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
The impact dynamics, impact effect, and post-impact unstable motion sup- pression of free-floating space manipulator capturing a satellite on orbit are analyzed. Firstly, the dynamics equation of free-floating space m...The impact dynamics, impact effect, and post-impact unstable motion sup- pression of free-floating space manipulator capturing a satellite on orbit are analyzed. Firstly, the dynamics equation of free-floating space manipulator is derived using the sec- ond Lagrangian equation. Combining the momentum conservation principle, the impact dynamics and effect between the space manipulator end-effector and satellite of the cap- ture process are analyzed with the momentum impulse method. Focusing on the unstable motion of space manipulator due to the above impact effect, a robust adaptive compound control algorithm is designed to suppress the above unstable motion. There is no need to control the free-floating base position to save the jet fuel. Finally, the simulation is proposed to show the impact effect and verify the validity of the control algorithm.展开更多
A robust controller for bank to turn(BTT) missiles with aerodynamic fins and reaction jet control system(RCS) is developed based on nonlinear control dynamic models comprising couplings and aerodynamic uncertainties. ...A robust controller for bank to turn(BTT) missiles with aerodynamic fins and reaction jet control system(RCS) is developed based on nonlinear control dynamic models comprising couplings and aerodynamic uncertainties. The fixed time convergence theory is incorporated with the sliding mode control technique to ensure that the system tracks the desired command within uniform bounded time under different initial conditions. Unlike previous terminal sliding mode approaches, the bound of settling time is independent of the initial state, which means performance metrics like convergence rate can be predicted beforehand. To reduce the burden of control design in terms of robustness, extended state observer(ESO) is introduced for uncertainty estimation with the output substituted into the controller as feedforward compensation. Cascade control structure is employed with the proposed control law and therein the compound control signal is obtained.Afterwards, control inputs for two kinds of actuators are allocated on the basis of their inherent characteristics. Finally, a number of simulations are carried out and demonstrate the effectiveness of the designed controller.展开更多
To solve the control allocation problem of dual aero/jet vane control missile, dynamics e- quations in longitudinal plane are derived, and the structure of compound control loop is designed based on attitude autopilot...To solve the control allocation problem of dual aero/jet vane control missile, dynamics e- quations in longitudinal plane are derived, and the structure of compound control loop is designed based on attitude autopilot. Four brief compound control allocation strategies are researched and an- alyzed. Furthermore, a new strategy called chain combination variable proportional coefficient strat- egy based on rudder effect is presented. By simulation of initial climb trajectory, the characteristics of all the strategies are researched, and the results illustrate that the new strategy can meet the re- quirement well.展开更多
Based on the pressure regulation circuit adopting electro-hydraulic proportional relief valve to control tension, a new type of electro-hydraulic compound control circuit with throttle control unit is presented, which...Based on the pressure regulation circuit adopting electro-hydraulic proportional relief valve to control tension, a new type of electro-hydraulic compound control circuit with throttle control unit is presented, which can obtain optimal dynamic damping ratio through real-time altering pressure-flow gain of the throttle control unit, improve the dynamic characteristic of tension follow-up control for the tension system with high inertia loads. Moreover, the characteristic when the cable linear velocity variation causes change of tension is investigated, and a compound control strategy is proposed. The theoretical analysis and experimental results show that the electro-hydraulic compound control circuit is effective and the characteristic of the compound control strategy is satisfactory.展开更多
Electric load simulator(ELS) systems are employed for electric power steering(EPS) test benches to load rack force by precise control. Precise ELS control is strongly influenced by nonlinear factors. When the steering...Electric load simulator(ELS) systems are employed for electric power steering(EPS) test benches to load rack force by precise control. Precise ELS control is strongly influenced by nonlinear factors. When the steering motor rapidly rotates, extra force is directly superimposed on the original static loading error, which becomes one of the main sources of the final error. It is key to achieve ELS precise loading control for the entire EPS test bench. Therefore, a three-part compound control algorithm is proposed to improve the loading accuracy. First, a fuzzy proportional–integral plus feedforward controller with force feedback is presented. Second, a friction compensation algorithm is established to reduce the influence of friction. Then, the relationships between each quantity and the extra force are analyzed when the steering motor rapidly rotates, and a net torque feedforward compensation algorithm is proposed to eliminate the extra force. The compound control algorithm was verified through simulations and experiments. The results show that the tracking performance of the compound control algorithm satisfies the demands of engineering practice, and the extra force in the ELS system can be suppressed by the net torque corresponding to the actuator’s acceleration.展开更多
The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the improved iron fertilization for climate change. The limitation of iron (F...The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the improved iron fertilization for climate change. The limitation of iron (Fe) for phytoplankton growth in HNLC regions was confirmed by sulfur compounds (S) such as volcanic ash and hydrogen sulfide (H2S) in batch cultures, whose chemical sediment of Fe3S4 showed 4.06 wt%. The technologies developed for iron fertilization since 1993 till now were not practical to provide sufficient amounts of bioavailable iron due to sedimentary iron sulfides induced by undersea volcanic sulfur compounds. The proposed technology for iron fertilization was improved to enhance the bioavailable iron to phytoplankton by keeping minimal sulfur compounds in HNLC regions. The low productivity of phytoplankton by grazing control in HNLC regions was 6% diatoms whose 52% was grazed by copepods and 42% by krill on the basis of data analysis in 2000 EisenEx Experiment at boundary of Antarctic and African tectonic plates. All of the previous iron fertilization experiments were conducted at volcanic sulfur compounds enriched HNLC regions. The present study revealed that the enhanced phytoplankton productivity in batch culture without sedimentary iron sulfides can be possible only if sulfur compounds are minimal, as is in Shag Rocks (53°S, 42°W) of South Georgia in Scotia Sea in the Southern Ocean.展开更多
Based on the analysis of the failure characteristics and backfilling effect of the compound roof at 1801 backfilling workface in Taiyuan coal mine,China,we propose a method of controlling the presubsidence of a compou...Based on the analysis of the failure characteristics and backfilling effect of the compound roof at 1801 backfilling workface in Taiyuan coal mine,China,we propose a method of controlling the presubsidence of a compound roof by using pre-stressed bolts to improve the backfilling ratio of the workface so as to maintain the global stability of the stope roof.In addition,PHASE simulation software was employed to analyze the influence law of pre-stressing force,length,and interval on roof subsidence at the workface.On the basis of the numerical simulation results,a model for calculating the pre-stressing force and length of the bolts,the interval between the bolts,as well as roof subsidence at the workface,was established by using SPSS regression analysis software.Moreover,the research results were applied successfully to the 1801 filling workface.According to the monitoring data of roof closure,it was found that the final subsidence value for the goaf roof was 350 mm and the filling ratio at the workface was 86%,which could fully meet the demand for safety production at the workface.The safe and effective control of the stope roof was therefore realized,which achieves the goal of safe and efficient backfilling mining under a compound roof.展开更多
The interaction between the high pressure gas and the control fluid and the movement mechanism of the control fluid in compound perforation were studied by a series of large-scale experiments, where the movement behav...The interaction between the high pressure gas and the control fluid and the movement mechanism of the control fluid in compound perforation were studied by a series of large-scale experiments, where the movement behavior of the control fluid was observed. The curves of measured pressure were analyzed, a mathematical model for the rigid movement of the control fluid was established, and the movement velocity of control fluid was analyzed. Moreover, the velocity from experimental results and velocity from an analytical solution were contrasted. The movement of the control fluid in the initial stage was similar to the rigid movement; however, the propagation of the pressure wave in the control fluid should be taken into account. Experimental results are significant for research on the movement mechanism of control fluid in compound perforation.展开更多
An investigation is conducted on optimizing the control allocation for trimmed flight on the compound helicopter.The compound helicopter features a single main rotor,a vectored thrust ducted propeller(VTDP)and lifting...An investigation is conducted on optimizing the control allocation for trimmed flight on the compound helicopter.The compound helicopter features a single main rotor,a vectored thrust ducted propeller(VTDP)and lifting wings.Due to the redundant controls for thrust,elevator deflection,and differential and symmetric flap deflection,there is a wide range of trim solutions in forward flight for compound helicopter.A method is developed to calculate optimal trim solutions.Firstly,aerodynamics models for deferent subsystems of the compound helicopter are conducted,which consider the mutual interaction of each part.Secondly,a flight dynamics model is developed based on which the method of trim optimization is performed.Finally,the method is demonstrated using a compound helicopter UH 60L/VTDP.The trim optimization of flight conditions from hover to 370 km/h is conducted using the optimization method.The controls,fuselage attitudes as well as the allocation of lift and thrust along with the flight speed are obtained.展开更多
To weaken the nonlinear coupling influence among the variables in the speed and tension system of reversible cold strip mill, a compound control(CC) strategy based on invariance principle was proposed. Firstly, invari...To weaken the nonlinear coupling influence among the variables in the speed and tension system of reversible cold strip mill, a compound control(CC) strategy based on invariance principle was proposed. Firstly, invariance principle was used to realize static decoupling between the speed and tension of reversible cold strip mill. Then, considering the influence caused by the time variation of steel coil radius and rotational inertia of the left and right coilers, as well as the uncertainties, a CC strategy that is composed of extended state observer(ESO) and global sliding mode control(GSMC) with backstepping adaptive was proposed,which further realized dynamic decoupling and coordination control for the speed and tension system. Theoretical analysis shows that the resulting closed-loop system is global bounded stable. Finally, the simulation was carried out on the speed and tension system of a 1422 mm reversible cold strip mill by using the actual data, and through the comparison of the other control strategies, validity of the proposed CC strategy was shown by the results.展开更多
[Objectives]This study was conducted to screen high-efficiency compound formulations and precise application technologies for the prevention and control of sugarcane brown rust. [Methods] Zineb, dinconazole, mancozeb,...[Objectives]This study was conducted to screen high-efficiency compound formulations and precise application technologies for the prevention and control of sugarcane brown rust. [Methods] Zineb, dinconazole, mancozeb, azoxystrobin, pyraclostrobin, difenoconazole·azoxystrobin, chlorothalonil and carbendazim were selected for field efficacy tests. [Results] Four formulations,(65% zineb WP 1 500 g+75% chlorothalonil WP 1 500 g+potassium dihydrogen phosphate 2 400 g+agricultural synergist 300 ml)/hm^(2),(12.5% dinconazole WP 1 500 g +75% chlorothalonil WP 1 500 g+potassium dihydrogen phosphate 2 400 g+agricultural synergist 300 ml)/hm^(2),(80% mancozeb WP 1 500 g+75% chlorothalonil WP 1 500 g+potassium dihydrogen phosphate 2 400 g+agricultural synergist 300 ml)/hm^(2) and(30% difenoconazole·azoxystrobin SC 900 ml+potassium dihydrogen phosphate 2 400 g+agricultural synergist 300 ml) had good control efficacy on sugarcane brown rust, and showed disease indexes all below 18.79 and control efficacy over 80.53%. The four formulations are ideal high-efficiency compound formulations for the prevention and control of sugarcane brown rust. They can be sprayed manually and by unmanned aerial vehicles on the foliar surface from July to August, once every 7 to 10 d, continuously for 2 times. [Conclusions] This study provides new technical support for accurate and efficient prevention and control of sugarcane rust.展开更多
[Objectives]This study was conducted to screen high-efficiency compound formulations and precise application technologies for the prevention and control of sugarcane brown stripe disease.[Methods]Carbendazim,benomyl,c...[Objectives]This study was conducted to screen high-efficiency compound formulations and precise application technologies for the prevention and control of sugarcane brown stripe disease.[Methods]Carbendazim,benomyl,chlorothalonil,azoxystrobin,pyraclostrobine and difenoconazole·azoxystrobin were selected for field efficacy tests.[Results]Three formulations,(50%carbendazim WP 1500 g+75%chlorothalonil WP 1500 g+potassium dihydrogen phosphate 2400 g+agricultural synergist 300 ml)/hm^(2),(50%benomyl WP 1500 g+75%chlorothalonil WP 1500 g+potassium dihydrogen phosphate 2400 g+agricultural synergist 300 ml)/hm^(2) and(25%pyraclostrobin 600 ml+potassium dihydrogen phosphate 2400 g+agricultural synergist 300 ml)/hm^(2) had good control effects on sugarcane brown stripe disease,and showed disease index below 14.02 and control efficacy above 84.41%.The three formulations are ideal high-efficiency compound formulations for the prevention and control of sugarcane brown stripe disease.They can be sprayed manually and by unmanned aerial vehicles on the foliar surface from July to August,once every 7 to 10 d,continuously for 2 times.[Conclusions]This study provides new technical support for accurate and efficient prevention and control of sugarcane brown stripe disease.展开更多
Objective: This study aims to systematically evaluate the efficacy and safety of compound kushen injection (CKI) in combination with chemotherapy in patients with gastric cancer (GC). Methods: A comprehensive electron...Objective: This study aims to systematically evaluate the efficacy and safety of compound kushen injection (CKI) in combination with chemotherapy in patients with gastric cancer (GC). Methods: A comprehensive electronic search was conducted by searching PubMed, EMBASE, Cochrane Library, Chinese Biological Medical disc, China National Knowledge Infrastructure and Wanfang databases (the last update January 20, 2018). All randomized controlled trials (RCTs) of CKI plus chemotherapy versus chemotherapy alone in GC patients were identified. The quality of each study was evaluated using the Jadad’s scale, and the meta-analysis was performed using Review Manager 5.3 and STATA 14 software. Results: A total of nine studies on 688 cases were included in this study. The results showed that CKI combined with chemotherapy had a better effect on improving patients’ overall response rate (ORR) and life quality. The consequences of Egger’s and Begg’s tests showed there was no significant publication bias. Conclusion: The current evidence showed that CKI may enhance the clinical efficacy of chemotherapy, improve the quality of life and increase the safety in patients with gastric cancer.展开更多
Objective:To establish the quality standard of Compound Shanzha Granules.Methods:Crataegi Fructus and Cassiae Semen were identified by TLC.The contents of Autrantio-obtusin and Chrysophanol in Cassiae Semen were deter...Objective:To establish the quality standard of Compound Shanzha Granules.Methods:Crataegi Fructus and Cassiae Semen were identified by TLC.The contents of Autrantio-obtusin and Chrysophanol in Cassiae Semen were determined by HPLC.Results:The relevant spots on TLC plates were clear by the blank reference.The contents showed good linearitis in the range of 0.0357~0.3570μg for Autrantio-obtusin and 0.0520~0.5200μg for Chrysophanol.Conclusions:The method are simple,accurate and reproducible.展开更多
Objective:To evaluate the efficacy and safety of different Chinese herbal compounds combined with Entecavir in the treatment of hepatitis B cirrhosis during the compensatory period by using mesh meta-analysis.Methods:...Objective:To evaluate the efficacy and safety of different Chinese herbal compounds combined with Entecavir in the treatment of hepatitis B cirrhosis during the compensatory period by using mesh meta-analysis.Methods:PubMed,CNKI,Wanfang and VIP databases were searched by computer,and the retrieval time was from the establishment of each database to October 5,2022.According to inclusion and exclusion criteria,literature search was conducted independently by two researchers.RevMan5.4.1 software provided by Cochrane was used for evaluation,and Stata16.0 software was used for statistical analysis.Results:A total of 34 RCTs were included,involving 16 TCM compounds and 1543 patients.The results of network meta-analysis showed that ALT indexes of liver function were listed as Yiqi Jiedu Tongluo Method>Luoshugan Tablet>Anluo Huaxian Wan>Qishenrugan Capsule>Qingganhuaji Decoction>Ganshuang Granules>Compound Biejia Rugan Tablet>Rougan Sanjie Decoction>Shugan Jianpi Decoction>Shenqi Fuzheng Huayu Decoction>Peituhua Decoction>Shugan Jianpi Huoxu prescription>Rhubarb Zhezhan Capsule combined with Entecavir treatment respectively;The order of HA index of liver fibrosis was Heluo Shugan Tablet>Shugan Jianpi Huoxui prescription>Anluo Huaxian Wan>Compound Biejia Ruangan Tablet>Rougan Sanjie Decoction>Ganshuang Granules>Danji Huoxui Decoction>Yiqi Jiedu Tongluo Method>Rhubarb Zhezhe Capsule>Fuzheng Huayu Table>Shugan Jianpi Decoction>Rougan Huayu Decoction>Peitu Huayu Decoction>Qingganhuaji Prescription>Shenqi Fuzheng Huayu prescription combined with Entecavir respectively;In order of adverse reactions from best to worst,Shuganjianpi Decoction,Qishenrugangan Capsule,Ganshuang Granules,Peituhuazhi Decoction,compound Biejiruganpian,and He Shugan Pian combined with entecavir,respectively;The effective rate of treatment was listed as Ganshuang Granules>Compound Biejia Ruangan Tablets>uoshugan Tablets>Rougansanjie Decoction>Rhubarb Zhezhe Capsules>Yiqi Jiedu Tongluo Method>Qingganhuaji prescription>Anluo Huaxia Wan>Shugan Jianpi Decoction>Fuzheng Huayu tablets>Peituhuazhi Decoction>Shenqi Fuzheng Huayu prescription combined with Entecavir respectively.Conclusion:Entecavir combined with supplementing qi and detoxifying and dredging collages is the best method to recover ALT index of liver function during the compensation period for hepatitis B cirrhosis;Entecavir combination and Luoshugan tablet were the best treatment for HA index of hepatic fibrosis;Entecavir combined with Shuganjianpi Decoction was the best treatment for adverse reactions;The best treatment efficiency was Entecavir combined with Ganshuang granules.展开更多
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supported by the National Natural Science Foundation of China(Nos.11072061 and 11372073)the Natural Science Foundation of Fujian Province(No.2010J01003)
文摘The impact dynamics, impact effect, and post-impact unstable motion sup- pression of free-floating space manipulator capturing a satellite on orbit are analyzed. Firstly, the dynamics equation of free-floating space manipulator is derived using the sec- ond Lagrangian equation. Combining the momentum conservation principle, the impact dynamics and effect between the space manipulator end-effector and satellite of the cap- ture process are analyzed with the momentum impulse method. Focusing on the unstable motion of space manipulator due to the above impact effect, a robust adaptive compound control algorithm is designed to suppress the above unstable motion. There is no need to control the free-floating base position to save the jet fuel. Finally, the simulation is proposed to show the impact effect and verify the validity of the control algorithm.
基金supported by the National Natural Science Foundation of China(11572036)
文摘A robust controller for bank to turn(BTT) missiles with aerodynamic fins and reaction jet control system(RCS) is developed based on nonlinear control dynamic models comprising couplings and aerodynamic uncertainties. The fixed time convergence theory is incorporated with the sliding mode control technique to ensure that the system tracks the desired command within uniform bounded time under different initial conditions. Unlike previous terminal sliding mode approaches, the bound of settling time is independent of the initial state, which means performance metrics like convergence rate can be predicted beforehand. To reduce the burden of control design in terms of robustness, extended state observer(ESO) is introduced for uncertainty estimation with the output substituted into the controller as feedforward compensation. Cascade control structure is employed with the proposed control law and therein the compound control signal is obtained.Afterwards, control inputs for two kinds of actuators are allocated on the basis of their inherent characteristics. Finally, a number of simulations are carried out and demonstrate the effectiveness of the designed controller.
文摘To solve the control allocation problem of dual aero/jet vane control missile, dynamics e- quations in longitudinal plane are derived, and the structure of compound control loop is designed based on attitude autopilot. Four brief compound control allocation strategies are researched and an- alyzed. Furthermore, a new strategy called chain combination variable proportional coefficient strat- egy based on rudder effect is presented. By simulation of initial climb trajectory, the characteristics of all the strategies are researched, and the results illustrate that the new strategy can meet the re- quirement well.
基金This project is supported by National Natural Science Foundation of China (No.50475105).
文摘Based on the pressure regulation circuit adopting electro-hydraulic proportional relief valve to control tension, a new type of electro-hydraulic compound control circuit with throttle control unit is presented, which can obtain optimal dynamic damping ratio through real-time altering pressure-flow gain of the throttle control unit, improve the dynamic characteristic of tension follow-up control for the tension system with high inertia loads. Moreover, the characteristic when the cable linear velocity variation causes change of tension is investigated, and a compound control strategy is proposed. The theoretical analysis and experimental results show that the electro-hydraulic compound control circuit is effective and the characteristic of the compound control strategy is satisfactory.
基金Supported by National Natural Science Foundation of China (Grant No. 51505178)China Postdoctoral Science Foundation (Grant No. 2014M561289)。
文摘Electric load simulator(ELS) systems are employed for electric power steering(EPS) test benches to load rack force by precise control. Precise ELS control is strongly influenced by nonlinear factors. When the steering motor rapidly rotates, extra force is directly superimposed on the original static loading error, which becomes one of the main sources of the final error. It is key to achieve ELS precise loading control for the entire EPS test bench. Therefore, a three-part compound control algorithm is proposed to improve the loading accuracy. First, a fuzzy proportional–integral plus feedforward controller with force feedback is presented. Second, a friction compensation algorithm is established to reduce the influence of friction. Then, the relationships between each quantity and the extra force are analyzed when the steering motor rapidly rotates, and a net torque feedforward compensation algorithm is proposed to eliminate the extra force. The compound control algorithm was verified through simulations and experiments. The results show that the tracking performance of the compound control algorithm satisfies the demands of engineering practice, and the extra force in the ELS system can be suppressed by the net torque corresponding to the actuator’s acceleration.
文摘The present study investigated quantitatively the significance of HNLC (high-nutrient low-chlorophyll) regions and its grazing control with the improved iron fertilization for climate change. The limitation of iron (Fe) for phytoplankton growth in HNLC regions was confirmed by sulfur compounds (S) such as volcanic ash and hydrogen sulfide (H2S) in batch cultures, whose chemical sediment of Fe3S4 showed 4.06 wt%. The technologies developed for iron fertilization since 1993 till now were not practical to provide sufficient amounts of bioavailable iron due to sedimentary iron sulfides induced by undersea volcanic sulfur compounds. The proposed technology for iron fertilization was improved to enhance the bioavailable iron to phytoplankton by keeping minimal sulfur compounds in HNLC regions. The low productivity of phytoplankton by grazing control in HNLC regions was 6% diatoms whose 52% was grazed by copepods and 42% by krill on the basis of data analysis in 2000 EisenEx Experiment at boundary of Antarctic and African tectonic plates. All of the previous iron fertilization experiments were conducted at volcanic sulfur compounds enriched HNLC regions. The present study revealed that the enhanced phytoplankton productivity in batch culture without sedimentary iron sulfides can be possible only if sulfur compounds are minimal, as is in Shag Rocks (53°S, 42°W) of South Georgia in Scotia Sea in the Southern Ocean.
基金the Qinglan Project,the National Key Basic Research Program of China (No.2013CB227905)the Science Fund for Creative Research Groups of the National Natural Science Foundation of China (No.51421003)
文摘Based on the analysis of the failure characteristics and backfilling effect of the compound roof at 1801 backfilling workface in Taiyuan coal mine,China,we propose a method of controlling the presubsidence of a compound roof by using pre-stressed bolts to improve the backfilling ratio of the workface so as to maintain the global stability of the stope roof.In addition,PHASE simulation software was employed to analyze the influence law of pre-stressing force,length,and interval on roof subsidence at the workface.On the basis of the numerical simulation results,a model for calculating the pre-stressing force and length of the bolts,the interval between the bolts,as well as roof subsidence at the workface,was established by using SPSS regression analysis software.Moreover,the research results were applied successfully to the 1801 filling workface.According to the monitoring data of roof closure,it was found that the final subsidence value for the goaf roof was 350 mm and the filling ratio at the workface was 86%,which could fully meet the demand for safety production at the workface.The safe and effective control of the stope roof was therefore realized,which achieves the goal of safe and efficient backfilling mining under a compound roof.
文摘The interaction between the high pressure gas and the control fluid and the movement mechanism of the control fluid in compound perforation were studied by a series of large-scale experiments, where the movement behavior of the control fluid was observed. The curves of measured pressure were analyzed, a mathematical model for the rigid movement of the control fluid was established, and the movement velocity of control fluid was analyzed. Moreover, the velocity from experimental results and velocity from an analytical solution were contrasted. The movement of the control fluid in the initial stage was similar to the rigid movement; however, the propagation of the pressure wave in the control fluid should be taken into account. Experimental results are significant for research on the movement mechanism of control fluid in compound perforation.
基金supported by the National Natural Science Foundation of China(No.51505216)
文摘An investigation is conducted on optimizing the control allocation for trimmed flight on the compound helicopter.The compound helicopter features a single main rotor,a vectored thrust ducted propeller(VTDP)and lifting wings.Due to the redundant controls for thrust,elevator deflection,and differential and symmetric flap deflection,there is a wide range of trim solutions in forward flight for compound helicopter.A method is developed to calculate optimal trim solutions.Firstly,aerodynamics models for deferent subsystems of the compound helicopter are conducted,which consider the mutual interaction of each part.Secondly,a flight dynamics model is developed based on which the method of trim optimization is performed.Finally,the method is demonstrated using a compound helicopter UH 60L/VTDP.The trim optimization of flight conditions from hover to 370 km/h is conducted using the optimization method.The controls,fuselage attitudes as well as the allocation of lift and thrust along with the flight speed are obtained.
基金Project(61074099)supported by the National Natural Science Foundation of ChinaProject(LJRC013)supported by Cultivation Program for Leading Talent of Innovation Team in Colleges and Universities of Hebei Province,ChinaProject(B705)supported by Doctor Foundation of Yanshan University,China
文摘To weaken the nonlinear coupling influence among the variables in the speed and tension system of reversible cold strip mill, a compound control(CC) strategy based on invariance principle was proposed. Firstly, invariance principle was used to realize static decoupling between the speed and tension of reversible cold strip mill. Then, considering the influence caused by the time variation of steel coil radius and rotational inertia of the left and right coilers, as well as the uncertainties, a CC strategy that is composed of extended state observer(ESO) and global sliding mode control(GSMC) with backstepping adaptive was proposed,which further realized dynamic decoupling and coordination control for the speed and tension system. Theoretical analysis shows that the resulting closed-loop system is global bounded stable. Finally, the simulation was carried out on the speed and tension system of a 1422 mm reversible cold strip mill by using the actual data, and through the comparison of the other control strategies, validity of the proposed CC strategy was shown by the results.
基金Supported by China Agriculture Research System of MOF and MARA (CARS-170303)Yunling Industrial Technology Leading Talent Training Project(2018LJRC56)+1 种基金Special Fund for the Construction of Modern Agricultural Industry Technology System in Yunnan ProvinceNanhua Research and Development Institution-Enterprise Cooperation Project。
文摘[Objectives]This study was conducted to screen high-efficiency compound formulations and precise application technologies for the prevention and control of sugarcane brown rust. [Methods] Zineb, dinconazole, mancozeb, azoxystrobin, pyraclostrobin, difenoconazole·azoxystrobin, chlorothalonil and carbendazim were selected for field efficacy tests. [Results] Four formulations,(65% zineb WP 1 500 g+75% chlorothalonil WP 1 500 g+potassium dihydrogen phosphate 2 400 g+agricultural synergist 300 ml)/hm^(2),(12.5% dinconazole WP 1 500 g +75% chlorothalonil WP 1 500 g+potassium dihydrogen phosphate 2 400 g+agricultural synergist 300 ml)/hm^(2),(80% mancozeb WP 1 500 g+75% chlorothalonil WP 1 500 g+potassium dihydrogen phosphate 2 400 g+agricultural synergist 300 ml)/hm^(2) and(30% difenoconazole·azoxystrobin SC 900 ml+potassium dihydrogen phosphate 2 400 g+agricultural synergist 300 ml) had good control efficacy on sugarcane brown rust, and showed disease indexes all below 18.79 and control efficacy over 80.53%. The four formulations are ideal high-efficiency compound formulations for the prevention and control of sugarcane brown rust. They can be sprayed manually and by unmanned aerial vehicles on the foliar surface from July to August, once every 7 to 10 d, continuously for 2 times. [Conclusions] This study provides new technical support for accurate and efficient prevention and control of sugarcane rust.
基金Supported by China Agriculture Research System of MOF and MARA(CARS-170303)Yunling Industrial Technology Leading Talent Training Project(2018LJRC56)+1 种基金Special Fund for the Construction of Modern Agricultural Industry Technology System in Yunnan ProvinceNanhua Research and Development Institution-Enterprise Cooperation Project of Nanhua City。
文摘[Objectives]This study was conducted to screen high-efficiency compound formulations and precise application technologies for the prevention and control of sugarcane brown stripe disease.[Methods]Carbendazim,benomyl,chlorothalonil,azoxystrobin,pyraclostrobine and difenoconazole·azoxystrobin were selected for field efficacy tests.[Results]Three formulations,(50%carbendazim WP 1500 g+75%chlorothalonil WP 1500 g+potassium dihydrogen phosphate 2400 g+agricultural synergist 300 ml)/hm^(2),(50%benomyl WP 1500 g+75%chlorothalonil WP 1500 g+potassium dihydrogen phosphate 2400 g+agricultural synergist 300 ml)/hm^(2) and(25%pyraclostrobin 600 ml+potassium dihydrogen phosphate 2400 g+agricultural synergist 300 ml)/hm^(2) had good control effects on sugarcane brown stripe disease,and showed disease index below 14.02 and control efficacy above 84.41%.The three formulations are ideal high-efficiency compound formulations for the prevention and control of sugarcane brown stripe disease.They can be sprayed manually and by unmanned aerial vehicles on the foliar surface from July to August,once every 7 to 10 d,continuously for 2 times.[Conclusions]This study provides new technical support for accurate and efficient prevention and control of sugarcane brown stripe disease.
文摘Objective: This study aims to systematically evaluate the efficacy and safety of compound kushen injection (CKI) in combination with chemotherapy in patients with gastric cancer (GC). Methods: A comprehensive electronic search was conducted by searching PubMed, EMBASE, Cochrane Library, Chinese Biological Medical disc, China National Knowledge Infrastructure and Wanfang databases (the last update January 20, 2018). All randomized controlled trials (RCTs) of CKI plus chemotherapy versus chemotherapy alone in GC patients were identified. The quality of each study was evaluated using the Jadad’s scale, and the meta-analysis was performed using Review Manager 5.3 and STATA 14 software. Results: A total of nine studies on 688 cases were included in this study. The results showed that CKI combined with chemotherapy had a better effect on improving patients’ overall response rate (ORR) and life quality. The consequences of Egger’s and Begg’s tests showed there was no significant publication bias. Conclusion: The current evidence showed that CKI may enhance the clinical efficacy of chemotherapy, improve the quality of life and increase the safety in patients with gastric cancer.
文摘Objective:To establish the quality standard of Compound Shanzha Granules.Methods:Crataegi Fructus and Cassiae Semen were identified by TLC.The contents of Autrantio-obtusin and Chrysophanol in Cassiae Semen were determined by HPLC.Results:The relevant spots on TLC plates were clear by the blank reference.The contents showed good linearitis in the range of 0.0357~0.3570μg for Autrantio-obtusin and 0.0520~0.5200μg for Chrysophanol.Conclusions:The method are simple,accurate and reproducible.
基金National Natural Science Foundation Project(82204755,81960751,81960761)Guangxi Natural Science Foundation Youth Fund Project(2020GXNSFBA297094)+2 种基金Guangxi young and middle-aged teachers basic ability improvement project(2022KY1667)Guangxi University of Traditional Chinese Medicine Sainz New School of Medicine research project(2022MS008,2022QJ001)Innovation and Entrepreneurship Training Program for College Students of Guangxi University of Traditional Chinese Medicine(National Level),Project Number:202213643002.
文摘Objective:To evaluate the efficacy and safety of different Chinese herbal compounds combined with Entecavir in the treatment of hepatitis B cirrhosis during the compensatory period by using mesh meta-analysis.Methods:PubMed,CNKI,Wanfang and VIP databases were searched by computer,and the retrieval time was from the establishment of each database to October 5,2022.According to inclusion and exclusion criteria,literature search was conducted independently by two researchers.RevMan5.4.1 software provided by Cochrane was used for evaluation,and Stata16.0 software was used for statistical analysis.Results:A total of 34 RCTs were included,involving 16 TCM compounds and 1543 patients.The results of network meta-analysis showed that ALT indexes of liver function were listed as Yiqi Jiedu Tongluo Method>Luoshugan Tablet>Anluo Huaxian Wan>Qishenrugan Capsule>Qingganhuaji Decoction>Ganshuang Granules>Compound Biejia Rugan Tablet>Rougan Sanjie Decoction>Shugan Jianpi Decoction>Shenqi Fuzheng Huayu Decoction>Peituhua Decoction>Shugan Jianpi Huoxu prescription>Rhubarb Zhezhan Capsule combined with Entecavir treatment respectively;The order of HA index of liver fibrosis was Heluo Shugan Tablet>Shugan Jianpi Huoxui prescription>Anluo Huaxian Wan>Compound Biejia Ruangan Tablet>Rougan Sanjie Decoction>Ganshuang Granules>Danji Huoxui Decoction>Yiqi Jiedu Tongluo Method>Rhubarb Zhezhe Capsule>Fuzheng Huayu Table>Shugan Jianpi Decoction>Rougan Huayu Decoction>Peitu Huayu Decoction>Qingganhuaji Prescription>Shenqi Fuzheng Huayu prescription combined with Entecavir respectively;In order of adverse reactions from best to worst,Shuganjianpi Decoction,Qishenrugangan Capsule,Ganshuang Granules,Peituhuazhi Decoction,compound Biejiruganpian,and He Shugan Pian combined with entecavir,respectively;The effective rate of treatment was listed as Ganshuang Granules>Compound Biejia Ruangan Tablets>uoshugan Tablets>Rougansanjie Decoction>Rhubarb Zhezhe Capsules>Yiqi Jiedu Tongluo Method>Qingganhuaji prescription>Anluo Huaxia Wan>Shugan Jianpi Decoction>Fuzheng Huayu tablets>Peituhuazhi Decoction>Shenqi Fuzheng Huayu prescription combined with Entecavir respectively.Conclusion:Entecavir combined with supplementing qi and detoxifying and dredging collages is the best method to recover ALT index of liver function during the compensation period for hepatitis B cirrhosis;Entecavir combination and Luoshugan tablet were the best treatment for HA index of hepatic fibrosis;Entecavir combined with Shuganjianpi Decoction was the best treatment for adverse reactions;The best treatment efficiency was Entecavir combined with Ganshuang granules.