70results about How to "No chemical change" patented technology

The invention discloses a porous ceramic carrier for a high-temperature and high-pressure inorganic filtering membrane and a preparation method for the porous ceramic carrier. The porous silicon carbide ceramic carrier is prepared by silicon carbide, a binding agent and a pore-forming agent, wherein the mass ratio of the silicon carbide to the binding agent is 80-90:10-20, and the utilization quantity of the pore-forming agent is 35-45% of the sum of the volumes of the silicon carbide, the binding agent and the pore-forming agent. The preparation method includes adding the binding agent and the pore-forming agent in silicon carbide powder; performing ball milling, drying and vacuum heat casting forming; and performing pressureless sintering for a formed blank. Sintering temperature rangesfrom 1250 DEG C to 1350 DEG C, and heat insulation time ranges from 2 hours to 4 hours. As raw materials form main materials by means of fine size grading, the binding agent and the pore-forming agent are added by a special process, technologies such as unique vacuum heat casting forming and the like are adopted, and mechanical strength and porosity of the porous carrier can be improved effectively. The prepared silicon carbide porous ceramic carrier has excellent performances of fine thermal shock resistance, low coefficient of thermal expansion, fine mechanical and chemical stability at high temperature and under high pressure, and the like.

The invention discloses a composite phosphate fruit and vegetable preservative and a usage method thereof. The preservative is compounded by the composite proportion of (0.8-1.2):(1.5-2.5):(0.05-0.15) of sodium pyrophosphate, citric acid and vitamin C. For the fresh-keeping of fruits such as freshly cut green apple, and the like, which contains polyphenoloxidase and chlorophyll, the preservative is compounded into the water solution with the massfraction of 1.0%-1.20% and the PH value of 2.0-3.0; according to the proportion of 100ml:100g of the solution and the freshly cut green apple, the freshly cut green apple is dipped into the solution at the temperature of 15-20 DEG C for keeping fresh; For the fresh-keeping of melons such as freshly cut potato, and the like, which contains polyphenoloxidase, the preservative is compounded into the water solution with the PH value of 5.5-6.0; according to the proportion of 100ml:100g of the solution and the freshly cut potato, the freshly cut potato is dipped into the solution at the temperature of 15-20 DEG C for keeping fresh. The preservative of the invention has dual efficacies such as browning prevention and greening prevention, affects no taste of the fruits and vegetables, has wide application range, simple and convenient operation and low expense and is generally suitable for the fruits and vegetables which are easy to be browned due to the promotion of the enzyme.

The invention discloses an underwater robot for submarine pipeline cutting. The underwater robot is mainly used for cutting submarine badly broken petroleum pipelines and comprises an ROV (remotely-operated vehicle) body, two cutting mechanisms, supporting legs and a small auxiliary manipulator, the ROV body comprises a frame, a buoyancy block, a propeller, a seven-degree-of-freedom manipulator, a five-degree-of-freedom manipulator, an underwater illumination device, a camera shooting device and a hydraulic electric control device, the supporting legs are uniformly distributed on two sides of the submarine pipeline cutting robot, a center line of the supporting legs is coincided with that of the cutting mechanisms, so that the ROV body is supported, the small auxiliary manipulator is connected below the submarine pipeline cutting robot through bolts and positioned in middle of the cutting mechanisms, the cutting mechanisms are fixed in the rearward front of the bottom of the submarine pipeline cutting robot through bolts, the cutting mechanisms and a pipeline are positioned by a positioning hydraulic cylinder, and the broken pipelines are cut by controlling rotation of a water cutter mechanism. The underwater robot can be automatically operated in deep water areas or special environments.

The invention discloses a laser veining method for improving the surface cell adhesion of medical implants. The method comprises the steps that (1) the surface of a medical material is subjected to chemical cleaning and deoiling, and mechanical grinding and polishing or laser polishing in sequence, and then the surface is cleaned again; (2) the medical material cleaned in the step (1) is placed on a workbench of a laser processing system, laser parameters are set, the laser processing system is started, laser rays scan the surface of the medical material surface at a certain speed through galvanometer scanning, and finally a veined surface is obtained through laser ablation, specifically, the processing process is carried out under inert gas shielding; and (3) the processed medical material is cleaned. The method can be widely applied to the medical implants of specific applications, enables the surfaces of the implants to obtain better cell adhesion performance, and improves the medical effects of the implants.

The invention relates to a phase-change energy-storage radiator, and belongs to the field of new type energy, energy conservation and environmental protection. The phase-change energy-storage radiator is used for storage and controlled releasing of heat energy in multiple grades. The phase-change energy-storage radiator comprises an outer heat preservation box and an energy-storage unit; a natural convection radiating runner is formed between the energy-storage unit and a heat preservation shell; and the natural convection radiating runner is controlled to be opened and closed, and therefore timing accumulated storage and releasing of the energy can be achieved. Heat insulation and energy storage can be completely achieved in the energy storage process of the phase-change energy-storage radiator, and meanwhile radiating can be controlled in the storage process. The device is large in energy-storage volume and small in size. According to a specially developed and allocated mixed chlorinated paraffin low-temperature phase-change energy-storage material, the energy-storage temperature scope is appropriate, the material is non-toxic and free of chemical changes, the energy-storage temperature scope and the heat release amount are not changed after repeated utilization, undercooling and overheating phenomena are avoided, and both the physical and chemical property and the reliability are excellent.

The invention relates to a cracking and hollowing resistant aerated concrete water repellent and a use method thereof. The water repellent is one of the following materials of: an organic silicone emulsion water repellent, a metal soap powder, a polyacrylate emulsion water repellent, a polyvinyl ester emulsion water repellent and a paraffin wax emulsion water repellent. The use method of the water repellent comprises a first doping method and later doping method. According to the invention, through adding the water repellent to an aerated concrete raw material, the water absorbing rate as well as wet swelling and drying shrinkage phenomenon of the aerated concrete can be reduced, common cracking and hollowing problems in the using process of the traditional aerated concrete are solved, large-scale popularization and application of the aerated concrete are promoted, and important technical benefits are obtained.

This invention relates to a kind of headset with aeration ear pad, including shell, speakers, speaker board, headband, linking handle, the speaker is fixed on the speaker board, the speaker board is fixed in the shell, its characteristic is that setting ring ear pad in the speaker board, installing lock seized location in the board, locking the ring ear pad in the seized location by pressure circle. The ear pad in this invention is made of nontoxic, good stability soft silicone and thermoplastic material, the structure is new, it also has the characteristic such as aeration, cool, sanitation, durable. Wearing long will not make the user feel pain pressure and stivy, it is a kind of headset that wearing comfortable, protecting the ears, listening with good effect, convenient, durable.

The invention provides a high-energy-content amorphous alloy material. The high-energy-content amorphous alloy material contains one or more of the following elements of Mg, Al, La, Ce and Zr, the heat value of the high-energy-content amorphous alloy material ranges from 0.7 kJ / g to 30 kJ / g, and preferably ranges from 10 kJ / g to 25 kJ / g. The amorphous alloy high-energy-content material not only has a lower ignition point, but also keeps a higher combustion heat value, and is safer, lower in cost and higher in yield compared with crystalline alloy nano powder. The amorphous alloy high-energy-content material can be applied to the fields of explosives, leads, fireworks, solid propellants and the like.

The invention provides a bamboo charcoal cellulosic fiber and a preparation method thereof. The fiber is obtained through the following steps: mixing bamboo charcoal pulp with spinning solution which is prepared by dissolving cellulose with ionic liquid, and spinning through a coagulating bath prepared by ionic liquid aqueous solution, wherein the content of the nano bamboo charcoal is 0.1-10 percent of the weight of the finished product fiber; the bamboo charcoal pulp is prepared from the following raw materials in percentage by weight: 5-25 percent of bamboo charcoal powder, 1-2 percent of bubbleless dispersant, 1-5 percent of a thickening agent, 4-6 percent of sodium hydroxide and the balance of de-ionized water. The preparation method has the characteristics of simple process, no equipment corrosion, small environmental pollution and high production efficiency; the prepared fiber finished product has the characteristics of high strength, good adsorption performance, superior antibacterial effect, uniform and consistent color and strong color fixation; a high-quality bamboo charcoal cellulosic fiber raw material is provided for textiles.

The invention relates to a method for improving corrosion resistance of the magnesium alloy surface through a short-pulse laser. The method comprises the steps that (1), a magnesium alloy material is subjected to sand papering to remove an oxidation layer and then subjected to acetone cleaning to remove oil; (2), the cleaned magnesium material is placed on a worktable of a nanosecond laser machining system, laser parameters are set, the laser machining system is started, the laser is made to scan on the surface of the magnesium alloy material in a certain speed through galvanometer scanning, and a remelting layer is obtained on the surface of the magnesium alloy material; and (3), the machined metal material is cleaned simply. According to the method for improving corrosion resistance of the magnesium alloy surface through the short-pulse laser, a laser direct writing system is utilized, and by changing the laser parameters such as the frequency, the scanning speed and the power, the fused depth, the area and the like of the metal surface can be controlled precisely; a chemical reagent does not need to be added additionally, so that environment protecting is achieved; arbitrary set of a machining area can be achieved; the machining speed is higher, and the production efficiency is improved; and the short-pulse laser with the low power is used, so that the situation that metal matrix performance remains unchanged is facilitated.

The invention discloses a pouring sealant for filling a gap between a charge and a shell of a warhead. The pouring sealant comprises hydroxyl-terminated polybutadiene, a curing agent, a plasticizer and a curing catalyst, wherein mol ratio of R=[NCO] in the curing agent to [OH] in the hydroxyl-terminated polybutadiene is 0.8-1.2, content of the plasticizer is 0-1.5 times that of the hydroxyl-terminated polybutadiene, and the content of the curing catalyst is 0-0.01wt% that of the hydroxyl-terminated polybutadiene. The pouring sealant disclosed by the invention can be used for effectively solving the problem of an inherent gap between the charge and the shell of the warhead of the conventional weapon, so that use safety performance of the warhead and penetration stability to a target are greatly improved; and by adopting the pouring sealant disclosed by the invention, fabricated charging can be carried out without prefabricating a grain, so that the warheads in various sizes and shapes are directly poured and moulded, the mass production capability is greatly improved and the charging process cost is greatly reduced.

The invention discloses a self-microemulsion nutrient composition containing coenzyme Q10 and a preparation method and application. The self-microemulsion nutrient composition comprises the following components in parts by weight: 1-15 parts of coenzyme Q10, 1-15 parts of curcumin, 10-50 parts of carrier oil, 15-75 parts of a nonionic surfactant, 1-5 parts of a cationic gemini surfactant, 5-30 parts of a cosurfactant and 0-2 parts of an antioxidant, wherein the components are prepared into a uniform, stable, clear and transparent solution. The self-microemulsion nutrient composition has good stability, crystallization of coenzyme Q10 is remarkably inhibited, and the product shelf life is prolonged. In the application process, the composition can be simply and conveniently added into systems of water-phase food, medicines and the like according to demand amounts, and is safe and effective. Meanwhile, the whole preparation process is green, environmental-friendly, low in energy consumption and easy in industrial production.

The invention discloses an acquisition method of aromatic plant volatile matters, which comprises the following steps: putting aromatic plants in an acquisition device containing activated carbon, and extracting gas until the aromatic plant volatile matters are adsorbed to the activated carbon, adding the activated carbon into a low-boiling-point low-toxicity organic solvent, treating in a water bath, boiling in aether, heating under reflux, cooling, standing, filtering to obtain a supernate, washing the filter residue with aether, merging the washing liquid into the supernate, and heating the supernate through water bath rotary distillation to obtain the light-yellow oily essential oil. The plant essential oil obtained by the method has the advantages of high purity, no damage on plants, no chemical change and low cost, implements in-situ extraction of the plant aromatic oil, is continuous, efficient, in-situ, natural and low in carbon, has no chemical change, acquires fresh natural aroma (aromatic plant volatile matters), and has important meanings for effectively utilizing natural resources and protecting the environment.

The present invention belongs to the field of ceramic material preparing technology, and features that the guide and guard roller is made of material comprising alpha-phase silicon nitride powder 55-85 wt%, ytterbium oxide 10-30 wt% and prefabricated beta-phase silicon nitride crystal seed 5-15 wt%. The making process of the guide and guard roller includes the following steps: mixing alpha-phase silicon nitride powder, beta-phase silicon nitride crystal seed and ytterbium oxide in the weight proportion, ball milling, drying, pelletizing, forming and sintering to obtain guide and guard roller blank, and final finish grinding. The guide and guard roller product has high toughness, high strength, high hardness, high wear resistance, service life as long as 7-8 times that of guide and guard roller of heat resistant steel and greatly raised work efficiency of high speed wire rolling machine.

The invention relates to a production method of an ultrafiltration membrane for extracting tannin from banana stem stoste. The steps are as follows: separating and pre-filtering the stoste pressed efficiently from banana stem using ultra filtration membrane with 15-20 nm pore size; concentrating the stoste with nanometer film of molecular weight cut-off in the range from 500 to 600, concentrating the stoste with nanometer film of molecular weight cut-off in the range from 800 to 1200 for the third times, extracting when separating organic matter and water under normal pressure for 1 to 2hrs, resolving the tannin matter from the extract, increasing the pressure of the reactor, and extracting for 1 to 3hrs after heating to 40 DEG C; concentrating to 1 / 5 to 1 / 10 of original volume, crystallizing after standing for a while, and repeating for 2 to 3 times, so as to obtain the tannin products. The production method provided by the invention is preceded under normal temperature, has few loss of active ingredient and is suitable to separate and concentrate vegetable tannin; and the production method provided by the invention has the advantages of only simple pressed transformation, repetition, simple process, extremely low power consumption, low cost, zero pollution to products, excellent selectivity and highly adaptability.

The invention discloses an extraction method for laminarin. The method includes the steps of airing and smashing fresh laminaria japonica to obtain laminaria japonica powder, conducting hot water extraction after conducting ethyl alcohol degreasing on the laminaria japonica powder, centrifuging the extracting solution to obtain supernate, conducting concentration and impurity removal on the supernate, conducting microfiltration film filtration, sequentially classifying filtrate, conducting ultrafiltration through filter materials of different molecular weights, and conducting drying to obtain laminarin of different molecule classifications. No high-temperature or chemical changes are caused in the operation process, it is sufficiently ensured that activity of polysaccharide and protein is not damaged, and components are highly enriched; by means of the combined effects of centrifugation, microfiltration and ultrafiltration, the high flow rate is kept, the obtained polysaccharide is high in purity and diverse in specification, and the extraction method has the advantages that continuous production and automatic operation are achieved, the energy consumption is low and the production period is short.

The invention relates to an evaporator, a cold and heat combined supply system of the evaporator and a vacuum generator. The evaporator comprises a waste liquid barrel, the cold and heat combined supply system and the vacuum generator, wherein waste liquid in the waste liquid barrel enters the cold and heat combined supply system through a liquid inlet valve arranged in a pipeline; the waste liquid is evaporated and concentrated, concentrated liquid is discharged; and steam is condensed into water and pumped into the vacuum generator to be discharged; and a refrigerant is subjected to closed-loop circulation in the cold and heat combined supply system, subjected to compression temperature rise and subjected to heat exchange with the waste liquid, then subjected to discharging and expansiontemperature reduction, sequentially cools the steam and water in a circulation water tank and then is subjected to compression recirculation.

The invention discloses an ethanol, acetone and n-butanol salting-out composite rectification separation recovery method and apparatus. According to the method, a biological n-butanol fermentation broth is delivered into a mash tower, and preliminary concentration is carried out. Waste mash liquid is discharged from the bottom of the tower, and crude alcohol is obtained at the tower top. The crude alcohol is directly subject to counter-current salting-out extraction with a salt solution in a salting-out tower, wherein a volume ratio of the salt solution to the crude alcohol is (0.1-5):1, and an extraction temperature is 60-90 DEG C. A tower-top feed liquid is composed of a gas-phase discharged feed and a liquid-phase discharged feed. The gas-phase discharged feed directly enters an acetone tower, and the liquid-phase discharged feed directly enters n-butanol. Bottom raffinate of the salting-out tower is evaporated and re-used. Through sequential separations of an n-butanol tower, the acetone-tower and an ethanol tower, the contents of obtained n-butanol, acetone and ethanol are respectively no less than 99.8%, 99%, and 95.1%. With the method, an n-butanol separation purification process is simpler; total solvent separation recovery efficiency is improved; and energy consumption is reduced.

The invention belongs to the field of uranium purification, and concretely relates to a concentration method for a uranyl nitrate solution. The method comprises the following steps: 1, determining a system used by the method; 2, carrying out water test; 3, verifying the performances of membranes; 4, carrying out nanofiltration membrane concentration; and 5, carrying out reverse osmosis membrane concentration. The method has the advantages of simplicity in membrane separation concentration technology and device, normal temperature operation, no chemical reaction, low energy consumption, cleanness and no pollution.

The invention discloses an application of a carbon nanomaterial to the preparation of a natural product. The natural product in a complex system is efficiently extracted and separated by using the carbon nanomaterial, so that trace components in the complex system can be quickly and accurately subjected to qualitative and quantitative analysis. The method is high in selectivity, is simple and convenient, is efficient, and opens up a new thought for preparing the natural product.

The invention relates to the technical field of polymer material synthesis, and in particular relates to a polyimide film for biogas purification and decarburization, a preparation method of the polyimide film comprises the following steps: (1) sulfonation or nitration of pyromellitic anhydride; (2) preparation of side chain polyamic acid; (3) preparation of a uio-66 (Zr) / ZIF-8 (Zn) organic metalskeleton compound; (4) preparation of a side-chain polyimide-uio-66(Zr) / ZIF-8(Zn) hybrid membrane. The polyimide membrane has a microporous structure. The permeability coefficient of CO2 and CH4 is 80-85 times of that of a traditional polyimide membrane, and CO2 / CH4 separation factor of is 23-30. Therefore, the polyimide membrane can be used in the field of biogas purification and decarbonizationas a separation membrane.

The invention discloses a glycyrrhiza extracting solution clarification and concentration membrane system. The glycyrrhiza extracting solution clarification and concentrated membrane system comprises a ceramic membrane clarification system and an RO (reverse osmosis) membrane concentrating system which are connected by a conveying pipeline; a glycyrrhiza crude extracting solution is pumped into the ceramic membrane clarification system for membrane system internal circulation to obtain a glycyrrhiza clarification solution; the obtained glycyrrhiza clarification solution is pumped into the RO membrane concentrating system by the conveying pipeline for concentration processing of the membrane system internal circulation to obtain dialysate; the dialysate enters a dialysate storage tank, and returns to the previous glycyrrhiza extracting working procedure for recycling; a concentration solution enters a concentration solution tank for subsequent processing treatment. The glycyrrhiza extracting solution clarification and concentration membrane system provided by the invention removes residual impurities in the glycyrrhiza extracting solution by utilizing the ceramic membrane clarification system so as to enrich effective ingredients; the RO membrane concentration system further purify and concentrate the clarification solution to obtain the high-quality glycyrrhiza concentration solution; the system operates at the normal temperature, has little loss of effective ingredients, and has no chemical change, and a product is not polluted because of the physical separation process.

The invention relates to an ornament loaded with a nano-titanium dioxide-silver exchange body, including a carrier pad, a carrier seat pad, and a carrier pendant. Nano-titanium dioxide silver exchange body pad, spray nano-titanium dioxide silver-exchange body solution B on the surface of the carrier seat cushion to form a spray-coated nano-titanium dioxide silver-exchange body seat cushion, soak the carrier pendant in nano-titanium dioxide silver-exchange body solution C to form a soaked nano-titanium dioxide silver exchange body Titanium dioxide silver exchange body pendant. Using the above method can form a variety of air purification products to purify the air in the room and in the car. At the same time of purification, negative ions are generated to optimize the indoor and in-vehicle air, improve the indoor and in-vehicle environment, and improve human health. Indoor and car air pollution is serious in our country, the development of this product has a broad market prospect.

The invention discloses an oily sludge treatment system which comprises an anaerobic distillation system and a condensation separation system, the anaerobic distillation system comprises a rotary cylinder and a shell surrounding the circumferential periphery of the rotary cylinder, a heating cavity is formed between the shell and the rotary cylinder, a heating system is arranged on the heating cavity, oily sludge is heated in the rotary cylinder to be subjected to anaerobic distillation, distillation gas generated by anaerobic distillation is conveyed to a condensation separation system to be subjected to condensation separation to obtain non-condensable gas, liquid oil and waste water, the non-condensable gas and the liquid oil serve as fuel to be supplied to the heating system, and the non-condensable gas and combustion-supporting gas pass through a heat exchanger, are preheated by smoke generated by combustion and then are conveyed to the heating system. Water and petroleum hydrocarbons in the oily sludge are distilled and separated in an oxygen-free environment, substances only change physically and do not change chemically, heating power consumption is low, non-condensable gas and liquid oil are recycled as fuel to be utilized, self-sufficiency is achieved, the operation cost is low, secondary pollution is avoided, and harmless treatment is achieved.

The invention relates to the technical field of astaxanthin, in particular to a preparation method of astaxanthin ester nano-composite particles. The preparation method comprises the following steps:dissolving protein in deionized water or a buffer solution, and hydrating to obtain an aqueous phase solution; dissolving astaxanthin ester in the oil phase to prepare an astaxanthin ester oil solution; adding the astaxanthin ester oil solution into the aqueous phase solution, adding tea polyphenol into the system at the same time, and then fully homogenizing and emulsifying the system by adoptinghigh-pressure microjet; adjusting the pH value of the emulsified system to 11-13 by using an alkaline substance, and carrying out secondary homogeneous emulsification; adjusting the pH value of the system subjected to secondary emulsification to 6.5-7.2 by using an acidic substance while stirring; and drying. The astaxanthin ester prepared by the method has obviously improved thermal stability and processing, storage and transportation stability, has good dispersibility in water, and has good processing and application performance; and in the preparation process, an alcohol solvent and a surfactant are not used, so that the problem of residues caused by the alcohol solvent and the surfactant is avoided, and the safety is improved.

The invention discloses a method for effectively converting commercial power into heat energy and a system thereof and a heat transferring medium, and belongs to the technical field of heat-energy application.The method includes the steps thatfirstly, the commercial power is converted into microwaves, and the microwaves are used for heating the heat transferring medium to generate high temperature; air, water or other heat-conducting media are used for bringing out the heat in the heat transferring medium, and a continuousheat-energy supply source is formed. The power of the microwaves or the volume and quality of the heat transferring mediumor different ingredients of the heat transferring mediumare controlled, different heating temperatures can be generated, and the heating efficiency is effectively improved, so that temperature requirements of different heat-energy supply sources are met. The heat transferring medium can repeatedly release high-heat energy under the triggering of the microwaves, is good in the high-temperature stability and capable ofbeing repeatedly used for a long term, and hasthe significant advantages of being simple in structure, rapid in heating and high in heat efficiency, having no exhaust emission, saving energy, protecting the environment and the like; electric energy with low power is used for generating high temperature which reaches 2000 DEG C, andthe heat value is greater than that of coal so that traditional coal, natural gas and other disposal fuels can be replaced.

The invention discloses a method for preparing flame-retardant and smoke-suppressing asphalt. According to the method, 65% to 75% of matrix asphalt, 5% to 10% of a flame retardant, 8% to 18% of a filler, 2% to 8% of a toughening agent, 5% to 12% of a stabilizer, 3% 11% of an odor neutralizer are used as raw materials, and the flame-retardant and smoke-suppressing asphalt is prepared through threesteps: heating for melting, developing treatment in an oven, and shearing. The flame retardant has excellent effects of flame retarding and smoke suppressing, can reduce or even completely prevent thegeneration of smoke in an asphalt production process, is highly efficient and environmentally friendly, and does no harm to the staff. The addition of stabilizer can improve the anti-aging performance of the asphalt, so that the asphalt does not change physically or chemically under use conditions of high temperature, low temperature and strong light, and the performance is kept stable. The odorneutralizer can improve odor generated in the asphalt production process, thereby improving construction conditions. The flame-retardant and smoke-suppressing asphalt in the invention is environmentally friendly, and has good effects of flame retarding and smoke suppressing and strong anti-aging capability; the preparation method is simple and easy to implement.

The invention relates to a novel crystal (defined as the crystal form VII) of paliperidone and a preparation method thereof. The reflection angle 2Theta in the X-ray powder diffraction pattern of the novel crystal has characteristic peaks at the following values: 8.14 degrees, 10.24 degrees, 12.40 degrees, 12.84 degrees, 13.02 degrees, 13.75 degrees, 14.56 degrees, 14.92 degrees, 16.18 degrees, 18.60 degrees, 19.14 degrees, 20.46 degrees, 21.42 degrees, 21.94 degrees, 24.58 degrees, 24.98 degrees, 27.98 degrees, 28.54 degrees and 31.19 degrees; the melting point in the DSC thermograms is 185.0 degrees centigrade. The crystal of the novel crystal form VII disclosed by the invention has a good stability under normal storage conditions. The solvent used during the preparation process has a high safety. The paliperidone can produce crystals in isopropanol easily. The obtained crystal has a high purity and is more helpful for the product development.