To address the impact of wind-power fluctuations on the stability of power systems,we propose a comprehensive approach that integrates multiple strategies and methods to enhance the efficiency and reliability of a sys...To address the impact of wind-power fluctuations on the stability of power systems,we propose a comprehensive approach that integrates multiple strategies and methods to enhance the efficiency and reliability of a system.First,we employ a strategy that restricts long-and short-term power output deviations to smoothen wind power fluctuations in real time.Second,we adopt the sliding window instantaneous complete ensemble empirical mode decomposition with adaptive noise(SW-ICEEMDAN)strategy to achieve real-time decomposition of the energy storage power,facilitating internal power distribution within the hybrid energy storage system.Finally,we introduce a rule-based multi-fuzzy control strategy for the secondary adjustment of the initial power allocation commands for different energy storage components.Through simulation validation,we demonstrate that the proposed comprehensive control strategy can smoothen wind power fluctuations in real time and decompose energy storage power.Compared with traditional empirical mode decomposition(EMD),ensemble empirical mode decomposition(EEMD),and complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN)decomposition strategies,the configuration of the energy storage system under the SW-ICEEMDAN control strategy is more optimal.Additionally,the state-of-charge of energy storage components fluctuates within a reasonable range,enhancing the stability of the power system and ensuring the secure operation of the energy storage system.展开更多
In this paper,guaranteed cost attitude tracking con-trol for uncertain quadrotor unmanned aerial vehicle(QUAV)under safety constraints is studied.First,an augmented system is constructed by the tracking error system a...In this paper,guaranteed cost attitude tracking con-trol for uncertain quadrotor unmanned aerial vehicle(QUAV)under safety constraints is studied.First,an augmented system is constructed by the tracking error system and reference system.This transformation aims to convert the tracking control prob-lem into a stabilization control problem.Then,control barrier function and disturbance attenuation function are designed to characterize the violations of safety constraints and tolerance of uncertain disturbances,and they are incorporated into the reward function as penalty items.Based on the modified reward function,the problem is simplified as the optimal regulation problem of the nominal augmented system,and a new Hamilton-Jacobi-Bellman equation is developed.Finally,critic-only rein-forcement learning algorithm with a concurrent learning tech-nique is employed to solve the Hamilton-Jacobi-Bellman equa-tion and obtain the optimal controller.The proposed algorithm can not only ensure the reward function within an upper bound in the presence of uncertain disturbances,but also enforce safety constraints.The performance of the algorithm is evaluated by the numerical simulation.展开更多
Introduction: Without appropriately trained healthcare workers (HCWs), infection prevention and control (IPC) cannot be implemented according to set standards. Although training is crucial, authorities rarely consider...Introduction: Without appropriately trained healthcare workers (HCWs), infection prevention and control (IPC) cannot be implemented according to set standards. Although training is crucial, authorities rarely consider those working in health facilities owned by the mining. We describe the training which was conducted in North Mara in Mara region mining health facilities. Methods: This was descriptive study on the training of IPC to HCWs of mining health facilities. The training was conducted to North Mara Gold Mine Limited on April 2024. We targeted the HCWs and supporting staff working in the health facilities of the mining communities. The duration of the training was five days. The sessions started with pre-training test to evaluate what participants understood before training and followed with training itself. The training was carried out using mixed adult learning methods like: illustrated lectures, demonstrations, brainstorming, small group activities, group discussions, role plays, case studies and simulations. The training was finalized with posttest. Results: A total of ten HCWs were trained out of 13 of the facility. In that training six were males and four were females. Also, out of the ten trained three were clinicians, four nurses, one lab technician, one pharmaceutical technician, one support staff. The average score of the results of the pretest was 70.7% with a range of 16% (minimum 64% and maximum 80%) and that of the posttest was 79.8% with a range of 12% (min 74% and max 88%). Conclusions: If HCWs are well trained to comply with IPC standards and transmission-based precautions, they have the ability to deliver safe health services and protect themselves, patients, environment and the community. Training of HCWs working at the mining, therefore, can be adapted in all mines to improve the quality of mining healthcare and respond to the need to improve the safety of mining communities.展开更多
Heavy metal pol ution, especial y cadmium pol ution, has threatened the safety production of rice. The research advance on law of absorption, distribution and accumulation of cadmium in rice and on recent safety contr...Heavy metal pol ution, especial y cadmium pol ution, has threatened the safety production of rice. The research advance on law of absorption, distribution and accumulation of cadmium in rice and on recent safety control technology of cadmium in rice grain was summarized in this paper. We hoped to lay a foundation for the safety production of rice.展开更多
As the sources of overt and covert potential safety hazards were widespread, the safety control and management of rural tourism became more complicated and difficult, which required more for technological support of r...As the sources of overt and covert potential safety hazards were widespread, the safety control and management of rural tourism became more complicated and difficult, which required more for technological support of rural tourism safety management. Based on the latitude of technological support, from the perspective of management practice of rural tourism safety, through analysis on inner symbiosis of management and technological support of rural tourism safety, the paper had studied three parts of control and management system of rural tourism safety, which were rural tourism safety identification, rural tourism safety isolation and control, and rural tourism safety treatment and solution; and the connotation of technological support during safety management had been discussed from the three aspects. It hoped to serve as reference for tourism safety management and control, so as to promote healthy, stable and sustainable development of tourism.展开更多
An effective quality control system is the key to ensuring the quality, safety and efficacy of traditional Chinese medicines(TCMs). However, the current quality standard research lacks top-level design and systematic ...An effective quality control system is the key to ensuring the quality, safety and efficacy of traditional Chinese medicines(TCMs). However, the current quality standard research lacks top-level design and systematic design,mostly based on specific technologies or evaluation methods. To resolve the challenges and questions of quality control of TCMs, a brand-new quality standard system, named "iVarious", was proposed. The system comprises eight elements in a modular format. Meaning of every element was specifically illustrated via corresponding research instances. Furthermore, frankincense study was taken as an example for demonstrating standards and research process, based on the "i Various" system. This system highlighted a holistic strategy for effectiveness,security, integrity and systematization of quality and safety control standards of TCMs. The establishment of"i Various" integrates multi-disciplinary technologies and progressive methods, basis elements and key points of standard construction. The system provides a novel idea and technological demonstration for regulation establishment of TCMs quality standards.展开更多
Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures...Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures, these studies have been conducted mainly in terms of qualitative and descriptive analysis. In addition, little attention has been given to family farms. This study addresses the food safety control practices adopted by firms with different governance structures in China. Food safety control is expressed by the following aspects, i.e., pollution-free, green, organic, and/or geographical indication prod- ucts certification, establishment of production records, and pesticide residue testing. Three types of governance structures that engage in agricultural production are distinguished: farmer cooperatives, agricultural companies, and family farms. The food safety control practices of various governance structures are investigated based on a database that comprises 600 vegetable and fruit enterprises in Zhejiang, China. The results show that (1) pesticide residue testing is adopted by the most firms, followed by products certification, and production records are adopted by the fewest firms, and (2) agricul- tural companies adopt more food safety control practices than family farms, while farmer cooperatives adopt the fewest food safety control practices. Governance structure features of a cooperative in terms of ownership, decision-making, and income distribution are the main reasons for the low level of food safety control in the cooperative.展开更多
Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was...Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50~C, and not detected at 54-68~C for 6-24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process.展开更多
The purpose was to define the control efficiency and safety of 20% cy- halofop-butyl WP on grass weeds in direct seeded rice fields, in order to provide the basis for chemical weeding. This study measured Leptochloa c...The purpose was to define the control efficiency and safety of 20% cy- halofop-butyl WP on grass weeds in direct seeded rice fields, in order to provide the basis for chemical weeding. This study measured Leptochloa chinensis(L.) Nees, Echinoch/oa crusgalli (L.) Beauv and other gramineous weed control efficiency with four concentrations of 20% cyhalofop-dutyl WP and 100 g/L cyhalofop-dutyl EC in direct seeded rice fields, and analyzed the yield-increasing effect and safety of rice. The results showed that 20% cyhalofop-butyl WP had a good control efficiency on grass weeds such as Leptochloa chinensis(L.) Nees, Echinoch/oa crusgalli(L.) Beauv and other grasses. The effective dosage of 90-150 g/hm2 was over 90.7% on Lep- foch/oa chinensis(L.) Nees and the comprehensive control effect of the grass weeds was above 86.7%, which was basically consistent with 100 g/L cyhalofop-dutyl EC. Furthermore, 20% cyhalofop-dutyl WP was high security for direct seeded rice fields. The yield of rice was increased by 10.18%-11.22% after spraying herbicide. There- fore, 20% of cyhalofop-dutyl WP can be used as a special herbicide for controlling Leptochloa chinensis(L.) Beauv in direct seeded rice fields, and has a good applica- tion prospect.展开更多
Offshore waters provide resources for human beings,while on the other hand,threaten them because of marine disasters.Ocean stations are part of offshore observation networks,and the quality of their data is of great s...Offshore waters provide resources for human beings,while on the other hand,threaten them because of marine disasters.Ocean stations are part of offshore observation networks,and the quality of their data is of great significance for exploiting and protecting the ocean.We used hourly mean wave height,temperature,and pressure real-time observation data taken in the Xiaomaidao station(in Qingdao,China)from June 1,2017,to May 31,2018,to explore the data quality using eight quality control methods,and to discriminate the most effective method for Xiaomaidao station.After using the eight quality control methods,the percentages of the mean wave height,temperature,and pressure data that passed the tests were 89.6%,88.3%,and 98.6%,respectively.With the marine disaster(wave alarm report)data,the values failed in the test mainly due to the influence of aging observation equipment and missing data transmissions.The mean wave height is often affected by dynamic marine disasters,so the continuity test method is not effective.The correlation test with other related parameters would be more useful for the mean wave height.展开更多
A bench-scale reactor(72 L) red with domestic sewage, was operated more than 3 months with three operation modes: traditional mode, modified mode and real-time control mode, so as to evaluate effects of the operati...A bench-scale reactor(72 L) red with domestic sewage, was operated more than 3 months with three operation modes: traditional mode, modified mode and real-time control mode, so as to evaluate effects of the operation mode on the system performance and to develop a feasible control strategy. Results obtained from fixed-time control study indicate that the variations of the pH and oxidation-reduction potential(ORP) profiles can represent dynamic characteristics of system and the cycle sequences can be controlled and optimized by the control points on the pH and ORP profiles. A control strategy was, therefore, developed and applied to real-time control mode. Compared with traditional mode, the total nitrogen(TN) removal can be increased by approximately 16% in modified mode and a mean TN removal of 92% was achieved in real-time control mode. Moreover, approximately 12.5% aeration energy was saved in real- time control mode. The result of this study shows that the performance of nitrogen removal was enhanced in modified operation mode. Moreover, the real-time control made it possible to optimize process operation and save aeration energy.展开更多
Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is emp...Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is employed to investigate the diff erence in control performance between TLD and TLCD. A series of RTHSs is presented with the premise of the same liquid length, mass ratio, and structural parameters. Herein, TLD and TLCD are physically experimented, and controlled structures are numerically simulated. Then, parametric studies are performed to further evaluate the diff erent performance between TLD and TLCD. Experimental results demonstrate that TLD is more eff ective than TLCD under diff erent amplitude excitations.展开更多
To develop technically feasible and economically favorable dynamic process control(DPC)strategies for an alternating activated sludge(AAS)system,a bench-scale continuous-flow alternating aerobic and anoxic reactor,per...To develop technically feasible and economically favorable dynamic process control(DPC)strategies for an alternating activated sludge(AAS)system,a bench-scale continuous-flow alternating aerobic and anoxic reactor,performing short-cut nitrogen removal from real domestic wastewater was operated under different control strategies for more than five months.A fixed-time control(FTC) study showed that bending-points on pH and oxidation-reduction potential(ORP)profiles accurately coincided with the major biologic...展开更多
Pyropia haitanensis is an economically important mariculture crop in China and has a high research value for several life phenomena, for example environmental tolerance. To explore the mechanisms underlying these char...Pyropia haitanensis is an economically important mariculture crop in China and has a high research value for several life phenomena, for example environmental tolerance. To explore the mechanisms underlying these characteristics, gene expression has been investigated at the whole transcriptome level. Gene expression studies using quantitative real-time PCR should start by selecting an appropriate internal control gene; therefore, the absolute expression abundance of six housekeeping genes (18S rRNA (18S), ubiquitin-conju-ating enzyme (UBC), actin (ACT), β-tubulin (TUB), elongation factors 2 (EF2), and glyceraldehyde-3-phos- phate dehydrogenase (GAPDH) examined by the quantitative real-time PCR in samples corresponding to different strains, life-cycle stages and abiotic stress treatments. Their expression stabilities were assessed by the comparative cycle threshold (Ct) method and by two different software packages: geNorm and NormFinder. The most stable housekeeping gene is UBC and the least stable housekeeping is GADPH. Thus, it is proposed that the most appropriate internal control gene for expression analyses in P. haitanensis is UBC. The results pave the way for further gene expression analyses of different aspects of P. haitanensis biology including different strains, life-history stages and abiotic stress responses.展开更多
A method of combining dynamic simulation with real-time control was proposed to fit the randomness and uncertainty in the high arch dam construction process. The mathematical logic model of high arch dam construction ...A method of combining dynamic simulation with real-time control was proposed to fit the randomness and uncertainty in the high arch dam construction process. The mathematical logic model of high arch dam construction process was established. By combining dynamic construction simulation with schedule analysis, the process of construction schedule forecasting and analysis based on dynamic simulation was studied. The process of real-time schedule control was constructed and some measures for dynamic adjustment and control of construction schedule were provided. A system developed with the method is utilized in a being constructed hydroelectric project located at the Yellow River in northwest China, which can make the pouring plan of the dam in the next stage (a month, quarter or year) to guide the practical construction. The application result shows that the system provides an effective technical support for the construction and management of the dam.展开更多
Transcutaneous auricular vagus nerve stimulation(ta-VNS)is a novel noninvasive treat-ment for stroke that directly stimulates the peripheral auricular branch of the vagus nerve.There have been recent reports that ta-V...Transcutaneous auricular vagus nerve stimulation(ta-VNS)is a novel noninvasive treat-ment for stroke that directly stimulates the peripheral auricular branch of the vagus nerve.There have been recent reports that ta-VNS combined with conventional rehabilitation training promotes the recovery of neurological function of patients with acute stroke.However,these were small-sample-sized studies on the recovery of neurological function in patients after percutaneous vagus nerve stimulation in the subacute and chronic phases after stroke.This double-blinded randomized controlled trial involved 60 acute ischemic or hemorrhagic stroke patients aged 18-80 years who received treatment in the Second Affiliated Hospital of Chongqing Medical University.The subjects were randomly assigned to receive ta-VNS or sham ta-VNS combined with conventional rehabilitation training.The follow-up results over 1 year revealed that ta-VNS combined with conventional rehabilitation training greatly improved the recovery of motor and sensory functions and emotional responses compared with sham ta-VNS combined with conventional rehabilitation training.There were no obvious side effects.These findings suggest that ta-VNS combined with conventional rehabilitation training for the treatment of acute ischemic or hemorrhagic stroke patients is safe and effective.展开更多
Plenty of dams in China are in danger while there are few effective methods for underwater dam inspections of hidden problems such as conduits,cracks and inanitions.The dam safety inspection remotely operated vehicle(...Plenty of dams in China are in danger while there are few effective methods for underwater dam inspections of hidden problems such as conduits,cracks and inanitions.The dam safety inspection remotely operated vehicle(DSIROV) is designed to solve these problems which can be equipped with many advanced sensors such as acoustical,optical and electrical sensors for underwater dam inspection.A least-square parameter estimation method is utilized to estimate the hydrodynamic coefficients of DSIROV,and a four degree-of-freedom(DOF) simulation system is constructed.The architecture of DSIROV's motion control system is introduced,which includes hardware and software structures.The hardware based on PC104 BUS,uses AMD ELAN520 as the controller's embedded CPU and all control modules work in VxWorks real-time operating system.Information flow of the motion system of DSIROV,automatic control of dam scanning and dead-reckoning algorithm for navigation are also discussed.The reliability of DSIROV's control system can be verified and the control system can fulfill the motion control mission because embankment checking can be demonstrated by the lake trials.展开更多
Real-time hybrid simulation is an attractive method to evaluate the response of structures under earthquake loads. The method is a variation of the pseudodynamic testing technique in which the experiment is executed i...Real-time hybrid simulation is an attractive method to evaluate the response of structures under earthquake loads. The method is a variation of the pseudodynamic testing technique in which the experiment is executed in real time, thus allowing investigation of structural systems with rate-dependent components. Real-time hybrid simulation is challenging because it requires performance of all calculations, application of displacements, and acquisition of measured forces, within a very small increment of time. Furthermore, unless appropriate compensation for actuator dynamics is implemented, stability problems are likely to occur during the experiment. This paper presents an approach for real-time hybrid simulation in which compensation for actuator dynamics is implemented using a model-based feedforward compensator. The method is used to evaluate the response of a semi-active control of a structure employing an MR damper. Experimental results show good agreement with the predicted responses, demonstrating the effectiveness of the method for structural control performance assessment.展开更多
With regard to precision/ultra-precision motion systems,it is important to achieve excellent tracking performance for various trajectory tracking tasks even under uncertain external disturbances.In this paper,to overc...With regard to precision/ultra-precision motion systems,it is important to achieve excellent tracking performance for various trajectory tracking tasks even under uncertain external disturbances.In this paper,to overcome the limitation of robustness to trajectory variations and external disturbances in offline feedforward compensation strategies such as iterative learning control(ILC),a novel real-time iterative compensation(RIC)control framework is proposed for precision motion systems without changing the inner closed-loop controller.Specifically,the RIC method can be divided into two parts,i.e.,accurate model prediction and real-time iterative compensation.An accurate prediction model considering lumped disturbances is firstly established to predict tracking errors at future sampling times.In light of predicted errors,a feedforward compensation term is developed to modify the following reference trajectory by real-time iterative calculation.Both the prediction and compen-sation processes are finished in a real-time motion control sampling period.The stability and convergence of the entire control system after real-time iterative compensation is analyzed for different conditions.Various simulation results consistently demonstrate that the proposed RIC framework possesses satisfactory dynamic regulation capability,which contributes to high tracking accuracy comparable to ILC or even better and strong robustness.展开更多
In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign met...In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethemet, system architecture, time characteristic parameters of control-loop ere, a performance analysis model for real-time Ethemet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51677058)。
文摘To address the impact of wind-power fluctuations on the stability of power systems,we propose a comprehensive approach that integrates multiple strategies and methods to enhance the efficiency and reliability of a system.First,we employ a strategy that restricts long-and short-term power output deviations to smoothen wind power fluctuations in real time.Second,we adopt the sliding window instantaneous complete ensemble empirical mode decomposition with adaptive noise(SW-ICEEMDAN)strategy to achieve real-time decomposition of the energy storage power,facilitating internal power distribution within the hybrid energy storage system.Finally,we introduce a rule-based multi-fuzzy control strategy for the secondary adjustment of the initial power allocation commands for different energy storage components.Through simulation validation,we demonstrate that the proposed comprehensive control strategy can smoothen wind power fluctuations in real time and decompose energy storage power.Compared with traditional empirical mode decomposition(EMD),ensemble empirical mode decomposition(EEMD),and complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN)decomposition strategies,the configuration of the energy storage system under the SW-ICEEMDAN control strategy is more optimal.Additionally,the state-of-charge of energy storage components fluctuates within a reasonable range,enhancing the stability of the power system and ensuring the secure operation of the energy storage system.
基金supported in part by the National Science Foundation of China(62173183)。
文摘In this paper,guaranteed cost attitude tracking con-trol for uncertain quadrotor unmanned aerial vehicle(QUAV)under safety constraints is studied.First,an augmented system is constructed by the tracking error system and reference system.This transformation aims to convert the tracking control prob-lem into a stabilization control problem.Then,control barrier function and disturbance attenuation function are designed to characterize the violations of safety constraints and tolerance of uncertain disturbances,and they are incorporated into the reward function as penalty items.Based on the modified reward function,the problem is simplified as the optimal regulation problem of the nominal augmented system,and a new Hamilton-Jacobi-Bellman equation is developed.Finally,critic-only rein-forcement learning algorithm with a concurrent learning tech-nique is employed to solve the Hamilton-Jacobi-Bellman equa-tion and obtain the optimal controller.The proposed algorithm can not only ensure the reward function within an upper bound in the presence of uncertain disturbances,but also enforce safety constraints.The performance of the algorithm is evaluated by the numerical simulation.
文摘Introduction: Without appropriately trained healthcare workers (HCWs), infection prevention and control (IPC) cannot be implemented according to set standards. Although training is crucial, authorities rarely consider those working in health facilities owned by the mining. We describe the training which was conducted in North Mara in Mara region mining health facilities. Methods: This was descriptive study on the training of IPC to HCWs of mining health facilities. The training was conducted to North Mara Gold Mine Limited on April 2024. We targeted the HCWs and supporting staff working in the health facilities of the mining communities. The duration of the training was five days. The sessions started with pre-training test to evaluate what participants understood before training and followed with training itself. The training was carried out using mixed adult learning methods like: illustrated lectures, demonstrations, brainstorming, small group activities, group discussions, role plays, case studies and simulations. The training was finalized with posttest. Results: A total of ten HCWs were trained out of 13 of the facility. In that training six were males and four were females. Also, out of the ten trained three were clinicians, four nurses, one lab technician, one pharmaceutical technician, one support staff. The average score of the results of the pretest was 70.7% with a range of 16% (minimum 64% and maximum 80%) and that of the posttest was 79.8% with a range of 12% (min 74% and max 88%). Conclusions: If HCWs are well trained to comply with IPC standards and transmission-based precautions, they have the ability to deliver safe health services and protect themselves, patients, environment and the community. Training of HCWs working at the mining, therefore, can be adapted in all mines to improve the quality of mining healthcare and respond to the need to improve the safety of mining communities.
基金Supported by the Twelfth Five-Year National Science and Technology Support Project(2012BAK17B03)National Nature Science Foundation of China(31401356)+1 种基金College Students’ Science and Technology Innovation Activities Project Plan(New Talent Plan) in Zhejiang Province(2013R409036)National College Students’ Innovative Entrepreneurial Training Program~~
文摘Heavy metal pol ution, especial y cadmium pol ution, has threatened the safety production of rice. The research advance on law of absorption, distribution and accumulation of cadmium in rice and on recent safety control technology of cadmium in rice grain was summarized in this paper. We hoped to lay a foundation for the safety production of rice.
基金Supported by Foundation Item of Natural Science of Fujian Province(2010J05149)Project of Minjiang College(YSY09001B)~~
文摘As the sources of overt and covert potential safety hazards were widespread, the safety control and management of rural tourism became more complicated and difficult, which required more for technological support of rural tourism safety management. Based on the latitude of technological support, from the perspective of management practice of rural tourism safety, through analysis on inner symbiosis of management and technological support of rural tourism safety, the paper had studied three parts of control and management system of rural tourism safety, which were rural tourism safety identification, rural tourism safety isolation and control, and rural tourism safety treatment and solution; and the connotation of technological support during safety management had been discussed from the three aspects. It hoped to serve as reference for tourism safety management and control, so as to promote healthy, stable and sustainable development of tourism.
基金financial support from National Major Scientific and Technological Special Project for "Significant New Drugs Development" (2014ZX09304307-002)Youth Development Research Foundation of NIFDC (2013WA8)the National Natural Foundation of China (81303214)
文摘An effective quality control system is the key to ensuring the quality, safety and efficacy of traditional Chinese medicines(TCMs). However, the current quality standard research lacks top-level design and systematic design,mostly based on specific technologies or evaluation methods. To resolve the challenges and questions of quality control of TCMs, a brand-new quality standard system, named "iVarious", was proposed. The system comprises eight elements in a modular format. Meaning of every element was specifically illustrated via corresponding research instances. Furthermore, frankincense study was taken as an example for demonstrating standards and research process, based on the "i Various" system. This system highlighted a holistic strategy for effectiveness,security, integrity and systematization of quality and safety control standards of TCMs. The establishment of"i Various" integrates multi-disciplinary technologies and progressive methods, basis elements and key points of standard construction. The system provides a novel idea and technological demonstration for regulation establishment of TCMs quality standards.
基金supported by the National Social Science Fund of China (13AZD079)the Zhejiang Provincial Natural Science Foundation of China (LQ14G030041 and LZ12G03003)the National Natural Science Foundation of China (71333011 and 71273234)
文摘Food safety issues constitute an international topic discussed by many scholars. Although there is an extensive body of literature on comparisons of food safety control practices across different governance structures, these studies have been conducted mainly in terms of qualitative and descriptive analysis. In addition, little attention has been given to family farms. This study addresses the food safety control practices adopted by firms with different governance structures in China. Food safety control is expressed by the following aspects, i.e., pollution-free, green, organic, and/or geographical indication prod- ucts certification, establishment of production records, and pesticide residue testing. Three types of governance structures that engage in agricultural production are distinguished: farmer cooperatives, agricultural companies, and family farms. The food safety control practices of various governance structures are investigated based on a database that comprises 600 vegetable and fruit enterprises in Zhejiang, China. The results show that (1) pesticide residue testing is adopted by the most firms, followed by products certification, and production records are adopted by the fewest firms, and (2) agricul- tural companies adopt more food safety control practices than family farms, while farmer cooperatives adopt the fewest food safety control practices. Governance structure features of a cooperative in terms of ownership, decision-making, and income distribution are the main reasons for the low level of food safety control in the cooperative.
文摘Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung. In order to sterilize the pathogenic bacteria completely in compost material, the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined. The results indicated, pathogenic indicator bacteria such as coliform bacteria, fecal coliform, Escherichia coli and salmonella were all 106 cfu/g dw at the beginning, died rapidly when cow dung temperature rose to above 50~C, and not detected at 54-68~C for 6-24 h heat treatment. Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination. Moreover, it was hardly influenced on the fermentation ability of composting microbe, organic decomposition bacteria. During heat treatment, the mesophile decreased rapidly and the thermophile stabilized or increased, and the most of composting microbe were bacillus in cow dung by fluorescence microscope, this indicated that bacillus was dominator and composting microbe in composting process.
基金Supported by Natural Science Foundation of Hunan Province(12JJ6026)Innovation Platform in Higher Educational Institutions of Hunan Province(14K053)Hunan Province Higher Educational Institutions Industrialization Program(13CY030)~~
文摘The purpose was to define the control efficiency and safety of 20% cy- halofop-butyl WP on grass weeds in direct seeded rice fields, in order to provide the basis for chemical weeding. This study measured Leptochloa chinensis(L.) Nees, Echinoch/oa crusgalli (L.) Beauv and other gramineous weed control efficiency with four concentrations of 20% cyhalofop-dutyl WP and 100 g/L cyhalofop-dutyl EC in direct seeded rice fields, and analyzed the yield-increasing effect and safety of rice. The results showed that 20% cyhalofop-butyl WP had a good control efficiency on grass weeds such as Leptochloa chinensis(L.) Nees, Echinoch/oa crusgalli(L.) Beauv and other grasses. The effective dosage of 90-150 g/hm2 was over 90.7% on Lep- foch/oa chinensis(L.) Nees and the comprehensive control effect of the grass weeds was above 86.7%, which was basically consistent with 100 g/L cyhalofop-dutyl EC. Furthermore, 20% cyhalofop-dutyl WP was high security for direct seeded rice fields. The yield of rice was increased by 10.18%-11.22% after spraying herbicide. There- fore, 20% of cyhalofop-dutyl WP can be used as a special herbicide for controlling Leptochloa chinensis(L.) Beauv in direct seeded rice fields, and has a good applica- tion prospect.
基金Supported by the National Key Research and Development Program of China(Nos.2016YFC1402000,2018YFC1407003,2017YFC1405300)
文摘Offshore waters provide resources for human beings,while on the other hand,threaten them because of marine disasters.Ocean stations are part of offshore observation networks,and the quality of their data is of great significance for exploiting and protecting the ocean.We used hourly mean wave height,temperature,and pressure real-time observation data taken in the Xiaomaidao station(in Qingdao,China)from June 1,2017,to May 31,2018,to explore the data quality using eight quality control methods,and to discriminate the most effective method for Xiaomaidao station.After using the eight quality control methods,the percentages of the mean wave height,temperature,and pressure data that passed the tests were 89.6%,88.3%,and 98.6%,respectively.With the marine disaster(wave alarm report)data,the values failed in the test mainly due to the influence of aging observation equipment and missing data transmissions.The mean wave height is often affected by dynamic marine disasters,so the continuity test method is not effective.The correlation test with other related parameters would be more useful for the mean wave height.
基金The Project of Beijing Science and Technology Committee (No.020620010120) ,the Hi_Tech Research and Development Program(863) of China (No.2004AA601020) ,the Project under Key International Cooperative Programs of NSFC(No.50521140075) and the Project of Key Laboratory of Beiing
文摘A bench-scale reactor(72 L) red with domestic sewage, was operated more than 3 months with three operation modes: traditional mode, modified mode and real-time control mode, so as to evaluate effects of the operation mode on the system performance and to develop a feasible control strategy. Results obtained from fixed-time control study indicate that the variations of the pH and oxidation-reduction potential(ORP) profiles can represent dynamic characteristics of system and the cycle sequences can be controlled and optimized by the control points on the pH and ORP profiles. A control strategy was, therefore, developed and applied to real-time control mode. Compared with traditional mode, the total nitrogen(TN) removal can be increased by approximately 16% in modified mode and a mean TN removal of 92% was achieved in real-time control mode. Moreover, approximately 12.5% aeration energy was saved in real- time control mode. The result of this study shows that the performance of nitrogen removal was enhanced in modified operation mode. Moreover, the real-time control made it possible to optimize process operation and save aeration energy.
基金National Natural Science Foundation of China under Grant Nos.51725901 and 51639006
文摘Tuned liquid damper (TLD) and tuned liquid column damper (TLCD) are two types of passive control devices that are widely used in structural control. In this study, a real-time hybrid simulation (RTHS) technique is employed to investigate the diff erence in control performance between TLD and TLCD. A series of RTHSs is presented with the premise of the same liquid length, mass ratio, and structural parameters. Herein, TLD and TLCD are physically experimented, and controlled structures are numerically simulated. Then, parametric studies are performed to further evaluate the diff erent performance between TLD and TLCD. Experimental results demonstrate that TLD is more eff ective than TLCD under diff erent amplitude excitations.
文摘To develop technically feasible and economically favorable dynamic process control(DPC)strategies for an alternating activated sludge(AAS)system,a bench-scale continuous-flow alternating aerobic and anoxic reactor,performing short-cut nitrogen removal from real domestic wastewater was operated under different control strategies for more than five months.A fixed-time control(FTC) study showed that bending-points on pH and oxidation-reduction potential(ORP)profiles accurately coincided with the major biologic...
基金The National High Technology Research&Development Program of China under contract No.2012AA10A411the National Natural Science Foundation of China under contract Nos 41176151 and 41276177
文摘Pyropia haitanensis is an economically important mariculture crop in China and has a high research value for several life phenomena, for example environmental tolerance. To explore the mechanisms underlying these characteristics, gene expression has been investigated at the whole transcriptome level. Gene expression studies using quantitative real-time PCR should start by selecting an appropriate internal control gene; therefore, the absolute expression abundance of six housekeeping genes (18S rRNA (18S), ubiquitin-conju-ating enzyme (UBC), actin (ACT), β-tubulin (TUB), elongation factors 2 (EF2), and glyceraldehyde-3-phos- phate dehydrogenase (GAPDH) examined by the quantitative real-time PCR in samples corresponding to different strains, life-cycle stages and abiotic stress treatments. Their expression stabilities were assessed by the comparative cycle threshold (Ct) method and by two different software packages: geNorm and NormFinder. The most stable housekeeping gene is UBC and the least stable housekeeping is GADPH. Thus, it is proposed that the most appropriate internal control gene for expression analyses in P. haitanensis is UBC. The results pave the way for further gene expression analyses of different aspects of P. haitanensis biology including different strains, life-history stages and abiotic stress responses.
基金National Natural Science Foundation of China(No.50539120)National Basic Research Program of China("973"Program,No. 2007 CB714101)+1 种基金National Science Fund for Distinguished Young Scholars of China(No.50525927)National Natural Science Founda-tion of China(No.50579045)
文摘A method of combining dynamic simulation with real-time control was proposed to fit the randomness and uncertainty in the high arch dam construction process. The mathematical logic model of high arch dam construction process was established. By combining dynamic construction simulation with schedule analysis, the process of construction schedule forecasting and analysis based on dynamic simulation was studied. The process of real-time schedule control was constructed and some measures for dynamic adjustment and control of construction schedule were provided. A system developed with the method is utilized in a being constructed hydroelectric project located at the Yellow River in northwest China, which can make the pouring plan of the dam in the next stage (a month, quarter or year) to guide the practical construction. The application result shows that the system provides an effective technical support for the construction and management of the dam.
基金supported by the Medical Scientific Research Project of Chongqing Municipal Health Commission of China,Nos.2018ZDXM022,2019MSXM017 and 2020MSXM106a grant from Chongqing General Hospital of China,No.2019ZDXM03(all to LCN and JXM).
文摘Transcutaneous auricular vagus nerve stimulation(ta-VNS)is a novel noninvasive treat-ment for stroke that directly stimulates the peripheral auricular branch of the vagus nerve.There have been recent reports that ta-VNS combined with conventional rehabilitation training promotes the recovery of neurological function of patients with acute stroke.However,these were small-sample-sized studies on the recovery of neurological function in patients after percutaneous vagus nerve stimulation in the subacute and chronic phases after stroke.This double-blinded randomized controlled trial involved 60 acute ischemic or hemorrhagic stroke patients aged 18-80 years who received treatment in the Second Affiliated Hospital of Chongqing Medical University.The subjects were randomly assigned to receive ta-VNS or sham ta-VNS combined with conventional rehabilitation training.The follow-up results over 1 year revealed that ta-VNS combined with conventional rehabilitation training greatly improved the recovery of motor and sensory functions and emotional responses compared with sham ta-VNS combined with conventional rehabilitation training.There were no obvious side effects.These findings suggest that ta-VNS combined with conventional rehabilitation training for the treatment of acute ischemic or hemorrhagic stroke patients is safe and effective.
基金Project(20100480964) supported by China Postdoctoral Science FoundationProjects(2002AA420090,2008AA092301) supported by the National High Technology Research and Development Program of China
文摘Plenty of dams in China are in danger while there are few effective methods for underwater dam inspections of hidden problems such as conduits,cracks and inanitions.The dam safety inspection remotely operated vehicle(DSIROV) is designed to solve these problems which can be equipped with many advanced sensors such as acoustical,optical and electrical sensors for underwater dam inspection.A least-square parameter estimation method is utilized to estimate the hydrodynamic coefficients of DSIROV,and a four degree-of-freedom(DOF) simulation system is constructed.The architecture of DSIROV's motion control system is introduced,which includes hardware and software structures.The hardware based on PC104 BUS,uses AMD ELAN520 as the controller's embedded CPU and all control modules work in VxWorks real-time operating system.Information flow of the motion system of DSIROV,automatic control of dam scanning and dead-reckoning algorithm for navigation are also discussed.The reliability of DSIROV's control system can be verified and the control system can fulfill the motion control mission because embankment checking can be demonstrated by the lake trials.
基金National Science Foundation Graduate Research Fellowship
文摘Real-time hybrid simulation is an attractive method to evaluate the response of structures under earthquake loads. The method is a variation of the pseudodynamic testing technique in which the experiment is executed in real time, thus allowing investigation of structural systems with rate-dependent components. Real-time hybrid simulation is challenging because it requires performance of all calculations, application of displacements, and acquisition of measured forces, within a very small increment of time. Furthermore, unless appropriate compensation for actuator dynamics is implemented, stability problems are likely to occur during the experiment. This paper presents an approach for real-time hybrid simulation in which compensation for actuator dynamics is implemented using a model-based feedforward compensator. The method is used to evaluate the response of a semi-active control of a structure employing an MR damper. Experimental results show good agreement with the predicted responses, demonstrating the effectiveness of the method for structural control performance assessment.
基金This work was supported in part by the National Nature Science Foundation of China(51922059)in part by the Beijing Natural Science Foundation(JQ19010)in part by the China Postdoctoral Science Foundation(2021T140371).
文摘With regard to precision/ultra-precision motion systems,it is important to achieve excellent tracking performance for various trajectory tracking tasks even under uncertain external disturbances.In this paper,to overcome the limitation of robustness to trajectory variations and external disturbances in offline feedforward compensation strategies such as iterative learning control(ILC),a novel real-time iterative compensation(RIC)control framework is proposed for precision motion systems without changing the inner closed-loop controller.Specifically,the RIC method can be divided into two parts,i.e.,accurate model prediction and real-time iterative compensation.An accurate prediction model considering lumped disturbances is firstly established to predict tracking errors at future sampling times.In light of predicted errors,a feedforward compensation term is developed to modify the following reference trajectory by real-time iterative calculation.Both the prediction and compen-sation processes are finished in a real-time motion control sampling period.The stability and convergence of the entire control system after real-time iterative compensation is analyzed for different conditions.Various simulation results consistently demonstrate that the proposed RIC framework possesses satisfactory dynamic regulation capability,which contributes to high tracking accuracy comparable to ILC or even better and strong robustness.
基金Projects(50875090,50905063) supported by the National Natural Science Foundation of ChinaProject(2009AA04Z111) supported by the National High Technology Research and Development Program of China+2 种基金Project(20090460769) supported by China Postdoctoral Science FoundationProject(2011ZM0070) supported by the Fundamental Research Funds for the Central Universities in ChinaProject(S2011010001155) supported by the Natural Science Foundation of Guangdong Province,China
文摘In order to optimize the embedded system implementation for Ethernet-based computer numerical control (CNC) system, it is very necessary to establish the performance analysis model and further adopt the codesign method from the control, communication and computing perspectives. On the basis of analyzing real-time Ethemet, system architecture, time characteristic parameters of control-loop ere, a performance analysis model for real-time Ethemet-based CNC system was proposed, which is able to include the timing effects caused by the implementation platform in the simulation. The key for establishing the model is accomplished by designing the error analysis module and the controller nodes. Under the restraint of CPU resource and communication bandwidth, the experiment with a case study was conducted, and the results show that if the deadline miss ratio of data packets is 0.2%, then the percentage error is 1.105%. The proposed model can be used at several stages of CNC system development.