The functional bamboos are defined as the ones artificially selected, cultivated and produced in the special functions. Based on the principles to broaden market and maximize benefits, the directional cultivation of t...The functional bamboos are defined as the ones artificially selected, cultivated and produced in the special functions. Based on the principles to broaden market and maximize benefits, the directional cultivation of the functional bamboos has effectively been used bio-techniques and directionally to breed and cultivate bamboo cultivars to meet human＇s needs. The functional bamboos should feature stability, excellent quality and convenient production as well as easy duplication. The functional bamboo cultivars should also enhance the scientization, standardization industrialization and mass production. Given no negative environmental impact, ou purpose is to select, cultivate and develop one or more functional bamboos cultivars to meet the consumers＇ material and spiritual needs and bring more economic ben efits for the producers. The authors believe that directionally breeding functiona bamboo cultivars is not only feasible in techniques, resources and policies, but also in economy and market development. This implicates great significance for the green economic development given the features of China＇s natural resources.展开更多
A novel behavioral model using three-layer time-delay feed-forward neural networks （TDFFNN）is adopted to model radio frequency （RF）power amplifiers exhibiting memory nonlinearities. In order to extract the paramet...A novel behavioral model using three-layer time-delay feed-forward neural networks （TDFFNN）is adopted to model radio frequency （RF）power amplifiers exhibiting memory nonlinearities. In order to extract the parameters, the back- propagation algorithm is applied to train the proposed neural networks. The proposed model is verified by the typical odd- order-only memory polynomial model in simulation, and the performance is compared with different numbers of taped delay lines（TDLs） and perceptrons of the hidden layer. For validating the TDFFNN model by experiments, a digital test bench is set up to collect input and output data of power amplifiers at a 60 × 10^6 sample/s sampling rate. The 3.75 MHz 16-QAM signal generated in the vector signal generator（VSG） is chosen as the input signal, when measuring the dynamic AM/AM and AM/PM characteristics of power amplifiers. By comparisons and analyses, the presented model provides a good performance in convergence, accuracy and efficiency, which is approved by simulation results and experimental results in the time domain and frequency domain.展开更多
This paper presents a bi-directional permanent-magnet linear actuator for directly driving electrohydraulic valves with low power consumption. Its static and dynamic performances were analyzed using the 2D finite elem...This paper presents a bi-directional permanent-magnet linear actuator for directly driving electrohydraulic valves with low power consumption. Its static and dynamic performances were analyzed using the 2D finite element method,taking into account the nonlinear characterization and the eddy current loss of the magnetic material. The experiment and simulation results agree well and show that the prototype actuator can produce a force of ±100 N with the maximum power being 7 W and has linear characteristics with a positive magnetic stiffness within a stroke of ±1 mm. Its non-linearity is less than 1.5% and the hysteresis less than 1.5%. The actuator's frequency response(-3 dB) of the displacement reaches about 15 Hz,and the most significant factor affecting the dynamic performance is identified as the eddy current loss of the magnetic material.展开更多
AIM: To examine the utility of Six Minute Walk Test (6MWT) in patients with chronic liver disease (CLD). METHODS: Two hundred and fifty subjects between the ages of 18 and 80 (mean 47) years performed 6MWT and the Six...AIM: To examine the utility of Six Minute Walk Test (6MWT) in patients with chronic liver disease (CLD). METHODS: Two hundred and fifty subjects between the ages of 18 and 80 (mean 47) years performed 6MWT and the Six Minute Walk Distance (6MWD) was measured. RESULTS: The subjects were categorized into four groups. Group A (n = 45) healthy subjects (control); group B (n = 49) chronic hepatitis B patients; group C (n = 54) chronic hepatitis C patients; group D (n = 98) liver cirrhosis patients. The four groups differed in terms of 6MWDs (P < 0.001). The longest distance walked was 421 ± 47 m by group A, then group B (390 ± 53 m), group C (357 ± 72 m) and group D (306 ± 111 m). The 6MWD correlated with age (r = -0.482, P < 0.01), hemoglobin (r = +0.373, P < 0.001) and albumin (r = +0.311, P < 0.001) levels. The Child-Pugh classification was negatively correlated with the 6MWD in cirrhosis (group D) patients (r = -0.328, P < 0.01). At the end of a 12 mo follow-up period, 15 of the 98 cirrhosis patients had died from disease complications. The 6MWD for the surviving cirrhotic patients was longer than for non-survivors (317 ± 101 vs 245 ± 145 m, P = 0.021; 95% CI 11-132). The 6MWD was found to be an independent predictor of survival (P = 0.024). CONCLUSION: 6MWT is a useful tool for assessing physical function in CLD patients. We suggest that 6MWD may serve as a prognostic indicator in patients with liver cirrhosis.展开更多
Assessment and learning must not be considered as two separate processes. In fact, assessment is an integral part of the learning process; it can be learning experience in itself. Active assessment strategies help stu...Assessment and learning must not be considered as two separate processes. In fact, assessment is an integral part of the learning process; it can be learning experience in itself. Active assessment strategies help students better understand the content they learn and develop skills that will be useful to them throughout their lives. Some of those skills are the ability to prepare effective oral and written reports and the ability to cooperate successfully with peers. Action research represents the process of systematic inquiry and it helps teachers to assess learning from the perspective of what they do in the classroom. The purpose is to find out ＂why＂ or ＂how＂ something happened the way it did. Therefore, a situation or problem should be carefully examined by a teacher. Teachers should analyze their own beliefs, values, and assumptions about teaching and learning, knowledge and curriculum, and how these impact the way they interact with students. Feedback should be used as part of assessment activities. Learning experience of students facilitated by teachers can be assessed through feedback.展开更多
This paper analyzes the relationship between the cultivated land use functions and the land rental decisions of rural households in three Dominant Functional Zones of Hubei, China. The results indicate that 41.10% of ...This paper analyzes the relationship between the cultivated land use functions and the land rental decisions of rural households in three Dominant Functional Zones of Hubei, China. The results indicate that 41.10% of the rural households in the study areas participated in the land rental market. The land rental market in the Key Development Zone has both a higher participation rate and land rent; the Agricultural Production Zone has a higher participation rate but a lower land rent; and the land rental market in the Key Ecological Zone is underdeveloped. The difference in regional function and economic level leads to a significant difference in the spatial variation of the cultivated land use multifunction. Overall, the cultivated land function of rural households has a significant impact on their land transfer behavior. The higher the Functions of Economic Contribution, Food Production, and Pension & Employment, the more willing the rural households are to rent in the land, while the higher the Function of Inheritance and Retainment of the cultivated land use, the more likely the peasants are to retain their cultivated land resources. Furthermore, the correlation coefficient is significantly higher in the Key Development Zone than in the Key Ecological Zone.展开更多
基金Supported by Special International Bamboo Research Cooperation Program of Southwest Flower InstituteResearch Institute of Forestry Chinese Academy of Forestry(ICPB-2014-006)~~
文摘The functional bamboos are defined as the ones artificially selected, cultivated and produced in the special functions. Based on the principles to broaden market and maximize benefits, the directional cultivation of the functional bamboos has effectively been used bio-techniques and directionally to breed and cultivate bamboo cultivars to meet human＇s needs. The functional bamboos should feature stability, excellent quality and convenient production as well as easy duplication. The functional bamboo cultivars should also enhance the scientization, standardization industrialization and mass production. Given no negative environmental impact, ou purpose is to select, cultivate and develop one or more functional bamboos cultivars to meet the consumers＇ material and spiritual needs and bring more economic ben efits for the producers. The authors believe that directionally breeding functiona bamboo cultivars is not only feasible in techniques, resources and policies, but also in economy and market development. This implicates great significance for the green economic development given the features of China＇s natural resources.
基金The National Natural Science Foundation of China(No.60621002)the National High Technology Research and Development Pro-gram of China(863 Program)(No.2007AA01Z2B4).
文摘A novel behavioral model using three-layer time-delay feed-forward neural networks （TDFFNN）is adopted to model radio frequency （RF）power amplifiers exhibiting memory nonlinearities. In order to extract the parameters, the back- propagation algorithm is applied to train the proposed neural networks. The proposed model is verified by the typical odd- order-only memory polynomial model in simulation, and the performance is compared with different numbers of taped delay lines（TDLs） and perceptrons of the hidden layer. For validating the TDFFNN model by experiments, a digital test bench is set up to collect input and output data of power amplifiers at a 60 × 10^6 sample/s sampling rate. The 3.75 MHz 16-QAM signal generated in the vector signal generator（VSG） is chosen as the input signal, when measuring the dynamic AM/AM and AM/PM characteristics of power amplifiers. By comparisons and analyses, the presented model provides a good performance in convergence, accuracy and efficiency, which is approved by simulation results and experimental results in the time domain and frequency domain.
文摘This paper presents a bi-directional permanent-magnet linear actuator for directly driving electrohydraulic valves with low power consumption. Its static and dynamic performances were analyzed using the 2D finite element method,taking into account the nonlinear characterization and the eddy current loss of the magnetic material. The experiment and simulation results agree well and show that the prototype actuator can produce a force of ±100 N with the maximum power being 7 W and has linear characteristics with a positive magnetic stiffness within a stroke of ±1 mm. Its non-linearity is less than 1.5% and the hysteresis less than 1.5%. The actuator's frequency response(-3 dB) of the displacement reaches about 15 Hz,and the most significant factor affecting the dynamic performance is identified as the eddy current loss of the magnetic material.
文摘AIM: To examine the utility of Six Minute Walk Test (6MWT) in patients with chronic liver disease (CLD). METHODS: Two hundred and fifty subjects between the ages of 18 and 80 (mean 47) years performed 6MWT and the Six Minute Walk Distance (6MWD) was measured. RESULTS: The subjects were categorized into four groups. Group A (n = 45) healthy subjects (control); group B (n = 49) chronic hepatitis B patients; group C (n = 54) chronic hepatitis C patients; group D (n = 98) liver cirrhosis patients. The four groups differed in terms of 6MWDs (P < 0.001). The longest distance walked was 421 ± 47 m by group A, then group B (390 ± 53 m), group C (357 ± 72 m) and group D (306 ± 111 m). The 6MWD correlated with age (r = -0.482, P < 0.01), hemoglobin (r = +0.373, P < 0.001) and albumin (r = +0.311, P < 0.001) levels. The Child-Pugh classification was negatively correlated with the 6MWD in cirrhosis (group D) patients (r = -0.328, P < 0.01). At the end of a 12 mo follow-up period, 15 of the 98 cirrhosis patients had died from disease complications. The 6MWD for the surviving cirrhotic patients was longer than for non-survivors (317 ± 101 vs 245 ± 145 m, P = 0.021; 95% CI 11-132). The 6MWD was found to be an independent predictor of survival (P = 0.024). CONCLUSION: 6MWT is a useful tool for assessing physical function in CLD patients. We suggest that 6MWD may serve as a prognostic indicator in patients with liver cirrhosis.
文摘Assessment and learning must not be considered as two separate processes. In fact, assessment is an integral part of the learning process; it can be learning experience in itself. Active assessment strategies help students better understand the content they learn and develop skills that will be useful to them throughout their lives. Some of those skills are the ability to prepare effective oral and written reports and the ability to cooperate successfully with peers. Action research represents the process of systematic inquiry and it helps teachers to assess learning from the perspective of what they do in the classroom. The purpose is to find out ＂why＂ or ＂how＂ something happened the way it did. Therefore, a situation or problem should be carefully examined by a teacher. Teachers should analyze their own beliefs, values, and assumptions about teaching and learning, knowledge and curriculum, and how these impact the way they interact with students. Feedback should be used as part of assessment activities. Learning experience of students facilitated by teachers can be assessed through feedback.
基金supported by China National Science Foundation[grant no.71573099 and 41371519]Additional support was provided by the Fundamental Research Funds for the Central Universities in China[grant no.2014RW013]
文摘This paper analyzes the relationship between the cultivated land use functions and the land rental decisions of rural households in three Dominant Functional Zones of Hubei, China. The results indicate that 41.10% of the rural households in the study areas participated in the land rental market. The land rental market in the Key Development Zone has both a higher participation rate and land rent; the Agricultural Production Zone has a higher participation rate but a lower land rent; and the land rental market in the Key Ecological Zone is underdeveloped. The difference in regional function and economic level leads to a significant difference in the spatial variation of the cultivated land use multifunction. Overall, the cultivated land function of rural households has a significant impact on their land transfer behavior. The higher the Functions of Economic Contribution, Food Production, and Pension & Employment, the more willing the rural households are to rent in the land, while the higher the Function of Inheritance and Retainment of the cultivated land use, the more likely the peasants are to retain their cultivated land resources. Furthermore, the correlation coefficient is significantly higher in the Key Development Zone than in the Key Ecological Zone.
