检索结果-南通市图书馆

Three-dimensional unstructured-mesh eutrophication model and its application to the Xiangxi River,China

Journal of Environmental Sciences 2012年第9期24卷 1569-1578页

作者： jian li Danxun li Xingkui Wang State Key Laboratory of Hydroscience and Engineering Department of Hydraulic Engineering Tsinghua University Beijing 100084 China

The Xiangxi River is one of the main tributaries in the Three Gorges reservoir, with the shortest distance to the Three Gorges Project Dam. Severe and frequent algal bloom events have occurred frequently in the Xiangxi River in recent years. Therefore, the current study develops a three-dimensional unstructured-mesh model to investigate the dynamic process of algal bloom. The developed model comprises three modules, namely, hydrodynamics, nutrient cycles, and phytoplankton ecological dynamics. A number of factors, including hydrodynamic condition, nutrient concentration, temperature, and light illumination, that would affect the evolution of phytoplankton were considered. Moreover, the wave equation was used to solve the free surface fluctuations and vertical Z-coordinates with adjustable layered thicknesses. These values, in turn, are suitable for solving the algal bloom problems that occurred in the fiver style reservoir that has a complex boundary and dramatically changing hydrodynamic conditions. The comparisons between the modeling results and field data of years 2007 and 2008 indicate that the developed model is capable of simulating the algal bloom process in the Xiangxi River with reasonable accuracy. However, hydrodynamic force and external pollution loads affect the concentrations of nutrients, which, along with the underwater light intensity, could consequently affect phytoplankton evolution. Thus, flow velocity cannot be ignored in the analysis of fiver algal bloom. Based on the modeling results, building an impounding reservoir and increasing the releasing discharge at appropriate times are effective ways for controlling algal bloom.

关键词： unstructured-mesh model algal bloom phytoplankton Xiangxi River

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

Effect of Cr_(2)O_(3) on properties of CaO-SiO_(2)-Fe_(t)O-MgO system and dissolution behavior of lime

引用

Journal of Iron and Steel Research International 2024年第4期31卷 870-881页

作者： Shan-nan li jian-li li Yue Yu Hang-yu Zhu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

The productivity of the chrome-containing semi-steel converter smelting process is directly affected by the slag-forming speed during the converter preliminary *** effects of Cr_(2)O_(3) content on the physicochemical properties of the CaO-SiO_(2)-Fe_(t)O-MgO system,such as melting temperature,solidification behavior,mineral composition,and lime dissolution rate,were *** results showed that the slag was an amorphous phase at 1500℃.When Cr_(2)O_(3) was added,Ca(Fe,Mg)Si_(2)O_(6) and spinel were formed in the *** the increase in Cr_(2)O_(3) content,the amount of spinel precipitation increased,and the dendritic FegO_(4) crystal gradually changed into the granular(Fe,Mg)(Fe,Cr)2O_(4) *** the Cr_(2)O_(3) content increased from O to 2.91 wt.%,the melting temperature of the slag rose,and the melting range of the slag expanded slightly,but the lime dissolution rate did not *** the Cr_(2)O_(3) content further increased to 9.09 wt.%,the melting temperature continued to rise,the melting range rapidly expanded,and the lime dissolution rate decreased.

关键词： Cr_(2)O_(3) Vanadium-titanium magnetite Converter Slag lime dissolution

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 MgO on structure and crystallization behavior of CaO–SiO_(2)–Al_(2)O_(3) inclusions in Si–Mn deoxidized steel

引用

Journal of Iron and Steel Research International 2024年第11期31卷 2774-2787页

作者： Qi Xu Yao-qing Meng jian-li li The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan430081HubeiChina

To avoid coarse crystallization of glassy inclusions in Si–Mn deoxidized steel during hot rolling, the effect of MgO on the structure and crystallization behavior of CaO–SiO_(2)–Al_(2)O_(3) inclusions was investigated. The results showed that the crystallization temperature of the oxide melts decreased with increasing MgO content from 0 to 15.7 wt.%, which suggested that the addition of MgO would increase the temperature range of the crystalline transition. The increase in MgO content could decrease the crystallization activation energy of inclusions. With the increase in MgO content, the relative fractions of O_(Si)^(0) and O_(Si)^(1) structure units increased, and those of structure units O_(Si)^(2), O_(Si)^(3), and O_(Si)^(4) decreased, increasing the depolymerization degree of the silicate structure. The crystallization ratio of glassy inclusions in the steel crucible increased from 19.7% to 98.3% with increasing MgO content from 0 to 15.7 wt.%. The addition of MgO improved the crystallization ability of inclusions, because MgO provides free oxygen O_(2−) to destroy the bridging oxygens and form non-bridging oxygens O^(−), which depolymerizes silicate network structure and simplifies the [SiO_(4)]-tetrahedral structure. In addition, MgO would promote the precipitation of the Mg-containing phases with a high melting point. When the MgO content was increased above 12.1 wt.%, MgO·Al_(2)O_(3) and 2MgO·SiO_(2) crystalline phases would precipitate from the inclusions.

关键词： Si-Mn deoxidized steel Glassy inclusion Structure Crystallization Plasticization

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

Trailing (L5) Neptune Trojans: 2004 KV18 and 2008 LC18

引用

Research in Astronomy and Astrophysics 2012年第11期12卷 1549-1562页

作者： Pu Guan li-Yong Zhou jian li Department of Astronomy & Key Laboratory of Modem Astronomy and Astrophysics in Ministryof Education Nanjing University Nanjing 210093 China

The population of Neptune Trojans is believed to be bigger than that of Jupiter Trojans and that of asteroids in the main belt, although only eight members of this distant asteroid swarm have been observed up to now. Six leading Neptune Trojans around the Lagrange point L4 discovered earlier have been studied in detail, but two trailing ones found recently around the L5 point, 2004 KV18 and 2008 LC18, have not yet been investigated. We report our investigations on the dynamical behaviors of these two new Neptune Trojans. Our calculations show that the asteroid 2004 KV18 is a temporary Neptune Trojan. Most probably, it was captured into the trailing Trojan cloud no earlier than 2.03 ×105 yr ago, and it will not maintain this position later than 1.65 × 105 yr in the future. Based on the statistics from our orbital simulations, we ar- gue that this object is more like a scattered Kuiper belt object. By contrast, the orbit of 2008 LC18 is much more stable. Among the clone orbits spreading within the orbital uncertainties, a considerable portion of clones may survive on the L5 tadpole orbits for 4 Gyr. The strong dependence of the stability on the semimajor axis and resonant angle suggests that further observations are badly required to constrain the orbit in the stable region. We also discuss the implications of the existence and dynamics of these two trailing Trojans over the history of the solar system.

关键词： solar system general -- Kuiper belt -- asteroids -- methods numerical

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

Modified precoding strategy over MIMO double-correlated channels

引用

The Journal of China Universities of Posts and Telecommunications 2009年第2期16卷 35-38页

作者： JIN li-biao li jian-zeng School of Information Engineering Communication University of China Beijing 100024 China

Double-correlated channels commonly occur due to insufficient scattering around both the transmitting and receiving antennas. In this article, the authors propose a linear precoding strategy with a modified system model over double-correlated channels. In this system model, an inner decorrelation strategy is added combined with precoding. First, a linear precoder that achieves minimum bit error rate （MBER） is proposed and analyzed based on the modified system model. The simulation results show that the bit error rate （BER） performance can be improved by decorrelation. Second, the influence of double correlation on multiple input and multiple output （MIMO） capacity is analyzed and simulated.

关键词： MIMO precoding decorrelation capacity

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

Sphericities of non-spherical objects

引用

Particuology 2012年第1期10卷 97-104页

作者： Teng li Shuixiang li jian Zhao Peng Lu lingyi Meng Department of Mechanics ＆Aerospace Engineering College of Engineering Peking University Beijing 100871 China

Sphericity, as one of the most important shape parameter for non-spherical objects, is extensively applied in evaluating the porosity or packing density of particles. In this paper, the sphericities of common non- spherical objects are deduced and investigated. Maximum sphericities and optimum shapes of these objects are presented as well. A decreasing order of sphericity from sphere （1.0） to regular tetrahedron （0.671） for objects with constant sphericity is given. Similar trends are found in most sphericity-aspect ratio relationships, which exhibit single Peak and the sphericity increases with the growth of aspect ratio before the peak point and decreases afterward. The peak loci of aspect ratio are all around 1.0 which makes the shape approaching to a sphere. The information in the paper could be useful as literature for general application.

关键词： SphericityAspect ratioNon-spherical particleOptimum shape

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

Silencing gamma-aminobutyric acid A receptor alpha 1 subunit expression and outward potassium current in developing cortical neurons

引用

Neural Regeneration Research 2011年第18期6卷 1404-1409页

作者： Tao Bo jiang li jian li Xingfang li Kaihui Xing Department of Pediatrics Second Xiangya Hospital Central South University Changsha 410011 Hunan Province China

We used RNA interference （RNAi） to disrupt synthesis of the cortical neuronal y-aminobutyric acid A receptor （GABAAR） al in rats during development, and measured outward K＋ currents during neuronal electrical activity using whole-cell patch-clamp techniques. Three pairs of small interfering RNA （siRNA） for GABAAR al subunit were designed using OligoEngine RNAi software. This siRNA was found to effectively inhibited GABAAR al mRNA expression in cortical neuronal culture in vitro, but did not significantly affect neuronal survival. Outward K^currents were decreased, indicating that GABAAR al subunits in developing neurons participate in neuronal function by regulating outward K＋ current.

关键词： γ-aminobutyric acid A receptor al subunit neuron development outward potassium current

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

Synthesis and application of rhodamine-based fluorescent probe dyes with spacer linker arm

引用

Chinese Chemical Letters 2007年第6期18卷 667-669页

作者： Yong Gao jian li li Zhen Shi College of Chemistry and Materials Science Fujian Normal University Fuzhou 350007 China Department of Chemistry Northwest University Xi’an 710069 China

When rhodamine-based fluorescent probe dyes are used to track target molecules they always perturb the behavior of target molecules because of steric hindrance effect. In order to minimize potential steric problems, a kind of rhodamine-based fluorescent probe dye with spacer linker arm was designed and synthesized and its application in immunofluorescence histochemistry was investigated.

关键词： Rhodamine Fluorescent probe dye Spacer linker arm Synthesis Immunofluorescence histochemistry

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

Effect of Fe2O3 on the size and components of spinel crystals in the CaO–SiO2–MgO–Al2O3–Cr2O3 system

引用

International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1113-1119页

作者： Qi-qiang Mou jian-li li Qiang Zeng Hang-yu Zhu The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China

size of spinel crystals in the CaO–SiO2–MgO –Al2O3–Cr2O3 system was investigated using lab experiments carried out in a carbon tube furnace. Scanning electron microscopy with energy-dispersive X-ray spectroscopy（SEM–EDS） and X-ray diffraction（XRD） were used to analyze the microstructure, components, and the mineral phases of synthetic slags. FactS age 7.1 was used to calculate the crystallization process of the molten slag. The results showed that the addition of Fe2O3 promoted the precipitation of spinel crystals and inhibited the formation of dicalcium silicate. The size of spinel crystals increased from 2.74 to 8.10 μm and the contents of chromium and iron in the spinel varied as the Fe2O3 addition was increased from 0 to 20 wt%. Fe2O3 thermodynamically provided the spinel-forming components to enhance the formation of FeCr2O4, MgFe2O4, and Fe3O4. The addition of Fe2O3 increased the fraction of liquid phase in a certain temperature range and promoted diffusion by decreasing the slag’s viscosity. Therefore, Fe2O3 is beneficial to the growth of spinel crystals in stainless steel slag.

关键词： ferric oxide stainless steel slag spinel crystal size chromic oxide

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

Silicon assistant carbothermal reduction for SiC powders

引用

Journal of University of Science and Technology Beijing 2008年第4期15卷 484-488页

作者： Kezhi li jian Wei Hejun li Chuang Wang Gengsheng Jiao National Key Laboratory of Thermostructure Composite Materials Northwestern Polytechnical University Xi＇an 710072 China

The silicon assistant method to increase the reaction yield of carbothermal reduction of silica at a lower temperature is reported. The effect of silicon on the carbothermal reduction process has been investigated in detail. Compared with traditional reduction, the introduction of silicon can change the reaction path and further increase the conversion of silicon carbide at a lower temperature. It is considered that the assistant reduction consists of three steps： vaporizing and melting of silicon, formation of silicon monoxide, and synthesis of silicon carbide. The morphology of the synthesized SiC powders through the silicon assistant method can be affected apparently by the experimental temperature.

关键词： carbide powders solid state reaction electron microscopy X-ray diffraction

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

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：