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Epidemiology and genetic characterization of tet(X4)-positive Klebsiella pneumoniae and Klebsiella quasipneumoniae isolated from raw meat in Chengdu City, China

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Biosafety and Health 2024年第2期6卷 116-124页

作者： Weishuai Zhai Yiqing Wang Honghu Sun Bo fu Qidi Zhang Congming Wu Jianzhong Shen dejun Liu Yang Wang National Key Laboratory of Veterinary Public Health and Safety College of Veterinary MedicineChina Agricultural UniversityBeijing 100193China Technology Innovation Center for Food Safety Surveillance and Detection Sanya InstituteChina Agricultural University Sanya 572025China Irradiation Preservation Key Laboratory of Sichuan ProvinceChengdu Institute of Food InspectionChengdu 611135China Collge of Veterlnary Medicine Qingdao Agricultural UniversityQingdao 266109China

The rapid spread of mobile tigecycline resistance presents a significant public health threat,particularly with the increasing prevalence of tet(X4)-positive Enterobacterales across various *** study aimed to inves-tigate the epidemic features and transmission dynamics of tet(X4)-positive Klebsiella pneumoniae(***-niae)through the analysis of 206 raw meats,including pork(n=182),beef(n=16),duck(n=5),and chicken(n=3).These samples were collected from schools,markets,and restaurants in Chengdu City,China.A total of 25 isolates were obtained from 13 administrative *** isolates exhibited resistance to tetracycline,tigecycline,ampicillin,chloramphenicol,and *** half of the isolates also demon-strated resistance to streptomycin(80%),sulfamethoxazole/trimethoprim(72%),ciprofloxacin(64%),and ampicillin/sulbactam(56%).Among these strains,14 distinct sequence types(STs)were identified,revealing evidence of inter-regional clonal spread,notably among 9 *** *** analysis revealed the presence of two *** ST5 closely resembling hypervirulent *** from ***,12 isolates were capable of transferring tigecycline resistance to Escherichia coli *** plasmid analysis showed that the tet(X4)-harboring plasmids in *** could be classified into four types,primarily belonging to the IncFIA(HI1)/HI1A/HI1B hybrid plasmid(n=16)and IncFII plasmid(n=7),which significantly contributed to the cross-species dissemination of tet(X4).In summary,this study highlights the prevalence of MDR tet(X4)-positive *** in Chengdu,driven predominantly by clonal expansion and plasmid-mediated horizontal gene *** findings emphasize the importance of contin-uous surveillance of tet(X4)-positive *** in raw meat and the implementation of effective measures to control their spread.

关键词： tet(X4) Tigecycline K.pneumoniae Clonal spread Horizontal transfer

Effect of Annealing Temperature on CrN Microspheres Synthesized by CAP Technology

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Wuhan University Journal of Natural Sciences 2014年第6期19卷 544-548页

作者： TIAN Canxin YAN Shaojian HAN Bin fu dejun School of Physics and Technology Wuhan University

CrN microspheres were synthesized by using a cathodic arc plasma source system. The obtained samples were annealed in air at temperatures of 300-800 ℃ for 60 min. The influence of annealing temperature on the microstructure and surface morphology of the CrN microspheres was investigated. The CrN microspheres were characterized by means of scanning electron microscopy, transmission electron microscopy and X-ray diffraction analysis. The results show that the CrN nanoparticles arranged into leaf-like structures before annealing. With the rising of the annealing temperature, the size of CrN crystal nanoparticals became larger. When the annealing temperature exceeded the oxidation point（500 ℃）, the CrN was oxidized and the leaf-like structure was broken. With further increase of the annealing temperature（700 ℃）, the arrangement of CrN nanoparticles was changed from leaf-like structure to be discrete.

关键词： CrN microsphere annealing temperature leaf-like structure cathodic arc plasma

CrN films deposited by ion source-assisted magnetron sputtering

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Nuclear Science and Techniques 2010年第5期21卷 289-293页

作者： LIU Chuansheng TIAN Canxin LI Ming HE Jun YANG HuiJuan YANG Bing WANG Hong Jun fu dejun Key Laboratory of Artificial micro- and nano-Materials of Ministry of Education and School of Physics and Technology Wuhan University 430072 Wuhan China School of Power and Mechanical Engineering Wuhan University 430072 Wuhan China

CrN coatings were deposited on Si(100) and piston rings by ion source assisted 40 kHz magnetron *** and composition of the coatings were characterized by X-ray diffraction,atomic force microscopy,scanning electron microscopy and transmission electron *** and tribological properties were assessed by microhardness and pin-on-disc *** ion source-assisted system has a deposition rate of 3.88 μm/h,against 2.2 μm/h without ion-source *** CrN coatings prepared with ion source assistance exhibited an increase in microhardness(up to 16.3 GPa) and decrease in friction coefficient(down to 0.48) at the optimized cathode source-to-substrate *** optimized conditions,CrN coatings were deposited on piston rings,with a thickness of 25 μm and hardness of 17.85 GPa.

关键词：溅射离子源磁控溅射氮化铬铬薄膜 Si(100) 透射电子显微镜扫描电子显微镜原子力显微镜

An ultralow-energy negative cluster ion beam system and its application in preparation of few-layer graphene

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Chinese Science Bulletin 2012年第27期57卷 3556-3559页

作者： WANG ZeSong ZHANG ZaoDi ZHANG Rui WANG ShiXu fu dejun LIU JiaRui Key Laboratory of Artificial Micro-and Nano-Materials of Ministry of Education ofChina School of Physics and Technology Wuhan UniversityWuhan 430072China Texas Center for Superconductivity University of HoustonHoustonTexas 77004USA

We developed a cluster ion beam system that produces negative cluster beams of C 1-C 10 with ion current of 4.5 nA-50 A at extraction voltages ranging from 6 to 20 *** system uses the injector of a tandetron accelerator and was established by inserting an electrostatic scanner on its ion-optical line and modifying its Faraday cup into a substrate *** of clusters enables ultrashallow ion implantation at energies as low as 600 eV/atom without *** carbon clusters C 2 and C 4 were implanted into Ni/SiO 2 /Si substrates and following post-thermal treatment graphene was *** spectroscopy showed characteristic 2D peaks with G-to-2D peak ratios revealing formation of 2-3 layers of *** Raman data reveals clear effect of nonlinear cluster-surface interaction in ion beam synthesis of two-dimensional nanomaterials.

关键词：离子束系统碳团簇低能量石墨应用制备表面相互作用拉曼光谱

Hyperfine Structure of Several Soils from Western Hubei and Inner Mongolia Studied by Mossbauer Spectroscopy

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Wuhan University Journal of Natural Sciences 2014年第3期19卷 257-261页

作者： Pelenovich V O CHEN Yilong XIAO Renzheng LIU Shouyin fu dejun Department of Physics and Technology Huazhong Normal University Key Laboratory of Artificial Micro-and Nano-Materials of Ministry of Education and Accelerator Laboratory School of Physics and TechnologyWuhan University

Soil samples taken from Xilamuren Grassland,Resonant Sand Bay,Inner Mongolia,and Yichang,western Hubei Province were investigated by Mssbauer spectroscopy at room temperature and 20 *** was supplemented with phase identification and elemental analysis to obtain information about the composition and structure types of Fe-containing *** samples collected from both Xilamuren Grassland and Resonant Sand Bay,Inner Mongolia were found to have small amount of iron 1%-2%.The main phases were determined as silica,albite,and *** or three dominant doublets were observed in the Mssbauer spectra of these samples,respectively and identified as corresponding to the valence states of Fe2＋and Fe3＋.A sextet observed in all the spectra is attributed to the hematite *** temperature Mssbauer measurements have revealed Morin transition.

关键词： Mossbauer spectroscopy hyperfine structure hematite

Structure and Magnetic Properties of ZnO:Cr Prepared by CrIonIm plantation into ZnO Crystals

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Wuhan University Journal of Natural Sciences 2013年第4期18卷 283-288页

作者： LIN Baozhu WANG Lingling Yuldashev Sh U fu dejun KANG T W Key Laboratory of Artificial Micro-and Nano-Materials of Ministry of Education/School of Physics and Technology Wuhan University Quantum-functional Semiconductor Research Center Dongguk University

ZnO：Cr layer was prepared by Cr ion implantation into ZnO bulk crystals. The structural, optical, and magnetic properties of the ZnO：Cr layer were studied with X-ray diffraction, photoluminescence, and superconductor quantum interferometer, respectively. The ZnO：Cr layer implanted Cr with a dose of 5 10 16 cm 2 remained wurtzite structure and exhibited near-band-edge photoluminescence at 3.365 eV with full-width at half-maximum of 8.4 meV at 10 K. The magnetic measurement showed that the ferromagnetism changed at room temperature by different Cr concentration. For samples implanted to high doses, remanent magnetization reached 1.805 10 -4 emu/g and coercive field was 244.5 Oe. Hall effect measurement showed a decrease of the resistivity from 251.7 cmto 28.6 cmafter annealing at 800 ℃. The magnetism is interpreted by bound magnetic polarons, which were taken into account of the process that electrons were locally trapped by oxygen vacancies and occupied the orbitals that overlapped with d shell of neighboring Cr ions.

关键词： ion implantation ZnO chromium ferromagnetic property

Influence of Target-Substrate Distance and Sputtering Power on Chromium Oxide Films Prepared by Medium-Frequency Magnetron Sputtering

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Wuhan University Journal of Natural Sciences 2010年第5期15卷 440-443页

作者： YANG Huijuan,HE Jun,TIAN Canxin,LIU Chuansheng,fu dejun School of Physics and Technology,Wuhan University,Wuhan 430072,Hubei,China School of Physics and Technology Wuhan University Wuhan Hubei China

Chromium oxide films were deposited on Si（100） substrates by medium-frequency（MF） unbalanced magnetron sputtering at different target-substrate distances DTS（60,100,120 mm） and sputtering power（2.8,5.6,11.2 kW）,*** structure,surface morphologies,and microhardness of the chromium oxide films were examined by X-ray diffraction（XRD）,atomic force microscopy（AFM）,and microhardness *** results indicate that elevated MF sputtering power can improve the crystallization of the films;The DTS value affects the structure of the films by changing the preferential orientation from CrO3（221） to Cr2O3（116）;The microhardness of the chromium oxide films is found to increase with the sputtering *** preparing the Cr2O3-dominated films with comparatively high-performance,the optimized condition is the target-substrate distance of 100 mm and MF sputtering power of 11.2 kW.

关键词： chromium oxide magnetron sputtering microstruc-ture hardness

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井地2.5维DC反演研究

物探化探计算技术 2019年第3期41卷 365-370页

作者：付德俊广东核力工程勘察院

开展了不同观测方式的井地2.5D直流电阻率反演研究。①从2.5维直流电阻率满足的边值问题出发,采用变分原理结合节点线性基函数推导了2.5维井地DC满足的积分弱解形式;②构建了二阶最大平滑稳定泛函的2.5维井地直流电阻率正则化目标函数,... 详细信息

开展了不同观测方式的井地2.5D直流电阻率反演研究。①从2.5维直流电阻率满足的边值问题出发,采用变分原理结合节点线性基函数推导了2.5维井地DC满足的积分弱解形式;②构建了二阶最大平滑稳定泛函的2.5维井地直流电阻率正则化目标函数,采用共轭梯度算法对正则化目标函数进行最优化求解,并采用逐步衰减正则化因子的求解策略来提高反演的稳定性;③设计了均匀半空间模型得到的数值解与解析解对比,电位的相对误差在2%以内,阐述正演算法的正确性和高精度。另外,分析了不同观测装置的2.5维井地直流电阻率异常体特征,并对不同观测方式对2.5维井地DC理论数据进行反演研究。研究结果表明,井中数据的引入提高了2.5DC对纵向探测的分辨率能力,同时提高了2.5DC反演有效性以及准确性。

关键词：井地直流电法共轭梯度法有限单元法最大平滑稳定因子

Polarization Characteristics of the Deformed Low-Mode Fiber Waveguides with Polarization Conservation

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Journal of Electromagnetic Analysis and Applications 2011年第4期3卷 128-132页

作者： Uygun V. Valiev Alexandr A. Simonov dejun fu Davron R. Dzhuraev 不详

In this work the results of polarization researches of low-optical fiber waveguides with conservation of polarization are presented. Obtained results quite convincingly testify regarding a high sensitivity low-mode regime of work of an optical fiber to anisotropic external influences, in comparison with one-mode regime of work of the same fibre. This result, can represent a big practical value at the realization of high-sensitivity fiber-optical devices of different physical values.

关键词： Birefringent Optical Fiber Single-Mode or Few-Mode Optical Fibers Fiber-Optical Sensor Polarization Optical Modulator Circularly Polarized Light Photoelastic Effect Anisotropic Deformations