40results about How to "Large working temperature zone" patented technology

The invention discloses a control method for a combined refrigerating multi-split air conditioner system. The multi-split air conditioner system is characterized in that two or more outdoor combined refrigerating modules are arranged the outdoor side to form a cold source system of the multi-split air conditioner system, each outdoor combined refrigerating module is composed of a first refrigerant vapor compression and refrigeration circulating loop and a second refrigerant circulating loop, one or more direct evaporation type indoor air cooler modules are arranged at the indoor side, and a refrigerant storing and conveying unit is connected with the part between each outdoor combined refrigerating module and the corresponding indoor air cooler module to form a closed circulating system through a liquid collecting tube, a main liquid supply tube and a main air return tube. According to the control method for the combined refrigerating multi-split air conditioner system, the number of the indoor and outdoor modules is decided according to the designed thermal load of an air conditioner, and the control method precisely regulates the refrigerating capacity to meet the heat control needs of round-the-clock running data machine rooms and electronic equipment; the control method for the combined refrigerating multi-split air conditioner system is capable of making the maximum use of the natural cold source of the day and night, transition season and winter so as to realize the great energy conservation and emission reduction of the air conditioner system.

The invention discloses an optical module working parameter adjusting method and an adjusting device. The method comprises the following steps of: detecting and obtaining an ambient temperature value; obtaining a reference bias current value and a reference modulated current value, which need to be compensated; when the ambient temperature value is more than a set temperature threshold value, obtaining an actual bias current compensated value and a modulated current compensated value by using a scaling factor which is not more than 1; when the ambient temperature value is not more than the set temperature threshold value, directly using the reference bias current value and the reference modulated current value as the actual bias current compensated value and the actual modulated current compensated value, respectively; and compensating a bias current and a modulated current of a laser according to the actual bias current compensated value and the actual modulated current compensated value. Through different adjustments carried out on working parameters under different conditions, a problem that the laser is degraded in performance and even damaged due to laser saturation can be solved.

The invention discloses a control method of a combined type air-conditioning system with a natural cooling function. The control method of the combined type air-conditioning system with the natural cooling function is characterized in that the system comprises a compressor module, an air-cooling heat exchange module, a multifunctional liquid storage device, a liquid pump, an air treatment module and control valves, wherein the air-cooling heat exchange module is composed of a heat exchanger assembly and a cooling fan; and the control method comprises the step that the three different work modes including a compression refrigeration work mode, a compression refrigeration and natural cooling coordinated operation combined refrigeration work mode and the natural cooling work mode are achieved by operating the control valves to change the flowing path of refrigeration media. According to the control method of the combined type air-conditioning system with the natural cooling function, fuzzy control is used for adjusting the refrigeration capacity, natural cooling is used for replacing compression refrigeration in low-temperature or transition seasons, natural cold resources are efficiently utilized, the control method is particularly suitable for control over the work environments of data centers, high-performance computers, communication base stations and power electronic equipment, and the energy consumption and operating cost of the air-conditioning system are greatly reduced.

The invention provides a noble metal doped SnO2 composite material and a preparation method thereof. The method comprises: (1) SnO2 superfine powder is mixed with noble metal powder with mass fraction ranging from 0.05 to 1.21, deionized water with mass fraction ranging from 20 to 40 percent is added to and stirred with the mixture into slurry, and the noble metal is one of or the mixture of two or more of Pd, Au, Cu and La or Ce; (2) the slurry is evenly coated on a ceramic substrate and is dried in a baking oven; and (3) the ceramic substrate is put into a muffle furnace and is sintered for 1 hour at the temperature from 600 to 700 DEG C, and after the room temperature is realized by furnace cooling, the noble metal doped SnO2 composite material can be obtained. Compared with common SnO2 materials, the noble metals doped in the invention, such as Pd, Au, Cu, La and Ce, and the like, can reduce the activation energy of adsorption of chemical gas, and can obviously improve the sensitivity and the response time of the SnO2 material.

The invention provides an alveolate magnetic heat exchange material preparing method, which is characterized in that a magnetic heat exchange material and a molding promoter are mixed according to a certain proportion and are uniformly mixed by a mixed material blender, then solvent, plasticizing agent and lubricant with a certain proportion are added, a kneader is used for kneading, second vacuum pugging processing is carried out, and then an alveolate magnetic heat exchange material blank is obtained with an alveolate porous mould by an extruder through extrusion molding. Finally, the blank is cut to be a certain size, is dried and solidified to obtain an alveolate magnetic heat exchange material with good comprehensive performances. The alveolate magnetic heat exchange material prepared by the technology disclosed by the invention has a porous structure, small flowing resistance and a good heat exchange effect, and because the integral bonding strength of the alveolate magnetic heat exchange material is high, the problems of abrasion and peeling can not occur in the use process, and the material is very suitable for being applied on a refrigerator.

The invention relates to a stepper for juxtaposedly pushing three or four piezoelectrics and a scanning probe microscope body thereof, in particular to a piezoelectric locator comprising three or four piezoelectrics, a base and slide blocks, wherein the three or four piezoelectrics which are triangularly or squarely arranged and are parallel in the telescopic direction are juxtaposedly fixed and elevated on the base; the slide blocks which are in sliding match with the three or four piezoelectrics in the telescopic direction are provided; positive pressures which enable the slide blocks and the free ends of the piezoelectrics to be pressed are arranged in the direction vertical to the telescopic direction; in the largest breakout friction to the slide blocks, which is generated by the three or four positive pressures, any largest breakout friction is smaller than the sum of other two or three frictions; the slide blocks press the free ends of the piezoelectrics through elastic force; the piezoelectrics and the base can be arranged integrally, and a piezoelectric scanatron fixed on the base is coated outside the stepper, thus a scanning probe microscope body which can work in a small space is formed. The invention has small size, simple and firm structure, and large working temperature zone and driving force, is suitable for various extreme physical conditions and approaches to an ideal stepper.

The invention discloses a current liquid-changing material of intercalation kaolin / modified titanium oxide nanometer composite particle, which is characterized by the following: adopting formamide intercalation kaolin micrometer particle as core of dispersing phase; making chromium ion modified titanium oxide nanometer particle as micrometer / nanometer nuclear shell structure particle of clad layer; improving TauE / eta0 value of current liquid-changing material and physical value excited by electric field; increasing sediment-proof property; displaying the relationship of cutting stress and electric field strength of different dispersing particle currents in the accompanying diagram.

The invention relates to a high-temperature high-toughness Ni-Co-Mn-Sn-Cu alloy with a high magnetocaloric effect, a preparation method, and application thereof, belongs to the technical field of magnetic materials, and particularly relates to the high-temperature high-toughness Ni-Co-Mn-Sn-Cu alloy with the high magnetocaloric effect, the preparation method, and the application thereof. The invention aims to solve the problems that an existing Ni-Mn-Sn ferromagnetic shape-memory alloy system is high in brittleness and hard to meet the use requirement under high temperature environment. A chemical general formula is Ni48-xCoxMn37Sn9Cu6, wherein x is mole fraction and is larger than 0 and smaller than or equal to 12; and the sum of mole number of elements in the alloy is 100. The method comprises the steps of (1) preparing materials; (2) carrying out electric arc meting; and (3) carrying out homogenization treatment so as to finally obtain an Ni48-xCoxMn37Sn9Cu6 magnetic refrigeration alloy material.

The invention relates to a method for preparing current liquid-change material, especially relating to a titanium oxide / acidamide derivative nanometer current liquid-change material. Compared with former relative method, the inventive current liquid-change material uses glacial acetic acid to restrain the hydrolyzation of butyl titanate, and prevents the reunite of nanometer particles via adjusting the pH value of solution and adding surface activator, The invention has easy operation and lower cost, which the prepared diffused phased material is core-shell nanometer particles that the nanometer titanium oxide particles is basic core, and the acidamide derivative with high dielectric constant is the coating layer. Said structure can improve the dielectric property and conducting property of material to make the current liquid-change have some excellent properties: strong current change effect, better anti-deposition stability, lower electricity density, and better chemical stability. The figure displays the relationship between diffused phased particle current liquid-change shear stress with different coating structures and the electric field intensity.

The invention relates to kaolin / TiO2 nanotube composite particle electrorheological fluid materials, compared with the conventional materials, the prepared electrorheological liquid discontinuous phase material has unique structure and a shape similar to cactus, wherein the porcelain clay is used as the base stock, the TiO2 nanotube is distributed onto the surface of the porcelain clay. The structure can be applied for improving the dielectric property and electrical conductance of the material.

The invention discloses an electromagnetic clutch active control contact type thermal switch device for a low temperature system. The electromagnetic clutch active control contact type thermal switch device comprises a cold end connecting plate, a left side plate, a thermal bridge, an upper sliding rod, a lower sliding rod, a first electromagnet, a second electromagnet, electromagnetic pure iron, a support rod, a right side plate and a hot end connecting plate. Whether the thermal bridge is in contact with thermally conductive blocks of the cold and hot end connecting plates or not corresponds to the on / off state of the thermal switch. The electromagnetic clutch active control contact type thermal switch device of the invention has the technical advantages of freely controllable on-off, fast response, large switching ratio, wide controllable temperature range, simple structure, easy operation and the like, and can be widely applied in the technical fields of low temperature physics research, cryogenic temperature calibration, space refrigeration and so forth.

The invention belongs to the field of magnetic refrigeration, and particularly relates to a temperature-graded magnetic heating material and a preparation method thereof. The temperature-graded magnetic heating material comprises a Ni50Mn37Sn13 alloy film layer and a Ni50Mn35In15 alloy film layer. The phase change temperature of the Ni50Mn37Sn13 alloy film layer ranges from 295 K to 305 K. The phase change temperature of the Ni50Mn35In15 alloy film layer ranges from 301 K to 310 K. The thickness ratio of the Ni50Mn37Sn13 alloy film layer to the Ni50Mn35In15 alloy film layer is 1:3 to 3:1. According to the temperature-graded magnetic heating material and the preparation method thereof, by carrying out gradient design and preparation on the magnetic heating material, the work temperature zone of an existing magnetic heating material can be expanded, and the magnetic heating effect of the material can be improved; and a design rule and a regulating and control mechanism of the magnetic heating material are set up, and the gradient magnetic heating temperature material is pushed to develop towards application.

The invention discloses a temperature measurement method based on trivalent rare earth ferrous oxides as temperature sensing materials, and belongs to the technical field of thermally responsive materials. The trivalent rare earth ferrous oxides are prepared through a pressureless sintering technology by using trivalent rare earth oxides and ferric oxides as the raw materials. Under the excitation of THz waves, the trivalent rare earth ferrous oxides can radiate out narrow band THz waves, and the center frequency of the narrow band THz waves obviously change along with temperature, so the trivalent rare earth ferrous oxides can be used as the temperature sensing materials and applied to temperature measurement. In the temperature measuring process, a circuit does not need to be led in, and the measurement effect can be good at low temperature. The working temperature range of the temperature sensing materials is wider, theoretically, 0K to antiferromagnetic-paramagnetic transition temperature (650-750K) can be achieved, and the working mode can be in a transmission type or a reflection type. In addition, due to the fact that the THz waves have a good permeance property to most of materials except for metal and strong polar materials, the THz waves can be used for measuring the internal temperature of a closed space.

The invention relates to a thin film material with a high electrocaloric effect near room temperature and a preparation method thereof, the chemical general formula of the thin film material is (1-x)Ba(Ti0.8Zr0.2)O<3-x>(Ba0.7Ca0.3)TiO<3-y>Sn, the value range of x is 0.1-0.7, and the value range of y is 0-0.06. The (1-x)Ba(Ti0.8Zr0.2)O<3-x>(Ba0.7Ca0.3)TiO<3-y>Sn thin film material provided by the invention has multiphase coexistence near room temperature, with the introduction of Sn, the Curie temperature is reduced, so that the (1-x)Ba(Ti0.8Zr0.2)O<3-x>(Ba0.7Ca0.3)TiO<3-y>Sn thin film materialobtains large electrocaloric temperature change near room temperature, thereby facilitating the enlarging of the working temperature range; and the material is good in application prospect in the field of electric card refrigeration devices.

The invention discloses a control method of a combined type air-conditioning system with a natural cooling function. The control method of the combined type air-conditioning system with the natural cooling function is characterized in that the system comprises a compressor module, an air-cooling heat exchange module, a multifunctional liquid storage device, a liquid pump, an air treatment module and control valves, wherein the air-cooling heat exchange module is composed of a heat exchanger assembly and a cooling fan; and the control method comprises the step that the three different work modes including a compression refrigeration work mode, a compression refrigeration and natural cooling coordinated operation combined refrigeration work mode and the natural cooling work mode are achieved by operating the control valves to change the flowing path of refrigeration media. According to the control method of the combined type air-conditioning system with the natural cooling function, fuzzy control is used for adjusting the refrigeration capacity, natural cooling is used for replacing compression refrigeration in low-temperature or transition seasons, natural cold resources are efficiently utilized, the control method is particularly suitable for control over the work environments of data centers, high-performance computers, communication base stations and power electronic equipment, and the energy consumption and operating cost of the air-conditioning system are greatly reduced.

The invention relates to a ZnO / beta-FeSi2 composite material and a method for preparing the same, in particular to a composite material and a method for preparing the same. The method solves the problem that beta-FeSi2 has poor oxidation resistance under a condition of long-term high temperature service. The ZnO / beta-FeSi2 composite material is prepared from a sodium oleate aqueous solution, the beta-FeSi2 and zinc acetate. The method for preparing the composite material comprises: step one, adding the beta-FeSi2 to the sodium oleate aqueous solution and stirring the mixture; step two, dissolving the zinc acetate in isopropyl alcohol, dripping ethylene alcohol amine to the isopropyl alcohol, heating the mixture through water bath, and stirring the mixture; step three, performing ultrasound treatment on the mixed liquid prepared in the step two, then adding the mixed liquid to the mixed liquid prepared in the step three, heating the mixture through the water bath, and stirring the mixture; and step four, performing drying and heat treatment to obtain the ZnO / beta-FeSi2 composite material. The ZnO / beta-FeSi2 composite material prepared by the method has good oxidation resistance under the condition of long-term high temperature service. The method has the advantages of simple process and convenient operation.

The invention discloses an MLCC (multilayer ceramic capacitor) dielectric material with an excellent insulation characteristic. BaTiO3 powder serves as a base material, components including, in percentage by mass, 0.3%-0.8% of Na0.5Bi0.5TiO3, 0-1.5% of (NiO)(1-x)(NbO2.5)x, 0-0.5% of (MnO)(1-y)(NbO2.5)y and 1.0%-3.0% of CaZrO3 are added, wherein x ranges from 0.6 to 0.8, and y ranges from 0.4 to 0.6. BaTiO3 powder serves as the base material, Na0.5Bi0.5TiO3 is added, and a BT-NBT mixture is prepared after calcination; (NiO)(1-x)(NbO2.5)x, (MnO)(1-y)(NbO2.5)y and CaZrO3 are added to the BT-NBT mixture, the mixture is subjected to ball milling, dried, sieved, granulated and pressed into a green body, the green body is calcined in the nitrogen and hydrogen mixed atmosphere at the temperature of 1,300-1,320 DEG C, and the MLCC dielectric material is prepared. The MLCC dielectric material has the capacitance change rate smaller than or equal to plus or minus 15%, high dielectric constant (41729), lower dielectric loss (0.026) and the resistivity higher than 1011 omega.cm within the temperature zone of subzero 55-150 DEG C.

The invention relates to the technical field of heat pipes, and discloses a liquid metal pulse heat pipe. The liquid metal pulse heat pipe comprises a pipe body, a rising pipeline and a returning pipeline; a heating chamber and a heat dissipation chamber which are independent mutually are sequentially constructed in the pipe body from bottom to top, and a low-boiling-point working medium and liquid metal are arranged in the heating chamber from top to bottom in a layered mode; the rising pipeline is arranged in the pipe body and penetrates through the heating chamber and the heat dissipation chamber; the returning pipeline is arranged in the pipe body and penetrates through the heating chamber and the heat dissipation chamber; and the returning pipeline and the rising pipeline are arrangedin a spaced mode. By heating the heating chamber, the low-boiling-point working medium is heated and evaporated into a gaseous work medium, and under the effect of the gas pressure, the liquid metaland the gaseous work medium are alternately conveyed from the heating chamber to the heat dissipation chamber along the rising pipeline in a segmented mode, and then conveyed from the heat dissipationchamber back to the heating chamber along the return pipeline; and the liquid metal pulse heat pipe has the advantages of high heat transfer efficiency and large heat transfer limit.

The invention discloses a bismuth titanate-based bismuth layered structure lead-free piezoelectric ceramic with a negative electrocaloric effect and a preparation method thereof. The chemical composition of the bismuth titanate-based bismuth layered structure lead-free piezoelectric ceramic is Bi<4-x>Ce<x>Ti<2.98> (WNb)<0.01>O<12>, wherein x is more than 0 and less than or equal to 0.07. The bismuth titanate-based bismuth layered structure lead-free piezoelectric ceramic has the characteristics of wide working temperature range and large negative electrocaloric effect, does not cause harm to the ecological environment and human health in the preparing, using and discarding processes, and is suitable for development of miniature refrigerators in the future.

The invention discloses a carbon-dioxide-combined-type heat pump hot water and air conditioning system and a control method thereof. The system consists of a carbon dioxide heat pump unit, a freon circulation unit and a water storage box, wherein the carbon dioxide heat pump unit adopts carbon dioxide as a refrigerating agent and forms a first heat pump circulation loop; and the freon circulation unit adopts freon as a refrigerating agent, and a gateable second heat pump circulation loop, a heat pump and refrigeration circulation loop and a refrigeration air conditioning circulation loop are formed by utilizing a four-way valve and each switching valve. By adopting the carbon-dioxide-combined-type heat pump hot water and air conditioning system and the control method thereof, different working modes of heating, cooling and hot water supplying can be realized in a wide temperature zone in the whole year; and stable, reliable and energy-saving operation of the system is ensured.

The invention discloses a current liquid-changing material of intercalation kaolin / modified titanium oxide nanometer composite particle, which is characterized by the following: adopting formamide intercalation kaolin micrometer particle as core of dispersing phase; making chromium ion modified titanium oxide nanometer particle as micrometer / nanometer nuclear shell structure particle of clad layer; improving TauE / eta0 value of current liquid-changing material and physical value excited by electric field; increasing sediment-proof property; displaying the relationship of cutting stress and electric field strength of different dispersing particle currents in the accompanying diagram.

The invention discloses a frequency converter thermal management system for an air conditioner unit, an air conditioner unit and a control method, which specifically include a control unit, a temperature detection unit, a frequency converter cooling unit, a first switch module and a second switch module, wherein the control units are respectively It is connected with the temperature detection unit, the first switch module and the second switch module; the inlet end of the inverter cooling unit is connected to the condenser in the refrigeration system of the air conditioner unit through the second switch module, and the inverter cooling unit is connected to the condenser in the refrigeration system. The outlet end is connected to the main evaporator in the refrigeration system of the air-conditioning unit through the first switch module; the temperature detection unit is used to detect the temperature of the refrigerant in the inverter cooling unit and send it to the control unit, and the control unit according to The detected temperature controls the opening value of the first switch module and the second switch module, so as to maintain the refrigerant in the inverter cooling unit within a preset range. The above scheme has the advantages of precise temperature control and strong applicability.

The invention relates to an electrorheological fluid material, in particular to a kaolin / dimethyl sulfoxide / carboxymethyl starch ternary system nanocomposite electrorheological fluid material. Compared with the binary system composite material used as the dispersed phase of electrorheological fluid in the past, the dispersed phase material prepared by the invention has a novel structure and belongs to the ternary system. It uses kaolin / dimethyl sulfoxide intercalation complex as the core, and then wraps carboxymethyl starch. The application of this ternary system improves the dielectric properties of the material and fully exerts the nano-synergistic effect, so that the electro-rheological fluid has a strong electro-rheological effect, a wide working temperature range, low cost and good anti-settling sex. The accompanying drawing shows the relationship between the shear stress and the electric field intensity of the electrorheological fluid of the kaolin / dimethyl sulfoxide / carboxymethyl starch ternary system nanocomposite particles.

The invention discloses an air conditioning unit, comprising a refrigeration system and a frequency converter. The refrigeration system includes a compressor, a condenser, a main evaporator, a flasher and a throttling unit. The inlet end of the compressor is connected with the main evaporator, and the outlet end is connected to the main evaporator. connected with the condenser, the throttle unit includes a first throttle element, a second throttle element and a third throttle element, the first throttle element is located between the condenser and the flasher, The second throttling element is located between the compressor and the flasher, and the third throttling element is located between the flasher and the main evaporator, characterized in that the frequency converter is provided with The inverter cooling unit, the inlet end of the inverter cooling unit is connected to the condenser, the outlet end of the inverter cooling unit is connected to the flasher through the first switch, and is connected to the flasher through the second switch. The main evaporators are connected. The air-conditioning unit of the invention has the advantages of simple structure, anti-condensation, and suitability for different working conditions.

The invention relates to a high-temperature high-toughness Ni-Co-Mn-Sn-Cu alloy with a high magnetocaloric effect, a preparation method, and application thereof, belongs to the technical field of magnetic materials, and particularly relates to the high-temperature high-toughness Ni-Co-Mn-Sn-Cu alloy with the high magnetocaloric effect, the preparation method, and the application thereof. The invention aims to solve the problems that an existing Ni-Mn-Sn ferromagnetic shape-memory alloy system is high in brittleness and hard to meet the use requirement under high temperature environment. A chemical general formula is Ni48-xCoxMn37Sn9Cu6, wherein x is mole fraction and is larger than 0 and smaller than or equal to 12; and the sum of mole number of elements in the alloy is 100. The method comprises the steps of (1) preparing materials; (2) carrying out electric arc meting; and (3) carrying out homogenization treatment so as to finally obtain an Ni48-xCoxMn37Sn9Cu6 magnetic refrigeration alloy material.

The invention discloses an electromagnetic clutch active control contact type thermal switch device for a low temperature system. The electromagnetic clutch active control contact type thermal switch device comprises a cold end connecting plate, a left side plate, a thermal bridge, an upper sliding rod, a lower sliding rod, a first electromagnet, a second electromagnet, electromagnetic pure iron, a support rod, a right side plate and a hot end connecting plate. Whether the thermal bridge is in contact with thermally conductive blocks of the cold and hot end connecting plates or not corresponds to the on / off state of the thermal switch. The electromagnetic clutch active control contact type thermal switch device of the invention has the technical advantages of freely controllable on-off, fast response, large switching ratio, wide controllable temperature range, simple structure, easy operation and the like, and can be widely applied in the technical fields of low temperature physics research, cryogenic temperature calibration, space refrigeration and so forth.

The invention relates to kaolin / TiO2 nanotube composite particle electrorheological fluid materials, compared with the conventional materials, the prepared electrorheological liquid discontinuous phase material has unique structure and a shape similar to cactus, wherein the porcelain clay is used as the base stock, the TiO2 nanotube is distributed onto the surface of the porcelain clay. The structure can be applied for improving the dielectric property and electrical conductance of the material.

The invention relates to a stepper for juxtaposedly pushing three or four piezoelectrics and a scanning probe microscope body thereof, in particular to a piezoelectric locator comprising three or fourThe invention relates to a stepper for juxtaposedly pushing three or four piezoelectrics and a scanning probe microscope body thereof, in particular to a piezoelectric locator comprising three or foure piezoelectrics and the base can be arranged integrally, and a piezoelectric scanatron fixed on the base is coated outside the stepper, thus a scanning probe microscope body which can work in a smalhe piezoelectrics and the base can be arranged integrally, and a piezoelectric scanatron fixed on the base is coated outside the stepper, thus a scanning probe microscope body which can work in a small space is formed. The invention has small size, simple and firm structure, and large working temperature zone and driving force, is suitable for various extreme physical conditions and approaches tol space is formed. The invention has small size, simple and firm structure, and large working temperature zone and driving force, is suitable for various extreme physical conditions and approaches toan ideal stepper.an ideal stepper. piezoelectrics, a base and slide blocks, wherein the three or four piezoelectrics which are triangularly or squarely arranged and are parallel in the telescopic direction are juxtaposedly fixed and epiezoelectrics, a base and slide blocks, wherein the three or four piezoelectrics which are triangularly or squarely arranged and are parallel in the telescopic direction are juxtaposedly fixed and elevated on the base; the slide blocks which are in sliding match with the three or four piezoelectrics in the telescopic direction are provided; positive pressures which enable the slide blocks and thlevated on the base; the slide blocks which are in sliding match with the three or four piezoelectrics in the telescopic direction are provided; positive pressures which enable the slide blocks and the free ends of the piezoelectrics to be pressed are arranged in the direction vertical to the telescopic direction; in the largest breakout friction to the slide blocks, which is generated by the three free ends of the piezoelectrics to be pressed are arranged in the direction vertical to the telescopic direction; in the largest breakout friction to the slide blocks, which is generated by the three or four positive pressures, any largest breakout friction is smaller than the sum of other two or three frictions; the slide blocks press the free ends of the piezoelectrics through elastic force; te or four positive pressures, any largest breakout friction is smaller than the sum of other two or three frictions; the slide blocks press the free ends of the piezoelectrics through elastic force; th