In this paper, a main structure of DC distributed power system is introduced;the stability of the output voltage in parallel system is put forward. This paper analyses the output impedance of master-slave current shar...In this paper, a main structure of DC distributed power system is introduced;the stability of the output voltage in parallel system is put forward. This paper analyses the output impedance of master-slave current sharing mode and average current sharing, analyses the stability of parallel system through simulation, there is Right-half plane (RHP) polar in the Bode plot of input impedance. At last this paper distinguishes whether this system is stability and verifies the validity of the simulation.展开更多
This Article introduced the concept, topology and function of voltage type Buck converter, built a small signal model, analysis the negative impedance character of converter, then simulated a Buck-type DC/ DC through ...This Article introduced the concept, topology and function of voltage type Buck converter, built a small signal model, analysis the negative impedance character of converter, then simulated a Buck-type DC/ DC through MATLAB, observed the dynamic response of converter to pulse-type power load, verified the small-signal theoretical by simulation, lay the foundation for analyzing DC system stability.展开更多
Hydrogen as a clean energy source is made full use, this paper researches the electrical model of PEMFC generator, analyzes the harmonic trend and its hazards when the generator operates with linear load and nonlinear...Hydrogen as a clean energy source is made full use, this paper researches the electrical model of PEMFC generator, analyzes the harmonic trend and its hazards when the generator operates with linear load and nonlinear load running synchronously, comparatively analyzes the commonly used harmonic suppression technology. Simulate and analyze the filter performance when APF is used. The results illustrate that as a filter device, APF can absorb the harmonic properly in PEMFC power system.展开更多
Frequency control technology can achieve the purpose of energy saving of power equipment, but also bring problems of harmonic loss formula. The relationship between the loss rate and load rate is constituted by formul...Frequency control technology can achieve the purpose of energy saving of power equipment, but also bring problems of harmonic loss formula. The relationship between the loss rate and load rate is constituted by formula derivation, and calculate the load rate when the loss rate is the minimum and the total power of power-consuming devices. Then design the digital PID controller and research the power-saving optimization feedback algorithms and design the software process. Finally, carry out the inverter switching algorithm based on ABB ACS510 low voltage inverter.展开更多
The diseases of sweet cherry caused by viruses and viroids have occurred in the main cherry producing areas of China and are increasing year by year, which has become an important factor affecting the yield and qualit...The diseases of sweet cherry caused by viruses and viroids have occurred in the main cherry producing areas of China and are increasing year by year, which has become an important factor affecting the yield and quality of sweet cherry. For this reason, this paper elaborated the prevention and countermeasures of virus diseases from six aspects, including soil treatment, cultivation of disease-free seedlings, prevention of disease and pest damage, reasonable pruning, water management, and treatment of virus diseases, in order to provide technical guidance for the disease resistance, high quality and high yield of facility cherry, as well as information reference for the further improvement of the technical system of virus disease prevention and cultivation of facility cherry.展开更多
Geographically replicating objects across multiple data centers improves the performance and reliability of cloud storage systems.Maintaining consistent replicas comes with high synchronization costs,as it faces more ...Geographically replicating objects across multiple data centers improves the performance and reliability of cloud storage systems.Maintaining consistent replicas comes with high synchronization costs,as it faces more expensive WAN transport prices and increased latency.Periodic replication is the widely used technique to reduce the synchronization costs.Periodic replication strategies in existing cloud storage systems are too static to handle traffic changes,which indicates that they are inflexible in the face of unforeseen loads,resulting in additional synchronization cost.We propose quantitative analysis models to quantify consistency and synchronization cost for periodically replicated systems,and derive the optimal synchronization period to achieve the best tradeoff between consistency and synchronization cost.Based on this,we propose a dynamic periodic synchronization method,Sync-Opt,which allows systems to set the optimal synchronization period according to the variable load in clouds to minimize the synchronization cost.Simulation results demonstrate the effectiveness of our models.Compared with the policies widely used in modern cloud storage systems,the Sync-Opt strategy significantly reduces the synchronization cost.展开更多
Chronic obstructive pulmonary disease(COPD)is emphysema and/or chronic bronchitis characterised by long-term breathing problems and poor airflow.The prevalence of COPD has increased over the last decade and the drugs ...Chronic obstructive pulmonary disease(COPD)is emphysema and/or chronic bronchitis characterised by long-term breathing problems and poor airflow.The prevalence of COPD has increased over the last decade and the drugs most commonly used to treat it,such as glucocorticoids and bronchodilators,have significant therapeutic effects;however,they also cause side effects,including infection and immunosuppression.Here we reviewed the pathogenesis and progression of COPD and elaborated on the effects and mechanisms of newly developed molecular targeted COPD therapeutic drugs.Among these new drugs,we focussed on thioredoxin(Trx).Trx effectively prevents the progression of COPD by regulating redox status and protease/anti-protease balance,blocking the NF-κB and MAPK signalling pathways,suppressing the activation and migration of inflammatory cells and the production of cytokines,inhibiting the synthesis and the activation of adhesion factors and growth factors,and controlling the cAMP-PKA and PI3K/Akt signalling pathways.The mechanism by which Trx affects COPD is different from glucocorticoid-based mechanisms which regulate the inflammatory reaction in association with suppressing immune responses.In addition,Trx also improves the insensitivity of COPD to steroids by inhibiting the production and internalisation of macrophage migration inhibitory factor(MIF).Taken together,these findings suggest that Trx may be the ideal drug for treating COPD.展开更多
This study aims to evaluate the effects of aflatoxins on growth performance and skeletal muscle of Cherry Valley meat male ducks as they grow and develop. One-day-old healthy meat male ducks(n = 180) were randomly div...This study aims to evaluate the effects of aflatoxins on growth performance and skeletal muscle of Cherry Valley meat male ducks as they grow and develop. One-day-old healthy meat male ducks(n = 180) were randomly divided into 2 groups; there were 6 replicates in each group and 15 ducks in each replicate. The control group was fed a basic diet, and the experimental group was fed a mold-exposed cottonseed meal diet containing aflatoxins instead of normal cottonseed meal. The experimental period was 35 days, and divided into two stages of 1 to 14 days(early stage) and 15 to 35 days(late stage). During the experimental period, live weight, breast muscle weight and thigh muscle weight of meat male ducks were measured weekly. Results showed as follows: 1) aflatoxins contained in the mold-exposed diet significantly reduced daily weight gain and feed intake, and increased feed-to-gain ratio of meat male ducks at different ages(P < 0.05); 2) the Gompertz equation(W_t = W_m exp {-exp [-B(t-t~*)]}) could successfully fit the growth curve and growth and developmental patterns of skeletal muscles of Cherry Valley meat male ducks(R^2≥0.97); 3) the relationship between chest muscle and live weight was the best described by a power regression and polynomial regression(R^2 = 0.99); the relationship between live weight and thigh muscle weight was the best described by linear regression, polynomial regression, and power regression(R^2 = 0.99); 4) aflatoxins in the mold-exposed diet significantly reduced live weight, breast muscle weight and thigh muscle weight of Cherry Valley meat male ducks at various ages; and 5) aflatoxins delayed the age at peak in growth of meat male ducks, and reduced weights at the peak for breast muscle, thigh muscle and whole body as well as the maximal daily weight gain. In summary,aflatoxins delayed growth of Cherry Valley meat male ducks and development of skeletal muscle.展开更多
During the COVID-19 epidemic,the treatment of critically ill patients has been increasingly difficult and challenging.During the epidemic,some patients with neurological diseases also have COVID-19,which could be misd...During the COVID-19 epidemic,the treatment of critically ill patients has been increasingly difficult and challenging.During the epidemic,some patients with neurological diseases also have COVID-19,which could be misdiagnosed and cause silent transmission and nosocomial infection.Such risk is high in a neurological intensive care unit(NCU).Therefore,prevention and control of epidemic in critically ill patients is of utmost importance.The principle of NCU care should include comprehensive screening and risk assessment,weighing risk against benefits and reducing the risk of COVID-19 transmission while treating patients as promptly as possible.展开更多
A new cyclometalated iridium（Ⅲ） complex [Ir（2-pq）2（HPIP）]C1 （lrl, 2-pq=3-phenylisoquinoline, HPIP= 2-（2-hydroxyphenyl）imidazo[4,5-f] 1,10-phenanthroline） was synthesized and applied to image mitochondria in...A new cyclometalated iridium（Ⅲ） complex [Ir（2-pq）2（HPIP）]C1 （lrl, 2-pq=3-phenylisoquinoline, HPIP= 2-（2-hydroxyphenyl）imidazo[4,5-f] 1,10-phenanthroline） was synthesized and applied to image mitochondria in living cells. Irl displayed excellent ability to selectively accumulate in mitochondria of live cells with no requirement of replacement of the culture medium. Due to Irl exhibiting better photostability than the commercially available mitochondrial trackers, this complex could be applicable for the imaging and tracking of the mitochondrial mor- phological changes over long periods of time. In addition, in vitro cytotoxicity investigation revealed that it! showed negligible cytotoxicity at the concentrations employed. Based on these, Irl is suitable for organelle-selective imaging in living cells.展开更多
文摘In this paper, a main structure of DC distributed power system is introduced;the stability of the output voltage in parallel system is put forward. This paper analyses the output impedance of master-slave current sharing mode and average current sharing, analyses the stability of parallel system through simulation, there is Right-half plane (RHP) polar in the Bode plot of input impedance. At last this paper distinguishes whether this system is stability and verifies the validity of the simulation.
文摘This Article introduced the concept, topology and function of voltage type Buck converter, built a small signal model, analysis the negative impedance character of converter, then simulated a Buck-type DC/ DC through MATLAB, observed the dynamic response of converter to pulse-type power load, verified the small-signal theoretical by simulation, lay the foundation for analyzing DC system stability.
文摘Hydrogen as a clean energy source is made full use, this paper researches the electrical model of PEMFC generator, analyzes the harmonic trend and its hazards when the generator operates with linear load and nonlinear load running synchronously, comparatively analyzes the commonly used harmonic suppression technology. Simulate and analyze the filter performance when APF is used. The results illustrate that as a filter device, APF can absorb the harmonic properly in PEMFC power system.
文摘Frequency control technology can achieve the purpose of energy saving of power equipment, but also bring problems of harmonic loss formula. The relationship between the loss rate and load rate is constituted by formula derivation, and calculate the load rate when the loss rate is the minimum and the total power of power-consuming devices. Then design the digital PID controller and research the power-saving optimization feedback algorithms and design the software process. Finally, carry out the inverter switching algorithm based on ABB ACS510 low voltage inverter.
基金Supported by Class A Project of Scientific Research Development Program of Colleges and Universities in Shandong Province (J17KA155)。
文摘The diseases of sweet cherry caused by viruses and viroids have occurred in the main cherry producing areas of China and are increasing year by year, which has become an important factor affecting the yield and quality of sweet cherry. For this reason, this paper elaborated the prevention and countermeasures of virus diseases from six aspects, including soil treatment, cultivation of disease-free seedlings, prevention of disease and pest damage, reasonable pruning, water management, and treatment of virus diseases, in order to provide technical guidance for the disease resistance, high quality and high yield of facility cherry, as well as information reference for the further improvement of the technical system of virus disease prevention and cultivation of facility cherry.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.62272026 and 62104014)the fund of the State Key Laboratory of Software Development Environment(No.SKLSDE-2022ZX-07)the Iluvatar CoreX semiconductor Co.,Ltd.
文摘Geographically replicating objects across multiple data centers improves the performance and reliability of cloud storage systems.Maintaining consistent replicas comes with high synchronization costs,as it faces more expensive WAN transport prices and increased latency.Periodic replication is the widely used technique to reduce the synchronization costs.Periodic replication strategies in existing cloud storage systems are too static to handle traffic changes,which indicates that they are inflexible in the face of unforeseen loads,resulting in additional synchronization cost.We propose quantitative analysis models to quantify consistency and synchronization cost for periodically replicated systems,and derive the optimal synchronization period to achieve the best tradeoff between consistency and synchronization cost.Based on this,we propose a dynamic periodic synchronization method,Sync-Opt,which allows systems to set the optimal synchronization period according to the variable load in clouds to minimize the synchronization cost.Simulation results demonstrate the effectiveness of our models.Compared with the policies widely used in modern cloud storage systems,the Sync-Opt strategy significantly reduces the synchronization cost.
文摘Chronic obstructive pulmonary disease(COPD)is emphysema and/or chronic bronchitis characterised by long-term breathing problems and poor airflow.The prevalence of COPD has increased over the last decade and the drugs most commonly used to treat it,such as glucocorticoids and bronchodilators,have significant therapeutic effects;however,they also cause side effects,including infection and immunosuppression.Here we reviewed the pathogenesis and progression of COPD and elaborated on the effects and mechanisms of newly developed molecular targeted COPD therapeutic drugs.Among these new drugs,we focussed on thioredoxin(Trx).Trx effectively prevents the progression of COPD by regulating redox status and protease/anti-protease balance,blocking the NF-κB and MAPK signalling pathways,suppressing the activation and migration of inflammatory cells and the production of cytokines,inhibiting the synthesis and the activation of adhesion factors and growth factors,and controlling the cAMP-PKA and PI3K/Akt signalling pathways.The mechanism by which Trx affects COPD is different from glucocorticoid-based mechanisms which regulate the inflammatory reaction in association with suppressing immune responses.In addition,Trx also improves the insensitivity of COPD to steroids by inhibiting the production and internalisation of macrophage migration inhibitory factor(MIF).Taken together,these findings suggest that Trx may be the ideal drug for treating COPD.
基金supported by the Agricultural Science and Technology Innovation program in Chinese Academy of Agricultural Sciences (ASTIP)
文摘This study aims to evaluate the effects of aflatoxins on growth performance and skeletal muscle of Cherry Valley meat male ducks as they grow and develop. One-day-old healthy meat male ducks(n = 180) were randomly divided into 2 groups; there were 6 replicates in each group and 15 ducks in each replicate. The control group was fed a basic diet, and the experimental group was fed a mold-exposed cottonseed meal diet containing aflatoxins instead of normal cottonseed meal. The experimental period was 35 days, and divided into two stages of 1 to 14 days(early stage) and 15 to 35 days(late stage). During the experimental period, live weight, breast muscle weight and thigh muscle weight of meat male ducks were measured weekly. Results showed as follows: 1) aflatoxins contained in the mold-exposed diet significantly reduced daily weight gain and feed intake, and increased feed-to-gain ratio of meat male ducks at different ages(P < 0.05); 2) the Gompertz equation(W_t = W_m exp {-exp [-B(t-t~*)]}) could successfully fit the growth curve and growth and developmental patterns of skeletal muscles of Cherry Valley meat male ducks(R^2≥0.97); 3) the relationship between chest muscle and live weight was the best described by a power regression and polynomial regression(R^2 = 0.99); the relationship between live weight and thigh muscle weight was the best described by linear regression, polynomial regression, and power regression(R^2 = 0.99); 4) aflatoxins in the mold-exposed diet significantly reduced live weight, breast muscle weight and thigh muscle weight of Cherry Valley meat male ducks at various ages; and 5) aflatoxins delayed the age at peak in growth of meat male ducks, and reduced weights at the peak for breast muscle, thigh muscle and whole body as well as the maximal daily weight gain. In summary,aflatoxins delayed growth of Cherry Valley meat male ducks and development of skeletal muscle.
文摘During the COVID-19 epidemic,the treatment of critically ill patients has been increasingly difficult and challenging.During the epidemic,some patients with neurological diseases also have COVID-19,which could be misdiagnosed and cause silent transmission and nosocomial infection.Such risk is high in a neurological intensive care unit(NCU).Therefore,prevention and control of epidemic in critically ill patients is of utmost importance.The principle of NCU care should include comprehensive screening and risk assessment,weighing risk against benefits and reducing the risk of COVID-19 transmission while treating patients as promptly as possible.
文摘A new cyclometalated iridium（Ⅲ） complex [Ir（2-pq）2（HPIP）]C1 （lrl, 2-pq=3-phenylisoquinoline, HPIP= 2-（2-hydroxyphenyl）imidazo[4,5-f] 1,10-phenanthroline） was synthesized and applied to image mitochondria in living cells. Irl displayed excellent ability to selectively accumulate in mitochondria of live cells with no requirement of replacement of the culture medium. Due to Irl exhibiting better photostability than the commercially available mitochondrial trackers, this complex could be applicable for the imaging and tracking of the mitochondrial mor- phological changes over long periods of time. In addition, in vitro cytotoxicity investigation revealed that it! showed negligible cytotoxicity at the concentrations employed. Based on these, Irl is suitable for organelle-selective imaging in living cells.
