检索结果-南通市图书馆

Solving Strength–Toughness Dilemma in Superhard Transition-Metal Diborides via a Distinct Chemically Tuned Solid Solution Approach

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Research 2023年第3期6卷 473-483页

作者： Xinlei Gu Chang Liu xinxin gao Kan Zhang Weitao Zheng Changfeng Chen State Key Laboratory of Superhard Materials Department of Materials Science and Key Laboratory of Automobile MaterialsMOEJilin UniversityChangchun 130012China International Center for Computational Methods&Software College of PhysicsJilin UniversityChangchun 130012China Department of Physics and Astronomy University of NevadaLas VegasNV 89154USA

Solid solution strengthening enhances hardness of metals by introducing solute atoms to create local distortions in base crystal lattice,which impedes dislocation motion and plastic deformation,leading to increased strength but reduced ductility and *** sharp contrast,superhard materials comprising covalent bonds exhibit high strength but low toughness via a distinct mechanism dictated by brittle bond deformation,showcasing another prominent scenario of classic strength–toughness tradeoff *** this less explored and understood problem presents a formidable challenge that requires a viable strategy of tuning main load-bearing bonds in these strong but brittle materials to achieve concurrent enhancement of the peak stress and related strain ***,we demonstrate a chemically tuned solid solution approach that simultaneously enhances hardness and toughness of superhard transition-metal diboride Ta_(1−x)Zr_(x)B_(2).This striking phenomenon is achieved by introducing solute atom Zr that has lower electronegativity than solvent atom Ta to reduce the charge depletion on the main load-bearing B–B bonds during indentation,leading to prolonged deformation that gives rise to notably higher strain range and the corresponding peak *** finding highlights the crucial role of properly matched contrasting relative electronegativity of solute and solvent atoms in creating concurrent strengthening and toughening and opens a promising avenue for rational design of enhanced mechanical properties in a large class of transition-metal *** strategy of concurrent strength–toughness optimization via solute-atom-induced chemical tuning of the main load-bearing bonding charge is expected to work in broader classes of materials,such as nitrides and carbides.

关键词： toughness deformation strengthening

Metabolic changes during larval–pupal metamorphosis of Helicoverpa armigera

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2023年第6期30卷 1663-1676页

作者： xinxin gao Jihong Zhang Qilian Qin Peipei Wu Huan Zhang Qian Meng State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijingChina University of Chinese Academy of Sciences BeijingChina

Energy metabolism is essential for insect metamorphosis. The accumulation and utilization of energy is still not completely clear during larval–pupal metamorphosis of holometabolous insects. We used metabolome and transcriptome analysis to reveal key metabolic changes in the fat body and plasma and the underlying metabolic regulation mechanism of Helicoverpa armigera, an important global agricultural insect pest, during larval–pupal metamorphosis. During the feeding stage, activation of aerobic glycolysis provided intermediate metabolites and energy for cell proliferation and lipid synthesis. During the non-feeding stages (the initiation of the wandering stage and the prepupal stage), aerobic glycolysis was suppressed, while, triglyceride degradation was activated in the fat body. The blocking of metabolic pathways in the fat body was probably caused by 20-hydroxyecdysone-induced cell apoptosis. 20-hydroxyecdysone cooperated with carnitine to promote the degradation of triglycerides and the accumulation of acylcarnitines in the hemolymph, allowing rapid transportation and supply of lipids from the fat body to other organs, which provided a valuable reference for revealing the metabolic regulation mechanism of lepidopteran larvae during the last instar. Carnitine and acylcarnitines are first reported to be key factors that mediate the degradation and utilization of lipids during larval–pupal metamorphosis of lepidopteran insects.

关键词： carbohydrate metabolism Lepidoptera lipid metabolism metamorphosis

Directly wireless communication of human minds via non-invasive brain-computer-metasurface platform

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

eLight 2022年第1期2卷 132-142页

作者： Qian Ma Wei gao Qiang Xiao Lingsong Ding Tianyi gao Yajun Zhou xinxin gao Tao Yan Che Liu Ze Gu Xianghong Kong Qammer HAbbasi Lianlin Li Cheng‑Wei Qiu Yuanqing Li Tie Jun Cui Institute of Electromagnetic Space Southeast UniversityNanjing 210096China School of Automation Science and Engineering South China University of TechnologyGuangzhou 510641China State Key Laboratory of Millimeter Wave Southeast UniversityNanjing 210096China Center of Intelligent Metamaterials Pazhou Laboratory Guangzhou 510330China Research Center for Brain-Computer Interface Pazhou LabGuangzhou 510330China Department of Electrical and Computer Engineering National University of SingaporeSingaporeSingapore University of Glasgow James Watt School of EngineeringGlasgow G128QQUK State Key Laboratory of Advanced Optical Communication Systems and Networks Department of ElectronicsPeking UniversityBeijing 100871China

Brain-computer interfaces(BCIs),invasive or non-invasive,have projected unparalleled vision and promise for assisting patients in need to better their interaction with the *** by the BCI-based rehabilitation technologies for nerve-system impairments and amputation,we propose an electromagnetic brain-computer-metasurface(EBCM)paradigm,regulated by human’s cognition by brain signals directly and *** experimentally show that our EBCM platform can translate human’s mind from evoked potentials of P300-based electroencephalography to digital coding information in the electromagnetic domain non-invasively,which can be further processed and transported by an information metasurface in automated and wireless *** wireless communications of the human minds are performed between two EBCM operators with accurate text ***,several other proof-of-concept mind-control schemes are presented using the same EBCM platform,exhibiting flexibly-customized capabilities of information processing and synthesis like visual-beam scanning,wave modulations,and pattern encoding.

关键词： communication computer surface

Integrative analysis of the transcriptome and metabolome reveals the importance of hepatokine FGF21 in liver aging

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Genes & Diseases 2024年第5期11卷 407-427页

作者： Wenchao Wang Junjie Qian Mingge Shang Yiting Qiao Jiacheng Huang xinxin gao Zhou Ye Xinyu Tong Kangdi Xu Xiang Li Zhengtao Liu Lin Zhou Shusen Zheng Division of Hepatobiliary and Pancreatic Surgery Department of SurgeryFirst Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhouZhejiang 310003China NHC Key Laboratory of Combined Multi-organ Transplantation HangzhouZhejiang 310003China Key Laboratory of the Diagnosis and Treatment of Organ Transplantation Research Unit of Collaborative Diagnosis and Treatment for Hepatobiliary and Pancreatic CancerChinese Academy of Medical Sciences(2019RU019)HangzhouZhejiang 310003China Key Laboratory of Organ Transplantation Research Center for Diagnosis and Treatment of Hepatobiliary DiseasesHangzhouZhejiang 310003China Shulan International Medical College Zhejiang Shuren UniversityHangzhouZhejiang 310015China Shulan(Hangzhou)Hospital Affiliated to Zhejiang Shuren University Shulan International Medical College HangzhouZhejiang 310000China

Aging is a contributor to liver ***,the concept of liver aging has become prominent and has attracted considerable interest,but its underlying mechanism remains poorly *** our study,the internal mechanism of liver aging was explored via multi-omics analysis and molecular experiments to support future targeted *** aged rat liver model was established with D-galactose,and two other senescent hepatocyte models were established by treating HepG2 cells with D-galactose and *** then performed transcriptomic and metabolomic assays of the aged liver model and transcriptome analyses of the senescent hepatocyte *** livers,genes related to peroxisomes,fatty acid elongation,and fatty acid degradation exhibited down-regulated expression with aging,and the hepatokine Fgf21 expression was positively correlated with the down-regulation of these *** senescent hepatocytes,similar to the results found in aged livers,FGF21 expression was also ***,the expressions of cell cycle-related genes were significantly down-regulated,and the down-regulated gene E2F8 was the key cell cycle-regulating transcription *** then validated that FGF21 overexpression can protect against liver aging and that FGF21 can attenuate the declines in the antioxidant and regenerative capacities in the aging *** successfully validated the results from cellular and animal experiments using human liver and blood *** study indicated that FGF21 is an important target for inhibiting liver aging and suggested that pharmacological prevention of the reduction in FGF21 expression due to aging may be used to treat liver aging-related diseases.

关键词： Antioxidant capability FGF21 Liver aging Liver regeneration Multiomics analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

低温风洞排气塔流致振动的理论及数值研究

航空动力学报 2024年第7期39卷 86-94页

作者：张伟高鑫鑫高荣张小斌程俊国防科技大学空天科学学院长沙410073 中国空气动力研究与发展中心四川绵阳621000 浙江大学制冷与低温工程研究所杭州310027

为分析排气塔在自然风载和内流共同作用下的结构安全性,采用理论和数值模拟方法分析了排气塔的流致振动响应情况.理论分析获得了排气塔在自然风载作用下的顺流响应和均值响应.采用计算流体力学方法,shear stress transport(SST)k-ω湍... 详细信息

为分析排气塔在自然风载和内流共同作用下的结构安全性,采用理论和数值模拟方法分析了排气塔的流致振动响应情况.理论分析获得了排气塔在自然风载作用下的顺流响应和均值响应.采用计算流体力学方法,shear stress transport(SST)k-ω湍流模型和动网格数值技术实现了排气塔的双向流固耦合数值模拟,获得了排气塔在内外流动混合作用下的速度、压力和涡量分布.表明排气塔在特定风载下的旋涡脱落频率接近1阶模态频率,塔体应力较小,在许用应力范围内.

关键词：排气塔流致振动低温风洞涡量流固耦合

A dual-band wireless communication of spoof plasmonic meta-waveguide

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第7期67卷 337-338页

作者： xinxin gao Geng-Bo WU Ze GU Qian MA Wenyi CUI Tiejun CUI Chihou CHAN State Key Laboratory of Terahertz and Millimeter Waves City University of Hong Kong State Key Laboratory of Millimeter Waves Southeast University Department of Electrical Engineering City University of Hong Kong

The ever-growing demands in wireless communications,computational imaging, and light detection necessitate the capability to freely manipulate electromagnetic *** and highly integrated devices hold great promise for the future of communications. Spoof plasmonic metamaterials, in particular, have shown potential in creating functional devices and systems due to their ultracompact and low-profile advantages [1–3].

关键词： communication wireless dual-band meta-waveguide plasmonic spoof

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

细菌生物膜与慢性创面感染

中华烧伤杂志 2019年第12期35卷 842-847页

作者：于家傲高欣欣吉林大学第一医院烧伤外科长春130021

细菌通常以生物膜的形式在慢性创面上定植、繁殖和侵袭性生长。有别于游离细菌,生物膜内的细菌在表观遗传学、生物学行为,特别是对抗抗生素和宿主免疫等方面均展现岀独特的机制。本文介绍了细菌生物膜的组成和结构功能,阐述了细菌生物... 详细信息

细菌通常以生物膜的形式在慢性创面上定植、繁殖和侵袭性生长。有别于游离细菌,生物膜内的细菌在表观遗传学、生物学行为,特别是对抗抗生素和宿主免疫等方面均展现岀独特的机制。本文介绍了细菌生物膜的组成和结构功能,阐述了细菌生物膜的耐药机制,论述了细菌生物膜感染创面的临床表现特点及生物膜的诊断方法,分析了针对细菌生物膜的治疗策略。谨以此文提示临床医师重视细菌生物膜感染,提倡对细菌生物膜进行深入研究,以提高慢性创面的治疗质量。

关键词：细菌生物膜感染慢性创面

在线全文

学校读者我要写书评

暂无评论

打结器连续打结试验方法与疲劳试验台设计

农业机械学报 2017年第10期48卷 84-91页

作者：尹建军王新新高强江苏大学现代农业装备与技术教育部重点实验室镇江212013

针对国内缺乏打结器连续打结的性能测试与疲劳试验系统,模拟方捆机捆草作业过程,提出了一种打结器连续打结试验方法与疲劳试验台设计方案。通过设计可模拟草捆回弹特性的拉绳装置使其在水平面按矩形轨迹拉绳,在绳针送绳动作配合下在垂... 详细信息

针对国内缺乏打结器连续打结的性能测试与疲劳试验系统,模拟方捆机捆草作业过程,提出了一种打结器连续打结试验方法与疲劳试验台设计方案。通过设计可模拟草捆回弹特性的拉绳装置使其在水平面按矩形轨迹拉绳,在绳针送绳动作配合下在垂直面形成矩形绳环,使受测试的打结器完成打结。试验台循环实现拉绳-送绳-打结动作,同时测试打结过程中的捆绳张力、主轴转矩和主轴转角。按此方案在Solidworks下建立了试验台机械系统三维模型,并对关键部件进行选型。构建了试验台参数测量与运动控制系统,基于拉绳-送绳-打结动作逻辑设计了试验台控制流程,采用Lab VIEW图形化编程语言编写了测试与控制程序。打结器疲劳试验台的运行试验结果表明,该试验台机械系统与测控系统运行可靠,连续打结效率为3个/min,可为打结器研发及短时疲劳寿命考核提供试验平台。

关键词：打捆机打结器试验台控制疲劳试验

基于SFLA-GA混合算法求解时间最优的旅行商问题

在线全文

学校读者我要写书评

暂无评论

电子与信息学报 2018年第2期40卷 363-370页

作者：张勇高鑫鑫王昱洁合肥工业大学计算机与信息学院合肥230009

该文以经典的对称旅行商问题(Symmetric Traveling Salesman Problem,STSP)为基础,求解时间最优的旅行商问题(Time Optimal TSP,TOTSP),将拟合函数引入到混合蛙跳遗传算法(SFLA-GA)的适应度函数来反映景点客流量随时间的变化,旨在旅游... 详细信息

该文以经典的对称旅行商问题(Symmetric Traveling Salesman Problem,STSP)为基础,求解时间最优的旅行商问题(Time Optimal TSP,TOTSP),将拟合函数引入到混合蛙跳遗传算法(SFLA-GA)的适应度函数来反映景点客流量随时间的变化,旨在旅游旺季为游客提供一条游览时间最短的路径推送服务。实验结果表明:相对于随机游览路径,SFLA-GA混合算法得到的游览路径明显节省了游览时间;与SFLA和混合粒子群遗传算法(PSO-GA)相比较,SFLA-GA混合算法具有计算量少、收敛速度快、对初始种群依赖性低以及全局性更好等优点,在求解TOTSP上搜索性能更强、时间更优。

关键词：时间最优的旅行商问题混合蛙跳遗传算法适应度函数拟合函数游览时间