检索结果-南通市图书馆

Detailed characterization of kHz-rate laser-driven fusion at a thin liquid sheet with a neutron detection suite

High Power laser Science and Engineering 2024年第1期12卷 13-23页

作者： Benjamin M.Knight Connor M.gautam Colton R.Stoner Bryan V.Egner Joseph R.smith Chris M.Orban Juan J.Manfredi Kyle D.Frische Michael l.Dexter Enam A.Chowdhury Anil K.Patnaik Department of Engineering Physics Air Force Institute of TechnologyWPAFBOHUSA Physics Department Marietta CollegeMariettaOHUSA Department of Physics The Ohio State UniversityColumbusOHUSA Department of Materials Science and Engineering and Department of Electrical and Computer ScienceThe Ohio State UniversityColumbusOHUSA Intense Energy Solutions LLCPlain CityOHUSA

We present detailed characterization of laser-driven fusion and neutron production(-10^(5)/second) using 8 mJ, 40 fs laser pulses on a thin(<1 μm) D_2O liquid sheet employing a measurement suite. At relativistic inte... 详细信息

We present detailed characterization of laser-driven fusion and neutron production(-10^(5)/second) using 8 mJ, 40 fs laser pulses on a thin(liquid sheet employing a measurement suite. At relativistic intensity(~ 5 × 10^(18)W/cm^(2))and high repetition rate(1 kHz), the system produces deuterium±deuterium(D-D) fusion, allowing for consistent neutron generation. Evidence of D-D fusion neutron production is verified by a measurement suite with three independent detection systems: an EJ-309 organic scintillator with pulse-shape discrimination, a ~3He proportional counter and a set of 36 bubble detectors. Time-of-flight analysis of the scintillator data shows the energy of the produced neutrons to be consistent with 2.45 MeV. Particle-in-cell simulations using the WarpX code support significant neutron production from D-D fusion events in the laser±target interaction region. This high-repetition-rate laser-driven neutron source could provide a low-cost, on-demand test bed for radiation hardening and imaging applications.

关键词： high-repetition-rate laser-driven fusion laser-plasma interaction liquid target neutron detectors

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cellular and molecular aspects of gastric cancer

引用

World Journal of gastroenterology 2006年第19期12卷 2979-2990页

作者： Malcolm g smith georgina l Hold Eiichi Tahara Emad M El-Omar Department of Medicine and Therapeutics Aberdeen University ForesterhillAberdeen AB25 2ZDScotlandUnited Kingdom

gastric cancer remains a global killer with a shifting burden from the developed to the developing world. The cancer develops along a multistage process that is defined by distinct histological and pathophysiological phases. Several genetic and epigenetic alterations mediate the transition from one stage to another and these include mutations in oncogenes, tumour suppressor genes and cell cycle and mismatch repair genes. The most significant advance in the fight against gastric caner came with the recognition of the role of Helicobacter pylori （H pylori） as the most important acquired aetiological agent for this cancer. Recent work has focussed on elucidating the complex host/microbial interactions that underlie the neoplastic process. There is now considerable insight into the pathogenesis of this cancer and the prospect of preventing and eradicating the disease has become a reality. Perhaps more importantly, the study of H pylori-induced gastric carcinogenesis offers a paradigm for understanding more complex human cancers. In this review, we examine the molecular and cellular events that underlie Hpyloriinduced gastric cancer.

关键词： gastric cancer Helicobacter pylori Hostmicrobial interactions Inflammation Molecular mechanisms Host genetics

来源：

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

Intensified river salinization alters nitrogen-cycling microbial communities in arid and semi-arid regions of China

引用

Eco-Environment & Health 2024年第3期3卷 271-280页

作者： Qingqing Pang Dan Wang Zewei Jiang Mohamed Abdalla lei Xie Xiang Zhu Fuquan Peng Pete smith longmian Wang.l.ngzhan Miao Jun Hou Peng Yu Fei He Bin Xu Nanjing Institute of Environmental Sciences Ministry of Ecology and EnvironmentNanjing 210042China College of Environment Hohai UniversityNanjing 210098China College of Agricultural Science and Engineering Hohai UniversityNanjing 210098China Institute of Biological&Environmental Sciences University of Aberdeen23 St Machar Dr.Aberdeen AB243UUUK School of Environmental Science and Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Shandong Academy of Environmental Sciences Co. LtdJinan 250100China

Freshwater salinization is receiving increasing global attention due to its profound influence on nitrogen cycling in aquatic ecosystems and the accessibility of water ***,a comprehensive understanding of the changes in river salinization and the impacts of salinity on nitrogen cycling in arid and semi-arid regions of China is currently lacking.A meta-analysis was first conducted based on previous investigations and found an intensification in river salinization that altered hydrochemical *** further analyze the impact of salinity on nitrogen metabolism processes,we evaluated rivers with long-term salinity gradients based on in situ *** genes and enzymes that were inhibited generally by salinity,especially those involved in nitrogen fixation and nitrification,showed low abundances in three salinity *** abundance of genes and enzymes with denitrification and dissimilatory nitrate reduction to ammonium functions still maintained a high proportion,especially for denitrification genes/enzymes that were enriched under medium *** bacteria exhibited various relationships with salinity,while dissimilatory nitrate reduction to ammonium bacterium(such as Hydrogenophaga and Curvibacter carrying nirB)were more inhibited by salinity,indicating that diverse denitrifying bacteria could be used to reg.l.te nitrogen *** genera exhibited symbiotic and mutual relationships,and the highest proportion of significant positive correlations of abundant genera was found under medium *** study emphasizes the role of river salinity on environment characteristics and nitrogen transformation rules,and our results are useful for improving the availability of river water resources in arid and semi-arid regions.

关键词： Arid and semi-arid regions Nitrogen cycle Nitrogen transforming functional bacteria River Salinity gradient

来源：

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

Estimating the Yield loss of Winter Wheat from Drought in the United States Southern Plains Region as Influenced by El Niño-Southern Oscillation (ENSO)

引用

Agricultural Sciences 2024年第9期15卷 1018-1034页

作者： Prem Woli gerald R. smith Charles R. long Francis M. Rouquette, Jr. Texas A&M Agrilife Research Center Overton USA

Wheat (Triticum aestivum l.) production is a major economic activity in most regional and rural areas in the Southern Plains, a semi-arid region of the United States. This region is vulnerable to drought and is projected to experience a drier climate in the future. Since the interannual variability in climate in this region is linked to an ocean-atmospheric phenomenon, called El Niño-Southern Oscillation (ENSO), droughts in this region may be associated with ENSO. Droughts that occur during the critical growth phases of wheat can be extremely costly. However, the losses due to an impending drought can be minimized through mitigation measures if it is predicted in advance. Predicting the yield loss from an imminent drought is crucial for stakeholders. One of the reliable ways for such prediction is using a plant physiology-based agricultural drought index, such as Agricultural Reference Index for Drought (ARID). This study developed ENSO phase-specific, ARID-based models for predicting the drought-induced yield loss for winter wheat in this region by accounting for its phenological phase-specific sensitivity to drought. The reasonable values of the drought sensitivity coefficients of the yield model for each ENSO phase (El Niño, la Niña, or Neutral) indicated that the yield models reflected reasonably well the phenomena of water stress decreasing the winter wheat yields in this region during different ENSO phases. The values of various goodness-of-fit measures used, including the Nash-Sutcliffe Index (0.54 to 0.67), the Willmott Index (0.82 to 0.89), and the percentage error (20 to 26), indicated that the yield models performed fairly well at predicting the ENSO phase-specific loss of wheat yields from drought. This yield model may be useful for predicting yield loss from drought and scheduling irrigation allocation based on the phenological phase-specific sensitivity to drought as impacted by ENSO.

关键词： ARID Drought Drought Index ENSO El Niño growth-Stage Model Phenological-Phase Prediction Semi-Arid Wheat Yield loss

来源：

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

Isolated lumbar Extension Resistance Training Is Effective at Improving Extension Power and Disability in Subjects with Diagnosed lumbar Multifidus Dysfunction

引用

Open Journal of Therapy and Rehabilitation 2024年第3期12卷 245-255页

作者： William Roger Peters James Thomas Ernest smith Mario guiseppe Zotti Adam leslie lincoln Benjamin James Enser Faculty of Medicine & Health Sciences Bond University Queensland Australia Back Neck Clinic Bundall Queensland Australia Kieser Australia Bundall Queensland Australia

Background: lumbar multifidus dysfunction is a prevalent cause of disability in individuals with lower back pain. Previous research hig.l.ghts the benefits of isolated lumbar extension training for non-specific lower back pain, however, studies examining its efficacy in lumbar multifidus dysfunction are lacking. Objective: To evaluate the effectiveness of isolated lumbar extension resistance training on disability and strength in individuals with lumbar multifidus dysfunction. Methods: Subjects underwent a physiotherapy led structured rehabilitation program incorporating isolated lumbar extension. Sessions were conducted twice weekly targeting momentary muscular failure with time under load 90 - 120 seconds and progressions aimed at 5 - 10 lbs increments. Outcomes were assessed using the Oswestry Disability Index and lumbar extension strength testing at baseline and after 12 weeks, with statistical analysis using t-test and chi-squared 2 × 2. Results: Forty-five subjects (24 male, 21 female) with a median age of 48 completed the intervention. Improvements were noted in Oswestry Disability Index scores (median pre: 24, post: 15) and maximal lumbar extension strength (median pre: 122 lb, post: 186 lb), with p ≤ 0.05. Overall, 89% showed improvement in disability scores, 67% moved to a better disability category, and 51% saw at least a 50% increase in strength. No significant gender differences were observed. Conclusions: Isolated lumbar extension resistance training is effective at improving extension power and disability in subjects with lumbar multifidus dysfunction.

关键词： low Back Pain Multifidus Muscle Strength Rehabilitation Resistance Training

来源：

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

Hepatitis A vaccine associated with autoimmune hepatitis

引用

World Journal of gastroenterology 2007年第15期13卷 2238-2239页

作者： PA Berry g smith-laing Medway Maritime Hospital Windmill Road GillinghamKentUnited Kingdom

To describe a case of probable relapsing autoimmune hepatitis associated with vaccination against hepatitis A virus （HAV）. A case report and review of literature were written concerning autoimmune hepatitis in association with hepatitis A and other hepatotropic viruses. Soon a^er the administration of formalin-inactivated hepatitis A vaccine, a man who had recently recovered from an uncharacterized but self-limiting hepatitic illness, experienced a severe deterioration （AST 1687 U/l, INR 1.4）. Anti-nuclear antibodies were detectable, and liver biopsy was compatible with autoimmune hepatitis. The observation supports the role of HAV as a trigger of autoimmune hepatitis. Studies in helper T-cell activity and antibody expression against hepatic proteins in the context of hepatitis A infection are summarized, and the concept of molecular mimicry with regard to other forms of viral hepatitis and autoimmunity is briefly explored.

关键词： Hepatitis A virus Vaccine Autoimmune hepatitis Helper T-cell Molecular mimicry

来源：

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

How might epigenetics contribute to ecological speciation？

引用

Current Zoology 2013年第5期59卷 686-696页

作者： g.l.ert smith Michael g. RITCHIE Department of Ecology and Evolutionary Biology University of California Irvine California USA School of Biology University of St Andrews St Andews Fife KY16 9TH Scotland UK

Speciation research has seen a renewed interest in ecological speciation, which emphasises divergent ecological se- lection leading to the evolution of reproductive isolation. Selection from divergent ecologies means that phenotypic plasticity can play an important role in ecological speciation. Phenotypic plasticity involves the induction of phenotypes over the lifetime of an organism and emerging evidence suggests that epigenetic marks such as cytosine and protein （histone） modifications might regu- late such environmental induction. Epigenetic marks play a wide role in a variety of processes including development, sex dif- ferentiation and allocation, sexual conflict, reg.l.tion of transposable elements and phenotypic plasticity. Here we describe recent studies that investigate epigenetic mechanisms in a variety of contexts. There is mounting evidence for environmentally induced epigenetic variation and for the stable inheritance of epigenetic marks between generations. Thus, epigenetically-based pheno- typic plasticity may play a role in adaptation and ecological speciation. However, there is less evidence for the inheritance of in- duced epigenetic variation across multiple generations in animals. Currently few studies of ecological speciation incorporate the potential for the involvement of epigenetically-based induction of phenotypes, and we argue that this is an important omission [Current Zoology 59 （5）： 686-696, 2013 ].

关键词： Ecological speciation Adaptation Reproductive isolation Phenotypic plasticity Epigenetic mechanisms

来源：

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

Efficient Vision Transformers for Autonomous Off-Road Perception Systems

引用

Journal of Computer and Communications 2024年第9期12卷 188-207页

作者： Max H. Faykus III Adam Pickeral Ethan Marquez Melissa C. smith Jon C. Calhoun Holcombe Department of Electrical and Computer Engineering Clemson University Clemson SC USA

The development of autonomous vehicles has become one of the greatest research endeavors in recent years. These vehicles rely on many complex systems working in tandem to make decisions. For practical use and safety reasons, these systems must not only be accurate, but also quickly detect changes in the surrounding environment. In autonomous vehicle research, the environment perception system is one of the key components of development. Environment perception systems allow the vehicle to understand its surroundings. This is done by using cameras, light detection and ranging (liDAR), with other sensor systems and modalities. Deep learning computer vision algorithms have been shown to be the strongest tool for translating camera data into accurate and safe traversability decisions regarding the environment surrounding a vehicle. In order for a vehicle to safely traverse an area in real time, these computer vision algorithms must be accurate and have low latency. While much research has studied autonomous driving for traversing well-structured urban environments, limited research exists evaluating perception system improvements in off-road settings. This research aims to investigate the adaptability of several existing deep-learning architectures for semantic segmentation in off-road environments. Previous studies of two Convolutional Neural Network (CNN) architectures are included for comparison with new evaluation of Vision Transformer (ViT) architectures for semantic segmentation. Our results demonstrate viability of ViT architectures for off-road perception systems, having a strong segmentation accuracy, lower inference speed and memory footprint compared to previous results with CNN architectures.

关键词： Semantic Segmentation Off-Road Vision Transformers CNNs Autonomous Driving

来源：

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

钙钛矿lED:半导体界早“瑞士军刀”

引用

科技纵览 2024年第6期 10-11页

作者： Matthew S.smith 不详

PelED可以用于显示器、指纹识别器、健康传感器和太阳能充电器。现代智能手机的触摸屏之下是一层又一层的玻璃、偏光器、滤色器、电容式触摸传感器等。如今,研究人员开发了一款多功能一体的潜在替代品:感光像素。这些像素的功能远远不... 详细信息

PelED可以用于显示器、指纹识别器、健康传感器和太阳能充电器。现代智能手机的触摸屏之下是一层又一层的玻璃、偏光器、滤色器、电容式触摸传感器等。如今,研究人员开发了一款多功能一体的潜在替代品:感光像素。这些像素的功能远远不止用于显示屏,它们还可以对放置在上面的物体进行成像、检测指纹,甚至为设备充电。

关键词：瑞士军刀智能手机滤色器指纹识别器触摸屏钙钛矿 lED 显示屏

来源：

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

***震撼搜索领域

引用

科技纵览 2024年第4期 8-9页

作者： MATTHEW S.smith 不详

ChatgPT在2022年11月30日发布时受到了热烈的称赞,同时也遭到了不少反对.事实很快清晰起来,人们想把那些向人工智能提出过的问题都抛给谷歌,但ChatgPT往往无法回答.

关键词：人工智能 gPT Chat

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：