214621 results about "Physical chemistry" patented technology

The invention belongs to the technical field of enamel glaze preparation, and particularly relates to a high-temperature-resistant compact enamel glaze preparation method, which comprises: 1, enamel frit preparation: mixing 45-65% by mass of silicon dioxide, 10-15% by mass of anhydrous borax, 5-10% by mass of sodium carbonate, 2-6% by mass of lithium carbonate, 2-6% by mass of calcium carbonate, 2-6% by mass of strontium carbonate, and 3-6% by mass of ice crystal to form a batch, melting at 1300 DEG C for 2-3 hours, carrying out water quenching to prepare an enamel material, drying, and sieving with a 200-mesh sieve to obtain enamel frit powder; step 2, preparing enamel glaze slip, namely mixing and ball-milling 40-55% of enamel frit powder, 15-30% of 316 # stainless steel powder, 5.5-10% of clay suspending agent and 25-50% of water in percentage by mass to obtain the enamel glaze slip; and step 3, enamel coating and firing. The enamel coating has excellent high temperature resistance and corrosion resistance and long service life, and the preparation process is simple in requirement, simple and convenient to operate and suitable for industrial production.

A semiconductor element is provided with a micro-structured metal oxide layer over a conductive feature at a hybrid bonding surface. The micro-structured metal oxide layer comprises fine metal oxide grains, such as nanograins. The grains can be formed over the conductive feature by oxidizing a metal comprised in the conductive feature, or by providing a metal oxide over the conductive feature. When directly bonded to another element, the micro-structured metal oxide layer can form strong bonds at the bonding interface at substantially reduced annealing temperature.

An apparatus is dedicated to controlling the voltage of a battery comprising at least two modules connected in series and each comprising at least one electrochemical cell, and each coupled to voltage balancing means. The apparatus comprises measurement means for determining first voltages across the terminals of each of the modules, calculation means for measuring a second voltage across the terminals of the battery and for determining a mean voltage per module representative of the second voltage divided by the number of modules, and processor means for comparing each measured first voltage with the mean voltage per module and for delivering to the balancing means signals representative of the result of the comparison whenever the first voltage of a module is greater than the mean voltage, such that the balancing means reduce the voltage across the terminals of the module.

The invention relates to a battery monomer, a battery device and a power utilization device, the battery monomer comprises an electrode assembly and an electrolyte, and the electrode assembly comprises a positive pole piece and a negative pole piece; the positive pole piece comprises a positive pole current collecting part and a positive pole film layer; the positive pole film layer comprises lithium-containing phosphate with an olivine structure; the negative pole piece comprises a negative pole current collecting part and a negative pole film layer, and the negative pole film layer comprises a carbon-based material; the electrolyte comprises a carboxylic ester solvent, a first additive and fluorine-containing lithium sulfimide, and the mass content of the carboxylic ester solvent is 8%-60%; the total mass content of the first additive is 2.5%-10%, the first additive comprises 1, 3-propane sultone with the mass content larger than or equal to 0, an ethylene carbonate derivative with the mass content larger than or equal to 0 and vinylene carbonate with the mass content larger than 0, and the ethylene carbonate derivative comprises a compound shown in the formula A; the mass content of the fluorine-containing lithium sulfimide is 4%-8%. According to the invention, the rapid charging performance and the cycle performance of the battery monomer can be improved. # imgabs0 # formula A

A recovery treatment apparatus for trichloroethane in sucralose production. The rotation of an output shaft of a motor (7) drives multiple gas suction assemblies (31) to rotate, so that a negative pressure environment is formed, and the transmission of tail gas from the bottom of a water washing tower (1) into a gas guide pipe (2) is accelerated; and at this time, multiple atomizing nozzles (19) spray mist and the mist is sprayed to the tail gas passing through a sieve plate (23), then HCl gas in the tail gas is absorbed when in contact with water, thereby achieving the effect of purifying toxic gas HCl. Along with the rotation of a rotating rod (10), a collar (12) further drives L-shaped connecting rods (14) and turning blocks (15) to turn filter materials, so that collision and displacement occur between the filter materials; and at this time, particulate impurities adsorbed on the surfaces of the filter materials are cleaned under the flow of water vapor, and meanwhile, the vibration generated by dynamically moving filter materials can also cause the adsorbed particulate impurities to be shaken off. Thus, the continuous purification and adsorption effect of filter materials is improved, and the service cycle of filter materials can be prolonged at the same time.

A hard carbon negative electrode material as well as a preparation method therefor and a use thereof. The hard carbon negative electrode material comprises a hard carbon base material, heteroatoms and metal monoatoms, wherein the metal monoatoms are doped into the hard carbon base material by means of the heteroatoms, the heteroatoms comprise at least one of N, P or S, and the metal monoatoms are metal monoatoms that can undergo an alloying reaction with sodium. The metal monoatoms are doped into the hard carbon base material by means of covalent (chemical bond) interactions with other heteroatoms, so that the doping of single atoms is achieved, thereby improving the overall capacity and rate capability of a sodium ion battery at normal temperature, and ensuring the capacity retention rate of the sodium ion battery under a low temperature condition.

Processes for extracting lithium from a clay mineral and compositions thereof are described. The extraction process includes providing a clay mineral comprising lithium, mixing a cation source with the clay mineral, performing a high-energy mill of the clay mineral, and performing a liquid leach to obtain a lithium rich leach solution.

Improved performance ion exchange membranes for use in REM, AEM and DMFC fuel cells, buffered fuel cells, hydrolysis, other applications comprise a molecular matrix of homopolymers, di-monomer, heteropolymers, copolymers, or block-polymers of fluorocarbon and hydrocarbon compounds combined with (i) skeletal support grid to improve durability, handling, reduce membrane swelling, and sequester dopants and nanoparticles from leakage; (ii) microporous membrane formed using a sacrificial filler process enhancing conductivity and limiting fuel crossover; (iii) hetero-ionomeric matrix of two-or-more membrane-bound acids e.g. sulphonic and phosphonic acid expanding usable range; (iv) permanent fillers enhancing conductivity and porosity including nanoparticles, metal-oxides, zeolites, silicates, GOs, CNTs, MOFs, POSS, and others; (v) ionic liquid doping to enhance membrane conductivity; (vi) membrane nanocoating preventing H2O2 diffusion; and / or (vii) catalytic nanocoating with metals, metal-oxides, and MOFs preventing atmospheric toxin catalyst poisoning. Combined with a heterogenous GDI, the IEM is integrated into iBFC power blade and energy bank applications.

To provide a metal paste capable of efficiently providing a joined body having reliability high in electrical and mechanical strength even when narrowed in pitch, and to provide a method for manufacturing the joined body.SOLUTION: A metal paste comprises metal particles and a solvent, and has a shear viscosity of 1 to 100 Pa_s, measured at a shear rate of 10 s-1 at 25°C, wherein a value (TI value) obtained by log-transforming a ratio of a shear viscosity measured at a shear rate of 0.1 s-1 and a shear viscosity measured at a shear rate of 1 s-1 is 0.7 to 1.0.SELECTED DRAWING: Figure 4

The invention discloses a water quality heavy metal pollution detection method and system based on Raman spectrum.The water quality heavy metal pollution detection method comprises the steps that water body Raman scattering light is collected in situ through a miniature optical fiber probe, and a continuous time sequence spectrum signal flow is generated; wavelet transform is combined with self-adaptive threshold setting, and high-frequency noise and effective spectral signals are separated; dynamically strengthening the characteristic peak of the target heavy metal through a frequency domain characteristic screening module, and inhibiting a water molecule interference peak at the same time; generating a cross-domain fusion feature vector; processing the fusion feature vector through a pre-trained heavy metal concentration prediction model, and outputting concentration prediction values of various heavy metals; a confidence score is dynamically calculated based on a deviation between a current predicted value and historical data distribution, and model parameter update and system calibration are automatically triggered. The method has the advantages that through acousto-optic signal cross-domain fusion and closed-loop self-calibration, the target peak is dynamically strengthened while water molecule interference is inhibited, and the real-time performance, the anti-interference performance and the prediction precision of heavy metal detection are improved.

A pyrolysis method and system are provided that enhances the production of C3 and C4 alkanes in the resulting pyrolysis effluent. More particularly, the disclosed pyrolysis method and system may be configured to enhance the production of C3 and C4 alkanes due to the use of certain pyrolysis catalysts and more intense pyrolysis conditions.

The invention belongs to the field of catalysts, and particularly relates to an alumina carrier as well as a preparation method and application thereof. The surface of the alumina carrier has oxygen-containing groups, and the density of the oxygen-containing groups on the surface of the alumina carrier is 0.15-5mmol / m < 2 >. Wherein the oxygen-containing group is at least one of hydroxyl, carboxyl and lactone group; the specific surface area of the alumina carrier is 10-150m < 2 > / g. The types, the number and the density of oxygen-containing groups on the surface of the obtained carrier are improved, and various index requirements of various supported catalysts on dispersion forms and dispersion degrees of different metal active components in the field of petrochemical engineering can be well met; and the carrier also has the characteristics of low bulk density, high water absorption rate, large pore volume and large average pore size, has a gain effect on uniform distribution of active metal components in the catalyst loading process, and has extremely high application value.

The invention relates to the technical field of quartz sand detection, in particular to a quartz sand impurity detection method which comprises the following steps: acquiring spectral data of a quartz sand sample, and obtaining spectral line interference degrees of characteristic peaks according to energy distribution conditions of the characteristic peaks of the spectral data; based on the peak shape variation condition of each characteristic peak and the offset condition of each characteristic peak and a matrix characteristic peak, the matrix interference degree of each characteristic peak is obtained, and the interference intensity of each characteristic peak is obtained by combining the anti-interference degree of each characteristic peak so as to optimize the chaos regulation factor when the chaos mapping population is initialized; and finally, combining with an optimization algorithm to obtain a characteristic wave band with minimum interference, and detecting the purity and impurity content of the quartz sand based on the characteristic wave band. The quartz sand impurity detection precision can be improved.

The invention belongs to the technical field of separation membrane materials, and provides a covalent organic framework membrane as well as a preparation method and application thereof. The preparation method comprises the following steps: preparing an organic phase solution containing a polyaldehyde monomer and a water phase solution containing a polyamine monomer; dropwise adding the organic phase solution to the aqueous phase solution for reaction, and dialyzing the solution after the reaction is finished to obtain a purified aqueous dispersion of the covalent organic framework nanosheet; and dispersing the aqueous dispersion, carrying out suction filtration to a hydrophilic support, and carrying out heat treatment and curing. The invention also discloses the covalent organic framework membrane prepared according to the method and application thereof. The covalent organic framework membrane is used for removing divalent ions in a saline solution. The covalent organic framework membrane disclosed by the invention has an ordered pore structure with a specific size and high ion selectivity; due to the strong covalent bond connection characteristic, the covalent organic framework film is endowed with acid and alkali resistance and high stability; the preparation method disclosed by the invention is simple, mild in condition and wide in application range.

Vacuum-integrated photoresist-less methods and apparatuses for forming metal hardmasks can provide sub-30 nm patterning resolution. A metal-containing (e.g., metal salt or organometallic compound) film that is sensitive to a patterning agent is deposited on a semiconductor substrate. The metal-containing film is then patterned directly (i.e., without the use of a photoresist) by exposure to the patterning agent in a vacuum ambient to form the metal mask. For example, the metal-containing film is photosensitive and the patterning is conducted using sub-30 nm wavelength optical lithography, such as EUV lithography.

The present invention provides a composite binder for a sulfide solid-state battery, a preparation method thereof and an application thereof, wherein the composite binder comprises a binder A, a binder B and a solvent, wherein the mass ratio of the binder A to the binder B is (1-10):(5-1), and the mass ratio of the total mass of the binder A and the binder B to the solvent is 1:(10-100). The present invention adopts a binder having a polar functional group and a low-polarity / non-polar binder for combination, thereby making the prepared composite binder have good compatibility with the sulfide solid electrolyte, that is, it does not affect the ionic conductivity of the sulfide solid electrolysis, and at the same time makes the sulfide solid electrolyte membrane have good mechanical properties and flexibility.

The invention discloses a lithium iron phosphate positive electrode material, a preparation method thereof and a lithium battery, and relates to the technical field of lithium ion batteries. According to the method, the pressing index of the lithium iron phosphate positive electrode material is tested by adopting a specific method, so that the pressing index meets a specific range, meanwhile, the average circularity of larger particles in a Dv50-Dv100 range meets a proper range, the lithium iron phosphate positive electrode material has better particle movement capability, and the particles can move at a higher speed to be rearranged during pressing, so that the particle size of the lithium iron phosphate positive electrode material is reduced, and the quality of the lithium iron phosphate positive electrode material is improved. Therefore, the positive pole piece with high compaction density can be obtained, the charge-discharge capacity of the battery can be improved, and meanwhile, the particles can be prevented from being broken when being pressed, so that the positive pole piece has good anti-pressure capability. By adopting the lithium iron phosphate positive electrode material provided by the invention, the lithium battery has relatively high energy density and capacity retention ratio.

The invention provides a gold mineral three-dimensional shape measuring method, and belongs to the technical field of process mineralogy. According to the method, a test sample is obtained through ore grinding, reselection, magnetic separation, flotation and nitric acid treatment, then an automatic mineralogical analysis sample is prepared through rolling, glue mixing, oscillation, curing, grinding and polishing and carbon spraying treatment in sequence, and then the three-dimensional morphological characteristics of gold minerals can be judged by combining automatic mineralogical analysis and specific calculation rules. And calculating a corresponding three-dimensional shape distribution rate. According to the method, special ore sample treatment steps are adopted, and enough gold minerals can be enriched; through the specific automatic mineralogical analysis sample preparation step, the probability of visible gold can be greatly improved; the three-dimensional form of the gold mineral can be obtained by adopting automatic mineralogy analysis and a specific calculation rule, manpower is saved, the testing efficiency is high, the influence of subjective factors of people is avoided, and data is more objective.

The present invention relates to the technical field of battery separators and provides a coated modified composite separator, a preparation method thereof and a coating slurry for preparing the composite separator. The coated modified composite separator includes a base membrane and a coating, wherein the coating is coated on either any one side or both sides of the base membrane, and the coating comprises at least two of the following: b2.1 high temperature resistant polymer microspheres, b2.2 high temperature resistant polymer nanofibers, and b2.3 inorganic particles. The coating in the modified composite separator of the present invention notably enhances the thermal dimensional stability of the base membrane, decreases the areal density of the composite separator, boosts the battery's energy density, lowers the probability of occurrence of thermal runaway, and improves battery safety.

The invention discloses a silicon-carbon negative electrode material and a preparation method and application thereof.The silicon-carbon negative electrode material comprises a porous carbon substrate, a silicon element distributed in pore channels of the porous carbon substrate and carbon coating the outer surfaces of the porous carbon substrate and the silicon element, the porous carbon substrate is prepared after two times of activating treatment, and the silicon element is prepared after two times of activating treatment. The porous carbon has dendritic pore channels and meets at least one of the following conditions: a, the volume ratio of micropores is 10-30%; b, the volume ratio of mesopores is 60-90%; c, the volume ratio of macropores is 0-10%; d, the specific surface area is not less than 200m < 2 > / g; e, the pore volume is not less than 0.4 cm < 3 > / g; and f, the average particle size D50 is 1-20 [mu] m. By activating the porous carbon substrate, more buffer spaces can be provided for volume expansion of nano silicon particles from the angle of substrate preparation, and the cycling stability of the silicon-carbon negative electrode material is remarkably improved.

The invention provides a method for leaching copper-cobalt sulfide ore under efficient oxygen pressure, and relates to the technical field of metallurgy. The method for efficiently leaching the copper-cobalt sulfide ores under the oxygen pressure comprises the following steps: mixing materials including the copper-cobalt sulfide ores, sulfuric acid and water, slurrying, and then carrying out an oxygen pressure leaching reaction; and after the oxygen pressure leaching reaction is finished, solid-liquid separation is carried out, and leaching residues and leaching liquid are obtained. According to the method, the self-exothermic reaction of the excess sulfur element in the copper-cobalt sulfide ore is utilized, additional heating is not needed in the reaction process, then the oxygen pressure leaching reaction can be rapidly completed at a high temperature in a short time, and SO2 is not generated in the reaction process. The method for high-efficiency oxygen pressure leaching of the copper-cobalt sulfide ore has the advantages of being high in reaction speed, low in reaction energy consumption, easy to operate, environmentally friendly, easy to achieve industrial application and the like.

The invention discloses an environment-friendly calcium-zinc composite heat stabilizer and a preparation method thereof, and relates to the technical field of heat stabilizers. The environment-friendly calcium-zinc composite heat stabilizer is prepared from the following raw materials in parts by mass: 10-20 parts of zinc stearate, 20-30 parts of calcium stearate, 10-15 parts of an auxiliary stabilizer, 5-8 parts of a plasticizer, 1-5 parts of an antioxidant and 2-5 parts of filler, wherein the auxiliary stabilizer is a mixture of beta-diketone, modified organic acid intercalated hydrotalcite and modified silicon dioxide; the modified organic acid intercalated hydrotalcite is obtained by splitting expanded vermiculite, adding zinc and lanthanum compounds, coprecipitating with organic acid, and adding a modifier; the modified silicon dioxide is obtained by adding a coupling agent into a solid substance obtained by splitting expanded vermiculite for modification and carrying out a series of chemical reactions with maleic anhydride and pentaerythritol. PVC plastic prepared by adding the calcium-zinc composite stabilizer into PVC paste resin and resin powder has good thermal stability.

A process system and process method for treating hydrogen sulfide-containing acid gas. The process system comprises a sulfur recovery unit, a tail gas treatment unit having an acid gas concentration function, and a flue gas alkaline scrubbing unit. The method comprises: subjecting sulfur-containing tail gas to concentration treatment by means of an absorption column (1) of the tail gas treatment unit, and then introducing same into the sulfur recovery unit to undergo a Claus reaction for separation, so as to obtain sulfur and sulfur recovery tail gas; introducing the sulfur recovery tail gas into the tail gas treatment unit, successively carrying out combustion and hydrotreating, and introducing the obtained gas into the absorption column (1) of the tail gas treatment unit; and in the tail gas treatment unit, introducing gas absorbed by the absorption column (1) into the flue gas alkaline scrubbing unit, and successively carrying out incineration and alkaline scrubbing, so as to discharge desulfurized gas. The content of SO2 in the tail gas treated by the process system is ≤50 mg / Nm3, and the requirements for full-period standard reaching of sulfur dioxide emission of tail gas during startup, shutdown and normal operations can be satisfied.

The present invention belongs to the field of sensors, and relates to an ion gel film with a microstructure on the surface, a preparation method, and an ion-type sensor. The preparation method comprises: sandblasting on a precursor substrate to obtain a substrate, forming a mixed solution of a polymer and an ionic liquid on the substrate to obtain a wet film, and drying and curing the wet film to obtain an ion gel film, wherein the precursor substrate has an arc-shaped recess array, and the sandblasting conditions include: the sandblasting particle size is 5000 mesh to 10000 mesh, and the sandblasting pressure is 2 bar to 10 bar. The ion gel film is used for an ion-type sensor, which can improve the detection sensitivity of the sensor.

The invention discloses a method for continuously and efficiently adsorbing and separating hydrogen isotopes. The hydrogen isotopes are separated by adopting a multi-tower variable-temperature variable-pressure device operated in a simulated moving bed operation mode. When the device runs, each adsorption tower needs to sequentially execute the following steps: 1, adsorption; 2, replacement; 3, heating; 4, vacuumizing and desorbing; 5, carrying out vacuum purging; 6, pressurizing and cooling; the operation mode of the simulated moving bed is that an adsorption tower is frequently, sequentially and synchronously moved along the gas flowing direction in the tower through all gas input and output ports, so that an adsorbent phase and a gas flowing phase in the tower form countercurrent flow, and the hydrogen isotope adsorption separation efficiency is enhanced. The invention relates to a technological process of cyclic adsorption, replacement, heating, vacuum desorption, pressurization and cooling, continuous and efficient hydrogen and isotope adsorption separation is realized, multi-tower serial adsorption and replacement are adopted in the process, and separation of hydrogen isotopes (such as H2 / D2) is enhanced; and the desorption efficiency of heavy components is improved by adopting a heating and vacuumizing depressurization coupling mode.

The invention provides a sodium ferric pyrophosphate positive electrode material cooperatively doped with anions and cations, a preparation method of the sodium ferric pyrophosphate positive electrode material and a sodium ion battery, and relates to the field of sodium ion batteries. The anion and cation synergistically doped ferric sodium phosphate pyrophosphate positive electrode material comprises an inner core and a coating layer covering the outer surface of the inner core, the inner core comprises ferric sodium phosphate pyrophosphate, the coating layer comprises carbon, the chemical formula of the ferric sodium phosphate pyrophosphate is Na4-2yFe2.91-xQx (PO4) 2-yP2O7Fy, x is more than 0 and less than or equal to 0.3, and y is more than or equal to 0.03 and less than or equal to 0.08; q comprises at least one of Sn, Ni, Cu, Mg and Mn. The introduced Q positive ions and F negative ions can keep the crystal structure of the body material stable, and the positive ions and the negative ions have a synergistic effect, so that the band gap of the positive electrode material is reduced, the state density near the Fermi level of the positive electrode material is increased, the conductivity of the positive electrode material is enhanced, the specific capacity of the positive electrode material is improved, and the rate and the cycle performance are promoted.

The present invention relates to a sodium-ion battery material, and specifically relates to a sodium ferric phosphate pyrophosphate composite material, and a preparation process, evaluation method and process optimization method therefor and the use thereof. The sodium ferric phosphate pyrophosphate composite material has a spinel-type NaFePO4 phase; and in an XRD diffraction pattern obtained by subjecting the sodium ferric phosphate pyrophosphate composite material to XRD diffraction using CuKα radiation, there are a characteristic diffraction peak T of sodium ferric phosphate pyrophosphate and a characteristic diffraction peak O of spinel-type NaFePO4 at 2θ of 33.6±0.2° and 32.8±0.2°, respectively, the peak intensities thereof are respectively IT and IO, and the diffraction peak intensity ratio Ir is equal to IT / IO, wherein 6.19≤Ir≤13.

Disclosed is a cylindrical lithium-ion battery, comprising a battery cell, a protection board, a first elastic conductive member, a second elastic conductive member and a fixing cap. The protection board is installed above the battery cell at intervals, a top surface of the protection board is provided with a metal contact. An upper end of the first elastic conductive member abuts against a bottom surface of the protection board and is electrically connected to a positive electrode of the protection board, and a lower end of the first elastic conductive member abuts against a top end of the battery cell and is electrically connected to a positive electrode of the battery cell. An upper end of the second elastic conductive member abuts against the bottom surface of the protection board and is electrically connected to a negative electrode of the protection board.

The invention relates to the technical field of solid-state lithium batteries, in particular to a cellulose acetate modified PEO-based solid-state electrolyte membrane, a solid-state lithium battery and a preparation method thereof.The preparation method comprises the steps that lithium bis (trifluoromethanesulfonyl) imide, cellulose acetate and polyethylene oxide are dissolved in a solvent, and a mixed solution is obtained; and curing the mixed solution in a mold to obtain the cellulose acetate modified PEO-based solid electrolyte membrane. According to the invention, the cellulose acetate is introduced to modify the polyethylene oxide solid electrolyte, and the prepared cellulose acetate modified PEO-based solid electrolyte membrane can generate a stable solid electrolyte interface rich in Li2O and LiF on the surface of a lithium negative electrode in situ in the application of a solid lithium battery, so that the growth ability of lithium dendrites is effectively inhibited, and the performance of the lithium battery is improved. The interface impedance is reduced, and the operating temperature range of the solid-state lithium battery is widened.

The embodiment of the invention relates to a lithium cobalt oxide positive electrode material with a composite phase as well as a preparation method and application of the lithium cobalt oxide positive electrode material. The chemical general formula of the lithium cobalt oxide positive electrode material with the composite phase is AXCo (1-y) M (1y) O2, wherein x is more than or equal to 0.5 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 0.03, A is Li or Li and Na, and M1 is one or more of A1, Zr, Ni, Mn, Y, Nb, La, Fe, Cu, Cr, Ti, W, Mg, Mo or Yb; the composite phase of the lithium cobalt oxide positive electrode material comprises an O2 phase, a T2 phase and an O3 phase; wherein the sum of the molar ratios of the O2 phase and the T2 phase in the composite phase is greater than or equal to 90%, and the molar ratio of the O3 phase is less than or equal to 10%. By regulating and controlling the composite phase proportion of the lithium cobalt oxide positive electrode material, the rate capability, the structural stability under high voltage, the stability of a thermodynamic structure, the specific capacity, a discharge platform and other characteristics of the positive electrode material can be effectively improved, so that the lithium cobalt oxide positive electrode material with high energy density and high stability is realized.