检索结果-南通市图书馆

Comparison of mixing layer height inversion algorithms using lidar and a pollution case study in Baoding, China

Journal of Environmental Sciences 2019年第5期31卷 81-90页

作者： Xiangguang Ji Cheng Liu Zhouqing Xie Qihou Hu Yunsheng Dong Guangqiang Fan Tianshu Zhang Chengzhi Xing zhuang wang Zeeshan Javed Jianguo Liu School of Environmental Science and Optoelectronic Technology University of Science and Technology of China Key Lab of Environmental Optics and Technology Anhui Institute of Optics and Fine Mechanics Hefei Institutes of Physical Science Chinese Academy of Sciences School of Earth and Space Sciences University of Science and Technology of China Center for Excellence in Regional Atmospheric Environment Institute of Urban Environment Chinese Academy of Sciences Anhui Province Key Laboratory of Polar Environment and Global Change University of Science and Technology of China

Beijing–Tianjin–Hebei area is suffering from atmospheric pollution from a long time. The understanding of the air pollution mechanism is of great importance for officials to design strategies for the environmental governance. Mixing layer height(MLH) is a key factor influencing the diffusion of air pollutants. It plays an important role on the evolution of heavy pollution events. Light detection and ranging(lidar), is an effective remote-sensing tool, which can retrieve high spatial and temporal evolution process within mixing layer(ML), especially the variation of MLH. There are many methods to retrieve MLH, but each method has its own applicable limitations. The Mie-lidar data in Beijing was firstly used to compare three different algorithms which are widely used under different pollution *** find that the multi-layer structure near surface may cause errors in the detection of mixing layer. The MLH retrieved based on image edge detection was better than another two methods especially under heavy polluted episode. Then we applied this method to investigate the evolution of the mixing layer height during a pollution episode in December2016. MLH at Gucheng county showed the positive correlation with the concentration of particulate matters during the start of this pollution episode. The elevated pollution level in Gucheng was not associated with MLH's decrease, and the significantly increased particulate matters raised the boundary layer, which trapped the pollutants near the surface.

关键词： Mixing layer Beijing–Tianjin–Hebei area Severe haze

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 ESR study of photochemical reactions of Co2（CO）6（PBu3）2 with quinones and phenothiazine

引用

Chinese Journal of Chemistry 1985年第2期3卷 89-95页

作者： YAN Rong-zhuang wang Han-Qing Lanzhou Institute of Chemical Physics,Academia Sinica,Lanzhou Lanzhou Institute of Chemical Physics Academia Sinica Lanzhou

The photochemical reactions of Co（CO）（PBu）with various quinones and phenothia-zine were studied by *** results indicate that the photolysis of Co（CO）（PBu）in the pre-sence of o-quinones led to the observation of an ESR spectrum,showing a broad 8 or 12 groups ofhyperfine lines due to interaction with cobalt （Co,I=7/2）.The results show that with o-quinonesthe cobalt radical adducts are formed via metal chelation to the carbonyl ***,whenCo（CO）（PBu）was irradiated in the presence of p-quinones,only the para-semiquinone radicalswere *** photolysis of Co（CO）（PBu）with phenothiazine in toluene yields pheno-thiazine *** sixteen and eighteen electrons rule have been used to account for these ob-servations.

关键词： Co ESR with quinones and phenothiazine CO

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

高阶剪切变形板理论下FG-GRC板的屈曲和弯曲分析

引用

工程力学 2023年第6期40卷 9-18页

作者：王壮壮马连生潍坊科技学院建筑工程学院山东潍坊262700

基于三阶剪切变形板理论(TSDPT)和正弦剪切变形板理论(SSDPT),研究了功能梯度石墨烯增强复合材料(FG-GRC)板的屈曲和弯曲行为,并通过与一阶剪切变形板理论(FSDPT)计算结果的比较,分析了TSDPT、SSDPT与FSDPT在FG-GRC板屈曲和弯曲力学行... 详细信息

基于三阶剪切变形板理论(TSDPT)和正弦剪切变形板理论(SSDPT),研究了功能梯度石墨烯增强复合材料(FG-GRC)板的屈曲和弯曲行为,并通过与一阶剪切变形板理论(FSDPT)计算结果的比较,分析了TSDPT、SSDPT与FSDPT在FG-GRC板屈曲和弯曲力学行为研究过程中的差异。材料的有效杨氏模量通过修正的Halpin-Tsai微观力学模型估算,有效泊松比通过混合律确定。利用最小势能原理推导出了包含五个未知量的控制方程,并获得了简支FG-GRC矩形板弯曲挠度和临界屈曲载荷Navier形式的解析解。数值结果表明:与TSDPT和SSDPT相比,FSDPT明显高估了FG-X型FG-GRC板的临界屈曲载荷而明显低估了其弯曲挠度,且略微低估了FG-O型FG-GRC板的临界屈曲载荷而略微高估了其弯曲挠度,而UD型和FG-A型FG-GRC板在三种理论下的计算结果几乎完全一致;TSDPT和SSDPT在计算FG-GRC板的弯曲挠度和临界屈曲载荷时结果十分相近;当板的总层数NL小于10层~15层时,弯曲载荷比率和临界屈曲载荷比率的变化非常显著,当总层数NL超过10层~15层时,弯曲载荷比率和临界屈曲载荷比率的变化趋于平缓;由于石墨烯纳米片(GPLs)极高的弹性模量,FG-GRC板中GPLs的重量分数f_(G)与板抵抗弯曲和屈曲的能力正相关。

关键词：石墨烯增强复合材料功能梯度材料 Navier法高阶剪切变形板理论弯曲屈曲

来源：

维普期刊数据库

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

Synergistic actions of complement and lysozyme in clearance of Escherichia coli from amphioxus Branchiostoma belcheri

引用

Progress in Natural Science:Materials International 2009年第2期19卷 179-185页

作者： Guangfeng wang a,Shicui Zhang a,Zhimeng zhuang b,Zhiping wang a a Department of Marine Biology,Ocean University of China,Qingdao 266003,China b Yellow Sea Fisheries Research Institute,Qingdao 266071,China Department of Marine Biology Ocean University of China Qingdao 266003 China Yellow Sea Fisheries Research Institute Qingdao 266071 China

Amphioxus appears to lack free circulating blood cells. How it clears invading pathogens from its body remains unknown to date. We demonstrate here that amphioxus Branchiostoma belcheri is capable of efficiently eliminating the invading bacterium Escherichia coli from its humoral fluid,and the complement and lysozyme are both involved in the elimination of the invading pathogen. Both the com-plement and lysozyme act in concert against the invading bacterium,but the complement appears to play a more dominant role than the lysozyme.

关键词： Amphioxus Branchiostoma Complement Lysozyme Humoral fluids Anti-bacterial activity

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

Variational Path-Integral Study on Bound Polarons in Parabolic Quantum Dots and Wires

引用

Chinese Physics Letters 2001年第5期18卷 668-671页

作者： CHEN Qing-Hu wang zhuang-Bing WU Fu-Li LUO Meng-Bo YUAN Yong-Hong JIAO Zheng-Kuan Department of Physics Zhejiang UniversityHangzhou 310027

The expression of the ground-state energy of the electron coupled simultaneously with a Coulomb potential and a longitudinal-optical phonon field in parabolic quantum dots and wires is derived within the framework of Feynman variational path integral *** obtain a general result with arbitrary electron-phonon coupling constant,Coulomb binding parameters,and confining potential strength,which could be used for further numerical calculation of polaron ***,it is shown that all the previous path-integral formulae for free polarons,bound polarons,and polarons confined in parabolic quantum dots and wires can be recovered in the present formalism.

关键词： properties. theory. polaron

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

Effect of pine wood nematode invasion on pine community functions in the Pinghu region, Zhejiang Province, eastern China

引用

Forestry Studies in China 2013年第4期15卷 302-309页

作者： zhuang wang Yan ZHANG Juan SHI You-Qing LUO Li-Li REN Yu-Ming SHI Key Laboratory for Silviculture and Conservation of Ministry of Education Beijing Forestry University State Forest Farm in Pinghu

In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various mixed percentages of Pinus massoniana and P. thunbergii and with different levels of damage. According to the results of rate of change in increment of DBH and stand volume, the forest ecosystem resistance against PWN increased with a reduction in the mixed ratio of pine. The resistance was highest with a mixed percentage of 50%. The invasion of PWN changed the corresponding relationship of increment between DBH and stand volume(pure stands > 7:3 conifer and broadleaf > 6:4 conifer and broadleaf > 5:5 conifer and broadleaf) among the P. thunbergii stands when there is no damage, but for P. massoniana stands this phenomenon did not occur. For the increment rate of DBH and stand volume, this significant change in P. thunbergii forest indicates that the resistance of pure P. thunbergii forest was higher than that of P. massoniana. The invasion of PWN accelerates the succession from pure stands to mixed stands and then to the broadleaf evergreen stands.

关键词： biological invasion community succession ,plant community function PinuS rnassoniana,PinuS thunbergii

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

Field investigation into directional hydraulic fracturing for hard roof in Tashan Coal Mine

引用

Journal of Coal Science & Engineering(China) 2013年第2期19卷 153-159页

作者： Bina-Xiana HUANG Bin YU Feng FENG Zhao LI You-zhuang wang Jin-Rong LIU School of Mines Key Laboratory of Deep Coal Resource Mining Ministry of Education of China China University of Mining & Technology Xuzhou 221116 China Datong Coal Mine Group Datong 037003 China

t Research and development of safe and effective control technology of hard roof is an inevitable trend at present. Directional hydraulic fracturing technology is expected to become a safe and effective way to control and manage hard roof. In order to make hard roof fracture in a directional way, a hydraulic fracture field test has been conducted in the third panel district of Tashan Coal Mine in Datong. First, two hydraulic fracturing drilling holes and four observing drilling holes were arranged in the roof, followed by a wedge-shaped ring slot in each hydraulic fracturing drilling hole. The hydraulic fracturing holes were then sealed and, hydraulic fracturing was conducted. The results show that the hard roof is fractured directionally by the hydraulic fracturing function of the two fracturing drilling holes; the sudden drop, or the overall downward trend of hydraulic pressure from hydraulic monitoring is the proof that the rock in the hard roof has been fractured. The required hydraulic pressure to fracture the hard roof in Tashan coal mine, consisting of carboniferous sandstone layer, is 50.09 MPa, and the fracturing radius of a single drilling hole is not less than 10.5 m. The wedge-shaped ring slot made in the bottom of the hydraulic fracturing drilling hole plays a guiding role for crack propagation. After the hydraulic fracturing drill hole is cracked, the propagation of the resulting hydraulic crack, affected mainly by the regional stress field, will turn to other directions.

关键词： hard roof hydraulic fracturing wedge-shaped ring slot crack propagation

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

Lipid droplets in the nervous system:involvement in cell metabolic homeostasis

引用

Neural Regeneration Research 2025年第3期20卷 740-750页

作者： Yuchen Zhang Yiqing Chen Cheng zhuang Jingxuan Qi Robert Chunhua Zhao Jiao wang School of Life Sciences Shanghai UniversityShanghaiChina School of Medicine Shanghai UniversityShanghaiChina Institute of Basic Medical Sciences Chinese Academy of Medical Sciences School of Basic MedicinePeking Union Medical CollegeBeijingChina Center of Excellence in Tissue Engineering Chinese Academy of Medical SciencesBeijingChina Beijing Key Laboratory of New Drug Development and Clinical Trial of Stem Cell Therapy BeijingChina

Lipid droplets serve as primary storage organelles for neutral lipids in neurons,glial cells,and other cells in the nervous *** droplet formation begins with the synthesis of neutral lipids in the endoplasmic ***,lipid droplets were recognized for their role in maintaining lipid metabolism and energy homeostasis;however,recent research has shown that lipid droplets are highly adaptive organelles with diverse functions in the nervous *** addition to their role in regulating cell metabolism,lipid droplets play a protective role in various cellular stress ***,lipid droplets exhibit specific functions in neurons and glial *** of lipid droplet formation leads to cellular dysfunction,metabolic abnormalities,and nervous system *** review aims to provide an overview of the role of lipid droplets in the nervous system,covering topics such as biogenesis,cellular specificity,and ***,it will explore the association between lipid droplets and neurodegenerative *** the involvement of lipid droplets in cell metabolic homeostasis related to the nervous system is crucial to determine the underlying causes and in exploring potential therapeutic approaches for these diseases.

关键词： Alzheimer's disease lipid droplet biogenesis lipid droplets lipid metabolism nervous system neurodegenerative disorders oxidative stress Parkinson's disease

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

Changes in carbon,nitrogen and phosphorus stoichiometry in decaying logs with gap positions in a subalpine forest

引用

Journal of Plant Ecology 2021年第4期14卷 692-701页

作者： Qin wang Wanqin Yang Han Li zhuang wang Chenhui Chang Rui Cao Bo Tan Long-term Research Station of Alpine Forest Ecosystems Department of Ecology and ForestryInstitute of ForestrySichuan Agricultural UniversityChengdu 611130China Department of Soil Ecology and Remediation School of Life ScienceTaizhou UniversityTaizhou 318000ZhejiangChina Systems Ecology Department of Ecological ScienceFaculty of ScienceVrije Universiteit AmsterdamDe Boelelaan 10851081HV AmsterdamThe Netherlands

Aims The redistribution of forest gaps based on solar radiation and precipitation(mainly rainfall and snowfall)can create heterogenous microenvironments inside and outside the ***,we investigated the effects of forest gaps on carbon(C),nitrogen(N)and phosphorus(P)stoichiometry in decaying logs by altering the *** Minjiang fir(Abies faxoniana)logs of decay classes I–V were incubated in situ on the floor under the gap center(GC),gap edge(GE)and closed canopy(CC)in a subalpine forest in the eastern Qinghai-Tibet *** C,N and P concentrations in decaying bark,sapwood and heartwood were measured in August from 2013 to *** Findings Our results showed that the N concentration in bark decreased from the CC to the GC,while the opposite trend was found in sapwood and ***,the C/N ratio in sapwood and heartwood of decay classes IV and V decreased from the CC to the GC,and the N/P ratio in heartwood of decay class V increased from the CC to the GC,implying that forest gaps have strong effects on C/N/P stoichiometry in highly decayed ***,highly decayed logs are more susceptible to the microenvironment,and the proportion of highly decayed logs under the CC or the GC should be appropriately adjusted if necessary.

关键词： forest gap decaying log carbon nutrients subalpine forest Abies faxoniana

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

Robotic stereotactic irradiation and reirradiation for spinal metastases： safety and efficacy assessment

引用

Chinese Medical Journal 2014年第2期127卷 232-238页

作者： wang Qi Song Yongchun zhuang Hongqing wang Xiaoguang Li Fengtong Dong Yang wang Jingsheng Yuan Zhiyong Tianjin Medical University Cancer Institute and Hospital Key Laboratory of Cancer Prevention and Therapy Cyberknife Center Department of Radiation Oncology& CyberKnife Center Tianjin 300060 China

Background Spine is the most common site of bone metastases in patients with *** external beam radiotherapy lacks precision to allow delivery of large fraction radiation but simultaneously limit the dose to spinal *** purpose of this study was to evaluate the safety and efficacy of CyberKnife（R） radiation therapy for spinal *** Seventy-three lesions in 62 patients treated with CyberKnife radiotherapy from September 2006 to June 2010 for spinal metastases were retrospectively *** tumors in 12 patients had received prior *** were followed clinically and radiographically for at least 12 months or until *** all patients,the spinal cord and thecal sac were contoured for dose-volume constraints,and maximum doses to 0.1,0.5,1,2,and 5-ml volumes were *** Using the CyberKnife System,20-48 Gy in one to five fractions for unirradiated patients,and 21-38 Gy in one to five fractions for the previously irradiatied patients,were *** 2-Gy normalized Biological Equvaient Dose （nBED） of unirradiated targets and irradiated targets were 49.6 Gy10/2 （range,31.25-74.8 Gy10/2） and 46.9 Gy10/2 （range,29.8-66 Gy10/2）,*** a median follow-up of 9.4 months （range,2.5-45 months）,twenty-nine patients （46.7％） were alive,whereas the others died of progressive ***-six patients （93.3％） reported complete or partial reduction of pain after CyberKnife radiotherapy at one-month follow-up,17 patients （28.3％） reported some degree of pain relief after first fraction of the treatment *** patients experienced local recurrence at fifth and ninth months *** maximum nBED for spinal cord and thecal sac of naive targets were 68.6 Gy2/2 （range,8.3-154.5Gy2/2） and 83.5 Gy2/2 （range,10.5-180.5 Gy2/2）,*** maximum nBED for spinal cord and thecal sac for the re-irradiated targets were 58.6 Gy2/2 （range,17.7-140 Gy2/2） and 70.5 Gy2/2 （range,21.7-141.3 Gy2/2）,r

关键词： spine metastases stereotactic body radiotherapy cyberknife radiosurgery radiation tolerance

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：