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Physical mechanisms of plant roots affecting weathering and leaching of loess soil

Science china Earth Sciences 2006年第9期49卷 1002-1008页

作者： LI Yong1,2. ZHANG Qingwen1,2. WAN Guojiang3. HUANG Ronggui3. PIAO Hechun3. BAI Lingyu2.& LI Lu2.1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, institute of Soil and Water Conservation, {4. Academy of Sciences, Yangling 712.00, china 2. institute of Agro-Environment and Sustainable Development, {4. Academy of Agricultural Sciences, Beijing 100081, china 3. institute of geochemistry, {4. Academy of Sciences, guiyang 550002. china 1. State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation Chinese Academy of Sciences Yangling 712100 China 2. institute of Agro-Environment and Sustainable Development Chinese Academy of Agricultural Sciences Beijing 100081 China 3. institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China

Plant roots have potential impacts on soil mineral weathering and *** objective is to understand the physical mechanisms of plant roots affecting weathering andleaching of loess soil. Root densities were measured through the method of a large-size dug profile,and transport fluxes of soil elements were determined using an undisturbed monolith soilinfiltration device on the hilly and gully regions of the chinese Loess Plateau. The results showthat the improvement effects of soil environment by plant roots are mainly controlled by the densityand weight of the fibrous roots with the diameters less than 1 mm. Plant roots have the strongereffects on soil physical properties than chemical properties. The principal components analysis(PCA) indicates that soil physical properties by plant roots account for 56.7% of variations in soilenvironment whereas soil chemical properties and pH contribute about 2.1}2. of the soil *** roles of plant roots in controlling soil weathering and leaching increased in the followingorder: infiltration enhancement > increase of bio-active substance > stabilization of soilstructure. The effects of plant roots on soil mineral weathering and leaching can be quantifiedusing the multiple regression models with the high prediction accuracies developed in this study.

关键词： plant roots, soil weathering and leaching rates, soil environment field, principal components analysis (PCA), chinese Loess Plateau.

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Advances in geochemical research on nanometer materials

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Progress in Natural Science:Materials International 2006年第4期16卷 331-337页

作者： ZHU Xiaoqing and WANG Zhonggang Key Laboratory of Ore Deposit geochemistry, institute of geochemistry, {3. Academy of Sciences,{4. [a]Key Laboratory of Ore Deposit geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang China

Important advances have been made in the field of geochemistry since nanometer science and technology were introduced into the field of geoscience. The nanometer particulates have been discovered in naturally-occurring ore deposits, volcano-eruptive materials and geo-gases, and a more detailed exploration of the metallogenic mechanism of endogenic metallic ore deposits has been conducted. It is considered that some ore-forming metals may transport in the form of native particulates. Because they have very strong capabilities of adsorption, adsorption is always regarded as an important mechanism of metallogenesis under supergenic and low temperature conditions. Therefore, a new technology of ore exploration has also been developed. This paper attempts to review the new advances in geochemical research on nanometer materials, as well as its perspectivess.

关键词： nanometer geochemistry adsorption metallogenic theory prospecting method.

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A restudy of Oryctocephalus indicus (Reed,1910)

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Progress in Natural Science:Materials International 2006年第11期16卷 1177-1182页

作者： ZHAO Yuanlong~1**, YUAN Jinliang~2. PENG Shanchi~ 2.3., YANG Xinglian~1, PENG Jin~1, LIN Jihpai~4. and GUO Qingjun~5(1. College of Resource and Environment of Guizhou University, {2. 550003. china 2. Nanjing {4. of Geology and Palaeontology, {3. Academy of Sciences, Nanjing 2.0008, china 3. State Key Laboratory of Papaeobiology and Stratigraphy, Nanjing {4. of Geology and Palaeontology, Nanjing 2.0008, china 4. Department of Geological Science, Ohio State University, Columbus, OH 4.0}10, USA 5. {4. of geochemistry, {3. Academy of Sciences,{14.) College of Resource and Environment of Guizhou University Guiyang 550003 China Nanjing institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China State Key Laboratory of Papaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Nanjing 210008 China Department of Geological Science Ohio State University Columbus OH 43210 United States institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China

Restudy on morphology of Oryctocephalus indicus (Reed, 1910), based on specimens from Guizhou, china and Nevada USA, suggests that the subspecies regarded previously as Oryctocephalus indicus indicus (Reed, 1910), O. indicus latus Zhao et Yuan 2.02. and O. indicus kobayashi Saito, 193., are synonymous, and Oryctocephalus americanus Sundberg et McCollum, 2.03.is a similar form of O. indicus. Oryctocephalus indicus is rediagnosed as having a glabella that is subconical in outline and tapering forward slightly; a thorax that comprises 12.segments, and a small pygidium that bears 2.3.axial rings with a terminal piece and a postaxial ridge. Oryctocephalus indicus is widely distributed in eastern Guizhou and ranges through a great interval of Kaili Formation. Its first appearance is almost identical with these events of trilobite extinction-recovery occurring at the end of the Early Cambrian, the alternation of acritach assemblages, the change of trace elements (REE) and stable isotopes (carbon) at the Wuliu-Zengjiaya section. As one of the key forms for defining the traditional Lower-Middle Cambrian boundary (the base of Cambrian Series 3.and Stage 5 in the new Cambrian chronstratigraphic standard), O. indicus has received detailed study and has more advantages than other species such as Ovatoryctocara granulata Tchernysheva, 1962.or Arthricocephalus chauveaui Bergeron, 1899.

关键词： Oryctocephalus indicus restudy Kaili Formation Cambrian Guizhou china.

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Population information extraction in Chaohu watershed based on RS and GIS

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chinese Science Bulletin 2003年第2期48卷 181-183页

作者： LIU Jianjun1,2.& LI Chunlai3.1. institute of {2., chinese Academy of Sciences,{3. 2. Graduate School, chinese Academy of Sciences, Beijing 10003., china 3. National Astronomical Observatories, chinese Academy of Sciences, Beijing 100012. china Correspondence should be addressed to Liu Jianjun (e-mail: dhsliujj@ ***) institute of geochemistry Chinese Academy of Sciences Guiyang China Graduate School Chinese Academy of Sciences Beijing China National Astronomical Observatories Chinese Academy of Sciences Beijing China

It is always difficult to extract population in-formation of small watershed during the region environment assessment. The report adopted compound areal interpola-tion to study the population in Chaohu watershed with the GIS technique and landuse interpretation data from remote sensing. The result indicated that the method is effective to extract population information of small watershed.

关键词：巢湖流域人口分布信息提取 RS GIS 小流域生态环境评价

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Mantle-derived sulfur and its time constraints on gold mineralization of Ailaoshan gold belt, china

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chinese Science Bulletin 1999年第S2期44卷 242-244页

作者： BI Xianwu institute of geochemistry, {2. Academy of Sciences,{3. institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China

IN the previous studies of hydrothermal deposits much attention was paid to their material sources ratherthan the mechanisms of dynamic association of ore-forming fluids. In recent years many studies haveshown that ore-forming elements were transferred into ore-forming solutions after some suitable mineralizerwas incorporated into hydrothermal solutions. Therefore, the time at which the mineralizer is incorporated into hydrothermal solutions could, to a great extent, reflect the time of ore deposition. In the dynamic study of the origin of ore deposits on a trial basis the author took the Ailaoshan gold belt in YunnanProvince as an example and carried out investigations into the sources of mineralizers (the anion coordinates of stable complexes of gold in hydrothermal solutions) in ore-forming hydrothermal solutions and theconstraints of relevant geological events on gold mineralization.

关键词： sulfur isotope mantle-derived sulfur dating gold mineralization Ailaoshan gold belt.

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Evidence of acid nature of ore-forming solutions

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chinese Science Bulletin 1999年第S2期44卷 199-201页

作者： CHEN Fu institute of geochemistry, {2. Academy of Sciences,{3. institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE author thinks that the ore-forming solution is formed not by the near-neutral brine but by the strongacid solutions. Some evidence are the following: （i） The simulating experiments showed that, all near-neutral supergenic water as volcanic hotspring water of Tengchong, K-brine of Mengyejing, seawater of Qingdao, oil-gasses-bearing water of Chitianhua, rain water of guiyang and CO2./sub>-bearing rain cannot form metal-bearing solutions by heating mixedabove-mentioned supergenic water with ore-source rocks as basalt, ore-bearing carbonate, sandstone andshale. The most content of Cu, Pb, Zn, Hg, Sb, As, Ag in solutions is only （0.3.0.5）×10-6.They cannot form any ore deposit. Oppositely, the acid solution of pH=1.0 is easy to form metal-bearingsolutions with every ore-source rocks. The most content of metal in solution is n×10-n×1000 × 10-6i.e. rose in 3.5 grades. The content of metals in humic acid-bearing solutions is variable, perhaps dueto the changes of humic components and content and due to easy-decomposition by oxidation or *** the best one in solutions to form ore-forming solution is only the acidic water.

关键词： ore-forming solution acid solution in nature genesis of brine.

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Epithermal gold deposits in china and potential assessment

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chinese Science Bulletin 1999年第S2期44卷 164-166页

作者： QIU Yuzhuo institute of geochemistry, {2. Academy of Sciences,{3. institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China

THE epithermal gold deposit (epi-gold) is one of the most important types in various gold deposits all overthe world. The discovery of several superlarge deposits of this type around the circum-Pacific Rim duringthe 1980s, greatly stimulated the interest in searching for epi-golds in the world as well as in china. Theepi-gold has become a major target in gold exploration in china during last two-decade "Golden *** discovery of the Zijinshan Cu (Au) deposit in SE china and the Axi and other Au deposits in NWchina is the significant success in gold prospecting in this field. The author suggested that it is the timeto do an overview and the potential assessment of epi-golds in china Some people are holding an optimistic idea on this topic mainly based on the following considerations: (i) as a host rock, the subaerial volcanic rocks of Mesozoic are widespread in East china; (ii)

关键词： epithermal gold deposit china potential assessment.

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Experimental measurement of the electrical conductivity of single crystal olivine at high temperature and high pressure under different oxygen fugacities

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Progress in Natural Science:Materials International 2006年第4期16卷 387-393页

作者： DAI Lidong, LI Heping, LIU Congqiang, CUI Tongdi, SHAN Shuangming, YANG Changjun, LIU Qingyou and DENG Heming Laboratory of the Earth’s Interior Materials and Fluid geochemistry, institute of geochemistry, {3. Academy of Sciences,{4. Graduate School of the {3. Academy of Sciences, Beijing 10003., china institute of geochemistry, {3. Academy of Sciences,{4. Guizhou University, {12. 550004. china Laboratory of the Earth's Interior Materials and Fluid geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Graduate School of the chinese Academy of Sciences Beijing 100039 China institute of geochemistry {2. Academy of Sciences Guiyang 550002 China Guizhou University Guiyang 550004 China

At 1.0-4.0 GPa and 112.1}14.3.K and under oxygen fugacity-controlled conditions (Ni + NiO, Fe + Fe3.4. Fe + FeO and Mo+ M0O2.buffers), a YJ-3.00t Model six-anvil solid high-pressure apparatus and a Sarltron-12.0 Impedance/Gain-Phase analyzer were employed to conduct an in situ measurement of the electrical conductivity of single crystal olivine. Experimental results showed that: (1) within the range of experimentally selected frequencies (103.106 Hz), the electrical conductivity of the sample is of great dependence on the frequency; (2. with the rise of temperature ( T), the electrical conductivity (σ) will increase, and the Arrenhius linear relationship is established between lgσ and 1/T; (3. under the control of oxygen buffer Fe+ Fe3.4. with the rise of pressure, the electrical conductivity tends to decrease whereas the activation enthalpy and independent-of-temperature preexponential factor tend to increase, with the activation energy and activation volume of the sample estimated at (1. 2. ± 0.08) eV and (0.105 ±0.02.) cm3.mol, respectively; (4. under given pressure and temperature conditions, the electrical conductivity tends to increase whereas the activation energy tends to decrease with increasing oxygen fugacity; and ( 5) the mechanism of electrical conduction of small polarons can provide insight into the behavior of electrical conduction of olivine under high pressure and high temperature.

关键词： olivine high temperature and high pressure electrical conductivity oxygen fugacity small polaron.

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Effect of Pb, Hg and Cd in soil on scavenging system of activated oxygen in tobacco leaves

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chinese Science Bulletin 1999年第S2期44卷 91-93页

作者： YAN Chongling~(1,2., HONG Yetang~1, WANG Shijie~1, LIN Peng~3. YANG Xianke~2. FU Shunzhen~2. ZHU Keyong~2.and WU Shanqi~2.1. State Key Laboratory of Environmental geochemistry, {2. Academy of Sciences, guiyang 550002. china 2. Guizhou {3. of Environmental Protection, guiyang 550002. china 3. Department of Biology, Xiamen University, Xiamen 3.1005, china State Key Laboratory of Environmental geochemistry Chinese Academy of Sciences Guiyang 550002 China Guizhou institute of Environmental Protection Guiyang 550002 China Department of Biology Xiamen University Xiamen 361005 China

Pb, Hg and Cd will affect human health by vegetative chain. In recent years, people more and more are concerned about heavy metal pollution of the soil-plant system. Many researchers studied the effect of single heavy metal on growth, photosynthesis, respiration and quality of plants, but few systematicstudies of the effect of heavy metals on the scavenging system of activated oxygen of plants. This note systematically studies the effect of Pb, Hg and Cd in soil on the scavenging system of activated oxygen in tobacco leaves. 1 Material and methods Material: Tobacco (Nicoticana tabacum L). Methods: Cultivating and measuring methods were according to reference. 2.Results Results of this study indicate that the common effect of Pb, Hg and Cd on activity of CAT is obvi-

关键词： Pb Hg and Cd scavenging system of activated oxygen tobacco.

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Mechanical behavior and failure mechanisms of rock bolts subjected to static-dynamic loads

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International Journal of Mining Science and Technology 2024年第3期34卷 281-288页

作者： Hongpu Kang guiyang Yuan Linpo Si Fuqiang Gao Jinfu Lou Jinghe Yang Shuangyong Dong CCTEG Coal Mining Research InstituteBeijing 100013China State Key Laboratory of Intelligent Coal Mining and Strata Control Beijing 100013China

This study explores the effects of dynamic and static loading on rock bolt performance a key factor in maintaining the structural safety of coal mine roadways susceptible to coal *** a housemade load frame to simulate various failure scenarios,pretension-impact-pull tests on rock bolts were conducted to scrutinize their dynamic responses under varied static load conditions and their failure traits under combined *** experimental results denote that with increased impact energy,maximum and average impact loads on rock bolts escalate significantly under pretension,initiating plastic deformation beyond a certain *** minor reductions in the yield load due to impactinduced damage,pretension aids in constraining post-impact deformation rate and fluctuation degree of rock ***,impact-induced plastic deformation causes internal microstructure dislocation,fortifying the stiffness of the rock bolt support *** magnitude of this fortification is directly related to the plastic deformation induced by the *** findings provide crucial guidance for designing rock bolt support in coal mine roadway excavation,emphasizing the necessity to consider both static and dynamic loads for improved safety and efficiency.

关键词： Rock bolt Pretension Static and dynamic load Impact

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