A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is proposed.In the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are compensated.The feedforward contr...A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is proposed.In the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are compensated.The feedforward controller is a novel input rate-dependent neural network hysteresis inverse model,while the feedback controller is a proportion integration differentiation(PID)controller.In the proposed inverse model,an input ratedependent auxiliary inverse operator(RAIO)and output of the hysteresis construct the expanded input space(EIS)of the inverse model which transforms the hysteresis inverse with multi-valued mapping into single-valued mapping,and the wiping-out,rate-dependent and continuous properties of the RAIO are analyzed in theories.Based on the EIS method,a hysteresis neural network inverse model,namely the dynamic back propagation neural network(DBPNN)model,is established.Moreover,a hybrid compensation scheme for the PEAs is designed to compensate for the hysteresis.Finally,the proposed method,the conventional PID controller and the hybrid controller with the modified input rate-dependent Prandtl-Ishlinskii(MRPI)model are all applied in the experimental platform.Experimental results show that the proposed method has obvious superiorities in the performance of the system.展开更多
This paper reports a contact cantilever MEMS switch. The designed switch has a metal cantilever that acts as an electrostatically activated switch with processing options to achieve dielectric isolation of the control...This paper reports a contact cantilever MEMS switch. The designed switch has a metal cantilever that acts as an electrostatically activated switch with processing options to achieve dielectric isolation of the controlvoltage path from the signal path. To obtain good material properties,an ANSYS FEA tool is used to optimize the structure. The RF MEMS switch is fabricated via a surface micromachining process. The switch has an actuation voltage of 12V,which is close to the simulated value of 11V. The measured and the HFSS simulated isolations are both higher than - 20dB from 0.05 to 10GHz. The measured insertion loss is less than - 0.9dB, relatively larger than the simulated loss of less than - 0.2dB from 0.05 to 10GHz. This is because a contact resistance introduced due to poor physical contact between the bottom lines and the metal cantilever.展开更多
Based on a short anode GTO structure (SA-GTO),a novel GTO structure called an injection efficiency controlled gate turn off thyristor (IEC-GTO) is proposed,in which the injection efficiency can be controlled via a...Based on a short anode GTO structure (SA-GTO),a novel GTO structure called an injection efficiency controlled gate turn off thyristor (IEC-GTO) is proposed,in which the injection efficiency can be controlled via an additional thin oxide layer located in the short anode contact region. The forward blocking, conducting, and switching characteristics are analyzed and compared with an SA-GTO and conventional GTO. The results show that the IEC-GTO can obtain a better trade-off relation between on-state and turn-off characteristics. Additionally,the width of the oxide layer covering the anode region and the doping concentration of the anode region are optimized, the process feasibility is analyzed, and a realization scheme is given. The results show that the introduction of an oxide layer would not increase the complexity of process of the IEC-GTO.展开更多
The aim was to study the main industry effect the double of the per capi- ta net income of farmers economic. The relation between six industry net income per capita income of farmers including grain, animal husbandry,...The aim was to study the main industry effect the double of the per capi- ta net income of farmers economic. The relation between six industry net income per capita income of farmers including grain, animal husbandry, flue-cured tobacco, walnut, long-term labor expot, seasonal labor export and the net income of farmers per capita in the Wazitian Village of Baoshan, Yunnan was studied by means of the effect main industry doubled net income of farmers per capita economic and the grey correlation analysis. The correlation degree of six industry and the net income of farmers per capita economic was long-term labor export〉seasonal labor export〉 walnut〉grain〉animal husbandry〉flue-cured tobacco. The pillar industry affecting the net income of farmers per capita economic was long-term labor export, seasonal la- bor export and walnut. The study provided the scionce theoretical basis and method of support for net income per capita economic multiplier of farmers in Baoshan, Yunnan province and even a similar low latitude mountain plateau.展开更多
Association rules are useful for determining correlations between items. Applying association rules to intrusion detection system (IDS) can improve the detection rate, but false positive rate is also increased. Weight...Association rules are useful for determining correlations between items. Applying association rules to intrusion detection system (IDS) can improve the detection rate, but false positive rate is also increased. Weighted association rules are used in this paper to mine intrustion models, which can increase the detection rate and decrease the false positive rate by some extent. Based on this, the structure of host-based IDS using weighted association rules is proposed.展开更多
Gut inflammation can occur in 30%-60% of patients with spondyloarthropathies.However, the presence of such gut inflammation is underestimated, only 27% of patients with histological evidence of gut inflammation have i...Gut inflammation can occur in 30%-60% of patients with spondyloarthropathies.However, the presence of such gut inflammation is underestimated, only 27% of patients with histological evidence of gut inflammation have intestinal symptoms, but subclinical gut inflammation is documented in two-thirds of patients with inflammatory joint disease.There are common genetic and immunological mechanisms behind concomitant inflammation in the joints and intestinal tract.A number of blood tests, e.g.erythrocyte sedimentation rate, orosomucoid, C-reactive protein, and white cell and platelet counts, are probably the most commonly used laboratory markers of inflammatory disease, however, these tests are difficult to interpret in arthropathies associated with gut inflammation, since any increases in their blood levels might be attributable to either the joint disease or to gut inflammation.Consequently, it would be useful to have a marker capable of separately identifying gut inflammation.Fecal proteins, which are indirect markers of neutrophil migration in the gut wall, and intestinal permeability, seem to be ideal for monitoring intestinal inflammation:they are easy to measure non-invasively and are specific for intestinal disease in the absence of gastrointestinal infections.Alongside the traditional markers for characterizing intestinal inflammation, there are also antibodies, in all probability generated by the immune response to microbial antigens and auto-antigens, which have proved useful in establishing the diagnosis and assessing the severity of the condition, as well as the prognosis and the risk of complications.In short, noninvasive investigations on the gut in patients with rheumatic disease may be useful in clinical practice for a preliminary assessment of patients with suspected intestinal disease.展开更多
SAW (Surface Acoustic Wave) filter bank is a single input, single or multi-output device consisting of multi-SAW-filters with input interconnection network or switch circuits, and can be divided into two categories...SAW (Surface Acoustic Wave) filter bank is a single input, single or multi-output device consisting of multi-SAW-filters with input interconnection network or switch circuits, and can be divided into two categories: channelizer (multi-output) and switchable (programmable, single output). The tbrmer is mainly used in military channelized receiver for spectrum analysis; the latter has wide application in frequency synthesizer and frequency-hopping radar and communication system receiver as anti-jamming filter, and has been widely used in various military electronic equipments ever since the 1970s. Research abroad was done mainly by Americans, few documents on related work done by Japan and Russia are available. Domestic research started in the 1980s, mainly by No. 26 Research Institute, China Electronics Technology Group Co., Institute of Acoustics, Chinese Academy of Sciences, No. 23 and No. 25 Research Institute, China Spaceflight Tech. Group Co. This paper first briefly introduces Chinese and foreign research on SAW filter banks; then discusses research progress in device design, the input interconnection network or switch circuit and miniaturization; and ends in a brief perspective of developing trends in future.展开更多
A multicast replication algorithm is proposed for shared memory switches. It uses a dedicated FIFO to multicast by replicating cells at receiver and the FIFO is operating with shared memory in parallel. Speedup is use...A multicast replication algorithm is proposed for shared memory switches. It uses a dedicated FIFO to multicast by replicating cells at receiver and the FIFO is operating with shared memory in parallel. Speedup is used to promote loss and delay performance. A new queueing analytical model is developed based on a sub-timeslot approach. The system performance in terms of cell loss and delay is analyzed and verified by simulation.展开更多
According to the positive correlation of coal ash content and natural gamma, using a new coal core reposition method, which is ordered by global and local extreme, coal samples from medium-thickness seam are reasonabl...According to the positive correlation of coal ash content and natural gamma, using a new coal core reposition method, which is ordered by global and local extreme, coal samples from medium-thickness seam are reasonably located. Inte- grated the data of coal macrostructure characteristics, coal petrography analysis and coal gas production test, it studies the rela- tionship between coalbody structure and amplitude variation of different well logging data, and the tectonic coal recognition method with well logging data in fresh-water mud invasion. The results show that: the anomalous response of natural gamma ray, neutron, density and apparent resistivity does not reflect the coalbody structure type. In fresh-water drilling mud invasion, using the crossplot technique of dual-lateral, RXO resistivity response and the coalbody structure can classify granulated coal accurately; the proposed method is of good practicability and high reliability.展开更多
Ischemic mitral regurgitation (IMR) is a common complication of acute myocardial infarction (AMI). Current evidences suggest that revascularization of the culprit vessels with percutaneous coronary artery interven...Ischemic mitral regurgitation (IMR) is a common complication of acute myocardial infarction (AMI). Current evidences suggest that revascularization of the culprit vessels with percutaneous coronary artery intervention (PCI) or coronary artery bypass grafting can be beneficial for relieving IMR. A 2.5-year follow-up data of a 61-year-old male patient with ST-segment elevation AMI complicated with IMR showed that mitral regurgitation area increased five days after PCI, and decreased to lower steady level three months after PCI. This finding suggest that three months after PCI might be a suitable time point for evaluating the possibility oflMR recovery and the necessity of surgical intervention of the mitral valve for AMI patient.展开更多
It is shown that in an open A-type system with spontaneously generated coherence, the transient evolution rule of the gain of lasing without inversion (LWI) is very sensitive to variation of the relative phase φbet...It is shown that in an open A-type system with spontaneously generated coherence, the transient evolution rule of the gain of lasing without inversion (LWI) is very sensitive to variation of the relative phase φbetween the probe and driving fields; the variety of the atomic exit rate γo and the ratio C of the atomic injection rates also have a considerable effect on the phase-dependent transient evolution rule of LWI gain. We find that when φ =0, the transient and stationary LWI gain increases with C increasing but decreases with γ0 increasing; when φ≠0, the effect of C and γ0 on LWI gain is just opposite to that when φb=0 ; in order to get the largest transient and stationary LWI gain, we need selecting suitable values of φ, γ0andC.展开更多
Based on the interprovincial panel data of 2000–2014, this paper carries out an empirical analysis on the relationship between energy abundance and economic growth to test the theoretical hypothesis of ‘resource cur...Based on the interprovincial panel data of 2000–2014, this paper carries out an empirical analysis on the relationship between energy abundance and economic growth to test the theoretical hypothesis of ‘resource curse' and explore its transmission mechanism for China and its three regions. The results show that, at the national level, positive correlation is present between energy abundance and economic growth, proving that the ‘resource curse' phenomenon does not exist in China as a whole. Moreover, material capital input, human capital input and the level of opening to the outside world could promote economic growth, while technology innovation input may hinder economic growth. As seen by region, a positive correlation also exists between the energy abundance and economic growth in the eastern and western regions, and there is no ‘resource curse' phenomenon either. In all three regions, the human capital input could promote economic growth. Material capital input could promote economic growth in the eastern but hinder economic growth in the western region; the level of opening to the outside world could promote economic growth in the eastern region. It is known through further survey and analysis on the transmission mechanism of resource curse that, at the national level, material capital input, human capital input, and the level of opening to the outside world present positive correlation with energy abundance, indicating that energy development becomes an important transmission factor by strengthening material capital input and human capital input and raising the level of opening to the outside world. However, technology innovation input presents negative correlation with energy development. As seen by region, both the material capital input and human capital input present positive correlation with energy development strength in the three regions. Similar as the eastern region, the level of opening to the outside world presents positive correlation with energy industry development in the middle and western regions; however, the energy development presents negative correlation with technology input level in the western region.展开更多
In this paper, an iterative 'one-shot' decorrelator for asynchronous code Division Multiple Access(CDMA) systems is proposed. This decorrelator feedbacks the decorrelated symbols of interfering users before de...In this paper, an iterative 'one-shot' decorrelator for asynchronous code Division Multiple Access(CDMA) systems is proposed. This decorrelator feedbacks the decorrelated symbols of interfering users before decision to mitigate their interferences. As a result, this decorrelator is a linear detector and does not need any amplitude information of users as in decision-feedback detectors. Compared with existing 'one-shot' decorrelator, it has reduced complexity and provided better performance while eliminating all Multiple Access Interference(MAI). The performance of this decorrelator is analyzed thoeritically, and analytical result is given. Numerical results show near-far resistant capability of this decorrelator in both AWGN and fading channel.展开更多
Because conditions for the grain production are not favorable and the input in the production factors ofmodern agriculture is not sufficient, the grain supply has been less than the demand for a long time. By means of...Because conditions for the grain production are not favorable and the input in the production factors ofmodern agriculture is not sufficient, the grain supply has been less than the demand for a long time. By means of greycorrelation analysis, this paper deals with the correlation situation among such input factors as the grain sown area, thetotal power of agricultural machinery, the fertilizer utilization volume, the actual irrigation area, the damage area, thenumber of farming labor force, in order to understand the major restricting and driving forces that have affected thegrain output in the recent 23 years. The analysis shows that the grain sown area and fertilizer utilization volume are thetwo most important leading factors that affect grain production in Guizhou Province, while the damage area and the totalpower of the farming-used machines are the following factors. Fertilizer utilization volume and the actual agriculturalmachinery and irrigation area are the two increasingly influential factors that affect grain production. The influence of thefarming labor force upon grain production became less strong. The main measures to increase grain production outputin Guizhou Province are to stabilize the arable land, increase the actual irrigation area, expedite the transfer of thefarming labor force and increase the input of modern agriculture.展开更多
As a part of the redundancy of organization, financial slack has become the focus of academic research. This paper takes the listed companies of manufacturing industry above Designated Size as sample, using multiple r...As a part of the redundancy of organization, financial slack has become the focus of academic research. This paper takes the listed companies of manufacturing industry above Designated Size as sample, using multiple regressionto examine the relationship between corporate financial slack and R & D investment under dynamic environment, using the Malmquist index method based on DEA model to analyze the innovation efficiency of Chinese manufacturing industry during the period of 2009-2013. The results show that: Financial slack and R & D investment intensity presents inverted "U" type relationship in?sample?companies, and the relationship is positively regulated by environmental dynamism; Financial slackpromotes R & D investment but have lag effect.展开更多
It is a research which could enter into contradiction with the current trend concerning the hip implants. It is known as sliding friction, which is characteristic of present artificial hip joints, is higher than in th...It is a research which could enter into contradiction with the current trend concerning the hip implants. It is known as sliding friction, which is characteristic of present artificial hip joints, is higher than in the case of rolling friction. The paper reports the studies of the functioning mode of a novel spherical bearing MoM (metal on metal) with rolling friction, with potential application for an artificial hip joint obtained by introducing a number of balls between the femoral head and the acetabular cup. After over 15 years of research upon the functional principle and constructive solution, a version that offered a coefficient of minimum friction in the hip joint came to light. This version was based on a constructive solution of motion with lower friction, "Omnitrack~ movement solutions", which has been modified and rebuilt to be used as a joint of a total hip prosthesis--MOMJ. The joint was built entirely in stainless steel, SS316L medical grade. Tests have been carried out on the experimental laboratory devices that showed very low values of the coefficient of friction (μ = 0.0225). For validation, the prosthesis had to be put through tests for 500,000 cycles, in terms of physiological motion and dynamic loading, according to ISO 14242-3. Testing was conducted on a multiaxial dynamics machine, MTS Bionix, equipped with system for hip implant testing. The testing results of this total hip prosthesis with rolling friction have been successful in signing up for a friction moment of 0.525 kNmm which means a coefficient of friction la = 0.0143, for a joint with femoral head diameter 28 mm.展开更多
This letter presents an efficient scheduling algorithm DTRR (Dual-Threshold Round Robin) for input-queued switches. In DTRR, a new matched input and output by round robin in a cell time will be locked by two self-adap...This letter presents an efficient scheduling algorithm DTRR (Dual-Threshold Round Robin) for input-queued switches. In DTRR, a new matched input and output by round robin in a cell time will be locked by two self-adaptive thresholds whenever the queue length or the wait-time of the head cell in the corresponding Virtual Output Queue (VOQ) exceeds the thresholds. The locked input and output will be matched directly in the succeeding cell time until they are unlocked. By employing queue length and wait-time thresholds which are updated every cell time simultane- ously, DTRR achieves a good tradeoff between the performance and hardware complexity. Simula- tion results indicate that the delay performance of DTRR is competitive compared to other typical scheduling algorithms under various traffic patterns especially under diagonal traffic.展开更多
基金National Natural Science Foundation of China(Nos.62171285,61971120 and 62327807)。
文摘A hybrid compensation scheme for piezoelectric ceramic actuators(PEAs)is proposed.In the hybrid compensation scheme,the input rate-dependent hysteresis characteristics of the PEAs are compensated.The feedforward controller is a novel input rate-dependent neural network hysteresis inverse model,while the feedback controller is a proportion integration differentiation(PID)controller.In the proposed inverse model,an input ratedependent auxiliary inverse operator(RAIO)and output of the hysteresis construct the expanded input space(EIS)of the inverse model which transforms the hysteresis inverse with multi-valued mapping into single-valued mapping,and the wiping-out,rate-dependent and continuous properties of the RAIO are analyzed in theories.Based on the EIS method,a hysteresis neural network inverse model,namely the dynamic back propagation neural network(DBPNN)model,is established.Moreover,a hybrid compensation scheme for the PEAs is designed to compensate for the hysteresis.Finally,the proposed method,the conventional PID controller and the hybrid controller with the modified input rate-dependent Prandtl-Ishlinskii(MRPI)model are all applied in the experimental platform.Experimental results show that the proposed method has obvious superiorities in the performance of the system.
文摘This paper reports a contact cantilever MEMS switch. The designed switch has a metal cantilever that acts as an electrostatically activated switch with processing options to achieve dielectric isolation of the controlvoltage path from the signal path. To obtain good material properties,an ANSYS FEA tool is used to optimize the structure. The RF MEMS switch is fabricated via a surface micromachining process. The switch has an actuation voltage of 12V,which is close to the simulated value of 11V. The measured and the HFSS simulated isolations are both higher than - 20dB from 0.05 to 10GHz. The measured insertion loss is less than - 0.9dB, relatively larger than the simulated loss of less than - 0.2dB from 0.05 to 10GHz. This is because a contact resistance introduced due to poor physical contact between the bottom lines and the metal cantilever.
文摘Based on a short anode GTO structure (SA-GTO),a novel GTO structure called an injection efficiency controlled gate turn off thyristor (IEC-GTO) is proposed,in which the injection efficiency can be controlled via an additional thin oxide layer located in the short anode contact region. The forward blocking, conducting, and switching characteristics are analyzed and compared with an SA-GTO and conventional GTO. The results show that the IEC-GTO can obtain a better trade-off relation between on-state and turn-off characteristics. Additionally,the width of the oxide layer covering the anode region and the doping concentration of the anode region are optimized, the process feasibility is analyzed, and a realization scheme is given. The results show that the introduction of an oxide layer would not increase the complexity of process of the IEC-GTO.
基金Supported by Yunnan Modern Agricultural Maize Industry Technology System Construction Program[(2009)53]Yunnan Modern Agricultural Maize Industry Technology System Construction Program[(2009)171]~~
文摘The aim was to study the main industry effect the double of the per capi- ta net income of farmers economic. The relation between six industry net income per capita income of farmers including grain, animal husbandry, flue-cured tobacco, walnut, long-term labor expot, seasonal labor export and the net income of farmers per capita in the Wazitian Village of Baoshan, Yunnan was studied by means of the effect main industry doubled net income of farmers per capita economic and the grey correlation analysis. The correlation degree of six industry and the net income of farmers per capita economic was long-term labor export〉seasonal labor export〉 walnut〉grain〉animal husbandry〉flue-cured tobacco. The pillar industry affecting the net income of farmers per capita economic was long-term labor export, seasonal la- bor export and walnut. The study provided the scionce theoretical basis and method of support for net income per capita economic multiplier of farmers in Baoshan, Yunnan province and even a similar low latitude mountain plateau.
文摘Association rules are useful for determining correlations between items. Applying association rules to intrusion detection system (IDS) can improve the detection rate, but false positive rate is also increased. Weighted association rules are used in this paper to mine intrustion models, which can increase the detection rate and decrease the false positive rate by some extent. Based on this, the structure of host-based IDS using weighted association rules is proposed.
文摘Gut inflammation can occur in 30%-60% of patients with spondyloarthropathies.However, the presence of such gut inflammation is underestimated, only 27% of patients with histological evidence of gut inflammation have intestinal symptoms, but subclinical gut inflammation is documented in two-thirds of patients with inflammatory joint disease.There are common genetic and immunological mechanisms behind concomitant inflammation in the joints and intestinal tract.A number of blood tests, e.g.erythrocyte sedimentation rate, orosomucoid, C-reactive protein, and white cell and platelet counts, are probably the most commonly used laboratory markers of inflammatory disease, however, these tests are difficult to interpret in arthropathies associated with gut inflammation, since any increases in their blood levels might be attributable to either the joint disease or to gut inflammation.Consequently, it would be useful to have a marker capable of separately identifying gut inflammation.Fecal proteins, which are indirect markers of neutrophil migration in the gut wall, and intestinal permeability, seem to be ideal for monitoring intestinal inflammation:they are easy to measure non-invasively and are specific for intestinal disease in the absence of gastrointestinal infections.Alongside the traditional markers for characterizing intestinal inflammation, there are also antibodies, in all probability generated by the immune response to microbial antigens and auto-antigens, which have proved useful in establishing the diagnosis and assessing the severity of the condition, as well as the prognosis and the risk of complications.In short, noninvasive investigations on the gut in patients with rheumatic disease may be useful in clinical practice for a preliminary assessment of patients with suspected intestinal disease.
文摘SAW (Surface Acoustic Wave) filter bank is a single input, single or multi-output device consisting of multi-SAW-filters with input interconnection network or switch circuits, and can be divided into two categories: channelizer (multi-output) and switchable (programmable, single output). The tbrmer is mainly used in military channelized receiver for spectrum analysis; the latter has wide application in frequency synthesizer and frequency-hopping radar and communication system receiver as anti-jamming filter, and has been widely used in various military electronic equipments ever since the 1970s. Research abroad was done mainly by Americans, few documents on related work done by Japan and Russia are available. Domestic research started in the 1980s, mainly by No. 26 Research Institute, China Electronics Technology Group Co., Institute of Acoustics, Chinese Academy of Sciences, No. 23 and No. 25 Research Institute, China Spaceflight Tech. Group Co. This paper first briefly introduces Chinese and foreign research on SAW filter banks; then discusses research progress in device design, the input interconnection network or switch circuit and miniaturization; and ends in a brief perspective of developing trends in future.
文摘A multicast replication algorithm is proposed for shared memory switches. It uses a dedicated FIFO to multicast by replicating cells at receiver and the FIFO is operating with shared memory in parallel. Speedup is used to promote loss and delay performance. A new queueing analytical model is developed based on a sub-timeslot approach. The system performance in terms of cell loss and delay is analyzed and verified by simulation.
文摘According to the positive correlation of coal ash content and natural gamma, using a new coal core reposition method, which is ordered by global and local extreme, coal samples from medium-thickness seam are reasonably located. Inte- grated the data of coal macrostructure characteristics, coal petrography analysis and coal gas production test, it studies the rela- tionship between coalbody structure and amplitude variation of different well logging data, and the tectonic coal recognition method with well logging data in fresh-water mud invasion. The results show that: the anomalous response of natural gamma ray, neutron, density and apparent resistivity does not reflect the coalbody structure type. In fresh-water drilling mud invasion, using the crossplot technique of dual-lateral, RXO resistivity response and the coalbody structure can classify granulated coal accurately; the proposed method is of good practicability and high reliability.
基金Acknowledgement This project were supported by the President's Grant of Nanfang Hospital (2014H002), the General Education Reform Project of Innovation to Enhance University in Guangdong Province 2015, Natural Science Foundation of Guangdong Province (2015A030310441), and National Natural Science Foundation of China (81570352).
文摘Ischemic mitral regurgitation (IMR) is a common complication of acute myocardial infarction (AMI). Current evidences suggest that revascularization of the culprit vessels with percutaneous coronary artery intervention (PCI) or coronary artery bypass grafting can be beneficial for relieving IMR. A 2.5-year follow-up data of a 61-year-old male patient with ST-segment elevation AMI complicated with IMR showed that mitral regurgitation area increased five days after PCI, and decreased to lower steady level three months after PCI. This finding suggest that three months after PCI might be a suitable time point for evaluating the possibility oflMR recovery and the necessity of surgical intervention of the mitral valve for AMI patient.
基金Supported by the National Natural Science Foundation of China (Grant No. 10675076 )the Natural Science Foundation ofShandong Province (Grant No. Y2006A21).
文摘It is shown that in an open A-type system with spontaneously generated coherence, the transient evolution rule of the gain of lasing without inversion (LWI) is very sensitive to variation of the relative phase φbetween the probe and driving fields; the variety of the atomic exit rate γo and the ratio C of the atomic injection rates also have a considerable effect on the phase-dependent transient evolution rule of LWI gain. We find that when φ =0, the transient and stationary LWI gain increases with C increasing but decreases with γ0 increasing; when φ≠0, the effect of C and γ0 on LWI gain is just opposite to that when φb=0 ; in order to get the largest transient and stationary LWI gain, we need selecting suitable values of φ, γ0andC.
基金Under the auspices of National Natural Science Foundation of China(No.41530634,41501137)
文摘Based on the interprovincial panel data of 2000–2014, this paper carries out an empirical analysis on the relationship between energy abundance and economic growth to test the theoretical hypothesis of ‘resource curse' and explore its transmission mechanism for China and its three regions. The results show that, at the national level, positive correlation is present between energy abundance and economic growth, proving that the ‘resource curse' phenomenon does not exist in China as a whole. Moreover, material capital input, human capital input and the level of opening to the outside world could promote economic growth, while technology innovation input may hinder economic growth. As seen by region, a positive correlation also exists between the energy abundance and economic growth in the eastern and western regions, and there is no ‘resource curse' phenomenon either. In all three regions, the human capital input could promote economic growth. Material capital input could promote economic growth in the eastern but hinder economic growth in the western region; the level of opening to the outside world could promote economic growth in the eastern region. It is known through further survey and analysis on the transmission mechanism of resource curse that, at the national level, material capital input, human capital input, and the level of opening to the outside world present positive correlation with energy abundance, indicating that energy development becomes an important transmission factor by strengthening material capital input and human capital input and raising the level of opening to the outside world. However, technology innovation input presents negative correlation with energy development. As seen by region, both the material capital input and human capital input present positive correlation with energy development strength in the three regions. Similar as the eastern region, the level of opening to the outside world presents positive correlation with energy industry development in the middle and western regions; however, the energy development presents negative correlation with technology input level in the western region.
文摘In this paper, an iterative 'one-shot' decorrelator for asynchronous code Division Multiple Access(CDMA) systems is proposed. This decorrelator feedbacks the decorrelated symbols of interfering users before decision to mitigate their interferences. As a result, this decorrelator is a linear detector and does not need any amplitude information of users as in decision-feedback detectors. Compared with existing 'one-shot' decorrelator, it has reduced complexity and provided better performance while eliminating all Multiple Access Interference(MAI). The performance of this decorrelator is analyzed thoeritically, and analytical result is given. Numerical results show near-far resistant capability of this decorrelator in both AWGN and fading channel.
文摘Because conditions for the grain production are not favorable and the input in the production factors ofmodern agriculture is not sufficient, the grain supply has been less than the demand for a long time. By means of greycorrelation analysis, this paper deals with the correlation situation among such input factors as the grain sown area, thetotal power of agricultural machinery, the fertilizer utilization volume, the actual irrigation area, the damage area, thenumber of farming labor force, in order to understand the major restricting and driving forces that have affected thegrain output in the recent 23 years. The analysis shows that the grain sown area and fertilizer utilization volume are thetwo most important leading factors that affect grain production in Guizhou Province, while the damage area and the totalpower of the farming-used machines are the following factors. Fertilizer utilization volume and the actual agriculturalmachinery and irrigation area are the two increasingly influential factors that affect grain production. The influence of thefarming labor force upon grain production became less strong. The main measures to increase grain production outputin Guizhou Province are to stabilize the arable land, increase the actual irrigation area, expedite the transfer of thefarming labor force and increase the input of modern agriculture.
文摘As a part of the redundancy of organization, financial slack has become the focus of academic research. This paper takes the listed companies of manufacturing industry above Designated Size as sample, using multiple regressionto examine the relationship between corporate financial slack and R & D investment under dynamic environment, using the Malmquist index method based on DEA model to analyze the innovation efficiency of Chinese manufacturing industry during the period of 2009-2013. The results show that: Financial slack and R & D investment intensity presents inverted "U" type relationship in?sample?companies, and the relationship is positively regulated by environmental dynamism; Financial slackpromotes R & D investment but have lag effect.
文摘It is a research which could enter into contradiction with the current trend concerning the hip implants. It is known as sliding friction, which is characteristic of present artificial hip joints, is higher than in the case of rolling friction. The paper reports the studies of the functioning mode of a novel spherical bearing MoM (metal on metal) with rolling friction, with potential application for an artificial hip joint obtained by introducing a number of balls between the femoral head and the acetabular cup. After over 15 years of research upon the functional principle and constructive solution, a version that offered a coefficient of minimum friction in the hip joint came to light. This version was based on a constructive solution of motion with lower friction, "Omnitrack~ movement solutions", which has been modified and rebuilt to be used as a joint of a total hip prosthesis--MOMJ. The joint was built entirely in stainless steel, SS316L medical grade. Tests have been carried out on the experimental laboratory devices that showed very low values of the coefficient of friction (μ = 0.0225). For validation, the prosthesis had to be put through tests for 500,000 cycles, in terms of physiological motion and dynamic loading, according to ISO 14242-3. Testing was conducted on a multiaxial dynamics machine, MTS Bionix, equipped with system for hip implant testing. The testing results of this total hip prosthesis with rolling friction have been successful in signing up for a friction moment of 0.525 kNmm which means a coefficient of friction la = 0.0143, for a joint with femoral head diameter 28 mm.
基金Supported by the National Natural Science Foundation of China (No.60472057).
文摘This letter presents an efficient scheduling algorithm DTRR (Dual-Threshold Round Robin) for input-queued switches. In DTRR, a new matched input and output by round robin in a cell time will be locked by two self-adaptive thresholds whenever the queue length or the wait-time of the head cell in the corresponding Virtual Output Queue (VOQ) exceeds the thresholds. The locked input and output will be matched directly in the succeeding cell time until they are unlocked. By employing queue length and wait-time thresholds which are updated every cell time simultane- ously, DTRR achieves a good tradeoff between the performance and hardware complexity. Simula- tion results indicate that the delay performance of DTRR is competitive compared to other typical scheduling algorithms under various traffic patterns especially under diagonal traffic.