检索结果-南通市图书馆

Journal of Advanced Ceramics 2023年第3期12卷 526-538页

作者： Dorota Szwagierczak beata Synkiewicz-Musialska Jan Kulawik Elżbieta Czerwińska Norbert pałka Kraków Division Łukasiewicz Research Network-Institute of Microelectronics and PhotonicsKraków 30-701Poland Institute of Optoelectronics Military University of TechnologyWarszawa 00-908Poland

With the development of low dielectric permittivity materials having an ultra-low sintering temperature,testing their dielectric properties at terahertz frequencies suitable for 6G communication systems and implementation of the fabricated materials in ultra-low temperature cofired ceramics(ULTCC)were the main goals of the *** tungstate Li_(2)WO_(4)was synthesized by a solid-state reaction and used for the preparation of green tapes and test structures with cofired internal conductive layers,which are destined for substrates of microwave and submillimeter wave *** behavior,thermal effects,and mass changes of the green tapes during heating were studied using a hot-stage microscope,differential thermal analysis,and thermogravimetry.A single-phase composition was revealed for being undoped and doped with AlF3–Cab_(4)O_(7)*** impact of frequency,temperature,the addition of AlF3–Cab_(4)O_(7)and Cubi_(2)O_(4)dopants,and sintering temperature was the subject of in-depth characterization of dielectric properties in a terahertz region.A glass-free composition,ultra-low sintering temperature of 590–630℃,low roughness of the green tapes,dense microstructure,compatibility with Ag conductors,low and stable dielectric permittivity of 5.0–5.8 in a broad range of 0.2–2 THz,and low dielectric loss of 0.008–0.01 at 1 THz are the main advantages of the developed ULTCC substrates.

关键词： Li_(2)WO_(4) ultra-low temperature cofired ceramics(ULTCC) tape casting dielectric properties terahertz frequency range

Myxomycete colonization on translocated and non-translocated dead leaves from temperate and tropical forests

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Studies in Fungi 2020年第1期5卷 462-470页

作者： Rojas C Stephenson SL Rojas pa Finca Experimental Interdisciplinaria de Modelos Agroecológicos University of Costa RicaTurrialba30502-Costa Rica Engineering Research Institute University of Costa RicaSan Pedro de Montes de Oca11501-Costa Rica Department of biological Sciences University of ArkansasFayettevilleAR 72701USA

samples of dead leaves on the forest floor were collected from a locality in central Costa Rica and another locality in northwest Arkansas in the United States and then were placed in fine-mesh nylon bags,autoclaved and left out in the field for four *** of the bags prepared with sterile material from each country were placed out in the country where they were collected,and the other half were placed in the other country.A characterization of forest structure and ground leaf chemistry was carried out for both localities and both leaf *** recollected,all samples were processed for myxomycetes with the use of the moist chamber culture *** cultures yielded a total of 156 records of myxomycetes representing 16 species,but only 13 records and six species were isolated from the samples left out in Costa *** hundred percent of cultures placed out in Arkansas produced myxomycetes,whereas only 68%of those placed out in Costa Rica were positive for these *** in species richness and number of records were observed across forests where the samples were placed out,and no differences were observed based on the origin of the *** suggested that myxomycete colonization in the studied areas is primarily affected by the dynamics of the forest type and secondarily by substrate *** myxomycete species recorded on leaves with poorer chemical values are also consistent with field *** the present study,the more open character of the temperate forest in Arkansas without a film of water layer covering the leaves on the ground seemed to have played a role in the establishment of myxomycete propagules in the sterile material during the time of the investigation.

关键词： Arkansas Costa Rica myxogastrids Pea Ridge slime molds Turrialba

Unusual substructure conformations observed in crystal structures of a dicistrovirus RNA-dependent RNA polymerase suggest contribution of the N-terminal extension in proper folding

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Virologica Sinica 2023年第4期38卷 531-540页

作者： Xiang Fang Guoliang Lu Yanchun Deng sa Yang Chunsheng Hou Peng Gong Key Laboratory of Special pathogens and biosafety Wuhan Institute of VirologyChinese Academy of SciencesWuhan430207China Institute of bast Fiber Crops Chinese Academy of Agricultural SciencesChangsha410205China University of Chinese Academy of Sciences Beijing100049China Institute of Apicultural Research Chinese Academy of Agricultural SciencesBeijing100193China Hubei Jiangxia Laboratory Wuhan430207China

The Dicistroviridae is a virus family that includes many insect *** viruses contain a positive-sense RNA genome that is replicated by the virally encoded RNA-dependent RNA polymerase(RdRP)also named 3D^(pol).Compared with the Picornaviridae RdRPs such as poliovirus(PV)3D^(pol),the Dicistroviridae representative Israeli acute paralysis virus(IAPV)3D^(pol) has an additional N-terminal extension(NE)region that is about 40-residue in *** date,both the structure and catalytic mechanism of the Dicistroviridae RdRP have remain *** we reported crystal structures of two truncated forms of IAPV 3D^(pol),namelyΔ85 andΔ40,both missing the NE region,and the 3D^(pol) protein in these structures exhibited three conformational *** palm and thumb domains of these IAPV 3D^(pol) structures are largely consistent with those of the PV 3D^(pol) ***,in all structures,the RdRP fingers domain is partially disordered,while different conformations of RdRP substructures and interactions between them are also *** particular,a large-scale conformational change occurred in the motif b-middle finger region in one protein chain of theΔ40 structure,while a previously documented alternative conformation of motif A was observed in all IAPV *** experimental data on one hand show intrinsic conformational variances of RdRP substructures,and on the other hand suggest possible contribution of the NE region in proper RdRP folding in IAPV.

关键词： Israeli acute paralysis virus(IAPV) Poliovirus RNA-dependent RNA polymerase(RdRP) Crystal structure Catalytic motif

Effect of rare-earth doping on adsorption of carbon atom on ferrum surface and in ferrum subsurface:A first-principles study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2021年第9期39卷 1144-1150页

作者： Yang Yang Xiang Zhou Faqing pan Zuju Ma Rongjian sa Jun Zheng Qimin Wang Key Laboratory of Green Fabrication and Surface Technology of Advanced Metal Materials(Ministry of Education) Research Center of Modem Surface and Interface EngineeringAnhui University of TechnologyMaanshan 243002China School of Materials Science and Engineering Anhui University of TechnologyMaanshan 243002China Institute of Oceanography Ocean CollegeMinjiang UniversityFuzhou 350108China School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China

The adsorption of carbon atom on Fe surface and in Fe subsurface with and without rare earth(La and Ce)substitution in the surface layer and subsurface layer was studied by first-principles *** carbon atom is predicted to adsorb at hollow and long bridge site on Fe(100)and Fe(110),***,the carbon atom shifts to occupy preferentially hollow site on both Fe(100)and Fe(110)with rare earth atom doping at surface *** lower adsorption energies involved with stronger adsorption abilities were obtained for carbon atoms on Fe surface with rare earth doping at surface layer,which was determined by the electronic structure of the surface *** La atom was pulled out the surface after carbon adsorption due to strong interaction of La-C,which is consistent with the more charge *** the subsurface region,the carbon atom prefers to occupy at octahedral site with rare earth doping at surface layer in Fe *** strong adsorption energies of the carbon atoms on Fe surface and in Fe subsurface with rare earth pose relevant insights into the interaction between carbon and rare earth,which helps to understanding the influence mechanism of rare earth in carburizing.

关键词： Carburizing Rare earth First-principles Adsorption energy Electronic structure

影像三维重建安全辅助单孔分体内镜治疗L_(5)/S_(1)极外侧腰椎间盘突出症

在线全文

学校读者我要写书评

暂无评论

中国组织工程研究 2025年第9期29卷 1876-1882页

作者：冯志萌孙宁孙兆忠李岳飞刘昌震李洒滨州医学院附属医院脊柱外科山东省滨州市256603

背景:单孔分体内镜作为一种新型的内镜技术,适用于治疗极外侧腰椎间盘突出症。但目前国内外针对L_(5)/S_(1)这一发病率极低的极外侧腰椎间盘突出症的研究资料甚少,尚无详尽描述单孔分体内镜治疗L_(5)/S_(1)极外侧腰椎间盘突出症的影像... 详细信息

背景:单孔分体内镜作为一种新型的内镜技术,适用于治疗极外侧腰椎间盘突出症。但目前国内外针对L_(5)/S_(1)这一发病率极低的极外侧腰椎间盘突出症的研究资料甚少,尚无详尽描述单孔分体内镜治疗L_(5)/S_(1)极外侧腰椎间盘突出症的影像解剖学资料。目的:通过影像三维重建确定骨性标志点,并以该标志点准确定位L_(5)出口神经根、L_(5)/S_(1)椎间隙及其他结构之间的位置关系,辅助单孔分体内镜经后外侧入路实现对L_(5)出口神经根的减压,治疗L_(5)/S_(1)极外侧腰椎间盘突出症。方法:选择符合纳入标准的29例L_(5)/S_(1)单侧极外侧腰椎间盘突出症患者,其中男12例,女17例;年龄48-74岁。将患者的腰椎CT数据资料导入Mimics 21.0软件中重建腰椎三维模型。测量L_(5)/S_(1)相关参数:①在横突根部下缘与峡部外侧缘的交点(H)所在矢状面上测量:H分别至L_(5)出口神经根上缘、下缘的垂直距离(a1,a2);H分别至L_(5)下终板、S1上终板的垂直距离(b1,b2);H至L_(5)椎弓根下缘的垂直距离(c);②H至L_(5)椎弓根内侧壁所在矢状面的左右水平距离(d);③H至硬脊膜外侧缘所在矢状面的左右水平距离(e);④H至L_(5)下终板最外侧缘所在矢状面的左右水平距离(f);⑤在L_(5)下终板最外侧缘所在矢状面上测量:H所在横断面分别至L_(5)出口神经根上缘、下缘的垂直距离(g1,g2);H所在横断面分别至L_(5)下终板、S1上终板的垂直距离(h1,h2);⑥H至L_(5)出口神经根最后缘所在冠状面的前后水平距离(i);⑦骶骨翼后缘最高点至L_(5)下终板最后缘所在冠状面的前后水平距离(j)。结果与结论:①男女之间各相关测量参数相比差异无显著性意义(P>0.05);②a1,a2,b1,b2,c,d,e,f,h1,h2,g1,g2,i,j患侧与健侧相比差异无显著性意义(P>0.05);③观测发现,a1与c之间相比差异无显著性意义(P>0.05),表明椎弓根下缘即为L_(5)出口神经根上缘,L_(5)出口神经根紧贴椎弓根下缘并经L_(5)椎体后方向前外侧走行,H均位于L_(5)出口神经根上方;④以H作为骨性标志点,无需向上探查,无需磨除峡部,只需向下、向外侧磨除部分骨质显露L_(5)出口神经根与椎间隙,向内侧有足够的安全距离避免损伤硬脊膜来完成侧隐窝、椎间孔区域的探查减压;⑤术者可在H、L_(5)下终板最外侧缘所在的矢状面及L_(5)横突与骶骨翼构成的“矩形区域”内进行操作,越靠近内下方区域(Kambin三角)越安全;⑥提示单孔分体内镜经后外侧入路治疗L_(5)/S_(1)极外侧腰椎间盘突出症,在镜下以H作为骨性标志点定位L_(5)出口神经根及椎间隙,能实现对L_(5)出口神经根的精准、安全、有效减压。

关键词：极外侧腰椎间盘突出症单孔分体内镜影像三维重建骨性标志数字化软件

基于无人机和地面调查的典型草原“种-面积”关系

在线全文

学校读者我要写书评

暂无评论

中国环境科学 2024年第9期44卷 5169-5179页

作者：朱萨宁高吉喜万华伟尤春赫杨雪郭雨桐祝晨佳吕娜中国环境科学研究院生态研究所北京100012 生态环境部卫星环境应用中心北京100094 北京林业大学草业与草原学院北京100091

本研究以呼伦贝尔市典型草原为研究对象,通过传统地面样方调查和无人机调查,系统研究了“种-面积”关系,确定了典型草原地面与无人机调查的最小调查面积.调查结果表明:1)典型草原的物种数量与调查面积呈非线性关系,“种-面积”关系呈现... 详细信息

本研究以呼伦贝尔市典型草原为研究对象,通过传统地面样方调查和无人机调查,系统研究了“种-面积”关系,确定了典型草原地面与无人机调查的最小调查面积.调查结果表明:1)典型草原的物种数量与调查面积呈非线性关系,“种-面积”关系呈现为S=aln(bA+1).基于组合样方法,至少要包括8个1m^(2)小样方,才能达到涵盖80%物种的目标,基于巢式样法,需要的最小调查面积为8.63m^(2);2)针对典型草原,无人机调查的平均物种发现率为传统地面调查方法的81.7%,无人机可作为地面调查的辅助手段,提高调查的效率;3)在典型草原物种监测中,可选取1个或2个组合样方,并使用无人机进行4~5次随机拍摄作为补充,此时可发现典型草原物种总数的84.7%~88.3%.该方法相对传统的3~5次重复样方调查,代表性更高,调查效率更高.

关键词： “种-面积”关系无人机地面调查典型草原

Generation of valley pump currents in silicene

在线全文

学校读者我要写书评

暂无评论

Chinese Physics b 2019年第1期28卷 570-574页

作者： John Tombe Jada Marcellino Mei-Juan Wang sa-Ke Wang Department of Physics Southeast University College of Science Jinling Institute of Technology

We propose a workable scheme for generating a bulk valley pump current in a silicene-based device which consists of two pumping regions characterized by time-dependent strain and staggered potentials, respectively. In a one-dimension model, we show that a pure valley current can be generated, in which the two valley currents have the same magnitude but flow in opposite directions. besides, the pumped valley current is quantized and maximized when the Fermi energy of the system locates in the bandgap opened by the two pumping potentials. Furthermore, the valley current can be finely controlled by tuning the device parameters. Our results are useful for the development of valleytronic devices based on two-dimensional materials.

关键词： valley currents charge pump quantization silicene

Radial profile of bottom quarks in jets in high-energy nuclear collisions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2021年第6期45卷 167-175页

作者： sa Wang Wei Dai ben-Wei Zhang Enke Wang Key Laboratory of Quark&Lepton Physics(MOE)and Institute of particle Physics Central China Normal UniversityWuhan 430079China Guangdong Provincial Key Laboratory of Nuclear Science Institute of Quantum MatterSouth China Normal UniversityGuangzhou 510006China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing CenterSouth China Normal UniversityGuangzhou 510006China School of Mathematics and Physics China University of GeosciencesWuhan 430074China

Angular correlations between a heavy quark(HQ)and its tagged jet are potentially new tools to gain insight into the in-medium partonic interactions in relativistic heavy-ion *** this work,we present the first theoretical study on the radial profiles of b mesons in jets in Pb+Pb collisions at the Large Hadron Collider(LHC).The initial production of a bottom quark tagged jet in p+p is computed by SHERpa,which matches the next-to-leading order matrix elements with contributions of parton showers,whereas the massive quark traversing the quark-gluon plasma is described by a Monte Carlo model,SHELL,which can simultaneously simulate light and heavy flavor in-medium energy loss within the framework of Langevin *** p+p collisions,we find that at lower PQ/T the radial profiles of heavy flavors in jets are sensitive to the heavy quark *** 0-10%Pb+Pb collisions at√SNN=5.02 TeV,we observe an inverse modification pattern of the b meson radial profiles in jets at4PQ/Tpared to those of D mesons:the jet quenching effects narrow the jet radial profiles of b mesons in jets while broadening those of D mesons in *** find that in A+A collisions,the contribution dissipated from the higher PQ/T>20 GeV region naturally has a narrower initial distribution and consequently leads to a narrower modification pattern of the radial profile;however the diffusion nature of the heavy flavor in-medium interactions will give rise to a broader modification pattern of the radial *** two effects consequently compete and offset with each other,and the b quarks in jets benefit more from the former and suffer less diffusion effect compared to that of c quarks in *** findings can be tested in the future experimental measurements at the LHC to gain better understanding of the mass effect of jet quenching.

关键词： jet quenching quark-gluon plasma heavy flavor jet radial profile mass effect

bcl-2和GPER在子宫内膜息肉患者组织中的表达及相关性分析

在线全文

学校读者我要写书评

暂无评论

中国妇幼保健 2024年第9期39卷 1686-1689页

作者：王潇洒张静盛理超鲁波绍兴市妇幼保健院浙江绍兴312000

目的分析b细胞淋巴瘤/白血病-2(bcl-2)和G蛋白耦联雌激素受体(GPER)在子宫内膜息肉患者组织中的表达及相关性,为临床诊治提供参考。方法选取2010年10月—2012年4月绍兴市妇幼保健院收治的子宫内膜息肉患者30例为研究组,正常子宫内膜... 详细信息

目的分析b细胞淋巴瘤/白血病-2(bcl-2)和G蛋白耦联雌激素受体(GPER)在子宫内膜息肉患者组织中的表达及相关性,为临床诊治提供参考。方法选取2010年10月—2012年4月绍兴市妇幼保健院收治的子宫内膜息肉患者30例为研究组,正常子宫内膜的30例患者为对照组。使用免疫组化Envision法检测bcl-2、GPER阳性率,分析二者的相关性。结果 bcl-2在研究组和对照组的阳性率分别为66.67%和26.67%,研究组的阳性率高于对照组,差异有统计学意义(χ^(2)=10.545,Pbcl-2在研究组增生期和分泌期的阳性率分别为68.75%和64.29%,差异无统计学意义(P>0.05)。bcl-2在对照组增生期和分泌期的阳性率分别为43.75%和7.14%,增生期的阳性率高于分泌期,差异有统计学意义(P0.05)。GPER在研究组增生期和分泌期的阳性率分别为56.25%和92.86%,分泌期的阳性率高于增生期,差异有统计学意义(Pbcl-2与GPER在子宫内膜息肉患者中的表达呈正相关(r_s=0.933,0.872,均Pbcl-2和GPER高表达使子宫内膜息肉组织凋亡减弱、增生加强,进而导致子宫内膜息肉的发生,并促进其发展。

关键词：子宫内膜息肉 G蛋白耦联雌激素受体 b细胞淋巴瘤/白血病-2 相关性

A modified multi-group model of angular and momentum distribution of cosmic ray muons for thickness measurement and material discrimination of slabs

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2018年第2期29卷 111-117页

作者： sa Xiao Wei-bo He Ming-Cong Lan Ying Chen Mao-bing Shuai Institute of Materials China Academy of Engineering PhysicsJiangyou 621907China Science and Technology on Surface Physics and Chemistry Laboratory Mianyang 621900China

Muon tomography is a capable imaging technique to measure the geometry of high-Z objects. However,most existed algorithms used in muon tomography have obscured the effects of angular distribution and momentum spectra of cosmic ray muons and reduced the spatial resolution. We present a modified multi-group model that takes into account these effects and calibrates the model by the material of lead. Performance tests establish that the model is capable of measuring the thickness of a Pb slab and identifying the material of an unknown slab on a reasonable exposure timescale, in both cases of complete and incomplete angular data. Results show that the modified multi-group model is helpful for improvements in image resolution in real applications.

关键词： Muon tomography Modified multi-group model Angular distribution Momentum spectra