检索结果-南通市图书馆

Acta Geologica Sinica(English Edition) 2018年第5期92卷 1981-1990页

作者： hu shuya ZHAO Quansheng WANG Guangcai ZHANG Jianwei FENG Juan Department of Environmental Science and Engineering Qingdao University School of Water Resources and Environment China University of Geosciences

The mineral rock salts present in the Mahai Salt Lake of the Qaidam basin exhibit high solubilities in water. In addition, the multicomponent underground brine exhibits a high salinity and is easily precipitated. In the natural state, brine transport in the brine layer is extremely slow, and the brine is in a relatively stable chemical equilibrium state with the rock salt media. However, during mining, both the seepage and the chemical fields fluctuate significantly, thereby disrupting the equilibrium and leading to variations in the chemical composition and dynamic characteristics of the brine. Therefore, we selected underground brine from the Mahai Salt Lake, collecting a total of 183 brine samples over three stages of mining（i.e., the early stage of underground brine extraction, the initial stage of mining, and the later stage of mining）. Using a range of analytical techniques, the chemical dynamics of the underground brine water and its evolution were systematically studied. We found that evaporation and enrichment were the main mechanisms of underground brine evolution in the Mahai Salt Lake, with cation exchange and mineral dissolution/precipitation being key factors in determining the dynamic characteristics and evolution of the brine.

关键词： Hydrochemical dynamics evolution exploitation process underground brine Mahai Salt Lake Qinghai-Tibet Plateau

Effects of spring fire and slope on the aboveground biomass, and organic C and N dynamics in a semi-arid grassland of northern China

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2019年第2期11卷 267-279页

作者： ZHAO Xiang hu shuya DONG Jie REN Min ZHANG Xiaolin DONG Kuanhu WANG Changhui College of Animal Science and Veterinary Medicine Shanxi Agricultural University State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing Institute of Science and Technology Information

The aboveground primary production is a major source of carbon(C) and nitrogen(N) pool and plays an important role in regulating the response of ecosystem and nutrient cycling to natural and anthropogenic disturbances. To explore the mechanisms underlying the effect of spring fire and topography on the aboveground biomass(AGB) and the soil C and N pool, we conducted a field experiment between April 2014 and August 2016 in a semi-arid grassland of northern China to examine the effects of slope and spring fire, and their potential interactions on the AGB and organic C and total N contents in different plant functional groups(C_3 grasses, C_4 grasses, forbs, Artemisia frigida plants, total grasses and total plants).The dynamics of AGB and the contents of organic C and N in the plants were examined in the burned and unburned plots on different slope positions(upper and lower). There were differences in the total AGB of all plants between the two slope positions. The AGB of grasses was higher on the lower slope than on the upper slope in July. On the lower slope, spring fire marginally or significantly increased the AGB of C_3 grasses, forbs, total grasses and total plants in June and August, but decreased the AGB of C_4 grasses and *** plants from June to August. On the upper slope, however, spring fire significantly increased the AGB of forbs in June, the AGB of C_3 grasses and total grasses in July, and the AGB of forbs and C_4 grasses in August. Spring fire exhibited no significant effect on the total AGB of all plants on the lower and upper slopes in 2014 and 2015. In 2016, the total AGB in the burned plots showed a decreasing trend after fire burning compared with the unburned plots. The different plant functional groups had different responses to slope positions in terms of organic C and N contents in the plants. The lower and upper slopes differed with respect to the organic C and N contents of C_3 grasses, C_4 grasses, total grasses, forbs, A. frigida plan

关键词： aboveground biomass plant functional group spring fire slope position N content organic C content semi-arid grassland

Porosity Distribution Characteristics and Geological Analysis of Brine Storage Medium in the Qaidam Basin, Western China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2018年第4期28卷 707-716页

作者： hu shuya XIAO Changlai LIANG Xiujuan ZHAO Quansheng WANG Guangcai ZHANG Jianwei FENG Juan Key Laboratory of Groundwater Resources and Environment of the Ministry of Education Jilin University College of Environmental and Resources Jilin University Department of Environmental Science and Engineering Qingdao University School of Water Resources and Environment China University of Geosciences

Underground brine is an unusual water resource that contains abundant mineral resources. It is distributed widely in the Qaidam Basin, western China, a hyperarid inland basin located in the northern Tibetan Plateau. Pores in the brine storage medium act as storage space and transmission channels of underground brine. Therefore, the porosity of brine storage medium determines its ability to store brine. In this study, Mahai Salt Lake was used as the research area as a modern saline lake located in the north area of the Qaidam Basin. A total of 100 porosity samples were collected from eight sampling points in two profiles of the research area at sampling depths of 1.30–314.78 m. The porosity distribution characteristics and influencing factors in brine storage medium were analysed according to the measured porosity data. Based on analysis of the pore structure characteristics, the brine storage medium contains intercrystalline pores, unlike conventional freshwater storage mediums. Moreover, the primary salt rock is susceptible to dissolution by lighter brine, facilitating the formation of secondary porosity. Due to the formation of secondary pores, a porosity greater than 20% remains even at buried depths greater than 100 m. Based on the geological statistical analysis, due to the geographic location, salt formation time, and depositional environment, the porosity values of Mahai Salt Lake do not exhibit a wider distribution, but also show more extreme values than a nearby salt lake. Based on the porosity characteristics by depth, due to the presence of secondary pores, flooding, stratigraphic static pressure, and other factors, porosity shows fluctuations with increasing depth.

关键词： porosity brine storage medium distribution characteristics geological analysis salt lakes in Qaidam Basin

Canopy structure:An intermediate factor regulating grassland diversity-function relationships under human disturbances

在线全文

学校读者我要写书评

暂无评论

Fundamental Research 2023年第2期3卷 179-187页

作者： Xiaoxia Zhao Yuhao Feng Kexin Xu Mengqi Cao shuya hu Qiuli Yang Xiaoqiang Liu Qin Ma Tianyu hu Maggi Kelly Qinghua Guo Yanjun Su State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China University of Chinese Academy of Sciences Beijing 100049China Institute of Ecology College of Urban and Environmental SciencePeking UniversityBeijing 100871China Patent Examination Cooperation Sichuan Center of the Patent Office China National Intellectual Property AdministrationChengduSichuan 610213China Department of Environmental Sciences Policy and ManagementUniversity of CaliforniaBerkeleyCA 94720United States Division of Agriculture and Natural Resources University of CaliforniaBerkeleyCA 94720United States Institute of Remote Sensing and Geographical Information Systems School of Earth and Space SciencesPeking UniversityBeijing 100871China

Grasslands are one of the largest coupled human-nature terrestrial ecosystems on Earth,and severe anthropogenic-induced grassland ecosystem function declines have been reported *** factors influencing grassland ecosystem functions is critical for making sustainable management *** structure is an important factor influencing plant growth through mediating within-canopy microclimate(e.g.,light,water,and wind),and it is found coordinating tightly with plant species diversity to influence forest ecosystem ***,the role of canopy structure in regulating grassland ecosystem functions along with plant species diversity has been rarely ***,we investigated this problem by collecting field data from 170 field plots distributed along an over 2000 km transect across the northern agro-pastoral ecotone of *** net primary productivity(ANPP)and resilience,two indicators of grassland ecosystem functions,were measured from field data and satellite remote sensing *** laser scanning data were collected to measure canopy structure(represented by mean height and canopy cover).Our results showed that plant species diversity was positively correlated to canopy structural traits,and negatively correlated to human activity *** structure was a significant indicator for ANPP and resilience,but their correlations were inconsistent under different human activity intensity *** to plant species diversity,canopy structural traits were better indicators for grassland ecosystem functions,especially for *** structure equation modeling analyses,we found that plant species diversity did not have a direct influence on ANPP under human ***,it had a strong indirect effect on ANPP by altering canopy structural *** to resilience,plant species diversity had both a direct positive contribution and an indirect contribution through mediating canopy *** study highlig

关键词： Grassland ecosystem function Canopy structure Plant species diversity human activity intensity Northern agro-pastoral ecotone

The response of soil respiration to different N compounds addition in a saline-alkaline grassland of northern China

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

Journal of Plant Ecology 2022年第5期15卷 897-910页

作者： huajie Diao Xiaopeng Chen Ge Wang Qiushi Ning shuya hu Wei Sun Kuanhu Dong Changhui Wang College of Grassland Science Shanxi Agricultural UniversityTaigu 030801China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China Shanxi Key Laboratory of Grassl and Ecological Protection and Native Grass Germplasm Innovation Shanxi Agricultural UniversityTaigu 030801China Youyu Loess Plateau Grassland Ecosystem Research Station Shanxi Agricultural UniversityTaigu 030801China Institute of Grassland Science Key Laboratory of Vegetation Ecology of the Ministry of EducationNortheast Normal UniversityChangchun 130024China

The increase in atmospheric nitrogen(N)deposition has profound effects on soil respiration(SR).However,the responses of SR to the addition of different N compounds,particularly in saline-alkaline grasslands remain unclear.A 3-year controlled field experiment was conducted to investigate the responses of SR to different N compounds(NH,NO,(NH),SO,and NH,HCO,)during the growing seasons in a saline-alkaline grassland located in the agro-pastoral ecotone of northern *** results demonstrated that SR showed a bimodal pattern and a significant interannual diference that was regulated by air or soil temperature and *** addition had a significant effect on SR,and the effect of N addition on SR varied yearly,which was related to seasonal *** mean SR across 3 years(2017-2019)was increased by 19.9%,13.0%and 16.6%with the addition of NH,NO,(NH,),SO,and NH,HCO3,*** highest effect of NH,NO3 addition on SR across 3 years was ascribed to the highest aboveground net primary production,belowground net primary production(BNPP)and soil NO,-***(C loss)was significantly increased while plant productivity(C input)did not significantly change under NH,HCO,addition,indicating a decrease in C *** addition,BNPP was the main direct factor influencing SR in this saline-alkaline grassland,and soil salinization(*** base cations and pH)indirectly affected SR through soil ***,NH,NO,addition overestimated the response of SR to N addition,and different N compounds should be considered,especially in saline-alkaline grassland.

关键词： nitrogen compounds soil respiration soil microorganism plant biomass saline-alkaline grassland

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

分析师关注与债券违约风险

财会通讯（下） 2019年第8期 125-128页

作者：胡书雅毕鹏石河子大学经济与管理学院佳木斯大学经济与管理学院

本文以2011—2016年我国上市公司为样本,分析了分析师关注对公司债券违约风险的影响。研究发现,随着分析师跟踪人数的增加,公司债券违约风险显著降低,分析师盈余预测误差越大,公司债券违约风险也越大。进一步研究表明,相比信息透明度较... 详细信息

本文以2011—2016年我国上市公司为样本,分析了分析师关注对公司债券违约风险的影响。研究发现,随着分析师跟踪人数的增加,公司债券违约风险显著降低,分析师盈余预测误差越大,公司债券违约风险也越大。进一步研究表明,相比信息透明度较高的公司,在信息透明度较低的公司中,无论是分析师跟踪人数还是盈余预测误差对债券违约风险的影响都更为显著,表明分析师关注对上市公司债券违约风险发挥了有效的监督作用。

关键词：公司债券违约风险分析师关注信息透明度监督效应

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

中国的屈原否定论探究

科教文汇 2011年第13期 59-60页

作者：胡书涯武汉大学湖北武汉430072

20世纪的《楚辞》研究中,我国晚清经学家廖季平首先提出"屈原否定论",在接下来的几十年内引起了学术界围绕屈原其人是否存在及其著作权问题的大规模讨论。

关键词：屈原否定

在线全文

学校读者我要写书评

暂无评论

学习动机理论在初中英语教学中的运用

英语教师 2022年第2期22卷 84-86,89页

作者：胡书亚扬州大学江苏扬州225000

在概述学习动机的定义和分类、分析我国初中生英语学习动机特点的基础上,探究学习动机理论在初中英语教学中的具体运用。提出外语学习动机可分为整体动机、情景动机和任务动机;也可以分为工具性动机和综合性动机;还可以分为内在动机和... 详细信息

在概述学习动机的定义和分类、分析我国初中生英语学习动机特点的基础上,探究学习动机理论在初中英语教学中的具体运用。提出外语学习动机可分为整体动机、情景动机和任务动机;也可以分为工具性动机和综合性动机;还可以分为内在动机和外在动机。我国初中生的英语学习以任务动机、工具性动机和外在动机为主,但整体动机、综合性动机和内在动机也存在于部分学生中。教师应充分激发初中生英语学习的内在动机,合理发挥工具性动机和外在动机的积极作用,尽可能结合初中生身心发展的特点,培养其英语学习的可持续性。

关键词：学习动机初中英语初中生

柴达木盆地马海盐湖储卤层渗透特征及卤水富集机制

在线全文

学校读者我要写书评

暂无评论

地理科学 2022年第11期42卷 2039-2046页

作者：胡舒娅任婕李吉庆赵全升青岛大学环境科学与工程学院山东青岛266100 青岛市生态环境局城阳分局生态环境监控中心山东青岛266109

通过野外抽水试验方法,确定了柴达木盆地马海盐湖储卤层渗透系数,并结合地下卤水赋存特征与沉积环境对其渗透性能进行分析。结果表明:本地区石盐层大多不纯,石盐晶体内包裹有泥、砂,且晶体间也有泥、砂充填。在石盐沉积期间,由于受到洪... 详细信息

通过野外抽水试验方法,确定了柴达木盆地马海盐湖储卤层渗透系数,并结合地下卤水赋存特征与沉积环境对其渗透性能进行分析。结果表明:本地区石盐层大多不纯,石盐晶体内包裹有泥、砂,且晶体间也有泥、砂充填。在石盐沉积期间,由于受到洪水与间歇性河流影响,导致地质环境演化过程中沉积形成的储卤层渗透性能在各处相差较大,区域地下卤水的连通性相对较弱。根据试验开采区27口开采井钻孔资料和地下卤水监测数据,进行了储卤层差异性分类,将钻孔所揭露储卤层划分为3种类型,不同类型储卤层卤水富集性能具有较大差异,表现为渗透系数和单井涌水量在平面分布上的较大数值差距。通过对钻孔岩心岩性、孔隙特征及补给条件等方面进行分析,得出卤水富集性能强的基本条件:储卤层具备天然良好的颗粒骨架和稳定的卤水补给来源与通道。依据储卤层渗透性能和卤水富集规律,将马海盐湖试验开采区划分出不同地下卤水富集区段。

关键词：渗透系数抽水试验卤水富集储卤层马海盐湖

在线全文

学校读者我要写书评

暂无评论

柴达木盆地盐湖卤水层给水度分布变化特征

地理科学 2017年第1期37卷 148-153页

作者：赵全升胡舒娅冯娟张建伟青岛大学环境科学与工程学院山东青岛266071 吉林大学环境与资源学院吉林长春130012

选择柴达木盆地马海盐湖作为研究对象,在研究区布置给水度采样点11处,采样深度1.61~148.5 m,采集给水度样品75件。结合研究区以往37处采样点的72个测试数据,共计取得48处采样点145个测试数据。根据给水度实测数据,采用数理统计方法分析... 详细信息

选择柴达木盆地马海盐湖作为研究对象,在研究区布置给水度采样点11处,采样深度1.61~148.5 m,采集给水度样品75件。结合研究区以往37处采样点的72个测试数据,共计取得48处采样点145个测试数据。根据给水度实测数据,采用数理统计方法分析了柴达木盆地马海盐湖卤水层给水度分布变化。其主要特征表现为:1给水度在水平方向上表现出较大的差异性,卤水层WⅠ至WⅤ的给水度分别介于0~0.263 5、0.009 4~0.209 9、0~0.277 8、0.006 2~0.135 9、0~0.107 7。在采样点MHK-022~MHK-026处,各卤水层给水度值较小,均小于0.06。在盐湖东北部,各卤水层给水度值较大,均大于0.08。2给水度在垂直方向上受地层静压力的影响随着深度的增加而减小,上部卤水层WⅠ的给水度均值为0.105,下部卤水层WⅤ的给水度均值已降至0.038 7,不足卤水层WⅠ给水度均值的40%。3给水度在垂直方向上还表现出旋回性的变化特征,这种沉积旋回的出现可能是对成盐期间气候波动的反映。

关键词：马海盐湖卤水层给水度分布变化