检索结果-南通市图书馆

Super-high bed sintering for iron ores:behaviors,causes and solutions of horizontal segregation on strand

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 Iron and Steel Research International 2024年第7期31卷 1590-1596页

作者： Liang-ping Xu Hui-bo Liu Zhong-lin Dong Qiang Zhong Yu-chao Zhao guang-hui Li School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083HunanChina

Horizontal segregation has been a constraint to the development and application of super-high bed *** eliminate the horizontal segregation of super-high bed sintering,several typical sintering machines were sampled and analyzed,and theoretical calculation was made to compare the bed depth and their differences in different areas within the mixture ***,solutions were proposed and applied to a 265 m^(2) sintering *** results showed that the horizontal seg-regation of the 265 m^(2) sintering machine was dominated by particles larger than 8 mm with horizontal segregation degree of 0.48,while 360 and 550 m^(2) sintering machines were affected by 5-8 mm and 1-3 mm particles with horizontal segregation degree of 0.27 and 0.31,*** analysis indicated the different segregation distribution results from the matching of the bed depth of each area within the mixture ***,the horizontal segregation degree not larger than 0.06 was achieved by optimizing the time parameters and the division of three zones on the 265 m^(2) sintering machine.

关键词： Super-high bed sintering Horizontal segregation Feeder Particle distribution Agglomeration

Flexible 2 × 2 multiple access visible light communication system based on an integrated parallel GaN/InGaN micro-photodetector array module

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

Photonics Research 2024年第4期12卷 793-803页

作者： ZENGYI XU XIANHAO lin ZHITENG LUO QIANYING lin JIANLI ZHANG guANGXU wang XIAOLAN wang FENGYI JIANG ZIWEI LI JIANYANG SHI JUNWEN ZHANG chao SHEN NAN CHI Key Laboratory for Information Science of Electromagnetic Waves(MoE) Department of Communication Science and EngineeringFudan UniversityShanghai 200433China National Institute of LED on Silicon Substrate Nanchang UniversityNanchang 330096China

In recent studies, visible light communication(VLC) has been predicted to be a prospective technique in the future 6G communication systems. To suit the trend of exponentially growing connectivity, researchers have intensively studied techniques that enable multiple access(MA) in VLC systems, such as the MIMO system based on LED devices to support potential applications in the Internet of Things(IoT) or edge computing in the nextgeneration access network. However, their transmission rate is limited due to the intrinsic bandwidth of ***, the majority of visible light laser communication (VLLC) research with beyond 10 Gb/s data rates concentrates on point-to-point links, or using discrete photodetector(PD) devices instead of an integrated array PD. In this paper, we demonstrated an integrated PD array device fabricated with a Si-substrated GaN/InGaN multiple-quantum-well(MQW) structure, which has a 4 × 4 array of 50 μm × 50 μm micro-PD units with a common cathode and anode. This single-integrated array successfully provides access for two different transmitters simultaneously in the experiment, implementing a 2 × 2 MIMO-VLLC link at 405 nm. The highest data rate achieved is 13.2 Gb/s, and the corresponding net data rate(NDR) achieved is 12.27 Gb/s after deducing the FEC overhead, using 2.2 GHz bandwidth and superposed PAM signals. Furthermore, we assess the Huffman-coded coding scheme, which brings a fine-grain adjustment in access capacity and enhances the overall data throughput when the user signal power varies drastically due to distance, weather, or other challenges in the channel condition. As far as we know, this is the first demonstration of multiple visible light laser source access based on a single integrated GaN/InGaN receiver module.

关键词： communication visible light

First wetland mapping at 10-m spatial resolution in South America using multi-source and multi-feature remote sensing data

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第10期67卷 3252-3269页

作者： Weiwei SUN Gang YANG Yuling HUANG Dehua MAO Ke HUANG lin ZHU Xiangchao MENG Tian FENG chao CHEN Yong GE Department of Geography and Spatial Information Techniques Ningbo UniversityNingbo 315211China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences&Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Natural Resources and Planning Bureau Shanghai Pudong New DistrictShanghai 200100China Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and AgroecologyChinese Academy of SciencesChangchun 130102China Faculty of Electrical Engineering and Computer Science Ningbo UniversityNingbo 315211China School of Geography Science and Geomatics Engineering Suzhou University of Science and TechnologySuzhou 215009China

Wetland degradation has been accelerating in recent years globally. Accurate information on the geographic distribution and categories of wetlands is essential for their conservation and management. Despite being the world′s fourth largest continent, South America has limited research on wetland mapping, and there is currently no available map that provides comprehensive information on wetland distribution and categories in the region. To address this issue, we used Sentinel-1, Sentinel-2 and SRTM data, developed a sample collection method and a wetland mapping method with a collection of multi-source features such as optical features, polarization features and shape features for South American wetlands. We produced a 10-m resolution wetland map based on the Google Earth Engine(GEE) platform. Our Level-1 wetland cover map accurately captured six wetland sub-categories with an overall accuracy of 96.24% and a kappa coefficient of 0.8649, while our Level-2 water cover map included five sub-categories with an overall accuracy of 97.23% and a kappa coefficient of0.9368. The results show that the total area of existing wetlands in South America is approximately 1,737,000 km~2, which is6.8% of the total land area. Among the ten wetland categories, shallow sea had the largest area(960,527.4 km~2), while aquaculture ponds had the smallest area 1513.6 km~2. Swamp had the second largest area(306,240.1 km~2). Brazil, Argentina,Venezuela, Bolivia, and Colombia were found to have the largest wetland areas, with Brazil and Colombia having the most diverse wetland categories. This product can serve as baseline data for subsequent monitoring, management, and conservation of South American wetlands.

关键词： Wetland mapping Google Earth Engine Sentinel imagery South America

同方期刊数据库

Inferring Mycobacterium Tuberculosis Drug Resistance and Transmission using Whole-genome Sequencing in a High TB-burden Setting in China

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2024年第2期37卷 157-169页

作者： FAN Yu Feng LIU Dong Xin CHEN Yi wang OU Xi chao MAO Qi Zhi YANG Ting Ting wang Xi Jiang HE Wen Cong ZHAO Bing LIU Zhen Jiang ABULIMITI Maiweilanjiang AIHEMUTI Maimaitiaili GAO Qian ZHAO Yan lin Key Laboratory of Medical Molecular Virology(MOE/NHC/CAMS) School of Basic Medical SciencesShanghai Medical CollegeFudan UniversityShanghai 200032China National Tuberculosis Reference Laboratory Chinese Center for Disease Control and PreventionBeijing 102206China Hangzhou Red Cross Hospital Hangzhou 310005ZhejiangChina Xinjiang Uygur Autonomous Region Center for Disease Control and Prevention Urumqi 830026XinjiangChina Tuberculosis Dispensary of Kashgar Prefecture Kashgar 844099XinjiangChina

Objective China is among the 30 countries with a high burden of tuberculosis(TB)worldwide,and TB remains a public health *** Prefecture in the southern Xinjiang Autonomous Region is considered as one of the highest TB burden regions in ***,molecular epidemiological studies of Kashgar are *** A population-based retrospective study was conducted using whole-genome sequencing(WGS)to determine the characteristics of drug resistance and the transmission *** A total of 1,668 isolates collected in 2020 were classified into lineages 2(46.0%),3(27.5%),and 4(26.5%).The drug resistance rates revealed by WGS showed that the top three drugs in terms of the resistance rate were isoniazid(7.4%,124/1,668),streptomycin(6.0%,100/1,668),and rifampicin(3.3%,55/1,668).The rate of rifampicin resistance was 1.8%(23/1,290)in the new cases and 9.4%(32/340)in the previously treated *** resistance mutations were detected more frequently in lineage 2 strains than in lineage 3 or 4 strains,respectively:18.6%vs.8.7 or 9%,Plineage,and drug resistance were the risk factors for recent *** the low rate of drug resistance,drug-resistant strains had a higher risk of recent transmission than the susceptible strains(adjusted odds ratio,1.414;95%CI,1.023–1.954;P=0.036).Among all patients with drug-resistant tuberculosis(DR-TB),78.4%(171/218)were attributed to the transmission of DR-TB *** Our results suggest that drug-resistant strains are more transmissible than susceptible strains and that transmission is the major driving force of the current DR-TB epidemic in Kashgar.

关键词： Mycobacterium tuberculosis Whole-genome sequencing(WGS) Transmission Drug resistance Xinjiang

Modified stapled hemorrhoidopexy for lower postoperative stenosis: A five-year experience

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastrointestinal Surgery 2024年第9期16卷 2787-2795页

作者： Yu-hong Liu Tzu-Chiao lin chao-Yang Chen Ta-Wei Pu Division of Colon and Rectal Surgery Department of SurgeryTri-Service General HospitalNational Defense Medical CenterTaipei 105Taiwan Division of Colon and Rectal Surgery Department of SurgeryTri-Service General Hospital Songshan BranchNational Defense Medical CenterTaipei 105Taiwan

BACKGROUND Stapled hemorrhoidopexy(SH)is currently a widely accepted method for treating the prolapse of internal *** anal stenosis is a critical complication of SH.A remedy for this involves the removal of the circumferential staples of the anastomosis,followed by the creation of a hand-sewn *** studies have reported modified SH procedures to improve *** hypothesized that our modified SH technique may help reduce complications of anal stenosis after *** To compare outcomes of staple removal at the 3-and 9-o’clock positions during modified SH in patients with mixed *** This was a single-center,retrospective,observational *** with grade III or IV hemorrhoids who underwent standard or modified SH at our colorectal center between January 1,2015,and January 1,2020,were *** operation time,blood loss,length of hospital stay,and incidence of minor or major complic-ations were *** Patients with grade III or IV hemorrhoids who underwent standard or modified SH at our colorectal center between January 1,2015 and January 1,2020,were *** time,blood loss,length of hospital stay,and incidence of minor or major complications were *** investigated 187 patients(mean age,50.9 years)who had undergone our modified SH and 313 patients(mean age,53.0 years)who had undergone standard *** the modified SH group,54%of patients had previously undergone surgical intervention for hemorrhoids,compared with the 40.3%of patients in the standard SH *** modified SH group included five(2.7%)patients with anal stenosis,while 21(6.7%)patients in the standard SH group had complications of anal *** was a significant relationship between the rate of postoperative anal stenosis and the modified SH:0.251(0.085-0.741)and 0.211(0.069-0.641)in multiple regression *** modified SH technique is a safe surgical method for advanced grade hemorrhoids and might result in

关键词： Anal canal Hemorrhoids Prolapse Stapled hemorrhoidopexy Postoperative anal stenosis Modified stapled hemorrhoidopexy

Experimental study on photodegradation and leaching of typical pesticides in greenhouse soil from Shouguang, Shandong Province, East China

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

Ecological Processes 2024年第2期 32-47页

作者： Li-Ting Hua Rui-lin Wu Cun-Lu Li chao-Nan wang Yi-Long Li Fu-Liu Xu MOE Laboratory for Earth Surface Processes College of Urban and Envi-ronmental Sciences Peking University Department of Ecology and Environment of Shanxi Province

Background Pesticide use contributes to national food security. The dissipation pathways and degradation mecha-nisms of pesticides have been widely studied and pesticide residues have remained a focus of public concern. How-ever, studies on the migration and transformation behaviors of pesticide residues in real-world greenhouse soils are insufficient. Therefore, in this study, we collected greenhouse soil from Shouguang, Shandong Province, and investi-gated the photodegradation and leaching of 17 common pesticides, which leave residues in the soil and are the most frequently used pesticides in Shouguang. The environmental behavior of pesticides in greenhouse soils will provide new information on pesticide residues in the real environment and provide a scientific basis for the prevention and control of pesticide pollution in greenhouse *** The photodegradation of trifloxystrobin followed a first-order kinetic equation, whereas those of emamec-tin benzoate, chlorantraniliprole, buprofezin, difenoconazole, pyraclostrobin, boscalid, tebuconazole, isoprothiolane, metalaxyl, and oxadixyl followed second-order kinetics. The half-lives of 17 pesticides under light and dark conditions ranged from 2.5–104(mean: 36.2) and 2.6–110(mean: 31.4) days, respectively. The half-lives of emamectin benzoate, pyraclostrobin, and metalaxyl in the light were 86.6%, 68.5%, and 94.5% of their half-lives in the dark, respectively. Chlorantraniliprole, metalaxyl, nitenpyram, diethofencarb, acetamiprid, carbendazim, and oxadixyl were leached to ≥ 90% in aqueous solution. Six pesticides, avermectin B1A, emamectin benzoate, trifloxystrobin, difenoconazole, pyraclostrobin, and buprofezin, were difficult to leach from aqueous *** The degradation rate of some pesticides was higher in the light environment than in the dark. The leaching potential of the leachable pesticides was nitenpyram ? metalaxyl > acetamiprid > carbendazim > diethofen-carb ≈ chlorantraniliprole > iso

关键词：

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

浅海粗糙海底声散射建模及声场特性

物理学报 2024年第3期73卷 126-133页

作者：汪磊黄益旺郭霖任超哈尔滨工程大学水声技术全国重点实验室哈尔滨150001 海洋信息获取与安全工信部重点实验室(哈尔滨工程大学) 工业和信息化部哈尔滨150001 哈尔滨工程大学水声工程学院哈尔滨150001 中国科学院声学研究所东海研究站上海201815

声散射是海洋声学的重要内容,海底表面的不平整性形成的声散射是海洋中引起声传播起伏的原因之一.针对海底表面粗糙度声散射问题,建立了水平分层浅海波导中海底散射声场模型.该模型将简正波理论与Lambert定律相结合.基于该模型获得了散... 详细信息

声散射是海洋声学的重要内容,海底表面的不平整性形成的声散射是海洋中引起声传播起伏的原因之一.针对海底表面粗糙度声散射问题,建立了水平分层浅海波导中海底散射声场模型.该模型将简正波理论与Lambert定律相结合.基于该模型获得了散射声场声压的振幅与相位的统计分布,并数值模拟了海底散射声场的强度及其空间相关系数,实现了粗糙界面条件下海底散射声场预报,揭示了散射声场空间特性随海底粗糙度的变化规律.结果表明,使用Lambert定律描述粗糙界面声散射时,在海底粗糙度小于波长情况下,随着空间距离的增大,空间两个不同位置的散射声场的空间相关系数具有周期性振荡衰减的变化规律,并且在垂直方向上,振荡周期更大,衰减更慢.当粗糙度增大时,水平和垂直相关系数振荡幅度逐渐增大,水平相关系数振荡周期数逐渐减少,在接收点逐渐靠近海底时,垂直相关系数不再发生衰减,这是海底声散射减弱的结果.本文模型理论亦可推广到粗糙海面的声散射建模中.对于非水平海底情况,采用耦合简正波或绝热简正波理论进行声传播建模,可以得到距离有关波导中粗糙界面的散射声场.

关键词：海底声散射简正波 Lambert定律空间相关

维普期刊数据库博看期刊

基于NSGA-Ⅱ算法选择光谱反射率重建样本的研究

在线全文

学校读者我要写书评

暂无评论

光谱学与光谱分析 2024年第5期44卷 1227-1232页

作者：林鹭王智峰李超辽宁科技大学计算机与软件工程学院辽宁鞍山114051

为解决光谱反射率重建过程中训练样本数目庞大导致工作量大,重建精度不高等问题,提出一种基于NSGA-Ⅱ算法的光谱反射率重建样本选择方法。近日Liang等提出了一种从大量样本数据中选取具有代表性样本的新方法,定义光谱重建误差为均方根... 详细信息

为解决光谱反射率重建过程中训练样本数目庞大导致工作量大,重建精度不高等问题,提出一种基于NSGA-Ⅱ算法的光谱反射率重建样本选择方法。近日Liang等提出了一种从大量样本数据中选取具有代表性样本的新方法,定义光谱重建误差为均方根误差与拟合优度系数的乘积,以这一标准选择光谱重建误差最小的样本作为代表性样本进行光谱反射率重建。受Liang等人工作的启发结合NSGA-Ⅱ算法选择代表性样本,先对全体训练样本使用多项式回归算法和伪逆法进行光谱反射率重建,再使用NSGA-Ⅱ算法,设定两个目标函数,一个是所需代表性样本个数的光谱均方根误差的和,另一个是拟合优度系数倒数的和,令两个目标函数值最小。将经过NSGA-Ⅱ算法挑选出的Pareto等级为1的全部样本按照样本出现次数由高至低排序,以此顺序从高到低依次选为代表性样本,直至达到所需代表性样本个数。若从Pareto等级为1的样本集合中挑选的代表性样本数不足所需要的个数则选择下一等级出现次数最多且没有被选择过的样本直至代表性样本数达到需求。将1269块无光泽Munsell标准色卡按照样本下标划分为偶数色卡、奇数色卡,第一组实验用Munsell奇数色卡为全体训练样本,从Munsell偶数色卡中随机选择20个色块为测试样本。第二组实验选用Munsell偶数色卡为全体训练样本,从Munsell奇数色卡中随机选取20个色块为测试样本。第三组实验训练样本与第一组相同,RC24色卡为测试样本。将该方法与Mohammadi、Cao、Liang等提出的三种样本选择方法进行对比。通过实验得到使用NSGA-Ⅱ算法结合多项式回归与伪逆法选择的代表性样本重建的光谱反射率在均方根误差和色差两个指标上均优于现有的样本选择方法,并且该方法不限于特定系统,具有通用性。

关键词：光谱反射率重建 NSGA-Ⅱ 多目标优化样本选择

Removal of rubidium from brine by an integrated film of sulfonated polysulfone/graphene/potassium copper ferricyanide

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第5期69卷 112-121页

作者： Huanxi Xu Peihua lin Pei-Jun Liu Hai-Gang Liu Hui-Bin guo chao-Xiang Wu Ming Fang Xu Zhang guan-Ping Jin Anhui Province Engineering Research Center of Flexible and Intelligent Materials School of Chemistry and Chemical EngineeringHefei University of TechnologyHefei 230009China Chemical Design and Research Institute Co. LTD of Qinghai ProvinceQinghai Engineering and Technology Research Center of Fine ChemicalXining 810008China

A novel integrated film of sulfonated polysulfone/graphene/potassium copper ferricyanide(KCuFC/SPSG)was used for selectively extracting rubidium ion(Rb^(+))from *** form KCuFC/SPSG,the precursor film of sulfonated polysulfone/graphene(SPSG)was synthesized by phase conversion process,which was alternately immersed in 0.1 mol·L^(-1)CuSO_(4)/K_(4)[Fe(CN)_(6)]by in-situ adsorption coupled co-precipitation *** data such as nuclear magnetic resonance spectrometer,Fourier transform infrared spectroscope,X-ray photoelectron spectroscope,X-ray diffraction,scanning electron microscope,and energy dispersive spectroscopy all verified that abundant KCuFC were uniformly located on the *** resulting KCuFC/SPSG was used in film separation *** the solution was fed into the system,the Rb^(+)could be selectively adsorption by KCuFC/*** the saturation adsorption,0.5 mol·L^(-1)NH_(4)Cl/HCl was fed into the film cell,Rb^(+)could be quickly desorbed by ion-exchange between Rb^(+)and NH_(4)^(+)in the lattice of *** purpose of separating and recovering Rb^(+)from the brine can be achieved after the repeated *** effects of pH,adsorption time,and interferential ions on the adsorption capacity of Rb^(+)were investigated by batch *** adsorption behavior fits the pseudo-second order kinetic process,while KCuFC has a higher adsorption capacity(Langmuir maximum sorption 165.4 mg·g^(-1)).In addition,KCuFC/SPSG shows excellent selectivity for Rb^(+)even in complex brine ***/SPSG could maintain 93.5%extraction efficiency after five adsorption/desorption cycles.

关键词： Rubidium extraction Potassium copper ferricyanide Sulfonated polysulfone Graphene oxide Adsorption