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China CDC weekly 2023年第5期5卷 103-107,I0006页

作者： Xinhua Chen Xufang Bai Xinghui Chen Nan Zheng juan yang juanjuan Zhang Hongjie Yu School of Public Health Fudan UniversityKey Laboratory of Public Health SafetyMinistry of EducationShanghai MunicipalityChina Shanghai Huashen Institute of Microbes and Infections Shanghai MunicipalityChina Shanghai Institute of Infectious Disease and Biosecurity Fudan UniversityShanghai MunicipalityChina

Summary What is already known about this topic?Previous studies have reported vaccine efficacy or effectiveness against severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron subvariants for several vaccine ***,there are currently few data on estimates of inactivated platform coronavirus disease 2019(COVID-19)vaccines,especially against the globally dominant subvariant—Omicron BA.5.

关键词： vaccine acute respiratory

A Novel Sparse Penalty for Singular Value Decomposition

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Chinese Journal of Electronics 2017年第2期26卷 306-312页

作者： WANG Caihua LIU juan MIN Wenwen QU Aiping The State Key Laboratory of Software Engineering School of ComputerWuhan University

Singular value decomposition(SVD) is a tool widely used in data denoising,matrix approximation,recommendation system,text mining and computer vision.A ma jority of applications prefer sparse singular vectors to capture inherent structures and patterns of the input data so that the results are *** present a novel penalty for SVD to achieve *** with the traditional penalties,the proposed penalty is scale,dimensional insensitive and bounded between 0 and 1,which are in favor of controlling *** by the penalty,we provide an efficient algorithm to pro ject a vector onto a given sparse level in O(n) expected *** efficient pro jection algorithm serve as a drudge for sparse SVD(SSVD).In experiments,SSVD is efficient and could capture the latent structures and patterns of the input data.

关键词： Sparse controllable projection(SCP) Sparse singular value decomposition(SSVD) Sparse low rank matrix approximation(SLRMA)

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光电转台RCS仿真研究

激光与红外 2024年第9期54卷 1440-1448页

作者：郭广宇齐放杜瑞娟周建华中国电子科技集团公司第十一研究所北京100015

通过软件仿真计算光电转台的雷达散射截面积(radar cross section,RCS)。基于散射的高频局部性原理完成目标的RCS预估,在S、C、X波段,0~3°入射余角条件下对光电转台的RCS进行仿真。将复杂的光电转台分解,研究各部分RCS特性并对光电转... 详细信息

通过软件仿真计算光电转台的雷达散射截面积(radar cross section,RCS)。基于散射的高频局部性原理完成目标的RCS预估,在S、C、X波段,0~3°入射余角条件下对光电转台的RCS进行仿真。将复杂的光电转台分解,研究各部分RCS特性并对光电转台开展隐身设计。对完成隐身设计后的转台进行仿真分析,隐身设计后均值大于0.5 m^(2)的RCS占比约为18.18%,光电转台隐身特性提升明显。

关键词：雷达散射截面积光电转台仿真计算隐身设计

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湖北省加州鲈产业发展现状分析及对策

安徽农业科学 2024年第17期52卷 86-89页

作者：付莹陆娟娟祝本强谢康乐夏理海湖南应用技术学院湖南常德415100 松滋市农业农村科技服务中心湖北松滋434200 松滋市畜牧兽医服务中心湖北松滋434200

湖北省是全国重要的淡水鱼生产地,淡水养殖产量多年来稳居全国首位,淡水养殖品种多样,养殖技术较为先进。近年来,加州鲈的养殖在全国各地蓬勃发展,养殖产量逐年增加。在新的养殖发展机遇下,根据渔业统计数据对湖北省加州鲈产业现状进行... 详细信息

湖北省是全国重要的淡水鱼生产地,淡水养殖产量多年来稳居全国首位,淡水养殖品种多样,养殖技术较为先进。近年来,加州鲈的养殖在全国各地蓬勃发展,养殖产量逐年增加。在新的养殖发展机遇下,根据渔业统计数据对湖北省加州鲈产业现状进行分析,探索湖北省加州鲈产业存在的问题,并对今后的发展提出相应的对策,以期对当前湖北省淡水渔业转型升级起到助力作用。

关键词：加州鲈养殖产量产业发展现状对策

Fabrication of N-doped carbon nanobelts from a polypyrrole tube by confined pyrolysis for supercapacitors

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Frontiers of Chemical Science and Engineering 2021年第5期15卷 1312-1321页

作者： Wei Wang Haijun Lv juan Du Aibing Chen College of Chemical and Pharmaceutical Engineering Hebei University of Science and TechnologyShijiazhuang050018China CAS Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuan030001China

In this present work,N-doped carbon nanobelts(N-CNBs)were prepared by a confined-pyrolysis approach and the N-CNBs were derived from a polypyrrole(Ppy)tube coated with a compact silica *** silica layer provided a confined space for the Ppy pyrolysis,thereby hindering the rapid overflow of pyrolysis gas,which is the activator for the formation of carbonaceous *** the same time,the confined environment can activate the carbon shell to create a thin wall and strip the carbon tube into belt *** process of confined pyrolysis realizes self-activation during the pyrolysis of Ppy to obtain the carbon nanobelts without adding any additional activator,which reduces pollution and preparation *** addition,this approach is simple to operate and avoids the disadvantages of other methods that consume time and *** as-prepared N-CNB shows cross-linked nanobelt morphology and a rich porous structure with a large specific surface *** supercapacitor electrode materials,the N-CNB can present abundant active sites,and exhibits a specific capacitance of 246 F·g^(−1),and excellent ability with 95.44%retention after 10000 *** indicates that the N-CNB is an ideal candidate as a supercapacitor electrode material.

关键词： carbon nanobelts polypyrrole N-doped confined pyrolysis supercapacitor

Achieving nitritation at low temperatures using free ammonia inhibition on Nitrobacter and real-time control in an SBR treating landfill leachate

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Journal of Environmental Sciences 2015年第4期27卷 157-163页

作者： Hongwei Sun Yongzhen Peng Shuying Wang juan Ma Key Laboratory of Beijing Water Quality Science and Water Environment Recovery Engineering Beijing University of Technology School of Environmental and Municipal Engineering Lanzhou Jiaotong University

Free ammonia（FA） inhibition on nitrite-oxidized bacteria（NOB） and real-time control are used to achieve nitrogen removal from landfill leachate via nitrite pathway at low temperatures in sequencing batch reactor. The inhibition of FA on NOB activity during the aerobic period was prolonged using real-time control. The degree of nitrite accumulation was monitored along with variations of the ammonia-oxidizing bacteria and NOB population using fluorescence in situ hybridization techniques. It is demonstrated that the end-point of ammonia oxidization is detected from the on-line measured dissolved oxygen,oxidization–reduction potential, and p H signals, which could avoid the loss the FA inhibition on NOB caused by excess aeration. At low temperature（13.0–17.6°C）, the level of nitrite pathway rapidly increased from 19.8% to 90%, suggesting that nitritation was successfully started up at low temperature by applying syntrophic association of the FA inhibition and real-time control, and then this high level of nitrite pathway was stably maintained for as long as 233 days. Mechanism analysis shows that the establishment of nitritation was primarily the result of predominant ammonia-oxidizing bacteria developed in the nitrifying bacteria population compared to NOB. This was mainly due to a gradual reduction of nitrite amount that is available to provide energy for the growth of NOB,eventually leading to the elimination of NOB from the bacterial clusters in sequencing batch reactor sludge system.

关键词： Landfill leachate Nitritation Low temperature Free ammonia Inhibition AOB and NOB

ON NEW STRATEGIES TO CONTROL THE ACCURACY OF WENO ALGORITHM CLOSE TO DISCONTINUITIES Ⅱ:CELL AVERAGES AND MULTIRESOLUTION

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Journal of Computational Mathematics 2020年第4期38卷 661-682页

作者： Sergio Amat juan Ruiz Chi-Wang Shu Department of Applied Mathematics and Statistics Universidad Politecnica de CartagenaSpain Division of Applied Mathematics Brown UniversityUSA

This paper is the second part of the article and is devoted to the construction and analysis of new non-linear optimal weights for WENO interpolation capable of rising the order of accuracy close to discontinuities for data discretized in the cell ***,now we are interested in analyze the capabilities of the new algorithm when working with functions belonging to the subspace L1\L2 and that,consequently,are piecewise smooth and can present jump *** new non-linear optimal weights are redesigned in a way that leads to optimal theoretical accuracy close to the discontinuities and at smooth *** will present the new algorithm for the approximation case and we will analyze its *** we will explain how to use the new algorithm in multiresolution applications for univariate and bivariate *** numerical results confirm the theoretical proofs presented.

关键词： WENO Cell averages New optimal weights Multiresolution schemes Im-proved adaption to discontinuities Signal processing

固相萃取/高效液相色谱-串联质谱法同时测定氟橡胶、氟树脂及其制品中多种全氟和多氟烷基化合物

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分析测试学报 2024年第8期43卷 1166-1179页

作者：周鑫月卢瑶罗雅丹黎娟王亚韡郑州大学河南先进技术研究院河南郑州450001 中国科学院生态环境研究中心北京100085

基于固相萃取/高效液相色谱-串联质谱(HPLC-MS/MS)技术,建立了氟橡胶、氟树脂及其制品中37种全氟和多氟烷基化合物(PFASs)的定量分析方法和19种PFASs的定性分析方法。采用25 mmol·L^(-1)乙酸铵甲醇/乙腈(1∶1,体积比)溶液对氟橡胶类、... 详细信息

基于固相萃取/高效液相色谱-串联质谱(HPLC-MS/MS)技术,建立了氟橡胶、氟树脂及其制品中37种全氟和多氟烷基化合物(PFASs)的定量分析方法和19种PFASs的定性分析方法。采用25 mmol·L^(-1)乙酸铵甲醇/乙腈(1∶1,体积比)溶液对氟橡胶类、氟树脂固体类和氟树脂纺织类样品进行超声振荡提取;采用四甲基叔丁基醚(MTBE)对氟树脂液体类样品进行超声振荡提取,提取液经Envi-carb和Oasis WAX柱固相萃取,并用甲醇和0.1%氨水甲醇洗脱。在10 mmol·L^(-1)乙酸铵溶液-乙腈流动相下采用Acquity UPLC BEH C18(2.1 mm×100 mm,1.7μm)色谱柱对目标化合物进行梯度洗脱分离,多反应监测模式(MRM)进行采集,内标法定量。结果表明,在5、10、20 ng·g^(-1)(氟橡胶类)和2.5、5、10 ng·g^(-1)(氟树脂类)加标水平下,氟橡胶类、氟树脂固体类、氟树脂纺织类和氟树脂液体类样品中37种PFASs的回收率分别为81.3%~109%、60.9%~111%、87.8%~125%和88.7%~140%;相对标准偏差(RSD)分别为1.4%~28%、1.5%~22%、1.8%~27%和1.4%~19%;检出限(LOD)分别为0.03~0.3 ng·g^(-1)、0.03~0.8 ng·g^(-1)、0.02~2 ng·g^(-1)和0.04~1 ng·g^(-1);定量下限(LOQ)分别为0.07~0.9 ng·g^(-1)、0.08~2 ng·g^(-1)、0.06~6 ng·g^(-1)和0.1~4 ng·g^(-1)。19种PFASs的回收率为0.300%~208%,适于半定量和定性分析。使用该方法测定10个氟橡胶和氟树脂样品,Σ_(37)PFASs含量为9.73~66.17 ng·g^(-1)。该方法操作简便、灵敏度高且定量准确,可为研究氟橡胶、氟树脂及其制品中PFASs的残留情况及完善我国出口贸易和国内履约执法监测提供技术支撑。

关键词：氟橡胶氟树脂全氟及多氟烷基化合物高效液相色谱-串联质谱固相萃取

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钒钛球团矿熔滴过程中有价元素及物相的变化

钢铁钒钛 2024年第4期45卷 105-112+128页

作者：谢洪恩郑魁黄楚朱凤湘刘娟攀钢集团研究院有限公司钒钛资源综合利用国家重点实验室攀钢集团西昌钢钒有限公司

模拟高炉冶炼气氛，对攀钢酸性钒钛球团矿在软熔和滴落过程中的物相组成和有价元素的变化进行了定量化的研究。结果表明，在钒钛球团矿的软熔滴落过程中，Ti和V逐渐从钛赤铁矿和钛铁矿迁移至渣相中。TiO2既可生成Ti进入金属铁，也可大... 详细信息

模拟高炉冶炼气氛，对攀钢酸性钒钛球团矿在软熔和滴落过程中的物相组成和有价元素的变化进行了定量化的研究。结果表明，在钒钛球团矿的软熔滴落过程中，Ti和V逐渐从钛赤铁矿和钛铁矿迁移至渣相中。TiO2既可生成Ti进入金属铁，也可大量生成碳氮化钛。滴落试验中V在金属铁中的收得率为36.03%，远高于Ti和Si的3.13%和17.20%。炉渣和金属铁吸收焦炭中的S与渣铁间的脱硫反应同时进行，金属铁中S所占的比例由软熔时的72.84%降低至滴落时的50%。软熔液泛渣中辉石和黑钛石超过80%，渣中超过70%的V和Ti分布于黑钛石中。软熔未滴落渣中辉石明显减少，橄榄石和尖晶石明显增加，尖晶石中的V和Ti明显增加。滴落试验过程中TiO2逐渐被还原，TiC和TiN的质量分数之和超过20%，炉渣逐渐由TiO2质量分数超过30%的高钛渣转变为TiO2质量分数低于10%的低钛渣，未滴落渣中黑钛石以及分布于其中的V和Ti明显减少，橄榄石以及分布于其中的V和Ti增加。

关键词：高炉钒钛球团矿软熔滴落物相组成有价元素碳氮化钛

秸秆还田与氮肥运筹对农田土壤可溶性氮组分的影响

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中国土壤与肥料 2024年第3期 49-56页

作者：隽英华何志刚刘慧屿刘艳陈玥辽宁省农业科学院植物营养与环境资源研究所辽宁沈阳110161

为探究秸秆还田配施氮肥对农田土壤可溶性氮转化特征的影响,研发东北冷凉区土壤氮素供应能力提高的秸秆还田技术,采用田间连续定位试验,对比分析了秸秆还田方式(不还田、粉碎翻压还田、堆腐旋耕还田)与氮肥运筹(N 180、210、240 kg/hm^(... 详细信息

为探究秸秆还田配施氮肥对农田土壤可溶性氮转化特征的影响,研发东北冷凉区土壤氮素供应能力提高的秸秆还田技术,采用田间连续定位试验,对比分析了秸秆还田方式(不还田、粉碎翻压还田、堆腐旋耕还田)与氮肥运筹(N 180、210、240 kg/hm^(2);氮肥基施、氮肥后移)作用下农田土壤无机氮(IN)、可溶性有机氮(DON)及可溶性全氮(DTN)的动态变化。结果表明,秸秆还田配施氮肥影响农田土壤可溶性氮组分含量,其作用行为受秸秆还田方式、施氮模式和生育时期的多重制约。秸秆还田配施低量氮肥(N 180 kg/hm^(2))土壤IN和DTN均低于无秸秆处理,而配施高量氮肥(N 240 kg/hm^(2))时高于无秸秆处理;秸秆还田土壤DON于生育前期(播种-拔节期)较无秸秆处理显著增加,而在生育中后期无规律性变化。随着施氮量增加,秸秆还田土壤IN和DTN显著增加,而DON仅于春玉米旺盛生长期(拔节期-灌浆期)显著增加。随着生育期推进,除秸秆堆腐旋耕还田土壤DON呈三峰曲线变化外,秸秆还田土壤IN、DON和DTN均呈双峰曲线变化,且峰值越来越低。由此可见,在东北农业产区,N 210 kg/hm^(2)用量下秸秆粉碎翻压还田配施15%氮肥的秸秆还田技术具有优化氮素管理、提高土壤肥力的潜力。

关键词：秸秆还田施氮方式无机氮可溶性有机氮可溶性全氮

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