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LD-pumped acousto-optic 2-switched Pr:YLF pulsed laser at 604 nm

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Chinese Optics Letters 2024年第8期22卷 77-81页

作者： Wei Yuan Canlin Jiang Huiying Xu zhiping cai School of Electronic Science and Engineering Xiamen UniversityXiamen 361005China Center for Modern Educational Technology Guizhou Normal UniversityGuiyang 550001China Fujian Key Laboratory of Ultrafast Laser Technology and Applications Xiamen UniversityXiamen 361005China

We demonstrated an actively acousto-optic Q-switched pulsed laser based on Pr:YLF at 604 nm.A 604 nm continuous-wave(CW)laser with a maximum output power of 3.84 W was achieved for the first time,to the best of our *** Q-switched laser with a maximum average output power of 0.384 W,a narrowest pulse duration of 44.5 ns,a maximum single pulse energy of~64.1μJ,and a maximum peak power of~1.44 kW was obtained at a repetition rate of 6 *** far as we know,this was the first report of such a narrow pulse duration,high-power,and high-energy Q-switched pulsed laser at604 *** beam quality factors M_x~2and M_y~2were measured to be 2.87 and 2.40,*** results show that acousto-optic Q-switching is a promising method for obtaining pulsed lasers.

关键词： 604 nm acousto-optics Q-switching pulsed laser Pr:YLF crystal

High-power Pr^(3+):YLF continuous wave lasers at 691.7 nm,701.4 nm,705.0 nm,and 708.7 nm

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Chinese Optics Letters 2024年第8期22卷 82-86页

作者： Run Fang Rongbin Dai Huiying Xu zhiping cai Department of Electronic Engineering Xiamen UniversityXiamen 361005China School of Physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China Fujian Key Laboratory of Ultrafast Laser Technology and Applications Xiamen UniversityXiamen 361005China

Lasers from^(1)I_(6)to^(3)F_(4)transitions were first demonstrated in a Pr^(3+):YLF crystal by inserting a birefringent *** powers up to 2.44 W,2.10 W,2.01 W,and 2.42 W were obtained at 691.7 nm,701.4 nm,705.0 nm,and 708.7 nm,*** slope efficiencies were 19.8%,16.5%,15.8%,and 19.4%,*** M_(x)^(2)and M_(y)^(2)factors were measured to be 2.29and 2.03 at 691.7 nm,2.23 and 1.86 at 701.4 nm,2.31 and 2.08 at 705.0 nm,and 2.41 and 2.04 at 708.7 nm,with corresponding power fluctuations of less than 5.3%,5.6%,5.8%,and 2.9%.

关键词： Pr^(3+):YLF laser high power laser Pr^(3+):YLF crystal

Multi-Scale Location Attention Model for Spatio-Temporal Prediction of Disease Incidence

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Intelligent Automation & Soft Computing 2024年第3期39卷 585-597页

作者： Youshen Jiang Tongqing Zhou Zhilin Wang zhiping cai Qiang Ni College of Computer National University of Defense TechnologyChangsha410073China Technical Service Center for Vocational Education National University of Defense TechnologyChangsha410073China School of Computing and Communications Lancaster UniversityLancasterLA14WAUK

Due to the increasingly severe challenges brought by various epidemic diseases,people urgently need intelligent outbreak trend *** disease onset is very important to assist *** of the exist-ing work fails to make full use of the temporal and spatial characteristics of epidemics,and also relies on multi-variate data for *** this paper,we propose a Multi-Scale Location Attention Graph Neural Networks(MSLAGNN)based on a large number of Centers for Disease Control and Prevention(CDC)patient electronic medical records research sequence source data *** order to understand the geography and timeliness of infec-tious diseases,speciﬁc neural networks are used to extract the geography and timeliness of infectious *** the model framework,the features of different periods are extracted by a multi-scale convolution *** the same time,the propagation effects between regions are simulated by graph convolution and attention *** compare the proposed method with the most advanced statistical methods and deep learning ***,we conduct comparative experiments on data sets with different time lengths to observe the predic-tion performance of the model in the face of different degrees of data *** conduct extensive experi-ments on real-world epidemic-related data *** method has strong prediction performance and can be readily used for epidemic prediction.

关键词： Spatio-temporal prediction infectious diseases graph neural networks

Watt-level acousto-optically Q-switched Pr:YLF laser at 639 nm

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Chinese Optics Letters 2024年第1期22卷 76-83页

作者：薛喻宸张瑞松戴征东王中玉许惠英蔡志平 Department of Electronic Engineering School of Electronic Science and Engineering(National Model Microelectronics College)Xiamen UniversityXiamen 361005China

We present a study on a watt-level acousto-optically Q-switched Pr:YLF laser at three different repetition rates(10 kHz,20 kHz,and 50 kHz)for the first time,to the best of our *** corresponding average output powers and pulse widths were measured to be 1.14 W,1.2 W,and 1.32 W,and 40 ns,52 ns,and 80 ns,respectively.A maximum pulse energy of0.11 mJ was obtained,corresponding to a peak power of up to 2.8 kW at a repetition rate of 10 *** simulated dynamics of a fast Q-switched Pr:YLF laser is in agreement with the *** laser's ability to generate stable pulses with high peak power and short pulse width makes it highly desirable for various practical applications,such as laser machining and material processing.

关键词： red pulsed laser Pr:YLF diode pump acousto-optical Q switching

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SGX隔离技术研究综述

华中科技大学学报（自然科学版） 2024年第2期52卷 1-15页

作者：崔津华蔡志平刘柯江湖南大学半导体学院(集成电路学院) 湖南长沙410082 国防科技大学计算机学院湖南长沙410073

Intel SGX(software guard eXtensions)通过创建一个可信执行环境(TEE或enclave)来保护用户使用中的数据,它可以阻止任何特权软件,例如操作系统和虚拟机管理程序等的任意访问,确保数据和代码的机密性和完整性.尽管SGX技术拥有高安全、... 详细信息

Intel SGX(software guard eXtensions)通过创建一个可信执行环境(TEE或enclave)来保护用户使用中的数据,它可以阻止任何特权软件,例如操作系统和虚拟机管理程序等的任意访问,确保数据和代码的机密性和完整性.尽管SGX技术拥有高安全、硬件级别的保护属性,但是其构建的可信执行环境在兼容性、性能和安全性等方面仍然存在关键的研究挑战.该综述首先系统地分析和总结了五个SGX自身设计约束,它们直接导致了SGX与二进制软件和运行时语言的不兼容性或可用性差问题,致使用户面临性能、安全性和兼容性无法全部兼顾的局面.然后,针对SGX兼容性/可用性挑战,全面梳理和总结了三种不同类型的解决方案,分析了它们的优缺点;针对SGX安全性问题,对当前流行的攻击技术进行了分类,描述了攻击关键要素和根本原因;针对SGX性能瓶颈,总结了制约enclave运行性能的主要因素,分析了SGX内部设计权衡.最后,总结了SGX研究的经验教训,展望了新一代enclave或TEE技术的研究趋势,指出了若干研究方向.

关键词：可信执行环境 Intel SGX 兼容性安全性性能机密计算

异色瓢虫对苹果-蛇床草微景观中两种蚜虫的捕食功能反应及选择偏好性

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植物保护学报 2024年第1期51卷 96-105页

作者：蔡志平张兴瑞肖云丽张建萍戈峰石河子大学农学院新疆绿洲农业病虫害治理与植保资源利用重点实验室石河子832000 中国科学院动物研究所农业虫害鼠害综合治理研究国家重点实验室北京100101 山东省农业技术推广中心济南250100 山东省农业科学院植物保护研究所济南250100

为评估异色瓢虫Harmonia axyridis对苹果-蛇床草微景观中2种寄主上绣线菊蚜Aphis spiraecola和胡萝卜微管蚜Semiaphis heraclei的生物防治潜能,在实验室条件下测定异色瓢虫1~4龄幼虫和雌、雄成虫对2种蚜虫3~4龄若蚜的捕食功能反应、寻... 详细信息

为评估异色瓢虫Harmonia axyridis对苹果-蛇床草微景观中2种寄主上绣线菊蚜Aphis spiraecola和胡萝卜微管蚜Semiaphis heraclei的生物防治潜能,在实验室条件下测定异色瓢虫1~4龄幼虫和雌、雄成虫对2种蚜虫3~4龄若蚜的捕食功能反应、寻找效应以及捕食偏好性。结果表明,异色瓢虫1~4龄幼虫和雌、雄成虫对绣线菊蚜和胡萝卜微管蚜的捕食功能反应均符合HollingⅡ型功能反应类型,其中,雌成虫对绣线菊蚜的捕食能力最强,为411.284,雄成虫对胡萝卜微管蚜的捕食能力最强,为356.403;2龄幼虫对绣线菊蚜的瞬时攻击率最大,为1.231,3龄幼虫对胡萝卜微管蚜的瞬时攻击率最大,为1.277。异色瓢虫各虫态对绣线菊蚜和胡萝卜微管蚜的寻找效应均随着蚜虫密度的升高而降低。当2种蚜虫共存且总密度为60头/皿时,不同密度比例下异色瓢虫对2种蚜虫均无显著偏好性;当总密度为240头/皿,绣线菊蚜与胡萝卜微管蚜的密度比例为1∶5、2∶4、3∶3和4∶2时异色瓢虫对绣线菊蚜表现出显著的偏好性,而在密度比例为1∶5、3∶3和4∶2时异色瓢虫对胡萝卜微管蚜表现出显著的负偏好性。表明异色瓢虫对苹果-蛇床草微景观中绣线菊蚜的防控潜能更好。

关键词：异色瓢虫绣线菊蚜胡萝卜微管蚜功能反应选择偏好苹果蛇床草

An Active Defense Solution for ARP Spoofing in OpenFlow Network

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Chinese Journal of Electronics 2019年第1期28卷 172-178页

作者： XIA Jing cai zhiping HU Gang XU Ming College of Computer National University of Defense Technology School of Computer and Software Nanjing University of Information Science & Technology

As an emerging network technology,Software-defined network(SDN), has been rapidly developing for recent years due to its advantage in network management and updating. There are still a lot of open problems while applying this novel technology in reality,especially for meeting security demands. The Address resolution protocol(ARP) spoofing, a representative network attack in traditional networks is *** implement the ARP spoofing in SDN network firstly and find that the threat of ARP attack still exists and has big impact on the network. We propose a novel mechanism as defense solution for ARP spoofing oriented to OpenFlow platform. Theoretical analyzation is given, and the mechanism is implemented as a module of POX controller. Experiment results and performance evaluations show that our solution can reduce the security threat of ARP spoofing remarkably on OpenFlow platform and related SDN platforms.

关键词： Software-defined network(SDN) Address resolution protocol(ARP) spoofing OpenFlow

Developing a New Security Framework for Bluetooth Low Energy Devices

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Computers, Materials & Continua 2019年第5期59卷 457-471页

作者： Qiaoyang Zhang Zhiyao Liang zhiping cai Macao University of Science and Technology Macao National University of Defense Technology Changsha410073China

Wearable devices are becoming more popular in our daily *** are usually used to monitor health status,track fitness data,or even do medical tests,*** the wearable devices can obtain a lot of personal data,their security issues are very *** by the consideration that the current pairing mechanisms of Bluetooth Low Energy(BLE)are commonly impractical or insecure for many BLE based wearable devices nowadays,we design and implement a security framework in order to protect the communication between these *** security framework is a supplement to the Bluetooth pairing mechanisms and is compatible with all BLE based wearable *** framework is a module between the application layer and the GATT(Generic Attribute Profile)layer in the BLE architecture *** the framework starts,a client and a server can automatically and securely establish shared fresh keys following a designed protocol;the services of encrypting and decrypting messages are provided to the applications conveniently by two functions;application data are securely transmitted following another protocol using the generated *** principles are followed by the design of the framework for security *** can protect BLE based wearable devices from replay attacks,Man-in-The-Middle attacks,data tampering,and passive *** conduct experiments to show that the framework can be conveniently deployed with practical operational cost of power *** protocols in this framework have been formally verified that the designed security goals are satisfied.

关键词： Bluetooth Low Energy security privacy protocol wearable devices Internet of Things

Multi-VMs Intrusion Detection for Cloud Security Using Dempster-shafer Theory

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Computers, Materials & Continua 2018年第11期57卷 297-306页

作者： Chak Fong Cheang Yiqin Wang zhiping cai Gen Xu Faculty of Information Technology Macao University of Science and TechnologyMacao College of Computer National University of Defense TechnologyChangsha410073China

Cloud computing provides easy and on-demand access to computing resources in a configurable *** flexibility of the cloud environment attracts more and more network services to be deployed on the cloud using groups of virtual machines(VMs),instead of being restricted on a single physical *** more and more network services are deployed on the cloud,the detection of the intrusion likes Distributed Denialof-Service(DDoS)attack becomes much more challenging than that on the traditional servers because even a single network service now is possibly provided by groups of VMs across the cloud *** this paper,we propose a cloud-based intrusion detection system(IDS)which inspects the features of data flow between neighboring VMs,analyzes the probability of being attacked on each pair of VMs and then regards it as independent evidence using Dempster-Shafer theory,and eventually combines the evidence among all pairs of VMs using the method of evidence *** the traditional IDS that focus on analyzing the entire network service externally,our proposed algorithm makes full use of the internal interactions between VMs,and the experiment proved that it can provide more accurate results than the traditional algorithm.

关键词： Intrusion detection cloud computing Dempster-Shafer theory evidence fusion