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Selective Atom-Cavity Interaction Scheme for Quantum Controlled-NOT Gate Using Four-Level Atoms in Cavity QED System 被引量:1
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作者 TANG Shi-Qing ZHANG Deng-Yu +2 位作者 XIE Li-Jun ZHAN Xiao-Gui GAO Feng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第2期247-251,共5页
We propose a scheme for realization a quantum Controlled-NOT gate operation using two four-level atoms through a selective atom cavity interaction in cavity quantum electrodynamics system. In our protocol, the quantum... We propose a scheme for realization a quantum Controlled-NOT gate operation using two four-level atoms through a selective atom cavity interaction in cavity quantum electrodynamics system. In our protocol, the quantum information is encoded on the stable ground states of the two atoms. During the interaction between atoms and single-mode vacuum cavity-field, the atomic spontaneous emission is negligible as the large atom-cavity detuning effectively suppresses the spontaneous decay of the atoms. The influences of the dissipation and the deviation of interaction time on fidelity and corresponding success probability of the quantum Controlled-NOT gate and the experimental feasibility of our proposal are also discussed. 展开更多
关键词 controlled-NOT gate four-level atom cavity QED FIDELITY
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Detecting Compromised Kernel Hooks with Support of Hardware Debugging Features 被引量:3
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作者 Shi Wenchang Zhou HongWei +1 位作者 Yuan JinHui Liang Bin 《China Communications》 SCIE CSCD 2012年第10期78-90,共13页
Although there exist a few good schemes to protect the kernel hooks of operating systems, attackers are still able to circumvent existing defense mechanisms with spurious context infonmtion. To address this challenge,... Although there exist a few good schemes to protect the kernel hooks of operating systems, attackers are still able to circumvent existing defense mechanisms with spurious context infonmtion. To address this challenge, this paper proposes a framework, called HooklMA, to detect compromised kernel hooks by using hardware debugging features. The key contribution of the work is that context information is captured from hardware instead of from relatively vulnerable kernel data. Using commodity hardware, a proof-of-concept pro- totype system of HooklMA has been developed. This prototype handles 3 082 dynamic control-flow transfers with related hooks in the kernel space. Experiments show that HooklMA is capable of detecting compomised kernel hooks caused by kernel rootkits. Performance evaluations with UnixBench indicate that runtirre overhead introduced by HooklMA is about 21.5%. 展开更多
关键词 operating system kernel hook integrity HARDWARE control flow
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Kinematics Analysis Based on Screw Theory of a Humanoid Robot 被引量:2
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作者 MAN Cui-hua FAN Xun +1 位作者 LI Cheng-rong ZHAO Zhong-hui 《Journal of China University of Mining and Technology》 EI 2007年第1期49-52,共4页
A humanoid robot is a complex dynamic system for its idiosyncrasy. This paper aims to provide a mathematical and theoretical foundation for the design of the configuration, kinematics analysis of a novel humanoid robo... A humanoid robot is a complex dynamic system for its idiosyncrasy. This paper aims to provide a mathematical and theoretical foundation for the design of the configuration, kinematics analysis of a novel humanoid robot. It has a simplified configuration and design for entertainment purpose. The design methods, principle and mechanism are discussed. According to the design goals of this research, there are ten degrees of freedom in the two bionic arms. Modularization, concurrent design and extension theory methods were adopted in the configuration study and screw theory was introduced into the analysis of humanoid robot kinematics. Comparisons with other methods show that: 1) only two coordinates need to be established in the kinematics analysis of humanoid robot based on screw theory; 2) the spatial manipulator Jacobian obtained by using twist and exponential product formula is succinct and legible; 3) adopting screw theory to resolve the humanoid robot arms kinematics question can avoid singularities; 4) using screw theory can solve the question of specification insufficiency. 展开更多
关键词 bionics arm screw theory extension theory Jacobian matrix modularization design
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Spatial and Temporal Changes of Wetlands on the Qinghai-Tibetan Plateau from the 1970s to 2010s 被引量:5
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作者 XUE Zhenshan LYU Xianguo +4 位作者 CHEN Zhike ZHANG Zhongsheng JIANG Ming ZHANG Kun LYU Yonglei 《Chinese Geographical Science》 SCIE CSCD 2018年第6期935-945,共11页
Wetlands on the Qinghai-Tibetan Plateau (QTP) perform a dazzling array of vital ecological functions and are one of the most fragile ecosystems in the world. Timely and accurate information describing wetland resour... Wetlands on the Qinghai-Tibetan Plateau (QTP) perform a dazzling array of vital ecological functions and are one of the most fragile ecosystems in the world. Timely and accurate information describing wetland resources and their changes over time is becoming more important in their protection and conservation. By using remote sensing data, this study intended to investigate spatial distribution and temporal variations of wetlands on the QTP at different watershed scales from 1970s to 2010s. Results show that wetlands on the QTP have undergone widespread degradation from 1970s to 2010s, with nearly 6.4% of their area being lost. Areas of freshwater marsh, salt marsh and wet meadow declined by 46.6%, 53.9% and 15.6%, respectively, while lake area increased by 14.6%. The most extensive losses of natural wet/ands have occurred in endorheic basins, such as in the Kunlun-Altun-Qilian Drainage Basin and Qiangtang Basin, which shrank by 44.5% and 33.1%, respectively. A pronounced increase in temperature tends to facilitate the evaporation process and reduce water availability for wetlands, One-third of the wetlands on the QTP are under threat of being submerged due to lakes rising in recent years. More research is needed to gain insight into the interaction mechanisms behind observed variations and potential impacts from further warming in the future. 展开更多
关键词 WETLAND spatial and temporal change climate change Qinghai-Tibetan Plateau (QTP)
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Assessment of Heavy Metals Control from Soil and Vegetable Plants in Different Growing Systems
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作者 Neculai Munteanu Vasile Stoleru Carmen Hura 《Journal of Agricultural Science and Technology(A)》 2012年第5期716-722,共7页
Heavy metals contents of soils and vegetable edible parts were studied at three crop systems (conventional, in conversion and organic) from seven traditional sites for vegetable growing in North-eastern Romania, dur... Heavy metals contents of soils and vegetable edible parts were studied at three crop systems (conventional, in conversion and organic) from seven traditional sites for vegetable growing in North-eastern Romania, during 2010. The main goal of the research was to find a correlation between the heavy metals contents and the crop systems. Determination of heavy metals was performed by atomic absorption spectrometry (AAS), using a Shimadzu spectrophotometer, 6300 version, equipped with graphite furnace and autosampler. Heavy metals contents in the soils varied with the metals and locations, according to the crop system. The following experimental average contents were determined: Mn-262.03 mg kg1, Zn-45.60 mg kgq, Cu-28.53 mg kgl, Pb-5.20 mg kg1 and Cd-1.84 mg kg1. In vegetable edible parts, heavy metal varied with metals, sites and plant species, without a significant correlation with crop system. The trend of heavy metals in conventional and organic crops was Zn 〉 Cu 〉 Mn = Pb 〉 Cd, but in conversion crops it was Zn 〉 Mn = Pb 〉 Cu 〉 Cd. The highest content was of Zn (4.85 mg kg't), at a cabbage crop in conversion. Cd was not detected in vegetable products and Pb was detected only in some vegetable samples. Research emphasized that heavy metals contents from soil and vegetable edible parts did not exceed the admitted maximum limits, according to Romanian and European Regulations. Final conclusion of research is that no correlations exist between crop systems and heavy metals contents from soil and plant. 展开更多
关键词 Vegetable growing conventional agriculture organic agriculture POLLUTION crop systems.
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Maglev self-excited vibration suppression with a virtual sky-hooked damper 被引量:1
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作者 李金辉 李杰 +1 位作者 周丹峰 王连春 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第6期1363-1371,共9页
This work addresses the problem of self-excited vibration,which degrades the stability of the levitation control,decreases the ride comfort,and restricts the construction cost of maglev system.Firstly,a minimum model ... This work addresses the problem of self-excited vibration,which degrades the stability of the levitation control,decreases the ride comfort,and restricts the construction cost of maglev system.Firstly,a minimum model containing a flexible bridge and a single levitation unit is presented.Based on the simplified model,the principle underlying the self-excited vibration is explored.After investigations about the energy transmission between the levitation system and bridge,it is concluded that the increment of modal damping can dissipate the accumulated energy by the bridge and the self-excited vibration may be avoided.To enlarge the equivalent modal damping of bridge,the sky-hooked damper is adopted.Furthermore,to avoid the hardware addition of real sky-hooked damper,considering the fact that the electromagnet itself is an excellent actuator that is capable of providing sufficiently fast and large force acting on the bridge to emulate the influence of the real sky-hooked damper,the technique of the virtual sky-hooked damper is proposed.The principle underlying the virtual sky-hooked damper by electromagnet is explored and the vertical velocity of bridge is estimated.Finally,numerical and experimental results illustrating the stability improvement of the vehicle-bridge interaction system are provided. 展开更多
关键词 MAGLEV vehicle-bridge interaction system self-excited vibration sky-hooked damper
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Digitally Controlled Boost PFC Converters Operating with Large Scale Load Fluctuations 被引量:1
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作者 刘艳丽 王清龙 +2 位作者 王宇翠 张烨 朱乐为 《Transactions of Tianjin University》 EI CAS 2014年第4期292-298,共7页
When boost power factor correction(PFC) circuit works with large scale load fluctuations, it is easy to cause a higher total harmonic distortion and a lower power factor because of traditional controllers and inductor... When boost power factor correction(PFC) circuit works with large scale load fluctuations, it is easy to cause a higher total harmonic distortion and a lower power factor because of traditional controllers and inductor current mode. To solve this problem, this paper proposes a PFC control system, which can operate with load fluctuations up to 1 000 W by using duty cycle feed-forward control theory to achieve smooth switching mode. The duty cycles in the next period of the control system are pre-estimated in the current cycle, which enhances the speeds of AD samplers and switching frequency, and reduces the cost and volume of the equipment to some extent. Introductions of system decoupling and feed-forward of input-voltage greatly improve the system performance. Both theoretical simulation and experimental results prove the advantage of the proposed scheme. 展开更多
关键词 power factor correction (PFC) large scale load fluctuation system decoupling FEED-FORWARD input voltage
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Control of Spiral Waves in an Excitable Medium by Applying Close Loop Feedback Scheme
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作者 LIU Yong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第12期1361-1364,共4页
In this paper, a scheme of close-loop feedback is proposed to induce transition of spiral pattern in the excitable media, which is described with the modified FitzHugh-Nagumo model. The numerical simulation results co... In this paper, a scheme of close-loop feedback is proposed to induce transition of spiral pattern in the excitable media, which is described with the modified FitzHugh-Nagumo model. The numerical simulation results confirm that the stable rotating spiral wave is removed and the whole media becomes homogeneous when appropriate intensity of feedback is used no matter whether the coupling feedback is imposed on the whole media or the sites in one line in the media. 展开更多
关键词 spiral wave close loop feedback FitzHugh-Nagumo model
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中国文学“走出去”之翻译系统建构 被引量:20
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作者 魏泓 赵志刚 《外语教学》 CSSCI 北大核心 2015年第6期109-113,共5页
翻译问题是个系统问题;本文从系统观视角对如何强化翻译功能的问题进行了比较全面的探讨。中国文学"走出去"是个系统工程,翻译是其中重要的子系统。翻译是翻译系统中的译者在源语系统与目标语系统之间基于主体间性之上的再创... 翻译问题是个系统问题;本文从系统观视角对如何强化翻译功能的问题进行了比较全面的探讨。中国文学"走出去"是个系统工程,翻译是其中重要的子系统。翻译是翻译系统中的译者在源语系统与目标语系统之间基于主体间性之上的再创造,译者应具有系统运作的多维能力,酌情采用增益翻译策略。翻译系统与原作系统、传播与接受系统、研究系统之间互为条件、互相作用。另外,经济政治等无形系统也会影响着翻译系统的运转与优化。我们应以系统思维来打造翻译的内部系统,建造翻译的相邻系统,铸造翻译外部的无形系统。 展开更多
关键词 中国文学“走出去” 翻译系统 增益策略 原作系统 传播与接受系统 无形系统
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Logical Design and Control of Network in Local Mine Air-Reversing System
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作者 李建民 王省身 《Journal of China University of Mining and Technology》 2001年第1期33-38,共6页
This paper sets up a mathematical model of switching network and switching function by utilizing graph theory to describe the logical function of different paths.The function varies with open and closed states of air ... This paper sets up a mathematical model of switching network and switching function by utilizing graph theory to describe the logical function of different paths.The function varies with open and closed states of air doors in a complex mine air sub network, and the computer program for solving the switching function of complex networks are offered. It gives the method for discriminating a reversible branch in a complex network by means of the switching function, and the method of counter inverted logical control of airflow inversion by means of open and short circuit conversion of key branches. The research has solved the problem of the stablization of air flow for normal ventination and reversing ventination in a diagonal network. 展开更多
关键词 mine ventination air reversing graph theory local mine air network
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Work entransy and its applications 被引量:14
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作者 CHENG XueTao LIANG XinGang 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第12期2097-2103,共7页
The entransy theory has been applied to the analyses of heat-work conversion systems. The physical meaning and the applications of work entransy are analyzed and discussed in this paper. Work entransy, which is clarif... The entransy theory has been applied to the analyses of heat-work conversion systems. The physical meaning and the applications of work entransy are analyzed and discussed in this paper. Work entransy, which is clarified to be a process dependent quantity, is not the entransy of work, but the system entransy change accompanying work transfer. The relationship between the work entransy and the output work is set up. When the application preconditions are satisfied, larger work entransy leads to larger output work. Entransy loss, which was proposed and applied to heat work conversion processes with irreversible heat transfer, is the net entransy flow into the system and the summation of work entransy and entransy dissipation. The application preconditions of entransy loss are also discussed. 展开更多
关键词 work entransy entransy loss thermodynamic processes APPLICATION LIMITATION
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A Condition for Entropy Exchange Between Atom and Field 被引量:1
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作者 闫学群 吕玉光 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第2期209-213,共5页
We study the entropy correlations between subsystems in a bipartite system.Our results show that there is an entropy exchange effect(i.e.,anticorrelation phenomenon) between atom and field.Especially we prove that the... We study the entropy correlations between subsystems in a bipartite system.Our results show that there is an entropy exchange effect(i.e.,anticorrelation phenomenon) between atom and field.Especially we prove that there exists a condition for complete entropy exchange between atom and field. 展开更多
关键词 quantum correlation entropy exchange atom and field
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Quantum field entropy of the system with interaction between moving Bell-state atoms and coherent light field
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作者 张彩花 萨楚尔夫 格日乐 《Optoelectronics Letters》 EI 2011年第6期475-477,共3页
The field entropy of the system with two moving atoms interacting with the coherent state is investigated by means of the full quantum theory. Under the different initial states with two atoms, the influences of the l... The field entropy of the system with two moving atoms interacting with the coherent state is investigated by means of the full quantum theory. Under the different initial states with two atoms, the influences of the light field intensity and the atomic motion on the field entropy are discussed. The results indicate that the motion of the atoms leads to strict periodicity in the field entropy evolution. When the two atoms are in the Bell state |β11〉 initially, the system is in a completely disentangled state. For the atoms initially at other Bell states, the field periodically entangles with the atoms. 展开更多
关键词 ATOMS Coherent light ENTROPY Quantum computers
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Climate change and infectious diseases of wildlife: Altered interactions between pathogens, vectors and hosts
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作者 Milena GALLANA Marie-Pierre RYSER-DEGIORGIS Thomas WAHLI Helmut SEGNER 《Current Zoology》 SCIE CAS CSCD 2013年第3期427-437,共11页
Infectious diseases result from the interactions of host, pathogens, and, in the case of vector-borne diseases, also vec- tors. The interactions involve physiological and ecological mechanisms and they have evolved un... Infectious diseases result from the interactions of host, pathogens, and, in the case of vector-borne diseases, also vec- tors. The interactions involve physiological and ecological mechanisms and they have evolved under a given set of environmental conditions. Environmental change, therefore, will alter host-pathogen-vector interactions and, consequently, the distribution, in- tensity, and dynamics of infectious diseases. Here, we review how climate change may impact infectious diseases of aquatic and terrestrial wildlife. Climate change can have direct impacts on distribution, life cycle, and physiological status of hosts, pathogens and vectors. While a change in either host, pathogen or vector does not necessarily translate into an alteration of the disease, it is the impact of climate change on the interactions between the disease components which is particularly critical for altered disease risks. Finally, climate factors can modulate disease through modifying the ecological networks host-pathogen-vector systems are belonging to, and climate change can combine with other environmental stressors to induce cumulative effects on infectious dis- eases. Overall, the influence of climate change on infectious diseases involves different mechanisms, it can be modulated by phenotypic acclimation and/or genotypic adaptation, it depends on the ecological context of the host-pathogen-vector interactions, and it can be modulated by impacts of other stressors. As a consequence of this complexity, non-linear responses of disease sys- tems under climate change are to be expected. To improve predictions on climate change impacts on infectious disease, we sug- gest that more emphasis should be given to the integration of biomedical and ecological research for studying both the physio- logical and ecological mechanisms which mediate climate change impacts on disease, and to the development of harmonized methods and approaches to obtain more comparable results, as this would support the discrimination of case-specific versus gen- eral mechanisms . 展开更多
关键词 Climate change WILDLIFE Disease Host Pathogen Vector Species interactions
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