[Objective] The aim of this study was to investigate the impacts of slow and controlled release fertilizers(SCRF)on the yield of qiubei hot pepper,its nutrient use efficiency and environment.[Method] Using Qiubei ho...[Objective] The aim of this study was to investigate the impacts of slow and controlled release fertilizers(SCRF)on the yield of qiubei hot pepper,its nutrient use efficiency and environment.[Method] Using Qiubei hot pepper(Capsicum frutescens L.)as the experimental material,we studied the fertilization effect and environment-protecting effect of SCRF.[Result] The result showed that SCRF could improve the agronomic characteristics of hot pepper.Compared to singly applied common fertilizers,SCRF increased economic yield by 20.90% and economic benefit by 13 234.35 Yuan/hm2,and the ratio of output to input was improved by 47.93%.In comparison with common straight fertilizers at same NPK proportion and rate,SCRF increased economic yield by 5.26% and economic benefit by 5 554.80 Yuan/hm2,and the ratio of output to input was improved by 9.91%.Under the reduced use of SCRF by 20%,SCRF increased economic yield by 12.38% and economic benefit by 9595.20 Yuan/hm2 compared with singly applied common fertilizers,and the ratio of output to input was improved by 65.95%.SCRF improved nitrogen,phosphorus and potassium use efficiencies by 12.42-17.53,3.35-5.24 and 5.37-14.02 percents respectively.[Conclusion] As the result of much reduced N and P application rates,SCRF would significantly economize fertilizer resources and minimize the pollution caused by the loss of fertilizer nutrients,which is of practical importance for environment protection.展开更多
There is limited information about the influence of slow or controlled release fertilizer(S/CRF) on rice yield and quality. In this study, japonica rice cultivar Nanjing 9108 was used to study the effects of three d...There is limited information about the influence of slow or controlled release fertilizer(S/CRF) on rice yield and quality. In this study, japonica rice cultivar Nanjing 9108 was used to study the effects of three different S/CRFs(polymer-coated urea(PCU), sulfur-coated urea(SCU), and urea formaldehyde(UF)) and two fertilization modes(both S/CRF and common urea(CU) as basal fertilizer, S/CRF as basal and CU as tillering fertilizer) on rice yield and quality. CU only was applied separately as control(CK). Results showed that, rice grain yield, chalky kernel rate, chalky area, overall chalkiness, and the content of gliadin, glutenin, and protein, all showed the trends of UF〉PCU〉SCU within the same fertilization mode, and showed the trends of S/CRF as basal and CU as tillering fertilizer〉both S/CRF and CU as basal fertilizer within the same type of S/CRF. In contrast, the contents of amylose, amylopectin, and starch, as well as taste value, and peak and hot viscosity showed trends of SCU〉PCU〉UF, and the trends of both S/CRF and CU as basal fertilizer〉S/CRF as basal and CU as tillering fertilizer. Among S/CRF treatments and fertilization modes, taste values of cooked rice were positively correlated with amylose, amylopectin, and starch contents, as well as gel consistency, peak viscosity, hot viscosity, and cool viscosity, while negatively correlated with globulin, gliadin, glutenin, and protein contents. The types of S/CRF and fertilization modes are important for improving rice yield and quality. Compared to CK, higher yield and similar quality of rice was achieved with UF as basal and CU as tillering fertilizer, and similar yield with improved appearance and eating and cooking quality of rice was achieved with either both UF and CU as basal fertilizer, or PCU as basal and CU as tillering fertilizer.展开更多
Polyurethane coated urea slow/controlled release fertilizer was prepared based on urea granules, isocyanate, polyols and paraffin. Isocyanate reacted with polyols to synthesize the polyurethane skin layer on urea gran...Polyurethane coated urea slow/controlled release fertilizer was prepared based on urea granules, isocyanate, polyols and paraffin. Isocyanate reacted with polyols to synthesize the polyurethane skin layer on urea granules surface. Paraffin serves as a lubricant during syntheses of polyurethane skin layers. The structure and nutrient release characteristics of the polyurethane skin layers were investigated by FTIR, SEM and TG. Urea nitrogen slow-release behavior of the polyurethane coated urea was tested. The experimental results indicated that compact and dense polyurethane skin layers with a thickness of 10-15 lam were formed on urea surface, the urea nitrogen slow-release time can reach 40-50 days. Paraffin proves to play a key role in inhibiting water to penetrate into urea, but excessive addition would decrease the polyurethane crosslinking density.展开更多
This study examined the release characteristics of different N forms in an uncoated slow/controlled-release compound fertilizer (UCRF) and the N uptake and N-use efficiency by rice plants. Water dissolution, soil le...This study examined the release characteristics of different N forms in an uncoated slow/controlled-release compound fertilizer (UCRF) and the N uptake and N-use efficiency by rice plants. Water dissolution, soil leaching, and pot experiments were employed. The dynamics of N release from the UCRF could be quantitatively described by three equations: the first-order kinetics equation [N1=N0 (1-e^-kt)], Elovich equation (N1=a + blnt), and parabola equation (N1=a + bt^0.5), with the best fitting by the first-order kinetics equation for different N (r= 0.9569^**-0.9999^**). The release potentials (No values estimated by the first-order kinetics equation) of different N in the UCRF decreased in the order of total N 〉 DON 〉 urea-N 〉 NH4^+-N 〉 NO3^-N in water, and total N 〉 NH4^+-N 〉 DON 〉 urea-N 〉 NO3^--N in soil, respectively, being in accordance with cumulative amounts of N release. The constants of N release rate (k values and b values) for different N forms were in decreasing order of total N 〉 DON 〉 NH4^+-N 〉 NO3^--N in water, whereas the k values were urea- N 〉DON 〉 NH4^+-N 〉 total N 〉 NO3^--N, and the b values were total N 〉 NH4^+-N 〉 DON 〉 NO3^--N 〉 urea-N in soil. Compared with a common compound fertilizer, the N-use efficiency, N-agronomy efficiency, and N-physiological efficiency of the UCRF were increased by 11.4%, 8.32 kg kg^-1, and 5.17 kg kg^-1, respectively. The ratios of different N to total N in the UCRF showed significant correlation with N uptake by rice plants. The findings showed that the first-order kinetics equation [Nt=N0 (l-e^kt)] could be used to describe the release characteristics of different N forms in the fertilizer. The UCRF containing different N forms was more effective in facilitating N uptake by rice compared with the common compound fertilizer containing single urea-N form.展开更多
Lignin is the main by-product of pulp and papermaking and is not effectively utilized. Conversion of industrial lignins into value-added materials is beneficial for the effective utilization of resources as well as fo...Lignin is the main by-product of pulp and papermaking and is not effectively utilized. Conversion of industrial lignins into value-added materials is beneficial for the effective utilization of resources as well as for environmental protection. Because of their adsorptivity, slow-release property,biocompatibility, and biodegradability, lignin and its derivatives find potential applications as eco-friendly slow/controlled release materials in agricultural fields. This report reviews the recent research advances in lignin-based slow/controlled release fertilizers and pesticides.展开更多
By using field trials, the migration and transformation of coated controlled release nitrogen (YZS80) in soil under the co-situs application mode were studied. The results indicated that YZS80 nitrogen dissolved out...By using field trials, the migration and transformation of coated controlled release nitrogen (YZS80) in soil under the co-situs application mode were studied. The results indicated that YZS80 nitrogen dissolved out in average speed of about 0.4%/d and 32% totally in 80 d compared with common compound fertUizer. For YZS80, in the vertical downward direction of application points, urea nitrogen content increased significantly (P 〈0.05) in the 45 -80 d and the 30 -60 cm soil layers; nitrate nitrogen content was little change range and in moderate (10 -100 mg/kg) in 0 -80 d and 10 -60 cm soil layers, but increased significantly ( P 〈0.05) 45 -80 d compared to 0 -45 d; ammonium nitrogen content was significant lower (P〈0.05) before 45 d in 10 -30 cm soil layers, but significant higher(P〈0.05) after 45 d in 10 -60 cm soil layers; NO3^- -N/NH4^+ -N meets gradually the needs of the crop with the extension of time. Under the co-situs application mode, the possibility of burning root and salt injury and loss dsk of nitrate leaching is a significant reduction.展开更多
Quantitative evaluation and analysis was made to the soil nutrients,rice yield,rice and fertilizer utilization rate,and economic and ecological benefits of the slow controlled release fertilizer in typical rice fields...Quantitative evaluation and analysis was made to the soil nutrients,rice yield,rice and fertilizer utilization rate,and economic and ecological benefits of the slow controlled release fertilizer in typical rice fields with middle-low yield by comparing the one-time application and split applications of slow-or controlledrelease fertilizer( CRF) with farmers fertilizer practice as the control,with the aim to explore the effect of CRF. Results showed that compared with the control,the application of CRF could meet balance nutrients required for rice growth,and the effective panicles and seed-setting rate were higher in the treatment groups of FVOL,SVOL,LADVOLwhich applied CRF. As for soil nutrients,soil pH maintained balance in FVOL,FCAI,SVOL,LADVOL. In addition,differences in soil nutrient reduction amount reached the extremely significant level between FVOLand SXNK.SVOLwhich applied CRF provided reasonable regulation of N,P and K release rate,which showed advantages over blending fertilization and farmers fertilizer practice. Comprehensive analysis found that the application of CRF could make rice tillering growth and decline leveled off,which effectively improved the quality of rice population,and it also had higher input-output ratio than that of the control and good economic benefits. In general,CRF suits to be used widely on rice crop in the regions with medium-low yield.展开更多
In order to select the long-acting,low toxic,low-risk and multi-functional new pesticides for the control of sugarcane borders and woolly aphids and precise and efficient application technology,the control effect of 1...In order to select the long-acting,low toxic,low-risk and multi-functional new pesticides for the control of sugarcane borders and woolly aphids and precise and efficient application technology,the control effect of 10% monosultap · thiamethoxam granular formulation and 1% Bt · clothianidin granular formulation on sugarcane borders and woolly aphids were studied.The results showed that 10% monosultap·thiamethoxam GR and 1% Bt·clothianidin GR had good control effects on sugarcane borders and woolly aphids.They were ideal slow-release,long-acting,low toxic and multi-functional new pesticides used to control sugarcane borders and woolly aphids.They could be used alternately with other pesticides to delay the emergence and development of pest resistance to pesticides.The best dosage of the two pesticides in the field was 45 kg/hm^2.They could be mixed with fertilizer( 1200-1800 kg/hm^2),scattered in sugarcane ditches or at the base of sugarcane plants,and covered with soil or film from January to July.The control effect on dead heart seedlings damaged by borers could be up to above 79.2%,and the control effect on sugarcane woolly aphids could reach more than 98.8%.In comparison with the control group,the actual yield and sugar content of sugarcane increased by above 41 555 kg/hm^2 and 6.5% respectively.The application of slow-release,long-acting,strong systemic and multi-functional new agents with fertilizer around roots is convenient,precise and efficient,labor-saving,time-saving and environmentally friendly,and is worthy of being widely applied in sugarcane areas.展开更多
In order to move tracked vehicles at an extremely slowspeed with automated mechanical transmission( AMT),slowdriving function was added in the original system. The principle and requirement of slowdriving function w...In order to move tracked vehicles at an extremely slowspeed with automated mechanical transmission( AMT),slowdriving function was added in the original system. The principle and requirement of slowdriving function were analyzed. Based on analysis of slow driving characteristic,identification of slowdriving condition and fuzzy control algorithm,a control strategy of the clutch was designed. In order to realize slowdriving,the clutch was controlled in a slipping mode as manual driving. The vehicle speed was increased to a required speed and kept in a small range by engaging or disengaging the clutch to the approximate half engagement point. Based on the control strategy,a control software was designed and tested on a tracked vehicle with AMT. The test results showthat the control of the clutch with the slowdriving function was smoother than that with original systemand the vehicle speed was slower and steadier.展开更多
In 2015, through the efforts of all the members in Slow Control Group in IMP, we had got several good results in the HIRFL and the HIMM control, monitor and alarm system, such as the establishment of SFC extraction el...In 2015, through the efforts of all the members in Slow Control Group in IMP, we had got several good results in the HIRFL and the HIMM control, monitor and alarm system, such as the establishment of SFC extraction electrostatic deflector motion control system, the upgrade of the new kicker controller, the improvement of HIMM ion source and cyclotron control system, etc. Brief introductions of our major achievements are listed below.展开更多
Transmission control protocol (TCP) has undergone several transformations. Several proposals have been put forward to change the mechanisms of TCP congestion control to improve its performance. A line of research tend...Transmission control protocol (TCP) has undergone several transformations. Several proposals have been put forward to change the mechanisms of TCP congestion control to improve its performance. A line of research tends to reduce speed in the face of congestion thereby penalizing itself. In this group are the window based congestion control algorithms that use the size of congestion window to determine transmission speed. The two main algorithm of window based congestion control are the congestion avoidance and the slow start. The aim of this study is to survey the various modifications of window based congestion control. Much work has been done on congestion avoidance hence specific attention is placed on the slow start in order to motivate a new direction of research in network utility maximization. Mathematical modeling of the internet is discussed and proposals to improve TCP startup were reviewed. There are three lines of research on the improvement of slow start. A group uses the estimation of certain parameters to determine initial speed. The second group uses bandwidth estimation while the last group uses explicit request for network assistance to determine initial startup speed. The problems of each proposal are analyzed and a multiple startup for TCP is proposed. Multiple startups for TCP specify that startup speed is selectable from an n-arry set of algorithms. We then introduced the e-speed start which uses the prevailing network condition to determine a suitable starting speed.展开更多
基金Supported by Special Fund for Agro-scientific Research in the Public Interest from Ministry of Agriculture(200903025-05)Fund from Kunming Municipal Science and Technology Committee(08S010201)~~
文摘[Objective] The aim of this study was to investigate the impacts of slow and controlled release fertilizers(SCRF)on the yield of qiubei hot pepper,its nutrient use efficiency and environment.[Method] Using Qiubei hot pepper(Capsicum frutescens L.)as the experimental material,we studied the fertilization effect and environment-protecting effect of SCRF.[Result] The result showed that SCRF could improve the agronomic characteristics of hot pepper.Compared to singly applied common fertilizers,SCRF increased economic yield by 20.90% and economic benefit by 13 234.35 Yuan/hm2,and the ratio of output to input was improved by 47.93%.In comparison with common straight fertilizers at same NPK proportion and rate,SCRF increased economic yield by 5.26% and economic benefit by 5 554.80 Yuan/hm2,and the ratio of output to input was improved by 9.91%.Under the reduced use of SCRF by 20%,SCRF increased economic yield by 12.38% and economic benefit by 9595.20 Yuan/hm2 compared with singly applied common fertilizers,and the ratio of output to input was improved by 65.95%.SCRF improved nitrogen,phosphorus and potassium use efficiencies by 12.42-17.53,3.35-5.24 and 5.37-14.02 percents respectively.[Conclusion] As the result of much reduced N and P application rates,SCRF would significantly economize fertilizer resources and minimize the pollution caused by the loss of fertilizer nutrients,which is of practical importance for environment protection.
基金the National Key R&D Program of China (2016YFD0300503)the Key Research Program of Jiangsu Province, China (BE2016344)+3 种基金the National Rice Industry Technology System, China (CARS01-27)the National Nature Science Foundation of China (31701350)the Program for Scientific Elitists of Yangzhou University, Chinaa Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions, China
文摘There is limited information about the influence of slow or controlled release fertilizer(S/CRF) on rice yield and quality. In this study, japonica rice cultivar Nanjing 9108 was used to study the effects of three different S/CRFs(polymer-coated urea(PCU), sulfur-coated urea(SCU), and urea formaldehyde(UF)) and two fertilization modes(both S/CRF and common urea(CU) as basal fertilizer, S/CRF as basal and CU as tillering fertilizer) on rice yield and quality. CU only was applied separately as control(CK). Results showed that, rice grain yield, chalky kernel rate, chalky area, overall chalkiness, and the content of gliadin, glutenin, and protein, all showed the trends of UF〉PCU〉SCU within the same fertilization mode, and showed the trends of S/CRF as basal and CU as tillering fertilizer〉both S/CRF and CU as basal fertilizer within the same type of S/CRF. In contrast, the contents of amylose, amylopectin, and starch, as well as taste value, and peak and hot viscosity showed trends of SCU〉PCU〉UF, and the trends of both S/CRF and CU as basal fertilizer〉S/CRF as basal and CU as tillering fertilizer. Among S/CRF treatments and fertilization modes, taste values of cooked rice were positively correlated with amylose, amylopectin, and starch contents, as well as gel consistency, peak viscosity, hot viscosity, and cool viscosity, while negatively correlated with globulin, gliadin, glutenin, and protein contents. The types of S/CRF and fertilization modes are important for improving rice yield and quality. Compared to CK, higher yield and similar quality of rice was achieved with UF as basal and CU as tillering fertilizer, and similar yield with improved appearance and eating and cooking quality of rice was achieved with either both UF and CU as basal fertilizer, or PCU as basal and CU as tillering fertilizer.
基金the National Key Technology R&D Program of the 11th Five-Year Period (No.2006BAD10B08)
文摘Polyurethane coated urea slow/controlled release fertilizer was prepared based on urea granules, isocyanate, polyols and paraffin. Isocyanate reacted with polyols to synthesize the polyurethane skin layer on urea granules surface. Paraffin serves as a lubricant during syntheses of polyurethane skin layers. The structure and nutrient release characteristics of the polyurethane skin layers were investigated by FTIR, SEM and TG. Urea nitrogen slow-release behavior of the polyurethane coated urea was tested. The experimental results indicated that compact and dense polyurethane skin layers with a thickness of 10-15 lam were formed on urea surface, the urea nitrogen slow-release time can reach 40-50 days. Paraffin proves to play a key role in inhibiting water to penetrate into urea, but excessive addition would decrease the polyurethane crosslinking density.
文摘This study examined the release characteristics of different N forms in an uncoated slow/controlled-release compound fertilizer (UCRF) and the N uptake and N-use efficiency by rice plants. Water dissolution, soil leaching, and pot experiments were employed. The dynamics of N release from the UCRF could be quantitatively described by three equations: the first-order kinetics equation [N1=N0 (1-e^-kt)], Elovich equation (N1=a + blnt), and parabola equation (N1=a + bt^0.5), with the best fitting by the first-order kinetics equation for different N (r= 0.9569^**-0.9999^**). The release potentials (No values estimated by the first-order kinetics equation) of different N in the UCRF decreased in the order of total N 〉 DON 〉 urea-N 〉 NH4^+-N 〉 NO3^-N in water, and total N 〉 NH4^+-N 〉 DON 〉 urea-N 〉 NO3^--N in soil, respectively, being in accordance with cumulative amounts of N release. The constants of N release rate (k values and b values) for different N forms were in decreasing order of total N 〉 DON 〉 NH4^+-N 〉 NO3^--N in water, whereas the k values were urea- N 〉DON 〉 NH4^+-N 〉 total N 〉 NO3^--N, and the b values were total N 〉 NH4^+-N 〉 DON 〉 NO3^--N 〉 urea-N in soil. Compared with a common compound fertilizer, the N-use efficiency, N-agronomy efficiency, and N-physiological efficiency of the UCRF were increased by 11.4%, 8.32 kg kg^-1, and 5.17 kg kg^-1, respectively. The ratios of different N to total N in the UCRF showed significant correlation with N uptake by rice plants. The findings showed that the first-order kinetics equation [Nt=N0 (l-e^kt)] could be used to describe the release characteristics of different N forms in the fertilizer. The UCRF containing different N forms was more effective in facilitating N uptake by rice compared with the common compound fertilizer containing single urea-N form.
基金financial support from the Independent Innovation and Achievements Transformation Project of Shandong Province (2014CGZH0302)
文摘Lignin is the main by-product of pulp and papermaking and is not effectively utilized. Conversion of industrial lignins into value-added materials is beneficial for the effective utilization of resources as well as for environmental protection. Because of their adsorptivity, slow-release property,biocompatibility, and biodegradability, lignin and its derivatives find potential applications as eco-friendly slow/controlled release materials in agricultural fields. This report reviews the recent research advances in lignin-based slow/controlled release fertilizers and pesticides.
基金Supported by Beijing Science Committee Project"Science & TechnologyNew Star"(2008B38)"The Research and Establishmentof Agrochemical Service System for New Type of Fertilizer"(d0706004040431)The Foundation for Youth Scholars of BeijingAcademy of Agriculture and Forestry Sciences"The Developmentand Evaluation of Micro Water-soluble Cementation Coated Slow-releaseFertilizers Suitable for Semiand Areas"~~
文摘By using field trials, the migration and transformation of coated controlled release nitrogen (YZS80) in soil under the co-situs application mode were studied. The results indicated that YZS80 nitrogen dissolved out in average speed of about 0.4%/d and 32% totally in 80 d compared with common compound fertUizer. For YZS80, in the vertical downward direction of application points, urea nitrogen content increased significantly (P 〈0.05) in the 45 -80 d and the 30 -60 cm soil layers; nitrate nitrogen content was little change range and in moderate (10 -100 mg/kg) in 0 -80 d and 10 -60 cm soil layers, but increased significantly ( P 〈0.05) 45 -80 d compared to 0 -45 d; ammonium nitrogen content was significant lower (P〈0.05) before 45 d in 10 -30 cm soil layers, but significant higher(P〈0.05) after 45 d in 10 -60 cm soil layers; NO3^- -N/NH4^+ -N meets gradually the needs of the crop with the extension of time. Under the co-situs application mode, the possibility of burning root and salt injury and loss dsk of nitrate leaching is a significant reduction.
文摘Quantitative evaluation and analysis was made to the soil nutrients,rice yield,rice and fertilizer utilization rate,and economic and ecological benefits of the slow controlled release fertilizer in typical rice fields with middle-low yield by comparing the one-time application and split applications of slow-or controlledrelease fertilizer( CRF) with farmers fertilizer practice as the control,with the aim to explore the effect of CRF. Results showed that compared with the control,the application of CRF could meet balance nutrients required for rice growth,and the effective panicles and seed-setting rate were higher in the treatment groups of FVOL,SVOL,LADVOLwhich applied CRF. As for soil nutrients,soil pH maintained balance in FVOL,FCAI,SVOL,LADVOL. In addition,differences in soil nutrient reduction amount reached the extremely significant level between FVOLand SXNK.SVOLwhich applied CRF provided reasonable regulation of N,P and K release rate,which showed advantages over blending fertilization and farmers fertilizer practice. Comprehensive analysis found that the application of CRF could make rice tillering growth and decline leveled off,which effectively improved the quality of rice population,and it also had higher input-output ratio than that of the control and good economic benefits. In general,CRF suits to be used widely on rice crop in the regions with medium-low yield.
基金Supported by Sugar Crop Research System(CARS-170303)Training Project of"Yunling Industry Technology Leading Talent"(2018LJRC56)Special Funds for Construction of Modern Agricultural Industrial Technology System of Yunnan Province(YNGZTX-4-92)
文摘In order to select the long-acting,low toxic,low-risk and multi-functional new pesticides for the control of sugarcane borders and woolly aphids and precise and efficient application technology,the control effect of 10% monosultap · thiamethoxam granular formulation and 1% Bt · clothianidin granular formulation on sugarcane borders and woolly aphids were studied.The results showed that 10% monosultap·thiamethoxam GR and 1% Bt·clothianidin GR had good control effects on sugarcane borders and woolly aphids.They were ideal slow-release,long-acting,low toxic and multi-functional new pesticides used to control sugarcane borders and woolly aphids.They could be used alternately with other pesticides to delay the emergence and development of pest resistance to pesticides.The best dosage of the two pesticides in the field was 45 kg/hm^2.They could be mixed with fertilizer( 1200-1800 kg/hm^2),scattered in sugarcane ditches or at the base of sugarcane plants,and covered with soil or film from January to July.The control effect on dead heart seedlings damaged by borers could be up to above 79.2%,and the control effect on sugarcane woolly aphids could reach more than 98.8%.In comparison with the control group,the actual yield and sugar content of sugarcane increased by above 41 555 kg/hm^2 and 6.5% respectively.The application of slow-release,long-acting,strong systemic and multi-functional new agents with fertilizer around roots is convenient,precise and efficient,labor-saving,time-saving and environmentally friendly,and is worthy of being widely applied in sugarcane areas.
基金Supported by the National Natural Science Foundation of China(51375053)
文摘In order to move tracked vehicles at an extremely slowspeed with automated mechanical transmission( AMT),slowdriving function was added in the original system. The principle and requirement of slowdriving function were analyzed. Based on analysis of slow driving characteristic,identification of slowdriving condition and fuzzy control algorithm,a control strategy of the clutch was designed. In order to realize slowdriving,the clutch was controlled in a slipping mode as manual driving. The vehicle speed was increased to a required speed and kept in a small range by engaging or disengaging the clutch to the approximate half engagement point. Based on the control strategy,a control software was designed and tested on a tracked vehicle with AMT. The test results showthat the control of the clutch with the slowdriving function was smoother than that with original systemand the vehicle speed was slower and steadier.
文摘In 2015, through the efforts of all the members in Slow Control Group in IMP, we had got several good results in the HIRFL and the HIMM control, monitor and alarm system, such as the establishment of SFC extraction electrostatic deflector motion control system, the upgrade of the new kicker controller, the improvement of HIMM ion source and cyclotron control system, etc. Brief introductions of our major achievements are listed below.
文摘Transmission control protocol (TCP) has undergone several transformations. Several proposals have been put forward to change the mechanisms of TCP congestion control to improve its performance. A line of research tends to reduce speed in the face of congestion thereby penalizing itself. In this group are the window based congestion control algorithms that use the size of congestion window to determine transmission speed. The two main algorithm of window based congestion control are the congestion avoidance and the slow start. The aim of this study is to survey the various modifications of window based congestion control. Much work has been done on congestion avoidance hence specific attention is placed on the slow start in order to motivate a new direction of research in network utility maximization. Mathematical modeling of the internet is discussed and proposals to improve TCP startup were reviewed. There are three lines of research on the improvement of slow start. A group uses the estimation of certain parameters to determine initial speed. The second group uses bandwidth estimation while the last group uses explicit request for network assistance to determine initial startup speed. The problems of each proposal are analyzed and a multiple startup for TCP is proposed. Multiple startups for TCP specify that startup speed is selectable from an n-arry set of algorithms. We then introduced the e-speed start which uses the prevailing network condition to determine a suitable starting speed.