In the present study, the effect of pollen grain sources on volatile com- pounds in bagged apple fruit of Yan Fuji 3, grown at two experiment sites and pol- linated by pollens of other five cultivars was evaluated, to...In the present study, the effect of pollen grain sources on volatile com- pounds in bagged apple fruit of Yan Fuji 3, grown at two experiment sites and pol- linated by pollens of other five cultivars was evaluated, to select appropriate poll- enizer cultivars for Fuji, and to provide a theoretical basis for improving the flavor and aroma of bagged apple fruit of Fuji. The results proved the significant metaxe- nia effect of the five pollenizer cultivars on volatile compounds of bagged apple fruit of Fuji. The numbers of both volatile compounds and characteristic aroma com- pounds in bagged apple fruit pollinated by Golden Delicious were larger and those of the fruit pollinated by Gala were smaller at both experiment sites. However, there were differences in the numbers of volatile compounds and characteristic aroma compounds among the fruits pollinated by Starkrimson, Jinxiuhaitang and Ruby at both experimental sites. The differences were caused by 12 compounds that only existed at a low level in certain samples. All of them were not the aroma contribu- tors except ethyl 2-methylbutyrate. The content of alcohols in bagged Fuji fruit was largely increased by Starkrimson and Ruby pollination; the content of aldehydes was obviously increased by Golden Delicious, Starkrimson and Gala pollination; the con- tents of esters and terpenes were significantly increased by Golden Delicious, Starkrimson and Ruby pollination. Jinxiuhaitang pollination showed no significant ef- fects for improving the content of four categories of volatile compounds. The metax- enia of the pollenizer cultivars on volatile compounds in bagged Fuji fruit was stable at the two experimental sites.展开更多
[ Objective] To study the influence of xenia effect to the fruit of watermelon. [ Method ] Self-crossing and crossing by inbreeding of more generation female parent, male parent :07-10-2-3-3( tall spherical, golden ...[ Objective] To study the influence of xenia effect to the fruit of watermelon. [ Method ] Self-crossing and crossing by inbreeding of more generation female parent, male parent :07-10-2-3-3( tall spherical, golden yellow peel with thin lines, red flesh), 07-32-2-3-5( tall spherical, green peel with greenish thick lines, red flesh), 07-33-1-2-3(tall spherical, green peel with greenish thin lines, red flesh) [ Result] It was found that Fo (07-10-2-3-3 × 07-32-2-3-5) and Fo (07-10-2-3-3 × 07-33-1-2-3) seed ripening was accelerated, and the sugar degree increased by 1.7 - 2.4%, and the flesh became crisp.[ Conclusion] The result demonstrates watermelon has xenia effect.展开更多
In order to start up the brushless DC motor (BLDCM) without reverse rotation and smoothly switch the running state of the motor, a novel startup and smoothly switching method for a sensodess BLDCM is presented. Base...In order to start up the brushless DC motor (BLDCM) without reverse rotation and smoothly switch the running state of the motor, a novel startup and smoothly switching method for a sensodess BLDCM is presented. Based on the saturation effect of the stator iron, six short voltage pulses are applied to determine the initial rotor position and the rotor can be found within 60°. After that, a series of short and long voltage pulses are used to accelerate the motor and the variation of the response current is utilized to detect the rotor position dynamically. When the motor reaches a certain speed at which the back-electromotive force (EMF) method can be applied, all the power devices are turned off and the running state of the motor is smoothly switched at the moment determined by the relationship between the terminal voltage waveform and the commutation phases. The experimental results verify the feasibility and validity of the proposed method.展开更多
In order to improve the thrust-power ratio index of the linear induction motor(LIM), a novel adaptive genetic algorithm (NAGA) is proposed for the design optimization of the LIM. A good-point set theory that helps...In order to improve the thrust-power ratio index of the linear induction motor(LIM), a novel adaptive genetic algorithm (NAGA) is proposed for the design optimization of the LIM. A good-point set theory that helps to produce a uniform initial population is used to enhance the optimization efficiency of the genetic algorithm. The crossover and mutation probabilities are improved by using the function of sigmoid and they can be adjusted nonlinearly between average fitness and maximal fitness with individual fitness. Based on the analyses of different structures between the LIM and the rotary induction motor (RIM) and referring to the analysis method of the RIM, the steady-state characteristics of the LIM that considers the end effects of the LIM is calculated and the optimal design model of the thrust-power ratio index is also presented. Through the comparison between the optimal scheme and the old scheme, the thrust-power ratio index of the LIM is obviously increased and the validity of the NAGA is proved.展开更多
[Objective] This study aimed to investigate the effects of high-oil maize pollen on kernel traits of common maize, so as to provide some basis for the production and quality improvement of high-oil maize. [Method] Thr...[Objective] This study aimed to investigate the effects of high-oil maize pollen on kernel traits of common maize, so as to provide some basis for the production and quality improvement of high-oil maize. [Method] Three hightoil maize varieties were cultivated to pollinate three common maize varieties. [Result] The kemel yield of common maize was increased or changed slightly, and the embryo weight was increased significantly after they were pollinated with the pollen of hightoil maize. The kemel embryo percentage and protein content of common maizethigh oil maize hybrids were higher than those of common maize inbreds. [Conclusion] The growth and development of kernel embryos, as well as the kernel quality of common maize was improved by pollination with hightoil maize.展开更多
In order to reduce the mismatch error, a direct current (DC) calibration method is introduced when the modulated microwave signal is measured. The microwave power is input to the left section of the power sensor, an...In order to reduce the mismatch error, a direct current (DC) calibration method is introduced when the modulated microwave signal is measured. The microwave power is input to the left section of the power sensor, and the DC power is input to the right of the power sensor. Due to the existence of parasitic loss and electromagnetic coupling, the microwave power results in a mismatch error. However, the DC power does not have the mismatch error. So the DC power applied in the right section can calibrate the mismatch error of the microwave power in the left section. The calibration factor is measured at different modulation rates and modulation depths.The measurement results show that the carrier frequency is the major factor influencing the measurement results. After calibration, the carrier frequency and the modulation rate have little effect on the output voltage. The frequency response becomes relatively flat in the frequency range up to 20 GHz, and the sensitivity on average is enhanced by about 0.12 mV/dBm. Therefore, the DC calibration method has a certain reference value for the terminal-type microwave power sensor.展开更多
AIM: To investigate whether the degree of rectal distension could define the rectum functions as a conduit METHODS: Response of the rectal and anal pressure to 2 types of rectal balloon distension, rapid voluminous ...AIM: To investigate whether the degree of rectal distension could define the rectum functions as a conduit METHODS: Response of the rectal and anal pressure to 2 types of rectal balloon distension, rapid voluminous and slow gradual distention, was recorded in 21 healthy volunteers (12 men, 9 women, age 41.7 ± 10.6 years). The test was repeated with sphincteric squeeze on urgent sensation. RESULTS: Rapid voluminous rectal distension resulted in a significant rectal pressure increase (P 〈 0.001), an anal pressure decline (P 〈 0.05) and balloon expulsion. The subjects felt urgent sensation but did not feel the 1^st rectal sensation. On urgent sensation, anal squeeze caused a significant rectal pressure decrease (P 〈 0.001) and urgency disappearance. Slow incremental rectal filling drew a rectometrogram with a "tone" limb representing a gradual rectal pressure increase during rectal filling, and an "evacuation limb" representing a sharp pressure increase during balloon expulsion. The curve recorded both the ist rectal sensation and the urgent sensation. CONCLUSION: The rectum has apparently two functions: transportation (conduit) and storage, both depending on the degree of rectal filling. If the fecal material received by the rectum is small, it is stored in the rectum until a big volume is reached that can affect a degree of rectal distension sufficient to initiate the defecation reflex. Large volume rectal distension evokes directly the rectoanal inhibitory reflex with a resulting defecation.展开更多
An RF transceiver composed of a zero-IF receiver and a direct up-conversion transmitter for cognitive radio applications is presented. The adjustable channel filter array in the receiver is used to suppress adjacent c...An RF transceiver composed of a zero-IF receiver and a direct up-conversion transmitter for cognitive radio applications is presented. The adjustable channel filter array in the receiver is used to suppress adjacent channel interference in televisions signal coexistence environments. The low noise amplifier (LNA) with wide dynamic range and high linearity is employed to enhance the anti-interference competence of the zero-IF receiver. Meanwhile, the high linearity power amplifier (PA) .is used to promote the adjacent channel power ratio (ACPR) characteristic of the direct up-conversion transmitter. The measured error vector magnitude (EVM) results show that the anti-interference competence of the zero-IF receiver is dramatically enhanced by employing a channel filter array. The measured ACPR of the direct up-conversion transmitter is -47. 98 dBc on the channel centered at 714 MHz when the output power is 27 dBm.展开更多
AIM: To examine the ability of cyclin-dependent kinase inhibitor (CDKI) roscovitine (Rosco) to enhance the antitumor effects of conventional chemotherapeutic agents acting by different mechanisms against human colorec...AIM: To examine the ability of cyclin-dependent kinase inhibitor (CDKI) roscovitine (Rosco) to enhance the antitumor effects of conventional chemotherapeutic agents acting by different mechanisms against human colorectal cancer. METHODS: Human colorectal cancer cells were treat-ed, individually and in combination, with Rosco, taxol, 5-Fluorouracil (5-FU), doxorubicine or vinblastine. The antiproliferative effects and the type of interaction of Rosco with tested chemotherapeutic drugs were de-termined. Cell cycle alterations were investigated by fluorescence-activated cell sorter FACS analysis. Apop-tosis was determined by DNA fragmentation assay. RESULTS: Rosco inhibited the proliferation of tumor cells in a time-and dose-dependent manner. The ef-ficacies of all tested chemotherapeutic drugs were markedly enhanced 3.0-8.42 × 103 and 130-5.28 × 103 fold in combination with 5 and 10 μg/mL Rosco, re-spectively. The combination of Rosco and chemothera-peutic drugs inhibited the growth of human colorectal cancer cells in an additive or synergistic fashion, and in a time and dose dependent manner. Rosco induced apoptosis and synergized with tested chemothera-peutic drugs to induce efficient apoptosis in human colorectal cancer cells. Sequential, inverted sequential and simultaneous treatment of cancer cells with combi-nations of chemotherapeutic drugs and Rosco arrested the growth of human colorectal cancer cells at various phases of the cell cycle as follows: Taxol/Rosco (G2/M-and S-phases), 5-FU/Rosco (S-phase), Dox/Rosco (S-phase) and Vinb/Rosco (G2/M-and S-phases). CONCLUSION: Since the eff icacy of many anticancer drugs depends on their ability to induce apoptotic cell death, modulation of this parameter by cell cycle inhibi-tors may provide a novel chemo-preventive and chemo-therapeutic strategy for human colorectal cancer.展开更多
The vertical distribution of carbon dioxide(CO2)is important for the calibration and validation of transport models and remote sensing measurements.Due to the large mass and volume of traditional instruments as well a...The vertical distribution of carbon dioxide(CO2)is important for the calibration and validation of transport models and remote sensing measurements.Due to the large mass and volume of traditional instruments as well as supporting systems,in-situ measurements of the CO2 vertical profile within the boundary layer are rare.This study used a miniaturized CO2 monitoring instrument based on a low-cost non-dispersive infrared(NDIR)sensor to measure the CO2 vertical profile and meteorological parameters of the lower troposphere(0–1000 m)in southwestern Shijiazhuang,Hebei Province,China.The sensors were onboard a tethered balloon with two processes:the ascending process and the descending process.The results showed that the overall trend of CO2 concentration decreased with height.Weather conditions and CO2 emission sources caused fluctuations in CO2 concentrations.The CO2 concentration varied from morning to afternoon due mainly to the faster spread of air mass during daytime,with strong convections and the accumulation of emissions at night.The low-cost sensor produced results consistent with the traditional gas chromatography method.The Weather Research and Forecasting model could not capture the CO2 profiles well due mainly to the bad performances in boundary layer height and the potential outdated fossil fuel emissions around the experimental site.This experiment is the first successful attempt to observe the CO2 vertical distribution in the lower troposphere by using lowcost NDIR sensors.The results help us to understand the vertical structure of CO2 in the boundary layer,and provide data for calibrating and validating transport models.展开更多
The purpose of the present research was to investigate the predictors to Chinese college students seeking psychological help from professionals. By surveying 1,408 Chinese college students at five universities in Chin...The purpose of the present research was to investigate the predictors to Chinese college students seeking psychological help from professionals. By surveying 1,408 Chinese college students at five universities in China's Mainland, the results showed that among the factors examined, problem severity and help-seeking attitudes directly predicted help-seeking intention, while gender and subjective norms had a significant effect on college students' professional psychological help-seeking intention through help-seeking attitudes. Overall, the model explained 25% and 38.0% (for half-1 and half-2 data sets, respectively) of the variances of help-seeking intention. The results indicated that mainland Chinese college students rationally knew that they should choose to seek such professional help when the problem got severer enough, although they were emotionally reluctant to seek professional psychological help due to negative subjective norms around them. The implications and limitations were discussed.展开更多
Without sufficient real training data,the data driven classification algorithms based on boosting method cannot solely be utilized to applications such as the mini unmanned helicopter landmark image detection.In this ...Without sufficient real training data,the data driven classification algorithms based on boosting method cannot solely be utilized to applications such as the mini unmanned helicopter landmark image detection.In this paper,we propose an approach which uses a boosting algorithm with the prior knowledge for the mini unmanned helicopter landmark image detection.The stage forward stagewise additive model of boosting is analyzed,and the approach how to combine it with the prior knowledge model is presented.The approach is then applied to landmark image detection,where the multi-features are boosted to solve a series of problems,such as rotation,noises affected,etc.Results of real flight experiments demonstrate that for small training examples the boosted learning system using prior knowledge is dramatically better than the one driven by data only.展开更多
The present paper investigates the relationship between Iranian intermediate level EFL (English as a Foreign Language) learners' personality traits and their preferences for Heron's Six Category Intervention Analy...The present paper investigates the relationship between Iranian intermediate level EFL (English as a Foreign Language) learners' personality traits and their preferences for Heron's Six Category Intervention Analysis (SCIA). There were 134 Iranian male and female learners participating in this study. A SCIA questionnaire containing 30 items was developed and validated to assess EFL learners' preferences for intervention categories. Moreover, Myers-Briggs Type Indicator (MBTI) was used in the research. Results indicated that whereas in some cases no significant differences were observed, there mostly existed numerous significant differences among language learners with different personality traits and their preferences for SCIA.展开更多
In general, it is important to operate the; airgap length uniformly for improving the system efficiency independent of the flatness of the reaction plate in a railway propulsion system by a linear induction motor (LI...In general, it is important to operate the; airgap length uniformly for improving the system efficiency independent of the flatness of the reaction plate in a railway propulsion system by a linear induction motor (LIM). And it is possible to operate the LIM propulsion system efficiently without a change of the LIM capacity through the airgap length control on the sloped rail. So, in this research, the authors introduce an airgap control system to control the airgap length which depends on the flatness of the secondary reaction plate when the LIM is operated, and design a rotary small-scaled LIM and its airgap control system before manufacturing the real system. Then, the authors analyze some characteristics of the LIM (thrust and normal force, input current, efficiency and power factor), and through the LIM control modeling, the authors finally analyze an effect of the airgap-length control of the LIM by the airgap control system.展开更多
This paper proposes an analysis and a direct power control (DPC) design of a wind turbine driven doubly-fed induction generator (DFIG) under unbalanced network voltage conditions. A DFIG model described in the positiv...This paper proposes an analysis and a direct power control (DPC) design of a wind turbine driven doubly-fed induction generator (DFIG) under unbalanced network voltage conditions. A DFIG model described in the positive and negative synchronous reference frames is presented. Variations of the stator output active and reactive powers are fully deduced in the presence of negative sequence supply voltage and rotor flux. An enhanced DPC scheme is proposed to eliminate stator active power oscillation during network unbalance. The proposed control scheme removes rotor current regulators and the decomposition processing of positive and negative sequence rotor currents. Simulation results using PSCAD/EMTDC are presented on a 2-MW DFIG wind power generation system to validate the feasibility of the proposed control scheme under balanced and unbalanced network conditions.展开更多
AIM:To investigate the association between prognosis of rectal cancer treated with chemoradiotherapy(CRT) and expression of sensitive-to-apoptosis(SAG),B-cell lymphoma-extra large(Bcl-X L) and Bcl-2 homologous antagon...AIM:To investigate the association between prognosis of rectal cancer treated with chemoradiotherapy(CRT) and expression of sensitive-to-apoptosis(SAG),B-cell lymphoma-extra large(Bcl-X L) and Bcl-2 homologous antagonist/killer(Bak).METHODS:Real-time quantitative polymerase chain reaction was used to determine the expression of proteins of interest,namely SAG,Bcl-X L,Bak and β-actin,in rectal carcinoma patients who had a follow-up period of 3 years after CRT.Biopsy specimens were excised from the rectal tumor preceding CRT.RESULTS:SAG,Bcl-X L and Bak proteins showed significant correlations with each other.In multivariate analysis,patients with high vs low SAG expression showed a statistically significant difference in 2-year survival rates:56% vs 73%,respectively(P = 0.056).On the other hand,there were no significant correlations between the expression levels of all three genes and metastatic rates or tumor responses to CRT.Mean overall survival in the patients with elevated SAG expression was 27.1 mo ± 3.9 mo [95% confidence interval(CI):19.3-34.9],and in patients with reduced expression,it was 32.1 mo ± 2.5 mo(95% CI:27.3-36.9).The corresponding values for Bcl-X L were 28.0 mo ± 4.1 mo(95% CI:19.9-36.1) and 31.7 mo ± 2.9 mo(95% CI:26.0-37.5),and those for Bak were 29.8 mo ± 3.7 mo(95% CI:22.5-37.2) and 30.6 mo ± 2.4 mo(95% CI:25.5-35.0),respectively.CONCLUSION:Two-year survival rates significantly correlated with low SAG expression,and SAG may be a candidate gene for good prognosis,independent of therapeutic response of different individuals.展开更多
Bedload governs riverbed channel variations and morphology, it is necessary to determine bedload discharge through an arbitrary cross section in a mountain fiver. A new system with submerged load cells has been develo...Bedload governs riverbed channel variations and morphology, it is necessary to determine bedload discharge through an arbitrary cross section in a mountain fiver. A new system with submerged load cells has been developed to directly measure bedload discharge. The system consists of: (1) an iron box which is 1 m long, 0.5 m wide and 0.1 m in depth, (2) two submerged load cells 0.7 m apart, (3) a pressure sensor and, (4) an electromagnetic velocity meter. This system has been designed to exclude the effect of the hydraulic pressure of water on direct measurements of bedload particle weight. Initial tests in a laboratory were conducted to examine the accuracy of measurements with the system under aerial conditions. The system has been installed in the supercritical flume in Ashi-arai-dani River of the Hodaka Sedimentation Observatory of the Disaster Prevention Research Institute (DPRI) of Kyoto University to obtain bedload discharge under natural conditions. Flume tests were conducted in this channel by artificial supply of uniform sediment particles of several grain sizes. The average velocity of the sediment particles near the bed was estimated using cross-correlation functions for weight waves obtained by the two load cells, Bedload discharge calculations were based on time integration of the product of sediment velocity and sediment weight obtained by the two load cells. This study clarifies the reasons why bedload measurements are difficult, and provides some solutions using the monitoring systems with submerged load cells through the field measurements. Additionally, the applicability of bedload measurement with the submerged load cells is explained based on experimental artificial sediment supply data.展开更多
This study presents analysis, control and comparison of three hybrid approaches for the direct torque control (DTC) of the dual star induction motor (DSIM) drive. Its objective consists of combining three different he...This study presents analysis, control and comparison of three hybrid approaches for the direct torque control (DTC) of the dual star induction motor (DSIM) drive. Its objective consists of combining three different heuristic optimization techniques including PID-PSO, Fuzzy-PSO and GA-PSO to improve the DSIM speed controlled loop behavior. The GA and PSO algorithms are developed and implemented into MATLAB. As a result, fuzzy-PSO is the most appropriate scheme. The main performance of fuzzy-PSO is reducing high torque ripples, improving rise time and avoiding disturbances that affect the drive performance.展开更多
基金Supported by Major Applied Technology Innovation Program of Agriculture in Shandong Province(2014)Special Scientific Research Fund for Taishan Scholars([2013]123)Earmarked fund for Modern Agro-industry Technology Research System of China(CARS-28)~~
文摘In the present study, the effect of pollen grain sources on volatile com- pounds in bagged apple fruit of Yan Fuji 3, grown at two experiment sites and pol- linated by pollens of other five cultivars was evaluated, to select appropriate poll- enizer cultivars for Fuji, and to provide a theoretical basis for improving the flavor and aroma of bagged apple fruit of Fuji. The results proved the significant metaxe- nia effect of the five pollenizer cultivars on volatile compounds of bagged apple fruit of Fuji. The numbers of both volatile compounds and characteristic aroma com- pounds in bagged apple fruit pollinated by Golden Delicious were larger and those of the fruit pollinated by Gala were smaller at both experiment sites. However, there were differences in the numbers of volatile compounds and characteristic aroma compounds among the fruits pollinated by Starkrimson, Jinxiuhaitang and Ruby at both experimental sites. The differences were caused by 12 compounds that only existed at a low level in certain samples. All of them were not the aroma contribu- tors except ethyl 2-methylbutyrate. The content of alcohols in bagged Fuji fruit was largely increased by Starkrimson and Ruby pollination; the content of aldehydes was obviously increased by Golden Delicious, Starkrimson and Gala pollination; the con- tents of esters and terpenes were significantly increased by Golden Delicious, Starkrimson and Ruby pollination. Jinxiuhaitang pollination showed no significant ef- fects for improving the content of four categories of volatile compounds. The metax- enia of the pollenizer cultivars on volatile compounds in bagged Fuji fruit was stable at the two experimental sites.
文摘[ Objective] To study the influence of xenia effect to the fruit of watermelon. [ Method ] Self-crossing and crossing by inbreeding of more generation female parent, male parent :07-10-2-3-3( tall spherical, golden yellow peel with thin lines, red flesh), 07-32-2-3-5( tall spherical, green peel with greenish thick lines, red flesh), 07-33-1-2-3(tall spherical, green peel with greenish thin lines, red flesh) [ Result] It was found that Fo (07-10-2-3-3 × 07-32-2-3-5) and Fo (07-10-2-3-3 × 07-33-1-2-3) seed ripening was accelerated, and the sugar degree increased by 1.7 - 2.4%, and the flesh became crisp.[ Conclusion] The result demonstrates watermelon has xenia effect.
文摘In order to start up the brushless DC motor (BLDCM) without reverse rotation and smoothly switch the running state of the motor, a novel startup and smoothly switching method for a sensodess BLDCM is presented. Based on the saturation effect of the stator iron, six short voltage pulses are applied to determine the initial rotor position and the rotor can be found within 60°. After that, a series of short and long voltage pulses are used to accelerate the motor and the variation of the response current is utilized to detect the rotor position dynamically. When the motor reaches a certain speed at which the back-electromotive force (EMF) method can be applied, all the power devices are turned off and the running state of the motor is smoothly switched at the moment determined by the relationship between the terminal voltage waveform and the commutation phases. The experimental results verify the feasibility and validity of the proposed method.
文摘In order to improve the thrust-power ratio index of the linear induction motor(LIM), a novel adaptive genetic algorithm (NAGA) is proposed for the design optimization of the LIM. A good-point set theory that helps to produce a uniform initial population is used to enhance the optimization efficiency of the genetic algorithm. The crossover and mutation probabilities are improved by using the function of sigmoid and they can be adjusted nonlinearly between average fitness and maximal fitness with individual fitness. Based on the analyses of different structures between the LIM and the rotary induction motor (RIM) and referring to the analysis method of the RIM, the steady-state characteristics of the LIM that considers the end effects of the LIM is calculated and the optimal design model of the thrust-power ratio index is also presented. Through the comparison between the optimal scheme and the old scheme, the thrust-power ratio index of the LIM is obviously increased and the validity of the NAGA is proved.
基金Supported by Scientific and Technological Development Plan of Shandong Province(2014GNC113001)Open Subject of National Key Laboratory of Crop Biology(2014KF11)~~
文摘[Objective] This study aimed to investigate the effects of high-oil maize pollen on kernel traits of common maize, so as to provide some basis for the production and quality improvement of high-oil maize. [Method] Three hightoil maize varieties were cultivated to pollinate three common maize varieties. [Result] The kemel yield of common maize was increased or changed slightly, and the embryo weight was increased significantly after they were pollinated with the pollen of hightoil maize. The kemel embryo percentage and protein content of common maizethigh oil maize hybrids were higher than those of common maize inbreds. [Conclusion] The growth and development of kernel embryos, as well as the kernel quality of common maize was improved by pollination with hightoil maize.
基金The National Natural Science Foundation of China(No.60976094)the National High Technology Research and Development Program of China(863 Program)(No.2007AA04Z328)
文摘In order to reduce the mismatch error, a direct current (DC) calibration method is introduced when the modulated microwave signal is measured. The microwave power is input to the left section of the power sensor, and the DC power is input to the right of the power sensor. Due to the existence of parasitic loss and electromagnetic coupling, the microwave power results in a mismatch error. However, the DC power does not have the mismatch error. So the DC power applied in the right section can calibrate the mismatch error of the microwave power in the left section. The calibration factor is measured at different modulation rates and modulation depths.The measurement results show that the carrier frequency is the major factor influencing the measurement results. After calibration, the carrier frequency and the modulation rate have little effect on the output voltage. The frequency response becomes relatively flat in the frequency range up to 20 GHz, and the sensitivity on average is enhanced by about 0.12 mV/dBm. Therefore, the DC calibration method has a certain reference value for the terminal-type microwave power sensor.
文摘AIM: To investigate whether the degree of rectal distension could define the rectum functions as a conduit METHODS: Response of the rectal and anal pressure to 2 types of rectal balloon distension, rapid voluminous and slow gradual distention, was recorded in 21 healthy volunteers (12 men, 9 women, age 41.7 ± 10.6 years). The test was repeated with sphincteric squeeze on urgent sensation. RESULTS: Rapid voluminous rectal distension resulted in a significant rectal pressure increase (P 〈 0.001), an anal pressure decline (P 〈 0.05) and balloon expulsion. The subjects felt urgent sensation but did not feel the 1^st rectal sensation. On urgent sensation, anal squeeze caused a significant rectal pressure decrease (P 〈 0.001) and urgency disappearance. Slow incremental rectal filling drew a rectometrogram with a "tone" limb representing a gradual rectal pressure increase during rectal filling, and an "evacuation limb" representing a sharp pressure increase during balloon expulsion. The curve recorded both the ist rectal sensation and the urgent sensation. CONCLUSION: The rectum has apparently two functions: transportation (conduit) and storage, both depending on the degree of rectal filling. If the fecal material received by the rectum is small, it is stored in the rectum until a big volume is reached that can affect a degree of rectal distension sufficient to initiate the defecation reflex. Large volume rectal distension evokes directly the rectoanal inhibitory reflex with a resulting defecation.
基金The National Natural Science Foundation of China(No.60621002)the National High Technology Research and Development Program of China(863 Program)(No.2009AA011801)
文摘An RF transceiver composed of a zero-IF receiver and a direct up-conversion transmitter for cognitive radio applications is presented. The adjustable channel filter array in the receiver is used to suppress adjacent channel interference in televisions signal coexistence environments. The low noise amplifier (LNA) with wide dynamic range and high linearity is employed to enhance the anti-interference competence of the zero-IF receiver. Meanwhile, the high linearity power amplifier (PA) .is used to promote the adjacent channel power ratio (ACPR) characteristic of the direct up-conversion transmitter. The measured error vector magnitude (EVM) results show that the anti-interference competence of the zero-IF receiver is dramatically enhanced by employing a channel filter array. The measured ACPR of the direct up-conversion transmitter is -47. 98 dBc on the channel centered at 714 MHz when the output power is 27 dBm.
文摘AIM: To examine the ability of cyclin-dependent kinase inhibitor (CDKI) roscovitine (Rosco) to enhance the antitumor effects of conventional chemotherapeutic agents acting by different mechanisms against human colorectal cancer. METHODS: Human colorectal cancer cells were treat-ed, individually and in combination, with Rosco, taxol, 5-Fluorouracil (5-FU), doxorubicine or vinblastine. The antiproliferative effects and the type of interaction of Rosco with tested chemotherapeutic drugs were de-termined. Cell cycle alterations were investigated by fluorescence-activated cell sorter FACS analysis. Apop-tosis was determined by DNA fragmentation assay. RESULTS: Rosco inhibited the proliferation of tumor cells in a time-and dose-dependent manner. The ef-ficacies of all tested chemotherapeutic drugs were markedly enhanced 3.0-8.42 × 103 and 130-5.28 × 103 fold in combination with 5 and 10 μg/mL Rosco, re-spectively. The combination of Rosco and chemothera-peutic drugs inhibited the growth of human colorectal cancer cells in an additive or synergistic fashion, and in a time and dose dependent manner. Rosco induced apoptosis and synergized with tested chemothera-peutic drugs to induce efficient apoptosis in human colorectal cancer cells. Sequential, inverted sequential and simultaneous treatment of cancer cells with combi-nations of chemotherapeutic drugs and Rosco arrested the growth of human colorectal cancer cells at various phases of the cell cycle as follows: Taxol/Rosco (G2/M-and S-phases), 5-FU/Rosco (S-phase), Dox/Rosco (S-phase) and Vinb/Rosco (G2/M-and S-phases). CONCLUSION: Since the eff icacy of many anticancer drugs depends on their ability to induce apoptotic cell death, modulation of this parameter by cell cycle inhibi-tors may provide a novel chemo-preventive and chemo-therapeutic strategy for human colorectal cancer.
基金This work was supported by the National Key R&D Program of China[grant number 2017YFB0504000]the National Natural Science Foundation of China[grant numbers 41705113 and 41877312].
文摘The vertical distribution of carbon dioxide(CO2)is important for the calibration and validation of transport models and remote sensing measurements.Due to the large mass and volume of traditional instruments as well as supporting systems,in-situ measurements of the CO2 vertical profile within the boundary layer are rare.This study used a miniaturized CO2 monitoring instrument based on a low-cost non-dispersive infrared(NDIR)sensor to measure the CO2 vertical profile and meteorological parameters of the lower troposphere(0–1000 m)in southwestern Shijiazhuang,Hebei Province,China.The sensors were onboard a tethered balloon with two processes:the ascending process and the descending process.The results showed that the overall trend of CO2 concentration decreased with height.Weather conditions and CO2 emission sources caused fluctuations in CO2 concentrations.The CO2 concentration varied from morning to afternoon due mainly to the faster spread of air mass during daytime,with strong convections and the accumulation of emissions at night.The low-cost sensor produced results consistent with the traditional gas chromatography method.The Weather Research and Forecasting model could not capture the CO2 profiles well due mainly to the bad performances in boundary layer height and the potential outdated fossil fuel emissions around the experimental site.This experiment is the first successful attempt to observe the CO2 vertical distribution in the lower troposphere by using lowcost NDIR sensors.The results help us to understand the vertical structure of CO2 in the boundary layer,and provide data for calibrating and validating transport models.
文摘The purpose of the present research was to investigate the predictors to Chinese college students seeking psychological help from professionals. By surveying 1,408 Chinese college students at five universities in China's Mainland, the results showed that among the factors examined, problem severity and help-seeking attitudes directly predicted help-seeking intention, while gender and subjective norms had a significant effect on college students' professional psychological help-seeking intention through help-seeking attitudes. Overall, the model explained 25% and 38.0% (for half-1 and half-2 data sets, respectively) of the variances of help-seeking intention. The results indicated that mainland Chinese college students rationally knew that they should choose to seek such professional help when the problem got severer enough, although they were emotionally reluctant to seek professional psychological help due to negative subjective norms around them. The implications and limitations were discussed.
基金Project (No. 2006AA10Z204) supported by the National Hi-Tech Research and Development Program (863) of China
文摘Without sufficient real training data,the data driven classification algorithms based on boosting method cannot solely be utilized to applications such as the mini unmanned helicopter landmark image detection.In this paper,we propose an approach which uses a boosting algorithm with the prior knowledge for the mini unmanned helicopter landmark image detection.The stage forward stagewise additive model of boosting is analyzed,and the approach how to combine it with the prior knowledge model is presented.The approach is then applied to landmark image detection,where the multi-features are boosted to solve a series of problems,such as rotation,noises affected,etc.Results of real flight experiments demonstrate that for small training examples the boosted learning system using prior knowledge is dramatically better than the one driven by data only.
文摘The present paper investigates the relationship between Iranian intermediate level EFL (English as a Foreign Language) learners' personality traits and their preferences for Heron's Six Category Intervention Analysis (SCIA). There were 134 Iranian male and female learners participating in this study. A SCIA questionnaire containing 30 items was developed and validated to assess EFL learners' preferences for intervention categories. Moreover, Myers-Briggs Type Indicator (MBTI) was used in the research. Results indicated that whereas in some cases no significant differences were observed, there mostly existed numerous significant differences among language learners with different personality traits and their preferences for SCIA.
文摘In general, it is important to operate the; airgap length uniformly for improving the system efficiency independent of the flatness of the reaction plate in a railway propulsion system by a linear induction motor (LIM). And it is possible to operate the LIM propulsion system efficiently without a change of the LIM capacity through the airgap length control on the sloped rail. So, in this research, the authors introduce an airgap control system to control the airgap length which depends on the flatness of the secondary reaction plate when the LIM is operated, and design a rotary small-scaled LIM and its airgap control system before manufacturing the real system. Then, the authors analyze some characteristics of the LIM (thrust and normal force, input current, efficiency and power factor), and through the LIM control modeling, the authors finally analyze an effect of the airgap-length control of the LIM by the airgap control system.
基金Project (No. 50577056) supported by the National Natural Science Foundation of China
文摘This paper proposes an analysis and a direct power control (DPC) design of a wind turbine driven doubly-fed induction generator (DFIG) under unbalanced network voltage conditions. A DFIG model described in the positive and negative synchronous reference frames is presented. Variations of the stator output active and reactive powers are fully deduced in the presence of negative sequence supply voltage and rotor flux. An enhanced DPC scheme is proposed to eliminate stator active power oscillation during network unbalance. The proposed control scheme removes rotor current regulators and the decomposition processing of positive and negative sequence rotor currents. Simulation results using PSCAD/EMTDC are presented on a 2-MW DFIG wind power generation system to validate the feasibility of the proposed control scheme under balanced and unbalanced network conditions.
基金Supported by Marmara University Research Fund, No. SAG-DKR-140305-0089
文摘AIM:To investigate the association between prognosis of rectal cancer treated with chemoradiotherapy(CRT) and expression of sensitive-to-apoptosis(SAG),B-cell lymphoma-extra large(Bcl-X L) and Bcl-2 homologous antagonist/killer(Bak).METHODS:Real-time quantitative polymerase chain reaction was used to determine the expression of proteins of interest,namely SAG,Bcl-X L,Bak and β-actin,in rectal carcinoma patients who had a follow-up period of 3 years after CRT.Biopsy specimens were excised from the rectal tumor preceding CRT.RESULTS:SAG,Bcl-X L and Bak proteins showed significant correlations with each other.In multivariate analysis,patients with high vs low SAG expression showed a statistically significant difference in 2-year survival rates:56% vs 73%,respectively(P = 0.056).On the other hand,there were no significant correlations between the expression levels of all three genes and metastatic rates or tumor responses to CRT.Mean overall survival in the patients with elevated SAG expression was 27.1 mo ± 3.9 mo [95% confidence interval(CI):19.3-34.9],and in patients with reduced expression,it was 32.1 mo ± 2.5 mo(95% CI:27.3-36.9).The corresponding values for Bcl-X L were 28.0 mo ± 4.1 mo(95% CI:19.9-36.1) and 31.7 mo ± 2.9 mo(95% CI:26.0-37.5),and those for Bak were 29.8 mo ± 3.7 mo(95% CI:22.5-37.2) and 30.6 mo ± 2.4 mo(95% CI:25.5-35.0),respectively.CONCLUSION:Two-year survival rates significantly correlated with low SAG expression,and SAG may be a candidate gene for good prognosis,independent of therapeutic response of different individuals.
基金supported in part by the Research Budget from the Research and Development Center,Nippon Koei Co.,Ltd
文摘Bedload governs riverbed channel variations and morphology, it is necessary to determine bedload discharge through an arbitrary cross section in a mountain fiver. A new system with submerged load cells has been developed to directly measure bedload discharge. The system consists of: (1) an iron box which is 1 m long, 0.5 m wide and 0.1 m in depth, (2) two submerged load cells 0.7 m apart, (3) a pressure sensor and, (4) an electromagnetic velocity meter. This system has been designed to exclude the effect of the hydraulic pressure of water on direct measurements of bedload particle weight. Initial tests in a laboratory were conducted to examine the accuracy of measurements with the system under aerial conditions. The system has been installed in the supercritical flume in Ashi-arai-dani River of the Hodaka Sedimentation Observatory of the Disaster Prevention Research Institute (DPRI) of Kyoto University to obtain bedload discharge under natural conditions. Flume tests were conducted in this channel by artificial supply of uniform sediment particles of several grain sizes. The average velocity of the sediment particles near the bed was estimated using cross-correlation functions for weight waves obtained by the two load cells, Bedload discharge calculations were based on time integration of the product of sediment velocity and sediment weight obtained by the two load cells. This study clarifies the reasons why bedload measurements are difficult, and provides some solutions using the monitoring systems with submerged load cells through the field measurements. Additionally, the applicability of bedload measurement with the submerged load cells is explained based on experimental artificial sediment supply data.
基金Project supported by Faculty of Technology,Department of Electrical Engineering,University of Batna,Algeria
文摘This study presents analysis, control and comparison of three hybrid approaches for the direct torque control (DTC) of the dual star induction motor (DSIM) drive. Its objective consists of combining three different heuristic optimization techniques including PID-PSO, Fuzzy-PSO and GA-PSO to improve the DSIM speed controlled loop behavior. The GA and PSO algorithms are developed and implemented into MATLAB. As a result, fuzzy-PSO is the most appropriate scheme. The main performance of fuzzy-PSO is reducing high torque ripples, improving rise time and avoiding disturbances that affect the drive performance.