检索结果-南通市图书馆

A new species of Malus in China,Malus shizongensis Liu ***

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2020年第10期19卷 2451-2457页

作者： LIU Zhen-zhong LI Zhong-xing GAO Hua BAO cha-na College of Horticulture Northwest A&F UniversityYangling 712100P.R.China State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple College of HorticultureNorthwest A&F UniversityYangling 712100P.R.China

Based on morphological,molecular biological,and molecular systematic studies,we describe here a new species of Malus from Yunnan,*** compared the morphology of this new species,Malus shizongensis Liu ***,with three Malus species,including ***,***,and *** the appearance of *** was similar to these three species,it differed in height,branch color,branch hair,and flower *** better identify the taxonomy of this new species,genome of *** and that of seven Malus species,including ***,***,***,***,***,***,and *** were analyzed.A phylogenetic tree based on genome analysis indicated that *** was close to ***,*** had its species-specific SNPs,and the number of species-specific SNPs was similar to that of three close species(***,***,and ***).Based on the above information,we named this new species as *** Liu ***.

关键词： Malus new species taxonomy

Enhancing the efficiency and scalability of perovskite solar cells through pseudo-halide salt addition

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第34期165卷 161-169页

作者： Dohun Baek Geon Yeong Park Jeongbeom cha Hyemi na Dong Seok Ham Min Kim School of Chemical Engineering Future Energy Research CenterJeonbuk National UniversityJeonju 54896Republic of Korea Graduate School of Integrated Energy-AI Jeonbuk National UniversityJeonju 54896Republic of Korea Chemical Materials Solutions Center Korea Research Institute of Chemical Technology(KRICT)Daejeon 34114Republic of Korea

Organic-inorganic halide perovskites have significant potential for application in next-generation solar ***,their applications are limited by challenges associated with large-area processability and long-term stability owing to the presence of pinholes and defect ***,we incorporated cesium formate in a perovskite active layer using a sequential perovskite fabrication process to eliminate the defect sites of perovskites and improve the film processability via roll-to-roll(R2R)*** addition of cesium formate salt to the PbI2 layer influences the perovskite crystal formation behavior as well as increases the perovskite crystallinity and decreases the defect ***,cesium formate addition eliminated small PbI2 grains and smoothed the perovskite surface,resulting in a large crystal grain *** formate ions interact with the PbI2 component and passivate halide vacancy defects,reducing nonradiative recombination and improving charge ***,the treated perovskite films were highly stable in air,exhibiting improved efficiency retention over time and achieving a power conversion efficiency(PCE)of>22%compared to the ***,the additive-treated perovskite film was processed using the R2R method,achieving a high PCE of>14%with minimal hysteresis.

关键词： Perovskite Solar Cells Pseudo-halide ion Stability Roll-to-roll process

Size-dependent transition of the deformation behavior of Au nanowires

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

nano Research 2015年第3期8卷 941-947页

作者： na-Young Park Ho-Seok nam PiI-Ryung cha Seung-Cheol Lee School of Advanced Materials Engineering Kookmin University Seou1136-702 R. O. Korea Future Convergence Research Division Korea Institute of Science and Technology (KIST) Seou1136-791 R. O. Korea Indo-Korea Science and Technology Center Korea Institute of Science and Technology (KIST) Seou1136-791 R. O. Korea

Inspired by the controversy over tensile deformation modes of single-crystalline 〈110〉/{111} Au nanowires, we investigated the dependency of the deformation mode on diameters of nanowires using the molecular dynamics technique. A new criterion for assessing the preferred deformation mode-slip or twin propagation--of nanowires as a function of nanowire diameter is presented. The results demonstrate the size-dependent transition, from superplastic deformation mediated by twin propagation to the rupture by localized slips in deformed region as the nanowire diameter decreases. Moreover, the criterion was successfully applied to explain the superplastic deformation of Cu nanowires.

关键词： Au nanowire molecular dynamics size-dependent transition tensile deformationmechanism

Collisionless tool orientation smoothing above blade stream surface using NURBS envelope

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 Zhejiang University-Science A(Applied Physics & Engineering) 2013年第3期14卷 187-197页

作者： Jing-hua XU Shu-you ZHANG Jian-rong TAN Ri-na sa State Key Laboratory of Fluid Power Transmission and Control Zhejiang University

In five-axis machining,tool orientation above a blade stream surface may lead to tool collision and a decrease in workpiece ***,collisionless tool orientation smoothing(TOS)becomes an important *** the basis of a constant scallop height tool path,the triangular facets in the faces,vertices format are constructed from cutter contact(CC)using the Voronoi incremental *** cutter location(CL)points candidate set is represented by an oblique elliptic cone whose vertex lies at CC using NURBS *** the CL point is above its CC is judged by the dot product between the normal vector and the point on triangulation nearest to the CL *** curvatures at CC are obtained by fitting a moving least square(MLS) quadratic patch to the local neighborhood of a vertex and calculating eigenvectors and eigenvalues of the Hessian *** surface elastic energy is employed as the weight in selection from the NURBS *** collision is judged by NURBS surface *** can then be expressed by selecting a CL point for each CC point and converted into a numerical control(NC)code automatically according to the postprocessor type of the machine *** proposed method is verified by finishing of a cryogenic turboexpander impeller of air separation equipment.

关键词： Tool orientation smoothing(TOS) Blade stream surface Triangular facet NURBS envelope Surface elastic energy

基于结构方程模型的大兴安岭北部天然林林下草本物种多样性驱动力分析

在线全文

学校读者我要写书评

暂无评论

西北林学院学报 2024年第2期39卷 13-20页

作者：王子瑞妙文豪呼日查高明龙刘磊李岩付宇萨如拉内蒙古农业大学林学院内蒙古呼和浩特010019 内蒙古农业大学农学院内蒙古呼和浩特010019 北京林业大学生态与自然保护学院北京100083

林下草本层植物在森林群落结构稳定性的调节和生态功能的发挥上具有非常重要的作用,是森林生态系统不可或缺的组成部分。以大兴安岭北部天然林为研究对象,运用结构方程模型探究气候、土壤和林分空间结构等环境因子对林下草本物种多样性... 详细信息

林下草本层植物在森林群落结构稳定性的调节和生态功能的发挥上具有非常重要的作用,是森林生态系统不可或缺的组成部分。以大兴安岭北部天然林为研究对象,运用结构方程模型探究气候、土壤和林分空间结构等环境因子对林下草本物种多样性的相对重要性,并探讨影响因子之间存在的复杂关系对林下草本物种多样性的影响机理。结果表明,从整体上来看,气候、土壤和林分空间结构对林下草本物种多样性均有较强的影响作用,其中气候的影响强度最大,土壤次之,林分空间结构的影响作用最小。从中介效应上来看,气候变化会导致土壤和林分空间结构发生变化,进而影响林下草本物种多样性,除此之外,还发现林分空间结构的改变,也会导致土壤性质发生变化,进而影响林下草本物种多样性。从影响系数上来看,影响林下草本物种多样性的驱动因子因各影响因素的不同而存在差异,年均降水、有机碳含量、混交度是分别表征气候因子、土壤因子、林分空间结构影响林下草本物种多样性的主导因子。在大兴安岭林区开展林下草本物种多样性保护及修复工作时,可适当调整混交度,维持合理的林分结构,并综合考虑改善土壤养分的森林经营方案。

关键词：草本物种多样性结构方程模型驱动力分析林分空间结构大兴安岭北部

维普期刊数据库博看期刊

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

Compensation trends of the angulation of first molars:retrospective study of 1403 malocclusion cases

在线全文

学校读者我要写书评

暂无评论

International Journal of Oral Science 2014年第3期6卷 175-181页

作者： Hong Su Bing Han sa Li Bin na Wen Ma Tian-Min Xu Department of Orthodontics School and Hospital of Stomatology Peking University Department of Stomatology Shenzhen People’s Hospital Graduate from School and Hospital of Stomatology Peking University Arrail International Dental Clinic

We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1 403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First,angulation of the upper first molar varied significantly with age and tipped most distally in cases aged,12 years and least distally in cases aged.16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability.

关键词： Angle classification angulation compensation first molar growth stages malocclusion sagittal skeletal patterns verticalskeletal patterns

Microbiological assessment of indoor air of a teaching hospital in Nigeria

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2012年第6期2卷 465-468页

作者： Awosika sa Olajubu FA Amusa na Department of Microbiology Olabisi Onabanjo University Department of Medical Microbiology & Parasitology Olabisi Onabanjo University Teaching Hospital Department of Plant Science & Applied Zoology Olabisi Onabanjo University

Objective:To investigate the quality of indoor air of different wards and units of Olabisi Ona.a.jo University Teaching Hospital, sagamu, to ascertain their contribution to infection rate in the ***:The microbial quality of indoor air of nine wards/units of Olabisi Ona.a.jo University Teaching Hospital, sagamu, Nigeria was conducted. Sedimentation technique using open Petri-dishes containing different culture media was employed and samplings were done twice daily, one in the morning shortly after cleaning and before influx of people/patients into the wards/units and the other in the evening when a lot of activities would have taken place in these wards. Isolates were identified according to standard ***:Results showed that there was a statistically significant difference(氈2= 6.0167) in the bacteria population of the different sampling time whereas it was not so for fungi population(氈2= 0.2857). Male medical ward(MMW) and male surgical general(MSG) recorded the highest bacterial and fungal growth while the operating theatre(OT) was almost free of microbial burden. The bacteria isolates were Staphylococcus aureus, Klebsiellasp., Bacillus cereus, Bacillus subtilis, Streptococcus pyogenes andSerratia marscenceswhile the fungi isolates includedAspergillus flavus, Penicilliumsp.,Fusariumsp.,Candida *** aureuswas the predominantly isolated bacterium whilePenicilliumsp. was the most isolated ***:Though most of the microbial isolates were potential and or opportunistic pathogens, there was no correlation between the isolates in this study and the surveillance report of nosocomial infection during the period of study, hence the contribution of the indoor air cannot be established. From the reduction noticed in the morning samples, stringent measures such as proper disinfection and regular cleaning, restriction of patient relatives' movement in and out of the wards/units need to be enforced so as to imp

关键词： Indoor air OOUTH Open-plate technique Nosocomial infections Staphylococcus aureus Microbiological assessment Microbial quality Bacterial isolate Fungal isolate Opportunistic pathogen Nosocomial infection Infection rate Microbial isolate Penicilliumsp Sedimentation technique

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

高温多次固化对复合材料力学性能影响

塑料科技 2024年第7期52卷 75-78页

作者：成艳娜张梦雨刘训新袁潇洒林雨辰元振毅中航西安飞机工业集团股份有限公司陕西西安710089 西安理工大学机械与精密仪器工程学院陕西西安710048

采用T800级高韧性碳布及碳带预浸料、T800级玻璃纤维预浸料、芳纶与石英混编预浸料制造层压板,探究高温高压多次固化对层压板力学性能的影响。连续经历5次高温高压固化,检测层压板孔隙缺陷、弯曲强度、剪切强度。结果表明:4种不同预浸... 详细信息

采用T800级高韧性碳布及碳带预浸料、T800级玻璃纤维预浸料、芳纶与石英混编预浸料制造层压板,探究高温高压多次固化对层压板力学性能的影响。连续经历5次高温高压固化,检测层压板孔隙缺陷、弯曲强度、剪切强度。结果表明:4种不同预浸料层压板的内部质量合格。随着固化次数的增加,T800级高韧性碳布层压板的弯曲强度下降最明显,T800级玻璃纤维预浸料层压板的剪切强度下降最明显。但是4种预浸料层压板的弯曲强度和剪切强度下降幅度均小于10%。芳纶与石英混编预浸料固化5次后的剪切强度最低值比理论指标低1.64%,其余材料的剪切强度均高于各层压板性能要求。

关键词：碳纤维玻璃纤维多次固化孔隙缺陷弯曲强度剪切强度