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Profiling the antibiotic resistome in soils between pristine and human-affected sites on the Tibetan Plateau

Journal of Environmental Sciences 2022年第1期34卷 442-451页

作者： Hang Wang Xiaoxuan Su Jianqiang Su Yongguan Zhu kai ding Key Lab of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China Yunnan Key Laboratory of Plateau Wetland Conservation Restoration and Ecological ServicesSouthwest Forestry UniversityKunming 650224China National Plateau Wetlands Research Center Southwest Forestry UniversityKunming 650224China

With increasing pressure from anthropogenic activity in pristine environments,the comprehensive profiling of antibiotic resistance genes(ARGs)is essential to evaluate the potential risks from human-induced antibiotic resistance in these under-studied ***,we characterized the microbial resistome in relatively pristine soil samples collected from four distinct habitats on the Tibetan Plateau,using a Smart chip based high-throughput q PCR *** compared these to soils from the same habitats that had been subjected to various anthropogenic activities,including residential sewage discharge,animal farming,atmospheric deposition,and tourism *** to pristine samples,an average of23.7%more ARGs were detected in the human-affected soils,and the ARGs enriched in these soils mainly encoded resistances to aminoglycoside and *** the four habitats studied,soils subjected to animal farming showed the highest risks of ARG enrichment and *** shown,the number of ARGs enriched(a total of 42),their fold changes(17.6 fold on average),and the co-occurrence complexity between ARGs and mobile genetic elements were all the highest in fecal-polluted *** well as antibiotics themselves,heavy metals also influenced ARG distributional patterns in Tibetan ***,compared to urban areas,the Tibetan Plateau had a low potential for ARG selection and exhibited low carriage of ARGs by mobile genetic elements,even in environments impacted by humans,suggesting that these ARGs have a limited capacity to *** present study examined the effects of multiple anthropogenic activities on the soil resistomes in relatively pristine environments.

关键词： Antibiotic resistance gene Resistome risk Tibetan plateau Animal farming Anthropogenic activity

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Evolution Handoff Strategy for Real-Time Video Transmission over Practical Cognitive Radio Networks

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China Communications 2015年第2期12卷 141-154页

作者： LIU Fa MA Yongkui ZHAO Honglin ding kai Communication Research Center Harbin Institute of Technology Department of Electrical Engineering and Computer Science University of California

The transmission delay of realtime video packet mainly depends on the sensing time delay(short-term factor) and the entire frame transmission delay(long-term factor).Therefore,the optimization problem in the spectrum handoff process should be formulated as the combination of microscopic optimization and macroscopic *** this paper,we focus on the issue of combining these two optimization models,and propose a novel Evolution Spectrum Handoff(ESH)strategy to minimize the expected transmission delay of real-time video *** the microoptimized model,considering the tradeoff between Primary User's(PU's) allowable collision percentage of each channel and transmission delay of video packet,we propose a mixed integer non-linear programming *** scheme is able to achieve the minimum sensing time which is termed as an optimal stopping *** the macro-optimized model,using the optimal stopping time as reward function within the partially observable Markov decision process framework,the EHS strategy is designed to search an optimal target channel set and minimize the expected delay of packet in the long-term real-time video ***,the minimum expected transmission delay is obtained under practical cognitive radio networks' conditions,i.e.,secondary user's mobility,PU's random access,imperfect sensing information,etc..Theoretical analysis and simulation results show that the ESH strategy can effectively reduce the transmission delay of video packet in spectrum handoff process.

关键词： practical cognitive radio networks spectrum handoff process partially observable Markov decision process video transmission

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A new proof of Honeycomb Conjecture by fractal geometry methods

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Frontiers of Mechanical Engineering 2013年第4期8卷 367-370页

作者： Tong ZHANG kai ding Research Center for Solid Mechanics Beihang University School of Engineering Brown University School of Instrument Science and Optical Engineering Beihang University

Based on fractal geometry,we put forward a concise and straightforward method to prove Honeycomb Conjecture—a classical mathematic *** wins the most efficient covering unit in the twodimensional space,compared with the other two covering units—triangle and *** this point of view,honeycomb is treated as a hierarchical fractal structure that fully fills the ***,the total side length and area are easily calculated and from the results,the covering efficiency of each possible unit is provided quantitatively.

关键词： Honeycomb Conjecture fractal geometry hierarchical fractal structure hierarchical structure Honeycombs side length Fractals

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High starter phosphorus fertilization facilitates soil phosphorus turnover by promoting microbial functional interaction in an arable soil

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Journal of Environmental Sciences 2020年第8期32卷 179-185页

作者： Hongzhe Li Qingfang Bi kai Yang Simon bo Lasson Bangxiao Zheng Li Cui Yongguan Zhu kai ding Key Laboratory of Urban Environment and Health Institute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of the Chinese Academy of Sciences Beijing 100049China Key Laboratory of Subtropical Soil Science and Plant Nutrition of Zhejiang Province College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China Department of Plant and Environmental Sciences Faculty of ScienceUniversity of CopenhagenThorvaldsensvej 401871 FrederiksbergDenmark Faculty of Biological and Environmental Sciences Ecosystems and Environment Research Programme Niemenkatu 73FI-15140 University of HelsinkiFinland State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

Microbial phosphorus(P)turnover is critical in C utilization efficiency in *** is therefore necessary to understand the P mobilization processes occurring during P fertilization in order to ensure both crop yield and environmental ***,we established a controlled pot experiment containing soil amended with three different levels of starter P fertilizer and collected soil samples after 30,60,and 90 days of *** microbial element cycling(QMEC)smart chip technology and 16S rRNA gene sequencing were used to investigate functional gene structures involved in carbon,nitrogen and P cycling and the bacterial community composition of the collected *** P fertilization did not significantly affect the structure of the soil microbial community,some rare microbiota were changed in particular phosphorus-solubilizing bacteria were enriched at the high P fertilization level,suggesting that the rare taxa make an important contribution to P turnover.P fertilization also altered the functional gene structure,and high P concentrations enhanced the functional gene diversity and *** redundancy analysis further revealed that changes in rare taxa and functional genes of soil microorganisms drive the alteration of soil P *** findings extend our understanding of the microbial mechanisms of P turnover.

关键词： Quantitative microbial element cycling(qmec)smart chip Functional genes Rare microbiota

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双梁桥式起重机主梁动态特性分析及响应面优化

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邵阳学院学报（自然科学版） 2024年第3期21卷 48-56页

作者：陈宇丁凯贡宇豪赵峻巢湖学院机械工程学院安徽巢湖238000

为提升起重机主梁结构的抗振性能,针对双梁桥式起重机主梁进行动力学分析,并基于响应面法对主梁结构进行动力学优化。针对双梁桥式起重机主梁模型进行有预应力的模态分析和谐响应分析,得出主梁结构的固有频率、振型及频响曲线,对比分析... 详细信息

为提升起重机主梁结构的抗振性能,针对双梁桥式起重机主梁进行动力学分析,并基于响应面法对主梁结构进行动力学优化。针对双梁桥式起重机主梁模型进行有预应力的模态分析和谐响应分析,得出主梁结构的固有频率、振型及频响曲线,对比分析结果,选择谐响应分析下的X方向、Y方向的最大位移作为后续优化设计的目标函数。通过灵敏度分析筛选设计变量,并运用面心复合设计获取样本点,构建Kriging响应面模型进行结构和材料参数优化。结果显示,优化后的主梁相比原型主梁,谐响应分析下的X方向、Y方向的最大位移分别降低了23.1%和25.5%,其质量降低了1.8%,这对主梁结构设计及抗振性能提升提供了技术支持。

关键词：起重机主梁模态分析响应谱分析响应面分析

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Train probe for beam diagnostics of the SC200 superconducting cyclotron

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Nuclear Science and Techniques 2020年第10期31卷 95-104页

作者： Le-Xing Hu kai-Zhong ding Yun-Tao Song Yu-Cheng Wu kai Yao Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Hefei CAS Ion Medical and Technical Devices Co. LtdHefei 230088China

The SC200 proton therapy system commissioned by the Hefei CAS Ion Medical and Technical Devices Co.,Ltd.(HFCIM;Hefei,China)and the Joint Institute for Nuclear Research(JINR;Dubna,Russia)has made significant progress.A main radial beam diagnostic system(MRBDS)equipped with a new type of train probe was developed to satisfy the requirements of beam *** this paper,the detailed design of the mechanical structure and electronics system of the MRBDS is *** electronics system,which includes hardware and software components,was tested and *** results show that measurement errors can be significantly reduced by the designed calibration *** repeatability of the mechanical structure was also verified,and the experimental results indicate that the unidirectional repeatability of the positioning is better than 0.3 ***,the MRBDS was used to measure the phase lag of the particles in the beam,and the results showed a high degree of agreement with theoretical calculations,which proved the applicability and high efficiency of the MRBDS.

关键词： Train probe Beam diagnostic Cyclotron Measurement and calibration Commissioning

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Numerical study on the response of the Earth's magnetosphere-ionosphere system to a super solar storm

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Science China Earth Sciences 2012年第6期55卷 1037-1042页

作者： WANGChi LI Hui GUO XiaoCheng ding kai HUANG ZhaoHui State Key LaboraWry of Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China Graduate School of Chinese Academy of Sciences Beijing 100049 China

With the approaching of the 24th solar cycle peak year （2012-2014）, the impacts of super solar storms on the geospace envi- ronment have drawn attentions. Based on the geomagnetic field observations during Carrington event in 1859, we estimate the interplanetary solar wind conditions at that time, and investigate the response of the magnetosphere-ionosphere system to this extreme solar wind conditions using global 3D MHD simulations. The main findings include： l） The day-side magnetopause and bow shock are compressed to 4.3 and 6.0 Re （Earth radius）, and their flanks are also strongly compressed. The magneto- pause shifts inside the geosynchronous orbit, exposing geosynchronous satellites in the solar wind in the magnetosheath. 2） During the storm, the region-1 current increases by about 60 times, and the cross polar potential drop increases by about 80 times; the reconnection voltage is about 5 to 6 times larger than the average storms, which means a larger amount of the solar wind energy enters the magnetosphere, resulting in strong space weather phenomena.

关键词： space weather solar storm magnetosphere-ionosphere system numerical simulation

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Investigation on induction brazing of profiled cBN wheel for grinding of Ti-6Al-4V

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Chinese Journal of Aeronautics 2021年第4期34卷 132-139页

作者： Qilin LI kai ding Weining LEI Jiajia CHEN Qingshan HE Zhenzhen CHEN School of Mechanical Engineering Jiangsu University of TechnologyChangzhou 213001China Nanjing Forestry University Nanjing 210010China Henan University of Technology Zhenzhou 450007China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education&Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310032China

Profiled monolayer cBN wheel was induction brazed for grinding of titanium dovetail slot in this *** at acquiring a uniform temperature distribution along the profiled surface and reducing the thermal deformation of the brazed wheel,a finite element model was established to investigate the temperature uniformity during induction brazing.A suitable induction coil and the related working parameters were designed and chosen based on the simulation ***-Cu-Ti alloy and cBN grains were applied in the induction brazing *** results showed geometric deformation of the brazed wheel was no more than 0.01 mm and chemical reaction layer were found on the brazed joint *** validation tests were carried out by grinding of Ti-6 Al-4 V *** to the electroplated wheel,the brazed wheel showed better performance such as low specific grinding energy and good ground quality in grinding of Ti-6 Al-4 V *** wear was found to be the main failure mode for the induction brazed wheel,while adhesion and grains pull-out were the main failure mode for the electroplated wheel.

关键词： Grinding performance Induction brazing Profiled cBN wheel Specific grinding energy Temperature uniformity

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Dimension reduction based SPM for image classification 25th

Dimension reduction based SPM for image classification

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第25届中国控制与决策会议

作者： Weihai Chen kai ding Xingming Wu School of Automation Science and Electrical Engineering Beihang University

ISBN: (纸本)9781467355322

It is difficult to classify images with high accuracy when the dataset is relatively large. We try to improve classification precision in spatial pyramid matching （SPM） framework by dimension reduction. When clustering high dimension data, researchers encounter dimensional curse problem which would weaken statistical significance of the data. This problem degrades the performance of SPM and other related works based on clustering property of the high dimensional "SIFT" features. We propose a global dimensional reduction approach, reducing 128-d SIFT features to 32-d, and follow processes of locality-constrained linear coding to calculate feature histogram. Experimental results show that the proposed method leads to a better clustering property for the local descriptors, and increases image classification precision comparing to other state of the art algorithms on several image ***2007Bosch2007

关键词： data clustering image classification dimension reduction.

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肩关节镜下肱二头肌长头腱转位强化缝合修复巨大肩袖撕裂损伤

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中国组织工程研究 2024年第35期28卷 5675-5680页

作者：丁凯姚雨婧李志鹏王磊顾长源束昊孙鲁宁南京中医药大学附属医院(江苏省中医院) 江苏省南京市210004 江苏省中医院骨科运动医学中心江苏省南京市210004

背景:肱二头肌长头腱转位是治疗巨大肩袖撕裂的常用手术方式,目前对于肱二头肌长头腱转位的临床疗效报道较少且转位后肩袖再撕裂的相关因素尚无定论。目的:观察肩关节镜下肱二头肌长头腱转位加强缝合治疗巨大肩袖撕裂的临床疗效。方法:... 详细信息

背景:肱二头肌长头腱转位是治疗巨大肩袖撕裂的常用手术方式,目前对于肱二头肌长头腱转位的临床疗效报道较少且转位后肩袖再撕裂的相关因素尚无定论。目的:观察肩关节镜下肱二头肌长头腱转位加强缝合治疗巨大肩袖撕裂的临床疗效。方法:回顾性分析2019年3月至2022年5月江苏省中医院收治的28例巨大肩袖撕裂患者的临床资料,年龄(61.79±10.50)岁,均在关节镜下行肱二头肌长头腱转位加强缝合进行修复。术前及术后1年,评估患者目测类比评分、加州大学洛杉矶分校(UCLA)评分、美国肩肘外科协会(ASES)评分、Constant-Murley肩关节功能评分及肩关节活动度;术后1年,利用肩关节MRI检查修复结构的完整性。根据术后1年的Sugaya分型将23例(28例失访5例)患者分为肌腱完整组(n=18)、肌腱撕裂组(n=5),根据术中肱二头肌长头腱质量分为正常组(n=8)、退变组(n=9)、部分撕裂组(n=6),对比上述指标的差异。结果与结论:(1)与术前比较,23例患者术后1年的目测类比评分、UCLA评分、ASES评分、Constant-Murley肩关节功能评分及肩关节活动度均明显改善(P0.05);正常组、退变组、部分撕裂组术后1年的目测类比评分、UCLA评分、ASES评分、Constant-Murley肩关节功能评分及肩关节活动度比较差异均无显著性意义(P>0.05);(2)术后1年,患侧肩关节MRI见18例患者缝合肌腱愈合良好,愈合率78%;(3)肩关节镜下肱二头肌长头腱转位加强缝合可为难以完成完全修补的巨大肩袖撕裂提供可靠修补,能明显缓解肩关节疼痛、恢复肩关节功能。

关键词：关节镜巨大肩袖撕裂肱二头长头腱转位加强缝合影响因素

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