检索结果-南通市图书馆

Pioneer organisms after F-F mass extinction in Dushan region,Guizhou province,and their significance in establishing new ecosystem

引用

Science China Earth Sciences 2006年第5期49卷 449-460页

作者： WANG Yue1, 2, WANG Xunlian1 & SHI Xiaoying1 1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China 2. School of Resources and Environment, Guizhou University, Guiyang 550003, China 1. School of Earth Sciences and Resources China University of Geosciences Beijing 100083 China 2. School of Resources and Environment Guizhou University Guiyang 550003 China

After mass extinctions, most areas became “ecologically barren areas” lacking or even without ecosystem over an extensive region. Studying the pioneer organisms and the reconstruction process of a new ecosystem in the “ecologically barren area” is very important for revealing the evo- lution after bio-mass extinctions. In the Dushan region, Guizhou province, China, the trace fossils appeared and flourished evidently earlier than body fossils after Frasnian-Famennian (F-F) mass extinction. The pioneer organisms and pathfinders in the “ecologically barren areas” are the trace-makers that are deposit-feeders with relatively simple structure and conformation on or near the deposit surface. The trace-makers have undergone an evolutionary process that their trace structures changed from simple to complex, and their living and moving areas and spaces enlarged from linear to planar and then to three-dimension spaces. Those characters show that the ability of the trace-makers to deposits and their efficiency of looking for food have been enhanced gradually and that those trace-makers constructed gradually a base for the new ecosystem. This process is similar to that of the trace fossils near the Precambrian-Cambrian boundary. In the Dushan area, only the recovery intervals have been identified for the Famennian body fossils, with no eminent radiation interval recognizable due to the Devonian-Carboniferous (C-D) mass ex- tinction. However, both the recovery and radiation intervals may be clearly recognized in the Famen- nian trace fossils based on their conformation and diversity. The evolution and diversification of the trace fossils in the “ecologically barren area” is considered to have played a role of necessary foun- dation for the recovery of body fossils in the ecological chain. With the gradual disappearance of the unfavourable environment factors resulting in the F-F mass extinction, a new ecosystem was reconstructed in the “ecologically barren area” through a three-

关键词： pioneer organisms, reconstruction of ecosystem, trace fossils, F-F mass extinction, Later Devonian, Dushan region, Guizhou province, China.

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

The role of aerial algae in the formation of the landscape of the Yunnan Stone Forest,Yunnan province, China

引用

Science China Earth Sciences 2004年第9期47卷 846-864页

作者： TIAN Youping1,3, ZHANG Jie2, SONG Linhua1 & BAO Haosheng2 1. Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China 2. Department of Geography, Nanjing University, Nanjing 210093, China 3. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Department of Geography Nanjing University Nanjing 210093 China School of Earth Sciences and Resources China University of Geosciences Beijing 100083 China

Aerial algae on the surface of carbonate rocks at the Stone Forest, Shilin County, Yunnan province, China, and their bioerosion were investigated in the field and studied in the laboratory in detail. Through the observation, identification and statistics of more than one hun- dred algal samples and rock samples with the optical microscopes (stereomicroscope, biological microscope) and the scanning electronic microscope (SEM), the relationships between erosional forms on the surface of the Stone Forest and algae and/or algal communities and the genetic mechanism for the formation of erosional forms were analyzed. It is suggested that aerial algae play an active role in bioerosive processes that may affect the formation of karst erosional forms. These effects include both direct and indirect ones. The direct effect is the initiative control (algal shape-controlling role) of algae on the formation of karst forms of various scales, mostly mi- cro-scale (<10-3m) and minor-scale (10-3-10-1m) erosional forms. The algal shape-controlling roles can be divided into the algal individual shape-controlling role and the algal community shape-controlling role. The former mostly controls the formation of micro-scale erosional forms, while the latter mostly controls the formation of micro-scale and smaller minor-scale erosional forms. The indirect effect refers to the promoting role of algae in the formation of karst forms, which may affect the formation of karst forms of all types and scales. The bioerosion of algae accelerates the weathering process of the whole Stone Forest karst landforms.

关键词： aerial algae, bioerosion, the Stone Forest, Yunnan province, China.

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

Sedimentary characteristics of Mg-rich carbonate formations and minerogenic fluids of magnesite and talc occurrences in early Proterozoic in eastern Liaoning province, China

引用

Science China Chemistry 2002年第z1期45卷 84-92页

作者：陈从喜鲁安怀蔡克勤翟裕生 School of Earth and Space Sciences Peking University Beijing 100871 China China University of Geosciences (Beijing) Beijing 100083 China

There are large to superlarge magnesite and talc deposits occurring in Mg-rich carbonate formations distributed in the early Proterozoic Dashiqiao Formation in eastern Liaoning province, China. The discovery of the sedimentary gypsum, isotopic geochemistry of Δ18osmow, Δ13cpdb, Δ34svcdt and Sr/Ba ratio of carbonate, talc, quartz and gypsums with field investigation and sample analysis in laboratory demonstrate that the formation of magnesite and talc deposits is closely related to marine evaporates, which then underwent reworking of regional metamorphism and hydrothermal metasomatism. Metasomatic fluids originating from the paleoseawater played a controlling role in the formation of talc deposits.

关键词： magnesite, talc, minerogenic fluid, eastern Liaoning province, early Proterozoic.

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

Analysis of cancer incidence and mortality data in Heilongjiang province cancer registries, China, 2015

引用

Oncology and Translational Medicine 2019年第4期5卷 182-187页

作者： Huixin Sun Bingbing Song Maoxiang Zhang Institute of Cancer Prevention and Treatment Harbin Medical UniversityHeilongjiang Academy of Medical ScienceHeilongjiang Cancer Center

Objective In recent years, the rising incidence of cancer has increased patients’ living and economic burdens. This study analyzed the incidence and death due to malignant tumors in tumor registries in Heilongjiang province (China) in 2015 to provide a scientific basis for the prevention and treatment of malignant tumors in this province. Methods Data on tumor incidence and patient deaths were collected from seven tumor registries in Heilongjiang province (China) in 2015. According to the stratification of urban and rural areas and patient sex, the crude, standard, and accumulative rates (0–74 years of age) were calculated. The 2000 China Population Census data and Segi’s standard population were used to calculate the age-standardized rates. Results In 2015, the incidence rate of malignant tumors in Heilongjiang cancer registries was 259.90/100 000. The age-standardized incidence rates in the Chinese and world standard populations were 158.89/100 000 and 155.06/100 000, respectively, with a cumulative incidence rate (0–74 years) of 17.68%. The incidence of malignant tumors in urban areas was 273.55/100 000, while that in rural areas was 220.32/100 000. The incidence of malignant tumors in men was 270.89/100 000, higher than that in women (249.04/100 000). Lung cancer had the highest incidence, followed by breast cancer, liver cancer, colorectal cancer, and thyroid cancer. The mortality rate of malignant tumors in Heilongjiang cancer registries was 164.69/100 000. The age-standardized mortality rates in Chinese and in world standard populations were 95.29/100 000 and 94.35/100 000, respectively, with a cumulative mortality rate (0–74 years) of 10.44%. The mortality rate of malignant tumors in urban areas was 169.51/100 000, while that in rural areas was 150.72/100 000. The mortality rate of malignant tumors in men was 201.64/100 000, higher than that in women (128.21/100 000). Lung cancer had the highest mortality, followed by liver cancer, stomach cancer, colorectal

关键词： tumor registration incidence mortality Heilongjiang province, China

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

The Origin of Pb-Zn Deposits in the Northern Kuandian Area, Liaoning province

引用

Global Geology 2001年第1期6卷 45-51页

作者： Qu Yajun and Wang Changfeng (Liaoning Institute of Ceological Survey, Shenyang, 110032. P. R. China) Liaoning Institute of Geological Survey Shenyang 110032 P.R. China

Carbonates and clastic rocks are well developed in the second-order basins of an Paleoproterozoic aulacogen in the northern Kuandian area, Liaoning province. The carbonates cousist of two parts, the upper and the lower carbonate forma- tions. The clastic rocks occured between the two formations. Two Pb-Zn ore belts exist in both of upper and lower carbo- nate formations and are called B and A-belt respectively. Several tens of Pb-Zn ore bodies are found in A-belt. Some Pb -Zn ore bodies are apparent in vertical zoning in a sequence of Fe-Zn-Pb-Ba from the lower to the upper. Geological and geochemical researches show that the ore components in the A-belt was exhalated from the liquid source bed deeply and was precipitated in a closed second-order basins. While those in the B-belt was derived from the upper crust and was de- opsited in a normal oceanic enviornment. The second-order basins in Liaodong-Ji’nan-North Korean Peninsular aulaco- gen at the margin of the Archean craton are promising sites for looking for the deposits formed by exhalation of the liquid source bed deeply under crust.

关键词： Liaoning province, northern Kuandian, Paleoproterozoic, carbonate rock, lead- zinc ore deposit

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

Study on the Vertical Integration of Agricultural Industry Hubei province under the Background of Intemet

引用

International Journal of Technology Management 2017年第6期 72-74页

作者： Zhang Yun Zhou Ling Yuan Hua Wuhan Donghu University WuhanHubei China 430212 Wuhan University of Technology WuhanHubei China 430070

According to the theory of modern industrial organization, effective agricultural industrial organization innovation is thekey to improve the competitiveness of China＇ s agricultural industry. At present, China＇ s agricultural industry organization is not perfectthere are some problems in the micro levels. Therefore, in order to promote the development of China＇ s agriculture, the key is to carry outeffective agricultural industrial organization innovation, cultivate and improve China＇ s agricultural industrial organization system, improvethe competitiveness of China＇ s agricultural market. In the ＂Internet＋＂ under the background of China＇ s rural finance is undergoing rapidchange, the subject of rural finance, financial factors, financial institutions continue to restructure. The traditional rural financial institutions musthave a clear understanding of the ＂Internet＋＂ brings opportunities and challenges, objective analysis of its advantages and disadvantages, domarket positioning and strategic transformation.

关键词： Internet, Hubei province, agricultural industry, development

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

Deep Metallogenic Speciality of Lithosphere in Amur province, Russia

引用

Global Geology 2003年第2期8卷 166-174页

作者： A.M.Petryshchevsky V.G.Khomich N.G.Boriskina Regional Problem Institute of Complex Analysis FEB RAS Birobidzan 679016 RussiaRegional Problem Institute of Complex Analysis FEB RAS Birobidzan 679016 RussiaGeological Institute of FEB RAS Vladivostok 690022 Russia

The spatial connections of endogenous deposits with anomalies of the vertical density gradient in lithosphere, calculated on the formulas for the spherical gravity sources are analyzed for Amur province. The spatial parameters of tin-bearing, tungsten-bearing and gold-bearing regional ore-magmatic systems (ore regions, belts, zones and areas) are characterized by correlation of deep gradient density anomalies in the crust and upper mantle with the extensivity of superficial ore mineralization. Tin-ore deposits are mainly connected with density heterogeneities of the upper crust layer (up to a depth of 20 km), and tungsten, molibdenium and polymetallic deposits-with anomalies of the density gradient in the low crust layer (at a depth of 30 km) and in the upper mantle (at a depth of 60～70 km). Gold-ore regions are characterized by the greatest vertical range of fluid-magmatic systems (about 100 km from the surface) and arethrough ones in relation to mantle and crust tectonic structures. Opportunity is shown for the 3D density gradient model of the Amur province lithosphere to be applied for constructing the forecast metallogenic models.

关键词： spatial parameters, Tin-bearing, 3D density gradient model, lithosphere, Amur province, heterogeneitic

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

The Ridge of Northeast:Changbai Mountain

引用

China's Foreign Trade 2019年第1期 60-63页

作者： Tao Wu 不详

Located on the border of Jilin province of China and Samjiyon County under Ryanggang province of North Korea,Changbai Mountain is adjacent to the southeast North *** Mountain is also called Beakdu Mountain because of the white pumice stones and snow accumulation on its *** the highest mountain in the northeast,Changbai Mountain is known as the“Ridge of Northeast”.

关键词： Changbai Mountain Jilin Sanjiyon county, lianggang province, north Korea

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

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

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：