Effects of biochar, cow bone, and eggshell on Pb availability to maize in contaminated soil irrigated with saline water   总被引：2，自引：0，他引：2  

Yaser A. Almaroai  Adel R. A. Usman  Mahtab Ahmad  Deok Hyun Moon  Ju-Sik Cho  Young Kyoo Joo  Choong Jeon  Sang Soo Lee  Yong Sik Ok 《Environmental Earth Sciences》2014,71(3):1289-1296

Toxicity of heavy metals adversely affects environment and human health. Organic materials derived from natural matters or wastes have been applied to soils to reduce the mobility of contaminants such as heavy metals. However, the application of cow bone powder (CB), biochar (BC), and eggshell powder (ES) is rarely investigated for the reduction of Pb bioavailability in soils irrigated with saline water. The objective of this study was to assess the effectiveness of CB, BC, and ES additions as immobilizing substances on Pb bioavailability in shooting range soil irrigated with deionized and saline water. Each additive of CB, BC, and ES at 5 % (w/w) was mixed with soils and then the deionized and saline water were irrigated for 21 days. With deionized water irrigation, the soils treated with CB, BC, and ES exhibited higher pH when compared with saline water irrigation. With saline water irrigation, the electrical conductivity, water-soluble anions, and cations were significantly increased in soils treated with CB, BC, and ES. The water-soluble Pb in soils treated with CB, BC, and ES was significantly decreased with saline water irrigation. On the other hand, the water-soluble Pb in soil treated with CB was increased with deionized water irrigation. Only BC with saline water irrigation decreased the Pb concentration in maize shoots.  相似文献   

黔西地区煤层埋深与地应力对其渗透性控制机制          下载免费PDF全文

徐宏杰  桑树勋  易同生  赵霞  刘会虎  李林 《地球科学》2014,39(11):1507-1516

基于黔西六盘水煤田和织纳煤田16口井36层次的试井资料, 采用地质统计分析等方法, 探讨了黔西地区煤储层渗透性的展布规律与地应力特征, 论证了煤层埋深与地应力对其渗透性的控制机制.研究表明, 研究区煤储层以特低渗-低渗透率储层(＜0.1×10-9m2)为主, 中渗透率储层(0.1×10-9~1.0×10-9m2)也占有相当大比例; 应力场类型在浅部表现为大地动力场型, 一定深度可能转化为准静水压力状态.煤储层渗透率及其埋深的负幂指数关系较为离散, 但在不同深度渗透率转折点与地应力场类型转变一致; 单井煤储层试井渗透率差异较大, 随地应力增大和埋深增加而降低, 平面展布受地应力强度控制由SW-NE具"低-高-低"发育规律.埋深对渗透率的控制实质是地应力的控制, 区域构造位置及其所处高应力场作用下的煤体形变与破碎致使孔裂隙压缩或闭合是该区渗透性差异的主要控制机制.   相似文献   

基于层次分析法的黄河上游水源涵养区生态系统恢复力评价——以甘南州、临夏州为例北大核心CSCD     

李鑫鹏  王朝平  邹松兵  岳玮  罗珊  王文澍  秦艺豪  桑骏  钱继坤  王春苗 《中国沙漠》2022,42(6):85-93

在全球气候变化背景下,人类活动对生态环境质量影响的定量评价是区域生态保护与高质量发展的关键问题。本文基于层次分析法(AHP)和GIS可视化空间分析技术,应用遥感反演的生态系统分类资料和社会经济统计资料等,构建了包含社会经济、土地压力、自然条件3个准则层的生态系统恢复力评价指标体系,结合指标时空尺度无量纲化与综合指数法,进行了甘肃省甘南州、临夏州2000—2020年的生态系统恢复力定量评估。结果表明:研究区域空间尺度生态恢复力范围分别为0.14—0.65(2000年)、0.12—0.72(2005年)、0.07—0.70(2010年)、0.12—0.70(2015年)、0.28—0.82(2020年);甘南生态系统恢复力较高,临夏生态系统恢复力较低,在空间分布上,生态系统恢复力呈现北低南高的总体特征,高生态恢复力的乡镇以草地、森林、灌木生态系统为主,低生态恢复力的乡镇以农田、城镇生态系统为主;在时序变化特征中,生态系统恢复力总体向好,呈现先上升、后下降、最后上升趋势,受人类活动与气候变化共同作用。  相似文献   

Distribution characteristics and factors influencing microbial communities in the core soils of a seawater intrusion area in Longkou City,China     

Sang  Shilei  Dai  Heng  Hu  Bill X.  Huang  Zhenyu  Liu  Yujiao  Xu  Lijia 《Hydrogeology Journal》2022,30(6):1833-1845

Microbes live throughout the soil profile. Microbial communities in subsurface horizons are impacted by a saltwater–freshwater transition zone formed by seawater intrusion (SWI) in coastal regions. The main purpose of this study is to explore the changes in microbial communities within the soil profile because of SWI. The study characterizes the depth-dependent distributions of bacterial and archaeal communities through high-throughput sequencing of 16S rRNA gene amplicons by collecting surface soil and deep core samples at nine soil depths in Longkou City, China. The results showed that although microbial communities were considerably impacted by SWI in both horizontal and vertical domains, the extent of these effects was variable. The soil depth strongly influenced the microbial communities, and the microbial diversity and community structure were significantly different (p < 0.05) at various depths. Compared with SWI, soil depth was a greater influencing factor for microbial diversity and community structure. Furthermore, soil microbial community structure was closely related to the environmental conditions, among which the most significant environmental factors were soil depth, pH, organic carbon, and total nitrogen.

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Shale Microstructure Extraction Based on Micro-CT and Permeability Inversion     

Zhang  Jicheng  Sang  Sheng  Ma  Tianran  Wang  Chunguang  Chen  Junguo 《Geotechnical and Geological Engineering》2022,40(6):3245-3254

Geotechnical and Geological Engineering - A shale rock sample was scanned by micro-CT technology, tomographic images of the rock sample were obtained, and the three-dimensional structure was...  相似文献   

北京及周边地区雷暴阵风锋特征统计分析     

何娜  丁青兰  俞小鼎  付宗钰  周璇  刘璐  李桑  柳克 《气象学报》2020,78(2):250-259

为全面和系统研究北京及周边地区阵风锋各方面特征,使用2006—2015年暖季（5—9月）北京多普勒雷达探测资料及北京、河北、天津自动气象站观测资料对北京及周边地区的阵风锋过程进行综合统计分析。结果表明,346次阵风锋过程有232次触发了对流,占总数的67%,表明阵风锋对雷暴具有较强的抬升触发能力。阵风锋在6—8月出现的日数占5—9月阵风锋总日数的85%;出现的时段主要是午后至傍晚（12—21时,北京时）,维持时间0.5—3 h;阵风锋在北京东南方向生成的数量最多,且触发对流的次数也最多;其次为偏东和东北方向;偏南和西南方向生成阵风锋数量居中,而偏北、偏西和西北地区阵风锋个例相对较少,触发对流的比例也相对较低。产生阵风锋的母风暴中48%为孤立雷暴（包括孤立多单体和超级单体风暴）,31%为雷暴群,21%为飑线;97%的母风暴最强回波在50 dBz以上,阵风锋的回波强度为10—25 dBz。91%的阵风锋移动速度集中在10—60 km/h,84%的阵风锋与母风暴的最大距离为1—60 km;在母风暴回波强度减弱到30 dBz以下时,80%的阵风锋能够继续维持的时间不超过2 h。阵风锋母风暴向东南方向移动的个例最多,从阵风锋和母风暴移动方向的关系来看,阵风锋与母风暴移向一致的情况占比最高,为32%,其次为母风暴无移动及阵风锋弧形扩散情况,各占17%;阵风锋与母风暴移向相反情况所占比例最低,只有3%。最后统计了阵风锋经过地面自动气象站时,自动观测量的变化情况。结果显示,阵风锋在经过地面自动气象站时会造成风速增大、温度降低、相对湿度增大、气压升高。   相似文献   

The 2.9-4.2 micron spectrum of Saturn: Clouds and CH₄, PH₃, and NH₃     

Sang J. Kim  T.R. Geballe 《Icarus》2005,179(2):449-458

We have used synthetic spectra to analyze a medium resolution 2.9-4.2 μm spectrum of Saturn's temperate region observed at UKIRT using CGS4. The synthetic spectra include CH₄, PH₃, and NH₃ lines, for which mixing ratios were adopted from recent Cassini results. The observed absorption features in the spectrum are well accounted for by lines of these molecular species formed 22 +/− 8 km above the 1 bar pressure level at ∼610 mbar. The influence of optically thin haze particles at higher altitudes on the spectrum is not pronounced, with higher spectral resolution probably required to constrain the effects of haze in this wavelength region. Fluorescent line emission by CH₄ in its ν₃ and ν₃+ν₄−ν₄ bands, detected in the 3.2-3.5 μm region, originates between 400 km (∼0.06 mbar) and 800 km (∼0.01 μbar) above the 1 bar level, with peak contributions from the two major contributing bands at 550 km (∼3 μbar) and 700 km (∼0.1 μbar), respectively.  相似文献   

Gas formation mechanism of marine carbonate source rocks in China   总被引：5，自引：1，他引：4  

ZHAO Wenzhi  WANG Zhaoyun  HE Haiqing  ZHANG Mingjie  WANG Hongjun  WANG Yunpeng & QIN Yong . Research Institute of Petroleum Exploration & Development  PetroChina  Beijing  China  . PetroChina Exploration & Production  Beijing  China  . Department of Geology  Lanzhou University  Lanzhou  China  . Guangzhou Geochemical Institute  Chinese Academy of Sciences  Guangzhou  China  . China University of Mining  Technology  Xuzhou  China 《中国科学D辑(英文版)》2005,48(4):441-453

It has been proven in exploration practice that thecarbonates in China not only can generate hydrocar-bons, but also form commercial reservoirs. The car-bonates are different from clastic rocks in view of theirdeposition environment as well as their sedimentaryand diagenetic processes. Therefore, the evaluationcriteria and hydrocarbon generation mechanism forcarbonates can not be the same as that for clasticrocks, and it is important to establish a special hydro-carbon generation mechanism and…  相似文献   

东北冷涡南落型强对流天气的潜势预报分析   总被引：1，自引：1，他引：0  

徐为进  吕冬红  沈利峰  刘方  王海青 《气象科学》2009,29(5):618-624

通过2005-2008年4-6月Micaps资料,查找500 hPa东北有冷涡,500 hPa和700 hPa江苏境内为大片的西北气流,当天午后到夜里出现强对流天气的若干典型个例,借助Micaps系统通过对一些个例的物理量资料分析,得出它们共同的发生强对流天气的机理;同时还分析得出诊断该类对流天气的不太适合使用的物理量和较适合使用的物理量;并分析个例的大气探空层结曲线,得出它们的对流层结与其它类型的区别,并剖析它们的一日转变情况;同时用Q矢量锋生函数方法分析,发现低层强锋生区域与强对流天气区域有较好的对应关系,锋生函数正值中心区域常出现个别站龙卷或大范围冰雹.  相似文献   

贺兰山东麓宁夏一次极值暴雨过程分析   总被引：5，自引：1，他引：4  

纪晓玲  桑建人  马筛艳  胡文东  杨侃 《气象科学》2010,30(3):332-337

利用常规气象资料和NCEP再分析资料,结合宁夏业务化的中尺度数值预报模式MM5输出产品,对2006年7月14日发生在贺兰山东麓宁夏的极值暴雨过程从降水特征、环流背景、影响系统、强降水落区及物理量特征等方面进行了分析。表明:此次极值暴雨是在2006年第4号台风"碧利斯"与副热带高压系统的相互作用、中β尺度低值系统影响和地面静止锋的触发下爆发的。强降水落区位于200 hPa青藏高压前部西北气流辐散区与500 hPa西南气流、700 hPa西南或偏南低空急流、850 hPa偏东气流三股气流辐合区相重叠区,中β尺度低值系统的右前侧与湿焓平流最强的区域。对流层高层干冷空气下侵是强降水的主要触发机制之一。非地转湿Q矢量与强降水落区有良好的对应关系,对短时强降水天气具有较好的描述能力和预报指导意义。  相似文献