检索结果-南通市图书馆

Effect of tillage state of paddy soils with heavy metal pollution on the nosZ gene of N_(2)O reductase

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 Environmental Sciences 2024年第3期137卷 469-477页

作者： Liping Jiang shiguang liu Shanyun Wang Libo Sun Guibing Zhu Key Laboratory of Drinking Water Science and Technology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China University of Chinese Academy of Sciences Beijing 100049China School of Environmental and Civil Engineering Jiangnan UniversityWuxi 214122China

Paddy soils are an important source of atmospheric nitrous oxide(N_(2)O).However,numerous studies have focused on N_(2)O production during the soil tillage period,neglecting the N_(2)O production during the dry fallow *** this study,we conducted an incubation experiment using the acetylene inhibition technique to investigate N_(2)O emission and reduction rates of paddy soil profiles(0-1 m)from Guangdong Province and Jinlin Province in China,with different heavy-metal pollution *** abundance and community structures of denitrifying bacteria were determined via quantitative-PCR and Illumina MiSeq sequencing of nosZ,nirK,and nirS *** results showed that the potential N_(2)O emission rate,N_(2)O production rate,and denitrification rate have decreased with increasing soil vertical depth and heavy-metal *** importantly,we found that the functional gene type of N_(2)O reductase switched with the tillage state of paddy soils,which cladeⅡnos Z genes were the dominant gene during the tillage period,while cladeⅠnos Z genes were the dominant gene during the dry fallow *** heavy-metal pollution has less effect on the niche differentiation of the nos Z *** N_(2)O emission rate was significantly regulated by the genus Bradyhizobium,which contains both N_(2)O reductase and nitrite reductase *** findings suggests that the nos Z gene of N_(2)O reductase can significantly impact the N_(2)O emission from paddy soils.

关键词： Pappy soils N_(2)O reductase nosZ gene Heavy-metal pollution

在线全文

学校读者我要写书评

暂无评论

连续梁悬浇施工0号块三角托架的设计与施工

天津建设科技 2024年第2期34卷 36-39页

作者：刘时光中铁十四局集团有限公司山东济南250000

为了保证连续梁悬浇0号块的顺利施工,以昌景黄高速铁路悬臂浇筑连续梁0号块为例,进行悬臂浇筑0号块钢管支架与三角托架的经济比选,确定了采用三角托架方案并介绍了其施工要点。通过Midas/Civil有限元分析软件的检算,三角托架的强度、刚... 详细信息

为了保证连续梁悬浇0号块的顺利施工,以昌景黄高速铁路悬臂浇筑连续梁0号块为例,进行悬臂浇筑0号块钢管支架与三角托架的经济比选,确定了采用三角托架方案并介绍了其施工要点。通过Midas/Civil有限元分析软件的检算,三角托架的强度、刚度和稳定性等均满足规范要求。

关键词：连续梁悬臂浇筑 0号块三角托架高速铁路

在线全文

学校读者我要写书评

暂无评论

面向崎岖海底界面的声-弹最小二乘偏移

地球物理学进展 2024年第2期39卷 851-866页

作者：柳世光孙晶波张东伟张高吴佳乐袁安龙中国石油辽河油田分公司盘锦124010

在海洋环境中,地震波通过声波介质和弹性波介质进行传播.在海水层中,地震波以纵波的声波形式传播;而在下伏海底构造层中,地震波以既有纵波又有横波的弹性波形式传播.海底界面存在多种干扰波.本文推导出适用于起伏海底界面的声-弹耦合方... 详细信息

在海洋环境中,地震波通过声波介质和弹性波介质进行传播.在海水层中,地震波以纵波的声波形式传播;而在下伏海底构造层中,地震波以既有纵波又有横波的弹性波形式传播.海底界面存在多种干扰波.本文推导出适用于起伏海底界面的声-弹耦合方程,旨在消除起伏海底界面所引起的散射和绕射干扰,从而实现声波场和弹性波场之间的稳定传递和转换.为解决起伏海底界面所产生的虚假散射噪声问题,本文提出了分层贴体网格剖分策略,通过坐标变换将起伏海底界面转换为水平海底界面,将物理域中的贴体网格转换为计算域中的矩形网格,以消除起伏海底和复杂构造的影响.模型测试结果表明,本文方法能够准确模拟起伏海底声-弹耦合介质的波场传递,产生稳定且清晰的波形.与传统的矩形网格声-弹耦合和单一弹性波方法相比,起伏海底声-弹耦合介质的最小二乘逆时偏移成像结果在信噪比和分辨率方面有显著的提高.

关键词：起伏地表起伏海底声-弹耦合贴体网格最小二乘逆时偏移

同方期刊数据库

Line drawing via saliency map and ETF

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2022年第5期16卷 159-171页

作者： shiguang liu Ziqi liu College of Intelligence and Computing Tianjin UniversityTianjin 300350China

Line drawing is a means of superior visual communication which can effectively convey useful information to *** usually draw what they see rather than what exists,which means the most attractive object is emphasized while the rest are ***,artists draw the whole object with coherent lines instead of fractured lines,which also contribute to the outstanding visual *** these perspectives,generating line drawings with saliency and coherence remains a great *** line drawing generation methods ignore these important properties and cannot generate coherent lines in some cases since they do not take into account how artists draw a *** this end,a novel saliency-aware line drawing method was proposed to better grasp the viewer’s attention on an ***,a saliency enhanced line extraction method combining saliency map and edge tangent flow was proposed to ensure the saliency and coherence of lines,especially in salient but low contrast ***,the salient information was highlighted while irrelevant details were eliminated by inhibiting lines in less salient areas to enhance the saliency of the line ***,the transparency of lines was adjusted to further emphasize important *** results showed that our method can generate line drawings with better visual saliency and coherence than the state-of-the-art methods.

关键词： line drawing saliency coherence

Design of digital calibration based on variable step size of sub-binary SAR ADC

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2024年第2期31卷 62-71页

作者： liu Wei Zhao Yanke Shang shiguang School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

Addressing the impact of capacitor mismatch on the conversion accuracy of successive approximation register analog-to-digital converter(SAR ADC),a 12-bit 1 MS/s sub-binary SAR ADC designed using variable step size digital calibration was *** least mean square(LMS)calibration algorithm was employed with a ramp signal used as the calibration *** errors,extracted under injected disturbances,underwent iterative training to optimize weight *** address the trade-off between conversion accuracy and speed caused by a fixed step size,a novel variable step size algorithm tailored for SAR ADC calibration was *** core circuit and layout of the SAR ADC were implemented using the Taiwan Semiconductor Manufacturing Company(TSMC)0.35μm complementary metal-oxide-semiconductor(CMOS)commercial *** of the SAR ADC calibration algorithm was conducted using Simulink,demonstrating quick convergence and meeting conversion accuracy requirements compared to fixed step size *** results indicated that the convergence speed of the LMS digital calibration algorithm with variable step size was approximately eight times faster than that with a fixed step size,also yielding a lower mean square error(MSE).After calibration,the simulation results for the SAR ADC exhibited an effective number of bit(ENOB)of 11.79 bit and a signal-to-noise and distortion ratio(SNDR)of 72.72 dB,signifying a notable enhancement in the SAR ADC performance.

关键词： successive approximation register analog-to-digital converter(SAR ADC) variable step size digital calibration disturbance technique

同方期刊数据库

Multipath affinage stacked-hourglass networks for human pose estimation

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2020年第4期14卷 155-165页

作者： Guoguang HUA Lihong LI shiguang liu School of Information and Electrical Engineering Hebei University of EngineeringHandan056038China School of Computer Science and Technology Division of Intelligence and ComputingTianjin UniversityTianjin300350China

Recently,stacked hourglass network has shown outstanding performance in human pose ***,repeated bottom-up and top-down stride convolution operations in deep convolutional neural networks lead to a significant decrease in the initial image *** order to address this problem,we propose to incorporate affinage module and residual attention module into stacked hourglass network for human pose *** paper introduces a novel network architecture to replace the stacked hourglass network of up-sampling operation for getting high-resolution *** refer to the architecture as an affinage module which is critical to improve the performance of the stacked hourglass ***,we also propose a novel residual attention module to increase the supervision of up-sample *** effectiveness of the introduced module is evaluated on standard *** experimental results demonstrated that our method can achieve more accurate and more robust human pose estimation results in images with complex background.

关键词： human pose estimation stacked hourglass network affinage module residual attention module

Helmholtz decomposition-based SPH

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Virtual Reality & Intelligent Hardware 2021年第2期3卷 118-128页

作者： Zhongyao YANG Maolin WU shiguang liu School of Computer Science and Technology Division of Intelligence and ComputingTianjin UniversityTianjin 300072China

Background SPH method has been widely used in the simulation of water *** a numerical method of partial differential equations,SPH can easily deal with the distorted and complex *** addition,the implementation of SPH is relatively simple,and the results are stable and not easy to ***,SPH method also has its own *** order to further improve the performance of SPH method and expand its application scope,a series of key and difficult problems restricting the development of SPH need to be *** In this paper,we introduce the idea of Helmholtz decomposition into the framework of smoothed particle hydrodynamics(SPH)and propose a novel velocity projection scheme for three-dimensional water ***,we apply Helmholtz decomposition to a three-dimensional velocity field and decompose it into three orthogonal ***,our method combines the idea of spatial derivatives in SPH to obtain a discrete Poisson velocity ***,the conjugate gradient(CG)is utilized to efficiently solve the Poisson *** The experimental results show that the proposed scheme is suitable for various situations and has higher efficiency than the current SPH projection *** Compared with the previous projection scheme,our solution does not need to modify the particle velocity indirectly by pressure projection,but directly by velocity field *** new scheme can be well integrated into the existing SPH framework,and can be applied to the interaction of water with static and dynamic obstacles,even for viscous fluid.

关键词： Water simulation SPH Helmholtz decomposition Conjugate gradient

Interfacial oxidized Pd species dominate catalytic hydrogenation of polar unsaturated bonds

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第1期17卷 228-234页

作者： Pengyao You Shaoqi Zhan Pengpeng Ruan Ruixuan Qin shiguang Mo Yazhou Zhang Kunlong liu Lansun Zheng Nanfeng Zheng State Key Laboratory for Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materialsand Department of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Department of Chemistry BMCUppsala UniversityBMC Box 576Uppsala S-75123Sweden Department of Chemistry University of OxfordOxford OX13QZUK

The determination of catalytically active sites is crucial for the design of efficient and stable catalysts toward desired ***,the complexity of supported noble metal catalysts has led to controversy over the locations of catalytically active sites(e.g.,metal,support,and metal/support interface).Here we develop a structurally controllable catalyst system(Pd/SBA-15)to reveal the catalytic active sites for the selective hydrogenation of ketones to alcohol using acetophenone hydrogenation as model *** investigations demonstrated that unsupported Pd nanocrystals have no catalytic activity for acetophenone ***,oxidized Pd species were catalytically highly active for acetophenone *** catalytic activity decreased with the decreased oxidation state of *** work provides insights into the hydrogenation mechanism of ketones but also other unsaturated compounds containing polar bonds,e.g.,nitrobenzene,N-benzylidene-benzylamine,and carbon dioxide.

关键词： oxidized Pd metal/oxide interface constant particle size Pd/SBA-15 acetophenone hydrogenation

Community-Level Practice Checklists for Health Protection During Cold Spells in China

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China CDC weekly 2024年第5期6卷 83-87页

作者： Jing Shang Mengzhen Zhao Zhao liu Xiya Zhang shiguang Miao Ishaq D.Sulaymon Wenjia Cai Institute of Urban Meteorology CMABeijingChina School of Management and Economics Beijing Institute of TechnologyBeijingChina School of Airport Economics and Management Beijing Institute of Economics and ManagementBeijingChina Department of Earth System Science Tsinghua UniversityBeijingChina Sand and Dust Storm Warning Regional Center National Center for MeteorologyJeddahSaudi Arabia Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjing CityJiangsu ProvinceChina

Communities play a crucial role in protecting the health of vulnerable populations such as the elderly,low-income groups,and high-risk individuals during cold ***,current strategies for responding to cold spells primarily consist of programmatic policies that lack practicality,specificity,and detailed implementation guidelines for community ***,this study aims to identify and analyze the challenges faced by communities in responding to cold spells,review international experiences,and develop a set of practical checklists for community-level health *** checklists will assist community workers and volunteers in effectively preparing for,responding to,and recovering from cold spells.

关键词： preparing income primarily