Through the Latour concept of philosophy of science of laboratory life,the life course of a(geo)ethnographer researcher is analyzed,in order to establish the emotional or more personal dimensions that do not usually a...Through the Latour concept of philosophy of science of laboratory life,the life course of a(geo)ethnographer researcher is analyzed,in order to establish the emotional or more personal dimensions that do not usually appear in research papers,but that have notable relevance in qualitative research.The text is structured in three large parts:A conceptual vision of the new experimental geography;the experimental geo-ethnography in old social,new social and place scenarios;and finally,the most personal and emotional dimension of the research.The first part establishes the geo-ethnographic experimental context and the assumptions in fieldwork,in addition to the geo-ethnographic reconciliation process.In the second part,the main qualitative research problems related to mobility,resistance and dynamics in place are established.Finally,in the third part the research perceptions,the personal experiences,and the emotional dimension of the research in remote rural areas are established.The laboratory life of a researcher,allows one to establish scalar conclusions and rigor in qualitative research.展开更多
The Ca(OH)_(2)/CaO thermochemical energy storage(TCES)system based on calcium looping has received extensive attention owing to its high energy storage density,prolonged energy storage time,and environmental friendlin...The Ca(OH)_(2)/CaO thermochemical energy storage(TCES)system based on calcium looping has received extensive attention owing to its high energy storage density,prolonged energy storage time,and environmental friendliness.The heat storage process of the Ca(OH)_(2)/CaO TCES system in a mixed heating reactor was evaluated in this study,by employing a combination of direct and indirect heating modes.The dehydration process was studied experimentally,and a numerical model was established and verified based on the experimental results.The dehydration behavior of 500 g of Ca(OH)_(2) powder was investigated in a fixed-bed reactor with mixed heating.The experimental and simulation results indicated that mixed heating causes combined centripetal and horizontal propulsion.Heat input is the main limiting factor in the heat storage process,because the radial advance of the reaction is hindered by the low thermal conductivity of the solid reactant particles.Heat transmission partitions were added to enhance the performance of the reactor.The performance of the modified reactor was compared with that of a conventional reactor.The radial heat transmission partitions in the modified reactor effectively enhance the energy storage rate and reduce the reaction time by 59.5%compared with the reactor without partitions.展开更多
In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different para...In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different parameters investigated by means of observation and a high-speed camera.Since the appearance of spiral flow makes the distribution of twophase flow more complicated,the flow patterns appearing in the experiments were divided into the Spiral Wavy Stratified Flow(SWS),the Spiral Bubble Flow(SB),the Spiral Slug Flow(SS),the Spiral Linear Flow(SL),the Spiral Axial Flow(SA),and the Spiral Dispersed Flow(SD) by the observations and with reference to the predecessors' research achievements.A flow pattern map has been drawn up.The influence of velocity,vane angle and vane area on flow pattern conversion boundary and pressure drop has been studied,with a solid foundation laid for the future research work.展开更多
In order to study the propagation mechanism of continuous rotating detonation wave,the H2/air continuous rotating detonation engine ignited by tangentially installed H2/O2pre-detonation tube is studied experimentally ...In order to study the propagation mechanism of continuous rotating detonation wave,the H2/air continuous rotating detonation engine ignited by tangentially installed H2/O2pre-detonation tube is studied experimentally using a tilt slot injector structure.The experimental results show that the stable rotating detonation wave can be gained successfully with the equivalent ratio of 0.93.The propagation frequency and velocity of rotating detonation wave range from 5200 to 5500 Hz and from 1518.5 to 1606.1 m/s,respectively.Three propagation modes,such as rotation,reversal and bifurcation,of detonation wave are verified through the analysis of propagation mechanism of rotating detonation wave.展开更多
The absence of effective therapies for castration-resistant prostate cancer(CRPC) establishes the need to develop novel therapeutic modality, such as targeted gene therapy, which is ideal for the treatment of CRPC. Bu...The absence of effective therapies for castration-resistant prostate cancer(CRPC) establishes the need to develop novel therapeutic modality, such as targeted gene therapy, which is ideal for the treatment of CRPC. But its application has been limited due to lack of favorable gene vector and the reduction of "bystander effect". Consequently, scientists all over the world focus their main experimental research on the following four aspects: targeted gene, vector, transfer means and comprehensive therapy. In this paper, we reviewed the latest advances of experimental research on targeted gene therapy for prostate cancer.展开更多
Polysocoharibe-peptide of Coriolus Versicolor (PSP) is a new anti-cancer immunomodulative drug. The present paper reports on the experimental research done with this drug. It was found that PSP had the ability to reco...Polysocoharibe-peptide of Coriolus Versicolor (PSP) is a new anti-cancer immunomodulative drug. The present paper reports on the experimental research done with this drug. It was found that PSP had the ability to recover hemolysin HC50, to increase the weight of the thymus, and increase the alexin of serum C3 and the IgG content of tumor bearing mice. FSP also significantly raised the pha-gocytic activity of macrophages in normal mice. PSP had a significant inhibitory effect on P38S and S180 cells. At the concentration of 1 mg/ml, PSP inhibited the proliferating activity of some human tumor call lines, such as SGC 7901, SPC, SLY and Mei. It had a direct toxic effect on SPC cells. PSP significantly inhibited the synthesis of nucleic acids of Ehrlich ascites carcinoma cells. In addition, PSP was antagonistic to the side effects of chemotherapy and radiotherapy.展开更多
?Fundamental experiments on lower hybrid current drive (LHCD) have been undertaken on HT-7 superconducting tokamak. The experiments on LHCD efficiency reveal its depen- deuce on plasma density and the toroidal magnet...?Fundamental experiments on lower hybrid current drive (LHCD) have been undertaken on HT-7 superconducting tokamak. The experiments on LHCD efficiency reveal its depen- deuce on plasma density and the toroidal magnetic field. Furthermore, the experiments on HT-7 successfully demonstrate the ability for LHCD to sustain long pulse tokamak discharges, such as discharges with full non-inductive current drive for several seconds. The experimental study to improve plasma confinements by LHCD suggests that the improvement should be due to the change o f current profile. It has also been demonstrated by the experiments that the lower hybrid wave may lead to an enhanced ionization of particles in the region where the wave is deposited.展开更多
The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, d...The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, distance of fin space, frost, and velocity of air flow etc. They mainly influence the thermal efficiency of an evaporator, and therefore its thermal efficiency has direct relationship with the whole efficiency of the quick freeze plant. Evaporators with different structural types have different heat transfer efficiency, in order to obtain high efficiency structure of evaporator, 8 evaporator models with different fin shape, tube diameter and tube arrangement are analyzed and compared. The calculation results show that the integral waved fins, equilateral-triangle arranged small diameter tubes and varying fin-spacing has the highest heat transfer coefficient. The experimental result also shows that the evaporator with this type of structure has better thermal efficiency. The experimental result is in good agreement with the calculation result, it can instruct engineering design for usual designer. A real quick-freeze equipment is designed and put into production. The result shows that, compared with traditional domestic quick-freeze equipments, this equipment decreases by 40% in size and by 20% in energy consumption.展开更多
The calculated and experimental research of sheet resistances of crystalline silicon solar cells by dry laser doping is investigated. The nonlinear numerical model on laser melting of crystalline silicon and liquid-ph...The calculated and experimental research of sheet resistances of crystalline silicon solar cells by dry laser doping is investigated. The nonlinear numerical model on laser melting of crystalline silicon and liquid-phase diffusion of phosphorus atoms by dry laser doping is analyzed by the finite difference method implemented in MATLAB. The melting period and melting depth of crystalline silicon as a function of laser energy density is achieved. The effective liquid-phase diffusion of phosphorus atoms in melting silicon by dry laser doping is confirmed by the rapid decrease of sheet resistances in experimental measurement. The plateau of sheet resistances is reached at around 15 Ω/. The calculated sheet resistances as a function of laser energy density is obtained and the calculated results are in good agreement with the corresponding experimental measurement. Due to the successful verification by comparison between experimental measurement and calculated results, the simulation results could be used to optimize the virtual laser doping parameters.展开更多
Dipole Research EXperiment（DREX） is a new terrella device as part of the Space Plasma Environment Research Facility（SPERF） for laboratory studies of space physics relevant to the inner magnetospheric plasmas. Adeq...Dipole Research EXperiment（DREX） is a new terrella device as part of the Space Plasma Environment Research Facility（SPERF） for laboratory studies of space physics relevant to the inner magnetospheric plasmas. Adequate plasma sources are very important for DREX to achieve its scientific goals. According to different research requirements, there are two density regimes for DREX. The low density regime will be achieved by an electron cyclotron resonance（ECR） system for the ‘whistler/chorus＇ wave investigation, while the high density regime will be achieved by biased cold cathode discharge for the desired ‘Alfvén＇ wave study. The parameters of ‘whistler/chorus＇ waves and ‘Alfvén＇ waves are determined by the scaling law between space and laboratory plasmas in the current device. In this paper, the initial design of these two plasma sources for DREX is described. Focus is placed on the chosen frequency and operation mode of the ECR system which will produce relatively low density ‘artificial radiation belt＇ plasmas and the seed electrons, followed by the design of biased cold cathode discharge to generate plasma with high density.展开更多
This paper introduces a new kind of armour block - hexagon multihole block on sloping breakwater. It has great characteristics such as good interlocking, strong resistance against waves and saving concrete. Through th...This paper introduces a new kind of armour block - hexagon multihole block on sloping breakwater. It has great characteristics such as good interlocking, strong resistance against waves and saving concrete. Through the hydraulic model test, the mechanism of stability of the block has been proved and the relations between stability and wave height, wave period, water depth, slope, laying method, porosity and cushion have been found. The effect of weight on steadiness have also been discovered. Finally, the method of design and some formulas are given.展开更多
To provide hexapod robots with strategies of locomotion planning, observation experiments were operated on a kind of ant with the use of high speed digital photography and computer assistant analysis. Through digitali...To provide hexapod robots with strategies of locomotion planning, observation experiments were operated on a kind of ant with the use of high speed digital photography and computer assistant analysis. Through digitalization of original analog video, locomotion characters of ants were obtained, the biomimetic foundation was laid for polynomial trajectory planning of multi-legged robots, which was deduced with mathematics method. In addition, five rules were concluded, which apply to hexapod robots marching locomotion planning. The first one is the fundamental strategy of multi-legged robots＇ leg trajectory planning. The second one helps to enhance the static and dynamic stability of multi-legged robots. The third one can improve the validity and feasibility of legs＇ falling points. The last two give criterions of multi-legged robots＇ toe trajectory figures and practical recommendatory constraints. These five rules give a good method for marching locomotion planning of multi-legged robots, and can be expended to turning planning and any other special locomotion.展开更多
Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Inves...Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Investigations on the tensile properties were performed as a function of thermoforming temperature,extensile speed and fiber orientation based on an orthogonal experiment design.The experimental results show that the automotive carpets are rate-dependent anisotropic one and very sensitive to the forming temperature.The tensile properties are strongly depended on the forming temperature when compared with the extensile speed and the fiber orientation.Experiments only varying with the temperature were performed because of the dominative effect of the temperature.Different deformation performances were observed with different temperatures.Deformation mechanisms at the thermoforming temperatures were presented to explain the nonlinear trend of the ultimate elongation with the temperatures based on the combination of the experimental observations and the corresponding polymer theories.展开更多
Reburning technology is one of the most cost-effective NOx reduction strategies for coal combustion systems. In this paper, a nitric oxide submodel incorporated into a comprehensive coal combustion model was developed...Reburning technology is one of the most cost-effective NOx reduction strategies for coal combustion systems. In this paper, a nitric oxide submodel incorporated into a comprehensive coal combustion model was developed for predicting NOx reduction in a 93 kW laboratory-scale coal combustion furnace by reburning. This NO submodel, including reburning mechanism, requires the solution of only two transport equations to model the behavior of NO reduction in the reburning process. A number of experiments have been performed in the same furnace, and the experimental data obtained from the optimized reburn configuration was used to validate the model. Measurements and predictions both show above 50% reduction of NO emissions for the optimized reburning process. Profile comparisons show that the predicted temperature and oxygen concentration match well with the measurements, and the general trend of predicted NO concentration is very similar to that measured. The results of this study show that the present nitric oxide submodel depicts quite well the observed behaviour of NO annihilation in the reburning process. It is expected that this usable and computationally economic model represents a useful tool to simulate the gaseous fuel reburning process for the researchers concerned with practical combustors.展开更多
in this paper, an experimental research the effect of ablating material on the reflection and the transmission of microwaves in arc-heated plasma flow is presented by using the C band microwave measuring system. The ...in this paper, an experimental research the effect of ablating material on the reflection and the transmission of microwaves in arc-heated plasma flow is presented by using the C band microwave measuring system. The results show that the ablating material with accidented surface and its high temperature have remarkably affected the reflection and the transmission of microwaves. The experiment proves that the system has outstanding precision and reliability.展开更多
Due to their significant roles in the radiation belts dynamics, chorus waves are widely investigaled in observations, experiments, and simulations. In this paper, numerical studies for the generation of chorus-like wa...Due to their significant roles in the radiation belts dynamics, chorus waves are widely investigaled in observations, experiments, and simulations. In this paper, numerical studies for the generation of chorus-like waves in a launching device, dipole research experiment （DREX）, are carried out by a hybrid code. The DREX plasma is generated b} electron cyclotron resonance （ECR）, which leads to an intrinsic temperature anisotropy of energetic electrons. Thus the whistler instability can be excited in the device. We then investigate the effects of three parameters, i.e., the cold plasma density no, the hot plasma density nh, and the parallel thermal velocity of energetic electrons, on the generation of chorus-like waves under the DREX design parameters. It is obtained that a larger temperature anisotropy is needed to excite chorus-like waves with a high nc with other parameters fixed. Then we fix the plasma density and parallel thermal velocity, while varying the hot plasma density. It is found that with the increase of nh, the spectrum of the generated waves changes from no chorus elements, to that with several chorus elements, and then further to broad-band hiss-like waves. Besides, different structures of chorus- like waves, such as rising-tone and/or falling-tone structures, can be generated at different parallel thermal velocities in the DREX parameter range.展开更多
The paper introduces the performances of magnetostrictive actuators and its applications,discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator,and makes test...The paper introduces the performances of magnetostrictive actuators and its applications,discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator,and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material.The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states,and can be used in low-frequency vibration control system of precise equipment.展开更多
A narrow annular test section of 1.5mm gap and 1800mm length was designed and manufactured, with good tightness and insulation. Experiments were carried out to investigate characteristics of flow instability of forced...A narrow annular test section of 1.5mm gap and 1800mm length was designed and manufactured, with good tightness and insulation. Experiments were carried out to investigate characteristics of flow instability of forced-convection in vertical narrow annuli. Using distilled water as work fluid, the experiments were conducted at pressures of 1.0~3.0MPa, mass flow rates of 3.0~25kg/h, heating power of 3.0~ 6.5kW and inlet fluid temperature of 20 oC, 40 oC or 60oC. It was found that flow instability occured with fixed inlet condition and heating power when mass flow rate was below a special value. Effects of inlet subcooling, system pressure and mass flow rate on the system behavior were studied and the instability region was given.展开更多
文摘Through the Latour concept of philosophy of science of laboratory life,the life course of a(geo)ethnographer researcher is analyzed,in order to establish the emotional or more personal dimensions that do not usually appear in research papers,but that have notable relevance in qualitative research.The text is structured in three large parts:A conceptual vision of the new experimental geography;the experimental geo-ethnography in old social,new social and place scenarios;and finally,the most personal and emotional dimension of the research.The first part establishes the geo-ethnographic experimental context and the assumptions in fieldwork,in addition to the geo-ethnographic reconciliation process.In the second part,the main qualitative research problems related to mobility,resistance and dynamics in place are established.Finally,in the third part the research perceptions,the personal experiences,and the emotional dimension of the research in remote rural areas are established.The laboratory life of a researcher,allows one to establish scalar conclusions and rigor in qualitative research.
文摘The Ca(OH)_(2)/CaO thermochemical energy storage(TCES)system based on calcium looping has received extensive attention owing to its high energy storage density,prolonged energy storage time,and environmental friendliness.The heat storage process of the Ca(OH)_(2)/CaO TCES system in a mixed heating reactor was evaluated in this study,by employing a combination of direct and indirect heating modes.The dehydration process was studied experimentally,and a numerical model was established and verified based on the experimental results.The dehydration behavior of 500 g of Ca(OH)_(2) powder was investigated in a fixed-bed reactor with mixed heating.The experimental and simulation results indicated that mixed heating causes combined centripetal and horizontal propulsion.Heat input is the main limiting factor in the heat storage process,because the radial advance of the reaction is hindered by the low thermal conductivity of the solid reactant particles.Heat transmission partitions were added to enhance the performance of the reactor.The performance of the modified reactor was compared with that of a conventional reactor.The radial heat transmission partitions in the modified reactor effectively enhance the energy storage rate and reduce the reaction time by 59.5%compared with the reactor without partitions.
基金supported by the National Natural Science Foundation of China (Grant number 51776015)
文摘In view of the importance of gas-liquid two-phase spiral flow and the few research reports at home and abroad,the gas-liquid two-phase spiral flow patterns have been researched in a horizontal pipe with different parameters investigated by means of observation and a high-speed camera.Since the appearance of spiral flow makes the distribution of twophase flow more complicated,the flow patterns appearing in the experiments were divided into the Spiral Wavy Stratified Flow(SWS),the Spiral Bubble Flow(SB),the Spiral Slug Flow(SS),the Spiral Linear Flow(SL),the Spiral Axial Flow(SA),and the Spiral Dispersed Flow(SD) by the observations and with reference to the predecessors' research achievements.A flow pattern map has been drawn up.The influence of velocity,vane angle and vane area on flow pattern conversion boundary and pressure drop has been studied,with a solid foundation laid for the future research work.
基金sponsored by National Defence Researching Fund(9140c300202120c30)the Fundamental Research Fund for the central Universities(30920130112007)
文摘In order to study the propagation mechanism of continuous rotating detonation wave,the H2/air continuous rotating detonation engine ignited by tangentially installed H2/O2pre-detonation tube is studied experimentally using a tilt slot injector structure.The experimental results show that the stable rotating detonation wave can be gained successfully with the equivalent ratio of 0.93.The propagation frequency and velocity of rotating detonation wave range from 5200 to 5500 Hz and from 1518.5 to 1606.1 m/s,respectively.Three propagation modes,such as rotation,reversal and bifurcation,of detonation wave are verified through the analysis of propagation mechanism of rotating detonation wave.
文摘The absence of effective therapies for castration-resistant prostate cancer(CRPC) establishes the need to develop novel therapeutic modality, such as targeted gene therapy, which is ideal for the treatment of CRPC. But its application has been limited due to lack of favorable gene vector and the reduction of "bystander effect". Consequently, scientists all over the world focus their main experimental research on the following four aspects: targeted gene, vector, transfer means and comprehensive therapy. In this paper, we reviewed the latest advances of experimental research on targeted gene therapy for prostate cancer.
文摘Polysocoharibe-peptide of Coriolus Versicolor (PSP) is a new anti-cancer immunomodulative drug. The present paper reports on the experimental research done with this drug. It was found that PSP had the ability to recover hemolysin HC50, to increase the weight of the thymus, and increase the alexin of serum C3 and the IgG content of tumor bearing mice. FSP also significantly raised the pha-gocytic activity of macrophages in normal mice. PSP had a significant inhibitory effect on P38S and S180 cells. At the concentration of 1 mg/ml, PSP inhibited the proliferating activity of some human tumor call lines, such as SGC 7901, SPC, SLY and Mei. It had a direct toxic effect on SPC cells. PSP significantly inhibited the synthesis of nucleic acids of Ehrlich ascites carcinoma cells. In addition, PSP was antagonistic to the side effects of chemotherapy and radiotherapy.
文摘?Fundamental experiments on lower hybrid current drive (LHCD) have been undertaken on HT-7 superconducting tokamak. The experiments on LHCD efficiency reveal its depen- deuce on plasma density and the toroidal magnetic field. Furthermore, the experiments on HT-7 successfully demonstrate the ability for LHCD to sustain long pulse tokamak discharges, such as discharges with full non-inductive current drive for several seconds. The experimental study to improve plasma confinements by LHCD suggests that the improvement should be due to the change o f current profile. It has also been demonstrated by the experiments that the lower hybrid wave may lead to an enhanced ionization of particles in the region where the wave is deposited.
基金This project is supported by National Key Technologies R&D Programme,China (No.2001BA501A22).
文摘The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, distance of fin space, frost, and velocity of air flow etc. They mainly influence the thermal efficiency of an evaporator, and therefore its thermal efficiency has direct relationship with the whole efficiency of the quick freeze plant. Evaporators with different structural types have different heat transfer efficiency, in order to obtain high efficiency structure of evaporator, 8 evaporator models with different fin shape, tube diameter and tube arrangement are analyzed and compared. The calculation results show that the integral waved fins, equilateral-triangle arranged small diameter tubes and varying fin-spacing has the highest heat transfer coefficient. The experimental result also shows that the evaporator with this type of structure has better thermal efficiency. The experimental result is in good agreement with the calculation result, it can instruct engineering design for usual designer. A real quick-freeze equipment is designed and put into production. The result shows that, compared with traditional domestic quick-freeze equipments, this equipment decreases by 40% in size and by 20% in energy consumption.
基金Supported by the National Natural Science Foundation of China under Grant No 61306076
文摘The calculated and experimental research of sheet resistances of crystalline silicon solar cells by dry laser doping is investigated. The nonlinear numerical model on laser melting of crystalline silicon and liquid-phase diffusion of phosphorus atoms by dry laser doping is analyzed by the finite difference method implemented in MATLAB. The melting period and melting depth of crystalline silicon as a function of laser energy density is achieved. The effective liquid-phase diffusion of phosphorus atoms in melting silicon by dry laser doping is confirmed by the rapid decrease of sheet resistances in experimental measurement. The plateau of sheet resistances is reached at around 15 Ω/. The calculated sheet resistances as a function of laser energy density is obtained and the calculated results are in good agreement with the corresponding experimental measurement. Due to the successful verification by comparison between experimental measurement and calculated results, the simulation results could be used to optimize the virtual laser doping parameters.
基金supported by National Natural Science Foundation of China(Nos.11505040,11261140326,11405038 and 51577043)China Postdoctoral Science Foundation(Nos.2016M591518,2015M570283)HIT.NSRIF under Grant No.2017008
文摘Dipole Research EXperiment（DREX） is a new terrella device as part of the Space Plasma Environment Research Facility（SPERF） for laboratory studies of space physics relevant to the inner magnetospheric plasmas. Adequate plasma sources are very important for DREX to achieve its scientific goals. According to different research requirements, there are two density regimes for DREX. The low density regime will be achieved by an electron cyclotron resonance（ECR） system for the ‘whistler/chorus＇ wave investigation, while the high density regime will be achieved by biased cold cathode discharge for the desired ‘Alfvén＇ wave study. The parameters of ‘whistler/chorus＇ waves and ‘Alfvén＇ waves are determined by the scaling law between space and laboratory plasmas in the current device. In this paper, the initial design of these two plasma sources for DREX is described. Focus is placed on the chosen frequency and operation mode of the ECR system which will produce relatively low density ‘artificial radiation belt＇ plasmas and the seed electrons, followed by the design of biased cold cathode discharge to generate plasma with high density.
文摘This paper introduces a new kind of armour block - hexagon multihole block on sloping breakwater. It has great characteristics such as good interlocking, strong resistance against waves and saving concrete. Through the hydraulic model test, the mechanism of stability of the block has been proved and the relations between stability and wave height, wave period, water depth, slope, laying method, porosity and cushion have been found. The effect of weight on steadiness have also been discovered. Finally, the method of design and some formulas are given.
基金Sponsored by the Ministerial Level Advanced Research Foundation(65822576)
文摘To provide hexapod robots with strategies of locomotion planning, observation experiments were operated on a kind of ant with the use of high speed digital photography and computer assistant analysis. Through digitalization of original analog video, locomotion characters of ants were obtained, the biomimetic foundation was laid for polynomial trajectory planning of multi-legged robots, which was deduced with mathematics method. In addition, five rules were concluded, which apply to hexapod robots marching locomotion planning. The first one is the fundamental strategy of multi-legged robots＇ leg trajectory planning. The second one helps to enhance the static and dynamic stability of multi-legged robots. The third one can improve the validity and feasibility of legs＇ falling points. The last two give criterions of multi-legged robots＇ toe trajectory figures and practical recommendatory constraints. These five rules give a good method for marching locomotion planning of multi-legged robots, and can be expended to turning planning and any other special locomotion.
基金Supported by National Natural Science Foundation of China(No.50305020)
文摘Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Investigations on the tensile properties were performed as a function of thermoforming temperature,extensile speed and fiber orientation based on an orthogonal experiment design.The experimental results show that the automotive carpets are rate-dependent anisotropic one and very sensitive to the forming temperature.The tensile properties are strongly depended on the forming temperature when compared with the extensile speed and the fiber orientation.Experiments only varying with the temperature were performed because of the dominative effect of the temperature.Different deformation performances were observed with different temperatures.Deformation mechanisms at the thermoforming temperatures were presented to explain the nonlinear trend of the ultimate elongation with the temperatures based on the combination of the experimental observations and the corresponding polymer theories.
基金Project 2004CB217704-4 supported by the Special Funds for Major State Basic Research Projects of China and 306012 by the Key Grant Project of Chinese Ministry of Education
文摘Reburning technology is one of the most cost-effective NOx reduction strategies for coal combustion systems. In this paper, a nitric oxide submodel incorporated into a comprehensive coal combustion model was developed for predicting NOx reduction in a 93 kW laboratory-scale coal combustion furnace by reburning. This NO submodel, including reburning mechanism, requires the solution of only two transport equations to model the behavior of NO reduction in the reburning process. A number of experiments have been performed in the same furnace, and the experimental data obtained from the optimized reburn configuration was used to validate the model. Measurements and predictions both show above 50% reduction of NO emissions for the optimized reburning process. Profile comparisons show that the predicted temperature and oxygen concentration match well with the measurements, and the general trend of predicted NO concentration is very similar to that measured. The results of this study show that the present nitric oxide submodel depicts quite well the observed behaviour of NO annihilation in the reburning process. It is expected that this usable and computationally economic model represents a useful tool to simulate the gaseous fuel reburning process for the researchers concerned with practical combustors.
文摘in this paper, an experimental research the effect of ablating material on the reflection and the transmission of microwaves in arc-heated plasma flow is presented by using the C band microwave measuring system. The results show that the ablating material with accidented surface and its high temperature have remarkably affected the reflection and the transmission of microwaves. The experiment proves that the system has outstanding precision and reliability.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.41674165,41631071,41474142,and 41674174)the China Postdoctoral Science Foundation(Grant No.2015M570283)
文摘Due to their significant roles in the radiation belts dynamics, chorus waves are widely investigaled in observations, experiments, and simulations. In this paper, numerical studies for the generation of chorus-like waves in a launching device, dipole research experiment （DREX）, are carried out by a hybrid code. The DREX plasma is generated b} electron cyclotron resonance （ECR）, which leads to an intrinsic temperature anisotropy of energetic electrons. Thus the whistler instability can be excited in the device. We then investigate the effects of three parameters, i.e., the cold plasma density no, the hot plasma density nh, and the parallel thermal velocity of energetic electrons, on the generation of chorus-like waves under the DREX design parameters. It is obtained that a larger temperature anisotropy is needed to excite chorus-like waves with a high nc with other parameters fixed. Then we fix the plasma density and parallel thermal velocity, while varying the hot plasma density. It is found that with the increase of nh, the spectrum of the generated waves changes from no chorus elements, to that with several chorus elements, and then further to broad-band hiss-like waves. Besides, different structures of chorus- like waves, such as rising-tone and/or falling-tone structures, can be generated at different parallel thermal velocities in the DREX parameter range.
基金Sponsored by National Nature Science Foundation of China(50005020)Youth Foundation Support Project of Ningbo Province(02J20102-07)
文摘The paper introduces the performances of magnetostrictive actuators and its applications,discusses the design methods for the structure and internal magnetic circuit of a giant magnetostrictive actuator,and makes tests on the output displacement and force characteristics for an actuator using homemade magnetostrictive material.The experimental result shows that the actuator has satisfactory output precisions and ranges in transient and stable states,and can be used in low-frequency vibration control system of precise equipment.
文摘A narrow annular test section of 1.5mm gap and 1800mm length was designed and manufactured, with good tightness and insulation. Experiments were carried out to investigate characteristics of flow instability of forced-convection in vertical narrow annuli. Using distilled water as work fluid, the experiments were conducted at pressures of 1.0~3.0MPa, mass flow rates of 3.0~25kg/h, heating power of 3.0~ 6.5kW and inlet fluid temperature of 20 oC, 40 oC or 60oC. It was found that flow instability occured with fixed inlet condition and heating power when mass flow rate was below a special value. Effects of inlet subcooling, system pressure and mass flow rate on the system behavior were studied and the instability region was given.
