An increasing amount of evidence demonstrates the anti-aging effect of Heshouwu in pill form. In this study, a subacute aging rat model was established by continuous intraperitoneal injection of D-galactose and treate...An increasing amount of evidence demonstrates the anti-aging effect of Heshouwu in pill form. In this study, a subacute aging rat model was established by continuous intraperitoneal injection of D-galactose and treated with Heshouwu decoction （a Chinese herb for tonifying the kidney, comprising Heshouwu pill, Herba Epimedii, Radix Salviae Miltiorrhiae, and Poria）. Heshouwu pill treated rats were the positive control group. Radioimmunoassay, immunohistochemical staining, and western blot assay showed hypothalamic gonadotropin-releasing hormone, hypothalamic substance P, and serum gonadotropin levels to be significantly increased in the model rats; the concentrations of hypothalamic ~3-endorphin, and serum levels of insulin-like growth factor I and testosterone were significantly decreased. 1713- and 3[3-hydroxysteroid dehydrogenase expression in testicular tissue was also decreased. Intragastric administration of Heshouwu decoction at high （9.6 g/mL/100 g）, medium （4.8 g/mL/100 g）, and low （2.4 g/mlJ100 g） doses, Heshouwu decoction pretreatment at a medium dose （4.8 g/mL/100 g）, and Heshouwu pill （2.06 g/mL/100 g） significantly reversed these changes. Heshouwu decoction pretreatment and high-dose Heshouwu decoction had the greatest anti-aging effects. These experimental findings indicate that Heshouwu decoction can improve hypothalamic-pituitary-testicular axis secretion in a subacute aging rat model, and prevent and delay gonadal axis aging, with an effect superior to that of Heshouwu pill.展开更多
Soft robots have become important members of the robot community with many potential applications owing to their unique flexibility and security embedded at the material level.An increasing number of researchers are i...Soft robots have become important members of the robot community with many potential applications owing to their unique flexibility and security embedded at the material level.An increasing number of researchers are interested in their designing,manufacturing,modeling,and control.However,the dynamic simulation of soft robots is difficult owing to their infinite degrees of freedom and nonlinear characteristics that are associated with soft materials and flexible geometric structures.In this study,a novel multi-flexible body dynamic modeling and simulation technique is introduced for soft robots.Various actuators for soft robots are modeled in a virtual environment,including soft cable-driven,spring actuation,and pneumatic driving.A pneumatic driving simulation was demonstrated by the bending modules with different materials.A cable-driven soft robot arm prototype and a cylindrical soft module actuated by shape memory alley springs inspired by an octopus were manufactured and used to validate the simulation model,and the experimental results demonstrated adequate accuracy.The proposed technique can be widely applied for the modeling and dynamic simulation of other soft robots,including hybrid actuated robots and rigid-flexible coupling robots.This study also provides a fundamental framework for simulating soft mobile robots and soft manipulators in contact with the environment.展开更多
The electrically driven six-legged robot with high carrying capacity is an indispensable equipment for planetary exploration, but it hinders its practicability because of its low efficiency of carrying energy. Meanwhi...The electrically driven six-legged robot with high carrying capacity is an indispensable equipment for planetary exploration, but it hinders its practicability because of its low efficiency of carrying energy. Meanwhile, its load capacity also affects its application range. To reduce the power consumption, increase the load to mass ratio, and improve the stability of robot, the relationship between the walking modes and the forces of feet under the tripod gait are researched for an electrically driven heavy-duty six-legged robot. Based on the configuration characteristics of electrically driven heavy-duty six-legged, the typical walking modes of robot are analyzed. The mathematical models of the normal forces of feet are respectively established under the tripod gait of typical walking modes. According to the MATLAB software, the variable tendency charts are respectively gained for the normal forces of feet. The walking experiments under the typical tripod gaits are implemented for the prototype of electrically driven heavy-duty six-legged robot. The variable tendencies of maximum normal forces of feet are acquired. The comparison results show that the theoretical and experimental data are in the same trend. The walking modes which are most available to realize the average force of distribution of each foot are confirmed. The proposed method of analyzing the relationship between the walking modes and the forces of feet can quickly determine the optimal walking mode and gait parameters under the average distribution of foot force, which is propitious to develop the excellent heavy-duty multi-legged robots with the lower power consumption, larger load to mass ratio, and higher stability.展开更多
The titled compound 1 as well as compounds 2 and 3 with similar chemical structures were prepared and characterized. The magnetic properties of 1 were investigated with SQUID (MPMS, quantum design) magnetometer. Studi...The titled compound 1 as well as compounds 2 and 3 with similar chemical structures were prepared and characterized. The magnetic properties of 1 were investigated with SQUID (MPMS, quantum design) magnetometer. Studies with Langmuir-Blodgett (LB) technique indicated that stable condensed film of 1 could be formed at air-water interface and could be transferred onto various solid substrate under suitable conditions.展开更多
Botnets often use domain generation algorithms(DGA)to connect to a command and control(C2)server,which enables the compromised hosts connect to the C2 server for accessing many domains.The detection of DGA domains is ...Botnets often use domain generation algorithms(DGA)to connect to a command and control(C2)server,which enables the compromised hosts connect to the C2 server for accessing many domains.The detection of DGA domains is critical for blocking the C2 server,and for identifying the compromised hosts as well.However,the detection is difficult,because some DGA domain names look normal.Much of the previous work based on statistical analysis of machine learning relies on manual features and contextual information,which causes long response time and cannot be used for real-time detection.In addition,when a new family of DGA appears,the classifier has to be re-trained from the very beginning.This paper presents a deep learning approach based on bidirectional long short-term memory(Bi-LSTM)model for DGA domain detection.The classifier can extract features without the need for manual feature extraction,and the trainable model can effectively deal with new unknown DGA family members.In addition,the proposed model only needs the domain name without any additional context information.All domain names are preprocessed by bigram and the length of each processed domain name is set as a value longer than the most samples.Bidirectional LSTM model receives the encoded data and returns labels to check whether domain names are normal or not.Experiments show that our model outperforms state-of-the-art approaches and is able to detect new DGA families reliably.展开更多
Atmosphere-Breathing Electric Propulsion(ABEP)can compensate for lost momentum of spacecraft operating in Very Low Earth Orbit(VLEO)which has been widely concerned due to its excellent commercial potential.It is a key...Atmosphere-Breathing Electric Propulsion(ABEP)can compensate for lost momentum of spacecraft operating in Very Low Earth Orbit(VLEO)which has been widely concerned due to its excellent commercial potential.It is a key technology to improve the capture efficiency of intakes,which collect and compress the atmosphere for ABEP.In this paper,the mechanism of the capture section affecting capture efficiency is investigated by Test Particle Monte Carlo(TPMC)simulations with 3D intake models.The inner surface smoothness and average collision number are determined to be key factors affecting capture efficiency,and a negative effect growth model is accordingly established.When the inner surface smoothness is less than 0.2,the highest capture efficiency and its corresponding average collision number interval are independent of the capture section’s geometry and its mesh size.When the inner surface smoothness is higher than 0.2,the capture efficiency will decrease by installing any capture section.Based on the present results,the manufacturing process and material selection are suggested to be prioritized during the intake geometry design in engineering projects.Then,the highest capture efficiency can be achieved by adjusting the length and mesh size of the capture section.展开更多
基金supported by the Talent Introduction Fund of Hebei University, No. 2010-183the Medical Science Special Fund of Hebei University, No. 2012A1005+1 种基金the Key Project of Hebei Provincial Health Department, No. 20110151a grant from Hebei Provincial Administration of Traditional Chinese Medicine, No. 2011104
文摘An increasing amount of evidence demonstrates the anti-aging effect of Heshouwu in pill form. In this study, a subacute aging rat model was established by continuous intraperitoneal injection of D-galactose and treated with Heshouwu decoction （a Chinese herb for tonifying the kidney, comprising Heshouwu pill, Herba Epimedii, Radix Salviae Miltiorrhiae, and Poria）. Heshouwu pill treated rats were the positive control group. Radioimmunoassay, immunohistochemical staining, and western blot assay showed hypothalamic gonadotropin-releasing hormone, hypothalamic substance P, and serum gonadotropin levels to be significantly increased in the model rats; the concentrations of hypothalamic ~3-endorphin, and serum levels of insulin-like growth factor I and testosterone were significantly decreased. 1713- and 3[3-hydroxysteroid dehydrogenase expression in testicular tissue was also decreased. Intragastric administration of Heshouwu decoction at high （9.6 g/mL/100 g）, medium （4.8 g/mL/100 g）, and low （2.4 g/mlJ100 g） doses, Heshouwu decoction pretreatment at a medium dose （4.8 g/mL/100 g）, and Heshouwu pill （2.06 g/mL/100 g） significantly reversed these changes. Heshouwu decoction pretreatment and high-dose Heshouwu decoction had the greatest anti-aging effects. These experimental findings indicate that Heshouwu decoction can improve hypothalamic-pituitary-testicular axis secretion in a subacute aging rat model, and prevent and delay gonadal axis aging, with an effect superior to that of Heshouwu pill.
基金Supported by the National Natural Science Foundation of China(Grant Nos.51822502 and 91948202)the National Key Research and Development Program of China(No.2019YFB1309500)the“111 Project”(Grant No.B07018).
文摘Soft robots have become important members of the robot community with many potential applications owing to their unique flexibility and security embedded at the material level.An increasing number of researchers are interested in their designing,manufacturing,modeling,and control.However,the dynamic simulation of soft robots is difficult owing to their infinite degrees of freedom and nonlinear characteristics that are associated with soft materials and flexible geometric structures.In this study,a novel multi-flexible body dynamic modeling and simulation technique is introduced for soft robots.Various actuators for soft robots are modeled in a virtual environment,including soft cable-driven,spring actuation,and pneumatic driving.A pneumatic driving simulation was demonstrated by the bending modules with different materials.A cable-driven soft robot arm prototype and a cylindrical soft module actuated by shape memory alley springs inspired by an octopus were manufactured and used to validate the simulation model,and the experimental results demonstrated adequate accuracy.The proposed technique can be widely applied for the modeling and dynamic simulation of other soft robots,including hybrid actuated robots and rigid-flexible coupling robots.This study also provides a fundamental framework for simulating soft mobile robots and soft manipulators in contact with the environment.
基金Supported by National Natural Science Foundation of China(Grant Nos.51505335,51275106)National Basic Research Program of China(973Program,Grant No.2013CB035502)
文摘The electrically driven six-legged robot with high carrying capacity is an indispensable equipment for planetary exploration, but it hinders its practicability because of its low efficiency of carrying energy. Meanwhile, its load capacity also affects its application range. To reduce the power consumption, increase the load to mass ratio, and improve the stability of robot, the relationship between the walking modes and the forces of feet under the tripod gait are researched for an electrically driven heavy-duty six-legged robot. Based on the configuration characteristics of electrically driven heavy-duty six-legged, the typical walking modes of robot are analyzed. The mathematical models of the normal forces of feet are respectively established under the tripod gait of typical walking modes. According to the MATLAB software, the variable tendency charts are respectively gained for the normal forces of feet. The walking experiments under the typical tripod gaits are implemented for the prototype of electrically driven heavy-duty six-legged robot. The variable tendencies of maximum normal forces of feet are acquired. The comparison results show that the theoretical and experimental data are in the same trend. The walking modes which are most available to realize the average force of distribution of each foot are confirmed. The proposed method of analyzing the relationship between the walking modes and the forces of feet can quickly determine the optimal walking mode and gait parameters under the average distribution of foot force, which is propitious to develop the excellent heavy-duty multi-legged robots with the lower power consumption, larger load to mass ratio, and higher stability.
文摘The titled compound 1 as well as compounds 2 and 3 with similar chemical structures were prepared and characterized. The magnetic properties of 1 were investigated with SQUID (MPMS, quantum design) magnetometer. Studies with Langmuir-Blodgett (LB) technique indicated that stable condensed film of 1 could be formed at air-water interface and could be transferred onto various solid substrate under suitable conditions.
基金This work was supported by the National Natural Science Foundation of China(NSFC)under the grant(No.U1836102).
文摘Botnets often use domain generation algorithms(DGA)to connect to a command and control(C2)server,which enables the compromised hosts connect to the C2 server for accessing many domains.The detection of DGA domains is critical for blocking the C2 server,and for identifying the compromised hosts as well.However,the detection is difficult,because some DGA domain names look normal.Much of the previous work based on statistical analysis of machine learning relies on manual features and contextual information,which causes long response time and cannot be used for real-time detection.In addition,when a new family of DGA appears,the classifier has to be re-trained from the very beginning.This paper presents a deep learning approach based on bidirectional long short-term memory(Bi-LSTM)model for DGA domain detection.The classifier can extract features without the need for manual feature extraction,and the trainable model can effectively deal with new unknown DGA family members.In addition,the proposed model only needs the domain name without any additional context information.All domain names are preprocessed by bigram and the length of each processed domain name is set as a value longer than the most samples.Bidirectional LSTM model receives the encoded data and returns labels to check whether domain names are normal or not.Experiments show that our model outperforms state-of-the-art approaches and is able to detect new DGA families reliably.
基金the auspices of National Key R&D Program of China(No.2020YFC2201100)the National Natural Science Foundation of China(No.52077169)+1 种基金the State Key Laboratory of Electrical Insulation and Power Equipment,China(No.EIPE22116)HPC Platform,Xi’an Jiaotong University,China。
文摘Atmosphere-Breathing Electric Propulsion(ABEP)can compensate for lost momentum of spacecraft operating in Very Low Earth Orbit(VLEO)which has been widely concerned due to its excellent commercial potential.It is a key technology to improve the capture efficiency of intakes,which collect and compress the atmosphere for ABEP.In this paper,the mechanism of the capture section affecting capture efficiency is investigated by Test Particle Monte Carlo(TPMC)simulations with 3D intake models.The inner surface smoothness and average collision number are determined to be key factors affecting capture efficiency,and a negative effect growth model is accordingly established.When the inner surface smoothness is less than 0.2,the highest capture efficiency and its corresponding average collision number interval are independent of the capture section’s geometry and its mesh size.When the inner surface smoothness is higher than 0.2,the capture efficiency will decrease by installing any capture section.Based on the present results,the manufacturing process and material selection are suggested to be prioritized during the intake geometry design in engineering projects.Then,the highest capture efficiency can be achieved by adjusting the length and mesh size of the capture section.
