114 results about "Stability study" patented technology

A methodology for reservoir understanding that performs investigation of asphaltene instability as a function of location in a reservoir of interest. In the preferred embodiment, results derived as part of the investigation of asphaltene instability are used as a workflow decision point for selectively performing additional analysis of reservoir fluids. The additional analysis of reservoir fluids can verify the presence of asphaltene flocculation onset conditions and / or determine the presence and location of phase-separated bitumen in the reservoir of interest.

A system and method for accomplishing power swing blocking and unstable power swing tripping schemes during disturbances of electrical networks is disclosed. The disclosed system and method eliminates the requirement of stability studies. The no-setting scheme utilizes the swing center voltage of the electrical network to carry out its functions.

A water level automatic control system of a landslide physical model test comprises water tanks, a control cabinet and a slope surface information acquisition device. Two water tanks are respectively arranged at the front and at the back of a landslide physical model test frame. Side faces of the two water tanks, which are contacted with a landslide model, are respectively provided with a plurality of groups of water feeding and discharging holes. Bottoms of the water tanks are connected with water inlet pipelines and water outlet pipelines respectively, water pumps and water inlet electromagnetic valves are arranged on the water inlet pipelines, and water outlet electromagnetic valves are arranged on the water outlet pipelines. Liquid level transmitters for monitoring water levels in the water tanks are arranged in two water tanks, the control cabinet is respectively connected with all the liquid level transmitters, the water pumps, the water inlet electromagnetic valves and the water outlet valves and used for receiving water level signals and controlling opening and closing of the water pumps and the electromagnetic valves, and the slope surface information acquisition device is arranged above the water tank arranged at the front of the landslide physical model test frame. The water level automatic control system of the landslide physical model test can monitor parameters of landslide surface displacement and the like under the condition of stored water level variation precisely and comprehensively and provide an important basis for landslide stability studies.

The invention belongs to the field of studies on stability of rock and earth masses under a multi-field coupling effect, and particularly relates to a thermo-hydro-mechanical multi-physical field coupling simulation experiment system suitable for the rock and earth masses and a use method thereof. The thermo-hydro-mechanical (THM) coupling simulation experiment system mainly comprises a monitoring mainframe, a triaxial pressure test mainframe, a heat pump control circulating system, a GDS pressure-volume controller group and a data collector; by carrying out gradual in-depth studies on influence of a mechanical unloading process on the mechanical properties and the hydraulic properties of the rock and earth masses and the influence of temperature loads on the damage evolution law, the permeability and the thermal conductivity of the rock and earth masses on the surrounding of a chamber, and the interaction and mutual influence conditions between of a stress field and a seepage field (HM), between the stress field and a temperature field (TM) and between the seepage field and the temperature field (TH) are disclosed.

The invention belongs to the technical field of cosmetics, and particularly relates to acne treatment essence cream and a preparing method thereof. The essence cream contains aluminum starch octenylsuccinate, salicylic acid, PCA zinc, zinc gluconate, nicotinamide, tangerine orange pericarp extract, amur corktree bark extract and retinyl palmitate. The acne treatment constituents in the essence cream are obtained through screening. The new acne treatment constituents in the essence cream can effectively restrain propionibacterium acnes. Experimental studies prove that a good acne treatment effect can be realized by adding the acne treatment constituents to the essence cream. Stability studies show that the essence cream has higher stability.

The invention belongs to the technical field of slope stability measurement and discloses a rock high slope stability analysis three-dimensional geomechanical model test method and the application thereof. The stability of the rock high slope is evaluated through a geomechanical model test method based on temperature rise, intensity reduction and lifting overload. The disclosed method comprises the whole test process, namely, the process of model design, model material test, model manufacturing, measurement system installation and model test. According to the method, the slope deformation distribution characteristics, the damage process and the damage mechanism can be obtained, the overall stability safety coefficient of the slope is obtained. Therefore, the overall stability of the high slope is evaluated. Finally, the method is applied to stability research of the high slope of the left bank dam abutment of the crane beach hydropower station. The initial cracking safety coefficient Kof the high slope is obtained. The initial cracking safety coefficient K ranges from 1.030 to 1.058. The limit safety factor k limit is equal to 1.417-1.579, and the overall stability of the slope isevaluated.

The invention relates to a preparation method of cistanche deserticola phenylethanoid glycosides. The method comprises the steps of: cistanche deserticola crushing, lixiviating, absorbent resin adsorption, elution, and concentration, etc. In research of the extraction and stability of cistanche deserticola phenylethanoid glycoside, under a weakly acidic condition with pH of 2-4, the cistanche deserticola phenylethanoid glycoside can have substantially improved stability, and under the condition, the cistanche deserticola phenylethanoid glycoside extracted from cistanche deserticola is mainly composed of echinacoside and verbascoside. And in cistanche deserticola phenylethanoid glycosides, the total content proportion of echinacoside and verbascoside is greater than 90%. The content of cistanche deserticola phenylethanoid glycosides extracted by the method of the invention is obviously higher when compared with other extraction methods. And the obtained cistanche deserticola extract has stable effective component content and relative light color. The method provided in the invention avoids decomposition and oxidation of cistanche deserticola phenylethanoid glycoside, and is in favor of product stability.

The invention relates to the technical field of petroleum exploration and development experimental facilities, in particular to a hard and brittle shale microfracture manufacturing method and a plugging capability testing system. The testing system comprises a stable gas source, a high-temperature and high-pressure dynamic displacement device, a shale sample clamp, an outlet liquid receiving device and a circulating press pump, wherein the stable gas source is connected with the high-temperature and high-pressure dynamic displacement device through a section of high-pressure pipeline, the shale sample clamp is used for clamping a shale sample to be tested and is connected with the high-temperature and high-pressure dynamic displacement device through screw threads, the outlet liquid receiving device is connected with the outlet end of the shale sample clamp through a valve, the circulating press pump is connected with the shale clamp through a high-pressure pipeline, and stable pressure is provided as the pressure of the circulating press pump through the stable gas source. The manufacturing method and the plugging capacity testing system can be used for plugging agent preference selection experiments and drilling liquid plugging capability test experiments, and a reliable testing means is provided for the researches of the well wall stability of a hard and brittle shale stratum.

The invention discloses a transient control method for controlling the synchronous stability of a virtual synchronous control inverter. At present, the research on the stability of an inverter mainly focuses on the small-disturbance stability of an inverter in a micro grid. There is relatively less research on the transient stability under large disturbance, and the stability mechanism is unclear. In view of the virtual power angle instability caused by inverter current saturation, reactive power plus transient control are introduced into virtual synchronous control, so that an inverter has a reachable stable equilibrium point in the transient process of current saturation, and the synchronous stability of the inverter under large disturbance is ensured. The technical problem that there may be no stable equilibrium point in the transient process for the system due to saturation of the inner current loop of an inverter is solved. Transient instability of virtual power angle after an inverter goes to a current source mode is prevented.

The invention discloses a multi-point displacement meter installation and automatic data collection method of a steeply inclined seam roadway. The method includes the steps of 1 hole drilling, 2 multi-point displacement meter installation and 3 automatic anchoring data collection. The hole drilling includes the steps that according to lithology deformation of the steeply inclined seam roadway, the direction along a dip angle is selected to be drilled for laying multi-point displacement meters. The multi-point displacement meter installation includes the steps that firstly measuring rods with anchor heads, protection pipes, exhaust pipes and grouting pipes are poked into drilled holes, the exhaust pipes and the grouting pipes are placed according to the direction of the drilled holes, then bases are fixed through a cement mortar accelerating agent, grouting is conducted for hole sealing, and finally displacement sensors are installed. The automatic anchoring data collection includes the steps that a data line of each displacement sensor is led into an intelligent data collection device, half-bridge connection is adopted, sampling is conducted once every day, and the frequency data of the multi-point displacement meters are collected and received automatically and stored in a USB flash disk memory. The method is simple and easy to implement, simple to operate, safe and reliable and lays the foundation for further steeply inclined seam roadway supporting stability study.

The invention provides an acid sensitivity lactobacillus bulgaricus strain and the usage thereof, belonging to the biological engineering technology field. An acid sensitivity strain L.B-FM-6 which is a lactobacillus delbrueckii subsp. bulgaricus is separated and screened in the research of the natural dairy ferment-tibet kefir. The research on the storage stability of the fermented dairy product, fermented juice and the fermented vegetable juice which are fermented by the combination of the strain L.B-FM-6 and other microbial strains solves the defects of short shelf life of the active lactobacillus drink and displays the superiority of the strains in fermenting the dairy product and the juice.

The present invention belongs to the technical field of cosmetics, and particularly relates to an acne removing and skin beautifying essence liquid and a preparation method thereof, wherein the essence liquid comprises an acne removing component, and the acne removing component comprises a phellodendron amurense tree bark extract and a rosa multiflora fruit extract. According to the present invention, the acne removing component is obtained through screening; the new acne removing component can effectively inhibit Propionibacterium acnes, and the test research results show that the product provides a good acne treating effect and a good whitening effect after the acne removing component is added to the essence liquid; and the stability research results show that the essence liquid has good stability.

The invention discloses a high- purity of osthol, structure proof with spectral analysis, method for preparation, stability study, acute toxicity study, the drug compositions containing osthol, and new drug utilities of the natural product. By the technique steps of extracted Chinese pharmacy conidium fruit with alcohol, decolorizing and enriching by large-hole adsorption resin, and separating and purifying, it can prepare osthol with a purity of above 98%. The study expresses that the osthol has a clear utility of anti-cancer, anti-auto lymphoma, and so on.

A system and method for accomplishing power swing blocking and unstable power swing tripping schemes during disturbances of electrical networks is disclosed. The disclosed system and method eliminates the requirement of stability studies. The no-setting scheme utilizes the swing center voltage of the electrical network to carry out its functions.

The invention provides a calculation method for judging a strong or weak alternating current and direct current hybrid system in an ultra high voltage direct current hierarchical access mode. The method comprises the following steps: establishing a characteristic equation of the system according to an equivalent model of the alternating current and direct current system in the ultra high voltage direct current hierarchical access mode; providing the definitions of a hierarchical critical short circuit ratio and a hierarchical boundary short circuit ratio; calculating the critical short circuit ratio and the boundary short circuit ratio of the alternating current and direct current system; and judging that the hybrid system is strong or weak according to the relative magnitudes of the short circuit ratio, the critical short circuit ratio and the boundary short circuit ratio. The quantitative calculation method provides a good theoretical basis for stability research of the hybrid system in the ultra high voltage direct current hierarchical access mode, and has certain guiding significance for construction and operation of ultra high voltage direct current hierarchical access engineering.

The invention discloses a test system and method for studying gravity type anchorage stability under a seismic load. The system comprises an anchorage system, a load system and a measuring system; theanchorage system is composed of a test chamber, a similar rock-soil layer, an anchorage body and a steel strand; the load system comprises a static load system and a dynamic load system; the static load system is composed of a weight, a gate-type loading frame, a pulley and the steel strand; the dynamic load system is composed of a vibrating table, a wood board and a sponge; and the measuring system comprises a precise dynamometer, an angle measurer, a micro pressure box, a laser range finder and a sound wave vibration measurer. The specific operations of the system comprise the following steps: producing a test module, arranging a monitoring system, loading the test module, debugging the monitoring system, model test testing and data recording. According to the test system for studying the gravity type anchorage stability under the seismic load provided by the invention, the simulation of different anchorage test prototypes can be realized, the dynamic response change of the anchorage body under the action of the seismic load is simulated simply and effectively, and the dynamic measurement of dynamic response data such as internal force, displacement, vibration speed and the likeof the anchorage body and surrounding rock and soil bodies in the loading process of dynamic loads is realized.

The invention discloses a deep anhydrite cavern group stability evaluation and layout optimization method in an oil storage environment. The evaluation method involved in the invention comprises four parts, i.e. deep anhydrite surrounding rock engineering geology characteristic analysis, deep anhydrite surrounding rock mechanical parameter analysis, reservoir cavern group stability study and cavern layout optimization design respectively. The method provided by the invention applies Hoek-Brwon empirical criterion and geological strength index to clarify the reduction rule of anhydrite surrounding rocks and rock mass mechanical parameters, and provides a parameter basis for cavern group surrounding rock stability numerical simulation. The invention puts forward an element safety factor method, and combines surrounding rock stress field, displacement field and plastic zone to comprehensively evaluate the cavern group surrounding rock stability. The method provided by the invention can be used for optimizing the layout scheme of deep anhydrite cavern groups in an oil storage environment, improving the oil storage efficiency of anhydrite caverns, and evaluating the stability of deep anhydrite cavern groups in an oil storage environment, and provides a reference method for scientific verification of deep anhydrite forewinning oil storage adaptability.

The invention provides a beta-HMX crystal form purity detection method based on an X-ray powder diffraction technology. A beta-HMX crystal form purity quantitative correction model and a correspondingcrystal form purity test method are established by combining an X-ray powder diffraction technology with a chemometrics partial least square method. On the basis of a multivariate data analysis method, effective information can be extracted from crossed and overlapped spectrums, thereby realizing quantitative crystal form analysis without independent characteristic spectrum peaks. The beta-HMX crystal form purity can be accurately determined within 10 to 15 min and the sample dosage is smaller than 50 mg; no complex sample preparation is needed in the detection process and the operation becomes safe and rapid; and a problem that the purity of the crystal form of a trace amount of sample is difficult to detect in links of a synthetic sample lab test stage, product accident research factoranalysis and the like an be solved. Therefore, the reliable and efficient detection basis can be provided for quality control of beta-HMX products and crystal form stability research of a production process and a long-term storage process.

The invention provides a flexible ac transmission system (FACTS) interactive influence degree evaluation method based on a modal series method, which comprises the following steps: a step A of providing system running conditions in a power system containing a FACTS device; a step B of inputting basic data of the system under each system running condition; a step C of performing load flow calculation to obtain a stable equilibrium point of the system; a step D of calculating nonlinear degree indexes; a step E of performing a step F if the calculation of the nonlinear degree indexes of all the system running conditions are finished, or else returning to the step B; and a step F of comparing the sizes of all the nonlinear degree indexes. The FACTS interactive influence degree evaluation method based on the modal series method has the advantages of being strong in application and definite in physical significance, can provide accurate guide for coordinated running of a plurality of FACTS, and can serve as measuring indexes for the nonlinear degree of the system to provide research methods for the work of power system analysis, stability study and the like.

Stable non-alcoholic transdermal hydrogel of dexibuprofen was prepared by using a simple manufacturing process, and the experimental trials showed that the pH modifying agent, antioxidant and water miscible solvent are the essential excipients to obtain stable non-alcoholic transdermal hydrogel of dexibuprofen. The dexibuprofen hydrogel prepared using carbopol as a gelling polymer produced an opaque gel, whereas hydrogel prepared using hyroxypropyl methylcellulose (HPMC) as a gelling polymer produced a transparent gel. There was no significant changes observed with respect to physical description, pH, assay and particularly to the related substance values when the hydrogels were subjected to the stability study at accelerated condition (40 DEG C / 75% RH) for 3 months in laminated tubes.

The invention provides a novel crystal form of a tenofovir maleate, a preparation method and a pharmaceutical application thereof. The novel crystal form in a salt form facilitates the more stable presence of the tenofovir ester. A study on the stability of the crystal form shows that the novel crystal form of the tenofovir ester maleate is more stable than that reported in previous documents and is excellent in flowability. The novel crystal form tremendously improves the stability during industrial production and flowability and compressibility during preparation, and greatly meets the needs of industrial production.

The invention discloses a stability study experiment table for rock ecological side slope new soil. The stability study experiment table comprises a side slope grade adjustment system, a parameter measuring system and a new soil spray-seeding system, wherein the side slope grade adjustment system comprises a base, a containing groove, an oil cylinder, a rotating shaft, a bearing pedestal, a dial and a pointer; wherein the containing groove and the rotating shaft are fixed into a whole, a bearing is installed at the end of the rotating shaft and assembled into the bearing pedestal, the bearing pedestal is fixed to the base, the two ends of the oil cylinder are connected with the base and the containing groove respectively, the dial and the pointer are fixed to the base and the containing groove respectively, and rock is laid inside the containing groove. The stability study experiment table has the advantages that on the condition of changing a side slope grade value, replacing rock and adjusting the new soil ratio and the spray-seeding thickness, the displacement, temperature, humidity and other parameters of new soil can be monitored in real time, and the influences caused by factors such as the side slope grade, the rock lithology, the roughness, the new soil ratio and thickness on the stability of the new soil can be researched.

The invention discloses an impedance calculation method of a double-fed fan rectifier based on double closed loop control, comprising establishing a relationship expression between electrical quantityand control quantity according to circuit topology and control block diagram, deriving an expression of the closed-loop impedance and verifying the expression of the closed-loop impedance. Establisha relational expression between the electrical quantity according to the circuit topology, comprising a duty ratio signal, a direct current side voltage, a grid-side voltage and a grid-side current, establish a mathematical model of current inner loop control and voltage outer loop control parts according to the control block diagram, then establish a mathematical model of phase-locked loop part according to relationship between the circuit and the control, and jointly derive an expression of the closed-loop impedance expression; finally, verify the correctness of the impedance calculation method by inputting the disturbance at different frequencies and calculating the impedance value. According to the impedance calculation method of the double-fed fan rectifier based on double closed loopcontrol, a foundation for the stability study of the double-fed fan rectifier is laid, and parameters can be adjusted by impedance analysis to avoid phenomena that harm the power system such as harmonic instability and the like.

The invention discloses a small-interference stability analysis method of a double-fed wind generator one-machine infinite system; the method comprises the following steps of step 1, modeling a dynamic mathematical model of the one-machine infinite system; step 2, performing linearization processing on the mathematical model of the system at the balance point to obtain a corresponding state matrix; step 3, obtaining a system characteristic value and a mode category, and predicting a state variable and a modal relationship according to participation factors; and step 4, according to system parameters or running states and external network parameters, calculating he sizes and the modal changes of different characteristic values. In the prior art, the technical problems that when the stability of the grid-connected system of the wind generator is researched, the model of some elements in the system, such as a transmission system model and a model of a control system, are not established in detail; and the influence of parameters in the system on the system model state in a detailed model are not researched and the like, are avoided.

The invention belongs to the technical field of pharmaceutical analysis, and particularly relates to an HPLC analytic method for Nicorandil-related substances. The HPLC analytic method is characterized in that a stationary phase is a reversed-phase column of carbon octadecyl silane, and a moving phase is a mixed solution of a buffer solution, methyl alcohol and tetrahydrofuran. The HPLC analytic method is quick, simple and accurate, is good in repeatability and suitable for control and stability study of the related substances, lays a foundation for formulating quality standards of the related substances, and makes drug quality control and medication safety possible. Through scaling down organic solvents and volatile salt, which have high toxicity, the acquisition time is shortened, the economic cost is lowered, the HPLC analytic method is suitable for large-scale production, and meanwhile, harms to experimenters and environments are reduced.

The invention discloses an impedance analyzing method for sub-synchronous oscillation of a thermal power unit. The method comprises the following steps: partitioning a system to be researched into a power supply and a power grid, building state space models in sequence for the power supply and the power grid, and calculating admittance function matrixes of the power supply and the power grid; then, drawing Bode diagrams of the admittance function matrixes of the power supply and the power grid on the same graph; and lastly, picking up apparent resonance points on the bode diagrams, and calculating system series connection resonance frequency and an excited axis modal according to the apparent resonance points. Based on the basic principle of the impedance analyzing method, the power supply of the thermal power unit is modeled uniformly in a state space form, and the dynamic features of a mechanical control system of the unit are included in the state space of the power supply and modeled finally in the form of electric quantity. Compared with a conventional method, the method has the advantages that sufficient calculation accuracy can be obtained, and the dynamic features of continuous frequencies can be analyzed, so that beneficial conditions are created for the stable research of an electric-electronic power system.

The invention discloses an antiviral drug which can be taken orally or molten - a ribavirin tablet and a manufacturing method thereof. The compositions of the preparation by weight percent are 3.8 to 20 percent of ribavirin, 71 to 83.25 percent of sugar and 9 to 12.95 percent of other pharmaceutic adjuvant. The manufacturing method comprises the following steps: 80 meshes of the ribavirin, 80 meshes of the sugar and other filler and disintegrating agent between 80 meshes and 100 meshes are taken and mixed; an adequate bonding agent is added into the mixture and particles are prepared, boiled, dried and integrated and added with lubricant; after uniform mixture, the weight of a stator plate is tested, and tabletting is performed; and after test qualification, packaging and full inspection are performed. The preparation lightens the passivity of patients in taking medicine and particularly solves the problem of medicine taking of infants, old patients, dental patients, upper respiratory tract virus infection patients and so on; and as shown by production for a plurality of years and sampling stability study, the quality of the preparation is stable.

The invention relates to a complete plane strain similar test system capable of applying gradient strain. The whole system comprises a plurality of combined modules, a detachable combined module, a horizontal gradient strain servo control system, a vertical strain servo control system, a connecting lifting control system and a data acquisition control system. Due to the adoption of the system, a more practical test condition is provided for an urban underground construction and a mining engineering; the test system can slide freely along with a rock via the modules of two sides and limits the movement in the direction vertical to a model, so as to realize the plane strain similar test. The upper pressure under a deep geological condition can be compensated by the vertical strain servo control system, and the horizontal gradient strain is applied by the horizontal gradient strain servo control system. The test condition of the test system can be well consistent with the actual engineering condition, the results of the test are more real and more reliable, and can guide the design and construction scientifically and reasonably, and therefore a scientific test condition is provided for the stability research of geotechnical engineering.

The invention belongs to the technical field of biological medicines and particularly relates to a cytokine TNF-alpha bioactivity evaluation in-vitro test method based on cytotoxic effect of cytokine TNF-alpha. The method is simple to operate, the expensive material and instrument are omitted, method verification can be completed, the requirements on method accuracy, precision and durability can be met completely, the activity test range can be 50% to 150%, the repeatability and intermediate precision test result are smaller than 10%, the test 4 parameter curve fitting constants R2 are larger than 0.99, and the double hole CV% is smaller than 15%. Thus, the cytokine TNF-alpha cytotoxic bioactivity can be tested rapidly, accurately and efficiently. In addition, the test method is stable and easy to implement, the promotion and high-throughput operation can be met completely, and the requirements of cytokine TNF-alpha bioactivity test on the basis of cytokine TNF-alpha cytotoxic effect and cytokine TNF-alpha bioactivity stability research are met.

The invention provides an R-lansoprazole crystal form and a preparation method therefor and relates to the field of medicinal chemical industry. 2[theta] values of characteristic peaks of an X-ray powder diffractogram of the R-lansoprazole crystal form are 6.01, 6.82, 8.80, 12.23, 13.33, 14.54, 17.96, 18.86, 19.91, 20.32, 20.75, 22.10, 23.08, 23.75, 26.09, 29.68 and 32.45. The preparation method for the R-lansoprazole crystal form provided by the invention is simple and is mild in conditions and stable and controllable in preparation process; and shown by stability research, the crystal form product prepared by the method has better physicochemical properties and higher stability, is suitable for being applied to pharmaceuticals and can be used for preventing and treating gastric acid related diseases when the product is applied to pharmaceutical compositions.