectively improve conductivity insufficiency of cobaltosic oxide; and volume effect of cobaltosic oxide during the cyclic process can be well overcome due to the particle size of 5-10 nm. Thus, the material has ultra-high electrochemical performance. According to the invention, the principle is simple, and the material is easy to produce.

The invention discloses a method for preparing a sodium-ion battery negative electrode material with sodium alga acid as a carbon source. The method comprises the steps that sodium alga acid is dissolved in deionized water at first, the temperature is kept at 60-90 DEG C in the whole process, stirring is carried out, and even viscous liquid is obtained, wherein 0.8-20 g of sodium alga acid is dissolved in each 100 mL of deionized water; the obtained even viscous liquid is frozen and dried to obtain the spongy sodium alga acid with a loose structure; finally, the obtained spongy sodium alga acid is roasted in the inert atmosphere and cooled to room temperature after roasting is finished, dilute acid soaking is carried out, the sodium alga acid is washed with water and ethyl alcohol to be neutral through suction filtration, then, vacuum drying treatment is carried out, and the sodium-ion battery negative electrode material is obtained. The prepared sodium alga acid derivative carbon material is used as the room temperature sodium-ion battery negative electrode material, the problems that a bulk carbon material is low in battery capacity and serious in volume expansion effect can be solved, and the material has the advantages of being high in cycling stability and high in battery capacity.

The invention relates to the field of foods, in particular to potato dietary fiber bread and a making method of the potato dietary fiber bread. The potato dietary fiber bread comprises, by mass, 10 parts to 40 parts of potato coarse dietary fiber starch, 10 parts to 40 parts of potato coarse dietary fiber submicron powder, 10 parts to 20 parts of high-hydrostatic-pressure synergetic enzymatic hydrolysis modified potato coarse dietary fiber powder, 4 parts to 12 parts of extrusion potato coarse dietary fiber powder, 5 parts to 12 parts of potato starch, 5 parts to 13 parts of potato modified starch, 2 parts to 6 parts of food gum, 1 part to 3 parts of egg white, 0.5 part to 3 parts of sugar, 0 part to 1 part of salt and 1 part to 3 parts of yeast. The potato dietary fiber bread does not contain gluten, the contents of protein, mineral substances, dietary fibers, vitamins and antioxidants are obviously higher than the contents of protein, mineral substances, dietary fibers, vitamins and antioxidants in existing wheat bread, and the potato dietary fiber bread is suitable for being eaten by the crowd allergic to wheat or celiac disease patients.

The invention brings forward a novel low-cost in-situ solid-phase preparation method. By the method, a silicon-graphene spheroidal composite material with a multilevel structure can be synthesized by one step. The composite material can be used as a high specific energy anode material to be applied in a lithium ion battery. Low-cost organic carbohydrate and inorganic transition metal salt which are respectively used as a carbon source and a metal catalyst precursor are selected to be uniformly mixed with a silicon nano-material; by a tube furnace heating method, in-situ catalytic growth of a graphene coated network happens on the surface of silicon nano-particles; and through the bridging effect of the graphene network, spheroidal micro-scale particles with a nanometer fine structure is self-assembled. The silicon-graphene spheroidal composite anode material with the multilevel structure has an advantage of high specific capacity. In addition, two main bottleneck problems such as poor electronic conductivity of a silicon anode material and severe volume effect during the cyclic process can be overcome simultaneously, and multiplying power and cycle performance of silicon anode can be raised greatly.

The invention discloses an inorganic fireproof heat insulation board and a preparation method thereof. The inorganic fireproof heat insulation board is characterized by including a hollow ceramic bead surface layer, a glass fiber grid cloth layer, an expanded perlite composite layer, a glass fiber grid cloth layer and a hollow ceramic bead bottom layer from top to bottom; potholes are arranged on the hollow ceramic bead layer, and grooves are arranged on the hollow ceramic bead bottom layer; non-woven cloth layers are arranged respectively on the hollow ceramic bead surface layer as well as the bottom layer; further, the hollow ceramic bead surface layer and the hollow ceramic bead bottom layer are made of hollow ceramic bead slurry, and the expanded perlite composite layer is made of expanded perlite composite layer slurry. The preparation method includes the following steps: preparing the hollow ceramic bead bottom layer; spreading the glass fiber grid cloth; preparing the expanded perlite composite layer; spreading the glass fiber grid cloth; preparing the hollow ceramic bead surface layer; compacting for formation; and demoulding and solidifying. The inorganic fireproof heat insulation board has the advantages of excellent heat insulation performance, low thermal conductivity, fire resistance and high fireproofing grade, environmental protection and the like; further, the integral compression strength is greatly improved.

Provided is a broadband optical frequency comb generating system based on phase lock control. The broadband optical frequency comb generating system comprises a narrow linewidth laser, optical splitters, a FP cavity electro-optic phase modulator, a first photoelectric detector, a second photoelectric detector, a bias Tree, a referential microwave signal and a point phase lock controlling module. A connection in the sequence of the optical splitter, the FP cavity electro-optic phase modulator, the optical splitter, the first photoelectric detector, the second photoelectric detector, the bias Tree, the referential microwave signal and the point phase lock controlling module is established. An input end of a phase lock controlling device is connected with an output end of the referential microwave signal, and an output end of the phase lock controlling device is connected with an input port a of the bias Tree. According to the broadband optical frequency comb scheme generated on the basis of an electric phase lock control method, the difficulties in the aspects such as the bandwidth, the weight, the volume and the electromagnetic compatibility in the traditional method are solved.

The invention relates to a preparation method of lithium ion battery nanoporous silicon negative electrode material, and belongs to the technical field of new energy materials and electrochemistry. The silicon material crushed and finely ground into the micro-nano silicon powder in the protective gas atmosphere, and then crushing pretreatment is performed and the metal nanoparticles on the surfaceof the silicon powder are washed away and dried so as to obtain the nano silicon powder; one-step or two-step metal nanoparticle assisted chemical etching is performed on the nano silicon powder, solid-liquid separation and drying are performed so as to obtain nanoporous silicon / metal composite material; or a detergent is applied to remove the metal nanoparticles on the surface of the nanoporoussilicon, solid-liquid separation and drying are performed so as to obtain the nanoporous silicon; and the nanoporous silicon / metal composite material or the nano-porous silicon is oxidized so as to obtain an oxidized nano-porous silicon / metal composite material or oxidized nano-porous silicon, and the nanoporous silicon / metal composite material, the nanoporous silicon, the oxidized nanoporous silicon / metal composite material or the oxidized nanoporous silicon are the lithium ion battery nanoporous silicon negative electrode material.

The present invention discloses a core pulling mechanism of an Audi car door cover plate injection mold. The core pulling mechanism comprises a first cavity slider (1), a second cavity slider (2), a top hole core slider (3), a moving mold core (4) and a fixed mold (05). The core pulling mechanism of the present invention adopts the following technical scheme that: the cavities are arranged on thefirst cavity slider and the second cavity slider, wherein the cavities provide the outer shaped surface for the shaped product, and the outer shaped surface of the shaped product requires the transverse core pulling; the first cavity slider and the second cavity slider are arranged on the moving mold; the top hole core slider of the top hole of the shaped product is arranged on the fixed mold; with mold opening and oblique guide pillar driving, the top hole core slider is longitudinally pulled while the second cavity slider is transversely pulled, then the first cavity slider is transversely pulled with the oil cylinder; finally the product is ejected from the moving mold core by an ejection rod. With the technical scheme of the present invention, the problems and the defects of complex mechanism, large volume, high cost, more failures and low efficiency are overcome, the purposes of mechanism simplifying, volume reducing, cost reducing, reliable operation and efficiency improving of the Audi car door cover plate injection mold are achieved.

The invention discloses a reflective optical fiber sensor device, which comprises a light source, an optical detector and a sensor probe, wherein the sensor probe is used for receiving and processing the incident light emitted by the light source and sending the obtained reflected light to the optical detector. The reflective optical fiber sensor device can overcome the defects that the sensor in the prior art has large volume, cannot be used in an environment with electromagnetic interference and has short service life and poor corrosion resistance, and has the advantages of small volume, wide application range, long service life and good corrosion resistance.

The invention discloses a watch-type man-machine mediated electronic equipment for conveniently acquiring information of a mobilephone. The watch-type man-machine mediated electronic equipment comprises a watchcase connected with a watchband, a circuit mainboard arranged in the watchcase, a touch-type display screen and a built-in battery, wherein the touch-type display screen is arranged on the watchcase, and the built-in battery is arranged in the watchcase and is connected with the circuit mainboard; the circuit mainboard comprises a main controller, a bluetooth module, an SOC (System on Chip) controller and a memory, wherein the bluetooth module, the SOC controller and the memory are respectively connected with the main controller, and the SOC controller is connected with the touch-type display screen. The watch-type man-machine mediated electronic equipment provides convenience for a user to acquire the mobilephone information in real time under the conditions that the user cannot hold the mobilephone conveniently or cannot listen to the prompt tone of the mobilephone in real time in noisy places, and can simply control the mobilephone without the need of holding the mobilephone; and meanwhile, the watch-type man-machine mediated electronic equipment can remind the user at regular time.

The invention discloses an up-conversion device capable of achieving full-gloss microwave based on cross polarization modulation. The up-conversion device comprises a narrow line width laser, a first polarization modulator, a microwave signal source, a first polarization controller, a first optical filter, a circulator, a polarization beam splitter, a third polarization controller, a fourth polarization controller, an optical coupler, a high nonlinear optical fiber, a tunable laser, a waveform generator, a strength modulator, a second polarization controller, a polarizer, a second optical fiber, a single mode optical fiber, a photoelectric detector, an electric amplifier, an electric frequency mixer and a low pass filter. The up-conversion device can solve the problems of base band digital signal up-conversion in a radio over fiber system, the change, caused by dispersion, of microwave power along with microwave frequency and periodic damping, caused by the change of propagation length, of microwave power.

The invention discloses an online monitoring system for hydrogen in power transformer oil based on a thin film technology. The online monitoring system comprises a hydrogen sensitive chip and a control assembly, wherein the hydrogen sensitive chip comprises a hydrogen sensitive element; the hydrogen sensitive element is a hydrogen sensitive sensor based on a Pd-Cr thin film; and the control assembly is used for converting physical property variation of the hydrogen sensitive chip in a measuring range into a signal to be output. The online monitoring system disclosed by the invention has the advantages of simple structure, low cost, high sensitivity, good stability and the like.

The invention provides a preparation method for a spherical cellulose aerogel, which relates to a preparation method for an aerogel. The objective of the invention is to overcome the problems that the phenomena of structure collapse and volume contraction of a conventional cellulose aerogel frequently occur and the specific surface area of an obtained aerogel is small. The method comprises the following steps: 1, putting vegetable fiber in a mixed solution of urea and NaOH and carrying out stirring after refrigeration for formation of a solution so as to obtain a vegetable fiber / alkaline urea solution; 2, mixing trichloromethane with ethyl acetate and then adding glacial acetic acid so as to obtain an organic solution; 3, titrating the vegetable fiber / alkaline urea solution into the organic solution of glacial acetic acid and carrying out ageing so as to obtain a gel; 4, putting the gel into a glacial acetic acid solution for solidification; and 5, replacing a hydrogel successively with absolute ethyl alcohol and tert-butyl alcohol and carrying out refrigeration and freeze-drying so as to obtain the aerogel. According to the invention, the phenomena of structure collapse and volume contraction of an aerogel in the process of drying are overcome, and the prepared cellulose aerogel has low density and a specific surface area of more than 240 m<2> / g.

The invention discloses an ultra-fast pulse power switch device comprising a semi-insulated ultra-fast semiconductor material, an air gap, a transmission line and coaxial terminals connected by turn. The invention also discloses a self energizing picosecond magnitude power pulse generator, a high voltage DC power supply are connected with resistances, capacitances in series to compose to a loop, the negtive pole of the high DC power supply is grounded, the ultra-fast pulse power switch device is connected in series with the load by the coaxial transmission lines, the series branch circuit is connected with the capacitances in parallel, the package shell of the ultra-fast pulse power switch device is grounded. The invention, comparing with the prior art, has simple whole structure, good portability, low cost and strong anti-harsh environment ability without any laser to trigger.

The invention relates to a method for preparation of a graphene / nano-silicon lithium ion battery cathode material by liquid phase physical technique. The preparation steps include: 1. dissolving a surfactant in deionized water in proportion to obtain a solution; 2. dispersing graphite powder and nano-silicon powder uniformly in the solution; 3. conducting ultrasonic cavitation treatment on the graphite powder and nano-silicon powder mixed dispersion solution; 4. carrying out centrifugal separation treatment on the solution; 5. standing the solution for certain time and taking the upper solution; 6. subjecting the supernatant to vacuum pumping filtration and drying to obtain grey powder; and 7. calcining the grey powder to obtain the graphene / nano-silicon composite material. The preparation process involved in the invention is simple and practicable, graphene and nano-silicon particles have good dispersibility, thus avoiding agglomeration of liquid phase method prepared graphene, and omitting secondary dispersion of liquid phase physical method prepared grapheme. Constant current charging-discharging result shows that the grapheme / silicon composite material overcomes the disadvantages of large volume change and poor electrical conductivity of silicon, and improves the performance of lithium ion battery cathode materials.