检索结果-南通市图书馆

Orbit and clock products for quad-system satellites with undifferenced ambiguity fixing approach

Satellite Navigation 2024年第1期5卷 125-139页

作者： Jiaqi Wu Xingxing Li Yongqiang Yuan Keke Zhang Xin Li jiaqing Lou Yun Xiong School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079China Hubei Luojia Laboratory 129 Luoyu RoadWuhan430079China German Research Centre for Geosciences GFZ Telegrafenberg14473PotsdamGermany Technische Universitat Berlin(TUB) Straße Des 17.Juni10623BerlinGermany

Integer Ambiguity Resolution(IAR)can significantly improve the accuracy of GNSS Precise Orbit Determination(POD).Traditionally,the IAR in POD is achieved at the Double Differenced(DD)*** this contribution,we develop an Un-Differenced(UD)IAR method for Global Positioning System(GPS)+BeiDou Navigation Satellite System(BDS)+Galileo navigation satellite system(Galileo)+Global'naya Navigatsionnaya Sputnikovaya Sistema(GLONASS)quad-system POD by calibrating UD ambiguities in the raw carrier phase and generating the so-called carrier *** on this method,we generate the UD ambiguity-fixed orbit and clock products for the Wuhan Innovation Application Center(IAC)of the International GNSS Monitoring and Assessment System(iGMAS).One-year observations in 2020 from 150 stations are employed to investigate performance of orbit and clock ***,the UD Ambiguity Resolution(AR)yields more resolved integer ambiguities than the traditional DD AR,scaling up to 9%,attributable to its avoidance of station baseline *** from the removal of ambiguity parameters,the computational efficiency of parameter estimation undergoes a substantial 70%*** with the float solution,the orbit consistencies of UD AR solution achieve the accuracy of 1.9,5.2,2.8,2.1,and 2.7 cm for GPS,BeiDou-2 Navigation Satellite System(BDS-2),BeiDou-3 Navigation Satellite System(BDS-3),Galileo,and GLONASS satellites respectively,reflecting enhancements of 40%,24%,54%,34%,and 42%.Moreover,the standard deviations of Satellite Laser Ranging(SLR)residuals are spanning 2.5–3.5 cm,underscoring a comparable accuracy to the DD AR solution,with discrepancies below 5%.A notable advantage of UD AR lies in its capability to produce the Integer Recovered Clock(IRC),facilitating Precise Point Positioning(PPP)AR without requiring additional Uncalibrated Phase Delay(UPD)*** assess the performance of quad-system kinematic PPP based on IRC,a network comprising 120 stations is uti

关键词： Multi-GNSS Precise orbit determination Integer recover clock Undifferenced ambiguity resolution iGMAS innovation application center

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

Geochemical fractionation and potential release behaviour of heavy metals in lead–zinc smelting soils

引用

Journal of Environmental Sciences 2024年第5期139卷 1-11页

作者： Xinghua Luo Chao Xiang Chuan Wu Wenyan Gao Wenshun Ke jiaqing Zeng Waichin Li Shengguo Xue School of Metallurgy and Environment Central South UniversityChangsha 410083China Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution Central South UniversityChangsha 410083China Department of Science and Environmental Studies The Education University of Hong KongHong Kong 999077China

The lack of understanding of heavy metal speciation and solubility control mechanisms in smelting soils limits the effective pollution *** this study smelting soils were investigated by an advanced mineralogical analysis(AMICS),leaching tests and thermodynamic *** aims were to identify the partitioning and release behaviour of Pb,Zn,Cd and *** integration of multiple techniques was necessary and displayed coherent *** addition to the residual fraction,Pb and Zn were predominantly associated with reducible fractions,and As primarily existed as the crystalline iron oxide-bound *** quantitative analysis further confirmed that Fe oxyhydroxides were the common dominant phase for As,Cd,Pb and *** addition,a metal arsenate(paulmooreite)was an important mineral host for Pb and *** pH-stat leaching indicted that the release of Pb,Zn and Cd increased towards low pH values while release of As increased towards high p H *** separate leaching schemes were associated with the geochemical behaviour under the control of minerals and were confirmed by thermodynamic *** calculations suggested that the formation of arsenate minerals(schultenite,mimetite and koritnigite)and the binding to Fe oxyhydroxides synchronously controlled the release of Pb,Zn,Cd and *** results emphasized the governing role of Fe oxyhydroxides and secondary insoluble minerals in natural attenuation of heavy metals,which provides a novelty strategy for the stabilization of multi-metals in smelting sites.

关键词： Smelting soils Heavy metal Fractionation AMICS Geochemical modelling

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

Flow-Slip Stability Behavior of Calcareous Sand Treated by Microbially Induced Carbonate Precipitation Technology

引用

Journal of Ocean University of China 2024年第5期23卷 1381-1389页

作者： KOU Hailei HE Xiang HOU Wangxiang LI Zhendong ZHANG Xixin AN Zhaotun LU jiaqing College of Engineering Ocean University of China

Flow-slip damage commonly destabilizes coastal slopes. Finding a slope stabilization method for calcareous sands in the South China Sea is crucial. Microbially induced calcite precipitation is a promising, eco-friendly method for soil stabilization. This study investigates the effect of microbial treatments, initial relative density, initial cell pressure, and initial stress ratio on the flow-slip stability of calcareous sand specimens by using constant shear drained tests. These tests lay the foundation to study the mechanical instability of sand slopes. Results show that the microbial-treated specimens maintain stable stresses longer, take longer to reach the instability, and withstand larger volumetric strains. Microbial treatment effectively enhances sand stability under constant shear drainage, with improvements amplified by higher initial relative density and initial cell pressure. In addition, a smaller initial stress ratio reduces shear effects on the specimen and increases resistance to flow slides. Microanalysis reveals that the flow-slip stability of calcareous sand slopes is enhanced by contact cementation, particle coating, void filling, and mutual embedment of calcium carbonate crystals.

关键词： clcareous sand constant shear drained tests flow-slip stability microbially induced carbonate precipitation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Pollution characteristics and quantitative source apportionment of heavy metals within a zinc smelting site by GIS-based PMF and APCS-MLR models

引用

Journal of Environmental Sciences 2024年第10期144卷 100-112页

作者： Huagang Lv Zhihuang Lu Guangxuan Fu Sifang Lv Jun Jiang Yi Xie Xinghua Luo jiaqing Zeng Shengguo Xue School of Metallurgy and Environment Central South UniversityChangsha 410083China Zhuzhou Qingshuitang Technology Co. Ltd.Zhuzhou 412000China New World Environment Protection Group of Hunan Changsha 410083China

The abandoned smelters present a substantial pollution threat to the nearby soil and *** this study,63 surface soil samples were collected from a zinc smelter to quantitatively describe the pollution characteristics,ecological risks,and source apportionment of heavy metal(loid)s(HMs).The results revealed that the average contents of Zn,Cd,Pb,As,and Hg were 0.4,12.2,3.3,5.3,and 12.7 times higher than the risk screening values of the construction sites,***,the smelter was accumulated heavily with Cd and Hg,and the contribution of Cd(0.38)and Hg(0.53)to ecological risk was 91.58%.ZZ3 and ZZ7 were the most polluted workshops,accounting for 25.7%and 35.0%of the pollution load and ecological risk,*** influence of soil parent materials on pollution was minor compared to various workshops within the *** with PMF,APCS-MLR and GIS analysis,four sources of HMs were identified:P1(25.5%)and A3(18.4%)were atmospheric deposition from the electric defogging workshop and surface runoff from the smelter;P2(32.7%)and A2(20.9%)were surface runoff of As-Pb foul acid;P3(14.5%)and A4(49.8%)were atmospheric deposition from the leach slag drying workshop;P4(27.3%)and A1(10.8%)were the smelting process of zinc *** paper described the distribution characteristics and specific sources of HMs in different process workshops,providing a new perspective for the precise remediation of the smelter by determining the priority control factors.

关键词： Smelter site Heavy metal(loid)s Source apportionment Positive matrix factorization Absolute principal component score-multiple linear regression

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

An integrated land change modeler and distributed hydrological model approach for quantifying future urban runoff dynamics

引用

Science China Earth Sciences 2024年第10期67卷 3288-3301页

作者： Asad Hussain MUHAMMAD Waseem MUHAMMAD Ajmal MUHAMMAD Atiq Ur Rehman Tariq MUHAMMAD jiaqing XIAO Tao YANG Pengfei SHI Institute for Disaster Risk Management School of Geographical ScienceNanjing University of Information Science and TechnologyNanjing 210044China The National Key Laboratory of Water Disaster Prevention Hohai UniversityNanjing 210098China Yangtze Institute for Conservation and Development Hohai UniversityNanjing 210098China College of Hydrology and Water Resources Hohai UniversityNanjing 210098China Centre of Excellence in Water Resources Engineering University of Engineering and TechnologyLahore 54890Pakistan Department of Agricultural Engineering Faculty of CivilAgricultural and Mining EngineeringUniversity of Engineering and TechnologyPeshawar 25120Pakistan

Climate and land use changes have a significant impact on the runoff generation process in urban environments, and these effects could get worse in the future. The combined contributions of these changes have increased the risk of ***, there is a need for integrated modeling to better understand the runoff variability, especially in small urban catchments. To quantify and separate the effects of land-use changes and climate change on the hydrological response of urban catchments with a distributed hydrological model(Storm Water Management Model, SWMM), this study introduces a new integrated approach based on the Machine Learning based land use change modeler and climate change scenarios under *** on supervised classification and land use change model analysis, accumulated impervious area increase from 22%(in2023) to 33%(in 2060) was observed in the study area. Furthermore, integrating this projected increase in imperviousness with future climate change into SWMM by considering three different scenarios i.e., S1(Climate Change), S2(Combined Land Use and Climate Change), and S3(Land use Change) resulted that climate change could cause an increase in runoff from 13.2% to18.3% in peak runoff and the contribution of land use could range from 9.1% to 18.6%. Similarly, in response to the coupled effects of climate and land-use change, the runoff would likely change from 24.53% to 39.66%. Conclusively, the study showed that despite climate change, intensive urban development by the substitution of impervious surfaces could also have a severe impact on the microclimate and hydrology of small catchments. Lastly, this study could provide a way forward for the future planning and management of water resources in small catchments which could be extended to larger catchments.

关键词： Climate change Land-use modeling Runoff simulation Percent Imperviousness TerrSet

来源：

维普期刊数据库

同方期刊数据库

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

Degradation of o-dichlorobenzene by DBD-NTP co-modified titanium gel catalyst

引用

Journal of Environmental Sciences 2024年第9期143卷 71-84页

作者： Wenbo Zhang Yi Xing Wei Su jiaqing Wang Haoqi Jia Yongkang Cui Jing Chen Hui Zhang School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants University of Science and Technology BeijingBeijing 100083China Guangdong Province Engineering Laboratory for Air Pollution Control Guangzhou 510530China College of Environmental and Resource Sciences Shanxi UniversityTaiyuan 030006China Sinosteel Maanshan Mine Research Institute Co.Ltd. Anhui 243071China

In order to study the degradation process of dioxins in industrial flue gas,the decomposition of o-dichlorobenzene(o-DCB)in a DBD plasma catalytic reactor was *** results showed that an NTP-catalyzed system,especially using the Cu Mn Ti Oxcatalyst,had better o-DCB degradation performance compared to plasma *** combination of the Cu Mn Ti Oxcatalyst with NTP can achieve a degradation efficiency of up to 97.2%for o-DCB;the selectivity of CO and CO_(2)and the carbon balance were 40%,45%,and 85%,*** dielectric constant and electrical property results indicated that the surface discharge capacity of the catalysts played a major role in the degradation of o-DCB,and a higher dielectric constant could suppress the plasma expansion and enhance the duration of the plasma discharge per discharge *** to the O1s XPS and O_(2)-TPD results,the conversion of CO to CO_(2)follows the M-v-K mechanism;thus,the active species on the catalyst surface play an important ***,the Cu Mn Ti Oxand NTP mixed system exhibited excellent stability,which is probably because Cu doping improved the lifetime of the *** work can provide an experimental and theoretical basis for research in the degradation of o-DCB by plasma catalyst systems.

关键词： o-dichlorobenzene(o-DCB) Non-thermal plasma catalysis Ozone concentration

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

An improved typhoon monitoring model based on precipitable water vapor and pressure

引用

Geodesy and Geodynamics 2024年第3期15卷 276-290页

作者： Junyu Li Haojie Li Lilong Liu jiaqing Chen Yibin Yao Mingyun Hu Liangke Huang Fade Chen Tengxu Zhang Lv Zhou College of Geomatics and Geoinformation Guilin University of TechnologyGuilin 541006China Guangxi Key Laboratory of Spatial Information and Geomatics Guilin 541006China Qinzhou Institute of Surveying and Mapping for Housing and Urban-Rural Development Co. Ltd.Qinzhou 535000China School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China School of Resources and Environmental Science and Engineering Hubei University of Science and TechnologyXianning 437100China

The potential of monitoring the movement of typhoons using the precipitable water vapor(PWV) has been confirmed. However, monitoring the movement of typhoon is focused on PWV, making it difficult to describe the movement of a typhoon in detail minutely and resulting in insufficient accuracy. Hence,based on PWV and meteorological data, we propose an improved typhoon monitoring mode. First, the European Centre for Medium-Range Weather Forecasts Reanalysis 5-derived PWV(ERA5-PWV) and the Global Navigation Satellite System-derived PWV(GNSS-PWV) were compared with the reference radiosonde PWV(RS-PWV). Then, using the PWV and atmospheric parameters derived from ERA5, we discussed the anomalous variations of PWV, pressure(P), precipitation, and wind speed during different typhoons. Finally, we compiled a list of critical factors related to typhoon movement, PWV and P. We developed an improved multi-factor typhoon monitoring mode(IMTM) with different models(i.e.,IMTM-I and IMTM-II) in different cases with a higher density of GNSS observation or only Numerical Weather Prediction(NWP) data. The IMTM was evaluated through the reference movement speeds of HATO and Mangkhut from the China Meteorological Observatory Typhoon Network(CMOTN). The results show that the root mean square(RMS) of the IMTM-I is 1.26 km/h based on ERA5-P and ERA5-PWV,and the absolute bias values are mostly within 2 km/h. Compared with the models considering the single factor ERA5-P/ERA5-PWV, the RMS of the IMTM-I is improved by 26.3% and 38.5%, respectively. The IMTM-II model manifests a residual of only 0.35 km/h. Compared with the single-factor model based on GNSS-PWV/P, the residual of the IMTM-II model is reduced by 90.8% and 84.1%, respectively. These results propose that the typhoon movement monitoring approach combining PWV and P has evident advantages over the single-factor model and is expected to supplement traditional typhoon monitoring.

关键词： Typhoon GNSS/ERA5 PWV Pressure Monitoring Improved model

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

Protective eff ect and mechanism of nanoantimicrobial peptide ND-C14 against Streptococcus pneumoniae infection

引用

World Journal of Emergency Medicine 2024年第1期15卷 28-34页

作者： Yangyang Guo Yaqi Sun Hongxia Wu Jian Lu Yuan Lin jiaqing Zhu Meihong Lai Meiqi Zhang Jun Wang Jungang Zheng Department of Intensive Care Medicine Hangzhou Traditional Chinese Medicine Hospital Affi liated to Zhejiang Chinese Medical UniversityHangzhou 310021China National Children’s Regional Medical Center National Clinical Research Center for Child HealthChildren’s HospitalZhejiang University School of MedicineHangzhou 310052China Department of Spleen and Stomach Diseases Hangzhou Traditional Chinese Medicine Hospital Affi liated to Zhejiang Chinese Medical UniversityHangzhou 310021China Department of Ultrasonic Medicine the First Affi liated Hospital of Ningbo UniversityNingbo 315010China Department of Anesthesiology the First Affi liated Hospital of Ningbo UniversityNingbo 315010China Zhejiang University School of Medicine Hangzhou 310058China The First People’s Hospital of Yuexi County Yuexi 616650China

BACKGROUND:Streptococcus pneumoniae(***)is a common pathogen that causes bacterial ***,with increasing bacterial resistance,there is an urgent need to develop new drugs to treat *** *** with a 14-carbon saturated fatty acid(ND-C14)is a novel nanoantimicrobial peptide designed by modifying myristic acid at the C-terminus of humanα-defensin 5(HD5)via an amide ***,it is unclear whether ND-C14 is effective against lung infections caused by ***:In vitro,three groups were established,including the control group,and the HD5 and ND-C14 treatment groups.A virtual colony-count assay was used to evaluate the antibacterial activity of HD5 and ND-C14 against *** morphological changes of *** treated with HD5 or ND-C14 were observed by scanning electron *** vivo,mice were divided into sham,vehicle,and ND-C14 treatment *** in the sham group were treated with 25μL of phosphate-buffered saline(PBS).Mice in the vehicle and ND-C14 treatment groups were treated with intratracheal instillation of 25μL of bacterial suspension with 2×108 CFU/mL(total bacterial count:5×10^(6) CFU),and then the mice were given 25μL PBS or intratracheally injected with 25μL of ND-C14(including 20μg or 50μg),*** rates were evaluated in the vehicle and ND-C14 treatment *** burden in the blood and bronchoalveolar lavage fluid were *** lung histology of the mice was assessed.A propidium iodide uptake assay was used to clarify the destructive eff ect of ND-C14 against ***:Compared with HD5,ND-C14 had a better bactericidal eff ect against *** because of its stronger ability to destroy the membrane structure of *** in *** vivo,ND-C14 significantly delayed the death time and improved the survival rate of mice infected with ***-C14 reduced bacterial burden and lung tissue ***,ND-C14 had a membrane per

关键词： Streptococcus pneumoniae Antimicrobial peptides Humanα-defensin 5 Infection

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

稀硫酸水解预处理对麦草制浆备料废渣酶水解糖化的影响

引用

南京林业大学学报（自然科学版） 2015年第4期39卷 137-142页

作者：吕佳青毕衍金严希希金永灿南京林业大学江苏省制浆造纸科学与技术重点实验室江苏南京210037 山东泉林纸业有限责任公司山东高塘252800

以制浆厂麦草备料废渣为原料,探讨了稀硫酸水解预处理对其主要化学成分及酶水解糖化效率的影响。结果表明:麦草备料废渣经170℃自水解预处理后,酶水解效率较低;预处理中加入不同量的稀硫酸水解有利于促进麦草备料废渣的酶水解糖化。未... 详细信息

以制浆厂麦草备料废渣为原料,探讨了稀硫酸水解预处理对其主要化学成分及酶水解糖化效率的影响。结果表明:麦草备料废渣经170℃自水解预处理后,酶水解效率较低;预处理中加入不同量的稀硫酸水解有利于促进麦草备料废渣的酶水解糖化。未经洗涤直接磨浆得到的预处理浆料的酶水解总糖得率高于经水洗后的浆料。预处理后物料不经洗涤直接酶水解的总糖转化率随预处理酸用量的增加呈先升后降的趋势,经稀硫酸水解(H2SO4质量分数0.32%,170℃)和PFI磨浆(8 000 r)预处理得到的麦草备料废渣浆料,未经洗涤在酶用量20μmol/(min·g)下酶水解,其葡聚糖和木聚糖转化率分别为71.9%和73.9%,总糖转化率达到最大值(近70%)。

关键词：麦草备料废渣稀硫酸水解预处理酶水解糖化糖转化率

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

Friction reactions induced by selective hydrogenation of textured surface under lubricant conditions

引用

Friction 2024年第1期12卷 174-184页

作者： Naizhou DU Xubing WEI Xiaowei LI Zan CHEN Shiqi LU jiaqing DING Cunao FENG Kai CHEN Jianghao QIAO Dekun ZHANG Kwang-Ryeol LEE Tiancai ZHANG School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201China Computational Science Center Korea Institute of Science and TechnologySeoul 136-791Republic of Korea Technology Development Department Shipbuilding Technology Research InstituteShanghai 200032China

The passivation of hydrogen atoms and the conformation of textured surfaces under oil-lubricated conditions are effective strategies to obtain amorphous carbon(a-C)films with extremely low *** is critical to understanding the influence mechanism of selective surface hydrogenation on the tribological behaviors of textured a-C film under oil-lubricated *** particular,the interactions of hydrogen atoms and lubricants are confusing,which is enslaved to the in situ characterization *** reactive molecular dynamics(RMD)simulations were conducted to analyze the friction response of textured a-C films with selective hydrogenation surfaces under oil-lubricated *** results indicate that the existence of hydrogen atoms on specific bump sites significantly decreases the friction coefficient(μ)of textured a-C film,which is highly dependent on the surface hydrogen *** repulsion between hydrogen atoms and lubricant molecules prompts the formation of a dense lubricant film on the surface of the mating ***,with the enhancement of the surface hydrogen content,the passivation of the friction interface and the repulsion between hydrogen atoms and lubricants play dominant roles in reducing the friction coefficient instead of hydrodynamic lubrication.

关键词： textured amorphous carbon(a-C) selective hydrogenation oil lubrication friction mechanism reactive molecular dynamics(RMD)

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：