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A Metallogenic Model of Gold Deposits of the Jiaodong Granite-Greenstone Belt 被引量:63
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作者 dengjun YANGLiqiang +2 位作者 SUNZhongshi WANOJianping WANGQingfei 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2003年第4期537-546,共10页
An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave... An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave, magnetic and gravity fields show that the crust-mantle structure and its coupling mechanism are the fundamental dynamic causes for the exchange and accumulation of materials and energy in the metallogenic system. Considering the evolution history of the structural setting, the tectono-metallogenic dynamics model of the area can be summarized as follows: (1) occurrence of the greenstone belt during the Archean-Proterozoic-the embryonic form of Au-source system; (2) stable tectonic setting in the Paleozoic-an intermittence in gold mineralization; (3) intensive activation and reformation of the greenstone belt in the Mesozoic-tectono-mineralization and tectono-diagensis; (4) posthumous structural activity in the Cenozoic-destruction of orebodies in the later stage. In the middle and late Indosinian, the Tancheng-Lujiang fault zone cut deeply into the upper mantle so that the ore-bearing fluids migrated to higher layers through the crust-mantle interaction, resulting in alteration and mineralization. 展开更多
关键词 Jiaodong granite-greenstone belt source of ore-forming materials crust-mantle structure tectono-metallogenic model
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Control of Deep Tectonics on the Superlarge Deposits in China 被引量:26
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作者 YANGLiqiang dengjun +4 位作者 WANGJianguo WEIYanguang WANGJianping WANGQinfei LUPing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第2期358-367,共10页
Seventy-three large-superlarge deposits in China were formed in 4 metallogenic epochs, and located in 6 metallogenic domains. By combing their time-space distribution and the relevant data of crustal thickness, we dis... Seventy-three large-superlarge deposits in China were formed in 4 metallogenic epochs, and located in 6 metallogenic domains. By combing their time-space distribution and the relevant data of crustal thickness, we discuss the control conditions of deep tectonics on superlarge deposits. The various spatial variation of the crustal thickness where deposits locate is closely related to their different tectonic setting. The crustal thickness of the region where deposits are in the Precatnbrian metallogenic epoch is 37.1 km and shows double-peak distribution, which is related to the different tectonic-mineralization processes in the Tarim-North China and Yangtze metallogenic domains. The crustal thickness of the region where deposits are in the Paleoproterozoic metallogenic epoch is 43.4 km and shows normal distribution, which is the result of 'pure' mineralization setting. The crustal thickness of the region where deposits are in the Late Palaeozoic-Early Mesozoic metallogenic epoch is about 41.2 km and shows multi-peak distribution, which can be related with dispersing distribution in the metallogenic domain of these superlarge deposits. The crustal thickness of the region where deposits are in the post-Indosinian metallogenic epoch is 37.3 km, and shows skew distribution, which resulted from different tectonic settings in eastern and western China. 展开更多
关键词 superlarge deposits deep tectonics metallogenic dynamics China
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From Cycles to Sequences:Sequence Stratigraphy and Relative Sea Level Change for the Late Cambrian of the North China Platform 被引量:23
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作者 MEIMingxiang MAYongsheng +1 位作者 dengjun CHENHuijun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2005年第3期372-383,共12页
In the Late Cambrian, the North China Platform was a typical carbonate ramp platform. The Upper Cambrian of the northern part of the North China Platform is famous for the development of bioherm limestones and storm c... In the Late Cambrian, the North China Platform was a typical carbonate ramp platform. The Upper Cambrian of the northern part of the North China Platform is famous for the development of bioherm limestones and storm calcirudites and can be divided from bottom to top into the Gushan, Changshan and Fengshan formations. In this set of strata, the deep-ramp mudstone and marls and the shallow-ramp packstones and grainstones constitute many carbonate meter-scale cycles of subtidal type. More tidal-flat dolomites are developed in the Upper Cambrian of the southern margin of the North China platform, in which limestone and dolomite beds also constitute many carbonate meter-scale cycles of the peritidal type. These cycles are marked by a variety of litho-facies successions. There are regularly vertical stacking patterns of meter-scale cycles in long-term third-order sequences, which is the key to discerning such sequences. Third- order sequence is marked by a particular sedimentary-facies succession that is the result of the environment-changing process of deepening and shoaling, which is genetically related to third-order sea level changes. Furthermore, four third- order sequences can be grouped in the Upper Cambrian of the North China Platform. The main features of these four third -order sequences in the northern part of the platform can be summarized as follows: firstly, sequence-boundaries are characterized by drowning unconformities; secondly, the sedimentary-facies succession is generally constituted by one from deep-ramp facies to shallow-ramp facies; thirdly, a succession of “CS (?)+HST” (i.e., “condensed section and high- stand system”) forms these four third-order sequences. The chief features for the third-order sequences in the southern part of the North China Platform comprises: more dolomites are developed in the HSTs of third-order sequences and also developed more carbonate meter-scale cycles of peritidal types; the sedimentary-facies succession of the third-order sequences is marked by “shallow 展开更多
关键词 squence stratigraphy relative sea level changes Late Cambrian North China Platform
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Crust-Mantle Structure and Coupling Effects on Mineralization : An Example from Jiaodong Gold Ore Deposits Concentrating Area, China 被引量:17
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作者 YangLiqiang dengjun +2 位作者 ZhangZhongjie WangGuangjie WangJianping 《Journal of China University of Geosciences》 SCIE CSCD 2003年第1期42-51,共10页
Based on the results of two dimension velo city structure, 1∶100 000 aeromagnetic anomaly, 1∶200 000 bouguer gravity anom aly and seismic anisotropy of Jiaodong and neighboring region in Shandong, China , the info... Based on the results of two dimension velo city structure, 1∶100 000 aeromagnetic anomaly, 1∶200 000 bouguer gravity anom aly and seismic anisotropy of Jiaodong and neighboring region in Shandong, China , the information of geophysical field was divided into two parts: deep and sh allow focus fields. And then, the information of two different fields was c ombined with that of deep seated geology and ore deposit features. The syntheti c result was adopted to analyze three dimension structure, to probe into crust mantle coupling effects of mineralization and dynamics of ore formation system . 展开更多
关键词 geophysical field crust mantle structure coupling effect dynamics of mineralization Jiaodong area of China.
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Metallogenic Effect of Transition of Tectonic Dynamic System 被引量:15
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作者 dengjun WangQingfei +3 位作者 WeiYanguang WangJianping SunZhongshi YangLiqiang 《Journal of China University of Geosciences》 SCIE CSCD 2004年第1期23-28,共6页
Tectonic dynamic system transition, one of the main factors in metallogenesis, controls metallogenic fluid movement and ore body location in orefields and on an ore deposit scale (mainly in the continental tectonic se... Tectonic dynamic system transition, one of the main factors in metallogenesis, controls metallogenic fluid movement and ore body location in orefields and on an ore deposit scale (mainly in the continental tectonic setting), and even the formation and distribution of large-scale deposit clusters. Tectonic dynamic system transition can be classified as the spacious difference of the tectonic dynamic system in various geological units and the temporal alteration of different tectonic dynamic systems. The former results in outburst of mineralization, while the latter leads to the metallogenic diversity. Both of them are the main contents of metallogenic effect of tectonic dynamic system transition, that is, the alteration of dynamic system, the occurrence of mineralization, and the difference of regional tectonic dynamic system and metallogenic diversity. Generally speaking, the coupling of spatial difference of tectonic dynamic system and its successive alternation controlled the tempo-spatial evolution regularity of mineralization on a larger scale. In addition, the analysis of mineralization factors and processes of typical ore deposits proved that the changes of tectonic stress field, the direct appearance of tectonic dynamic system transition, may lead to the accident of mineralization physical-chemical field and the corresponding accidental interfaces were always located at ore bodies. 展开更多
关键词 tectonic dynamic system transition metallogenic diversity interface mineralization.
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Formation Mechanism of "Drag Depressions" and Irregular Boundaries in Intraplate Deformation 被引量:11
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作者 dengjun HUANGDinghua +6 位作者 WANGQingfei HOUZengqian LüQingtian YAOLingqing XINHongbo ZHANGQiang WEIYanguang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第1期267-272,共6页
Almost all intraplate caprocks experienced strong deformation during the convergence of microplates, and then disintegrated into many secondary geologic units with the special characters, such as irregular boundaries ... Almost all intraplate caprocks experienced strong deformation during the convergence of microplates, and then disintegrated into many secondary geologic units with the special characters, such as irregular boundaries and particular structural assemblages. In order to understand the formation mechanism of these special phenomena, a rheological experiment on the structural scenery of the Tongling area is carried out. The result shows that the primary regular and uniform boundaries of the Tongling area becomes irregular because of the enclosing and confinement of surrounding geological units in the process of 'compression-shearing-rotation-drag'; simultaneously, two specific 'drag depressions' developed at two opposite corners of the block. The former and the later phenomena can be regarded as a typical regional-scale rheological effect and necessary outcome of intraplate deformation respectively. 展开更多
关键词 intraplate deformation simulation experiment drag depression irregular boundaries Tongling area
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Study on characteristics of controllable active thermo-atmosphere of a vitiated coflow combustor 被引量:11
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作者 WUZhijun dengjun LILiguang 《Chinese Science Bulletin》 SCIE EI CAS 2005年第7期704-707,共4页
Turbulent combustion remains to be one of most complicated technologies due to the complexities of turbulence and combustion as well as the interaction of both. This paper presents a vitiated coflow combustor, which i... Turbulent combustion remains to be one of most complicated technologies due to the complexities of turbulence and combustion as well as the interaction of both. This paper presents a vitiated coflow combustor, which is newly used for the fundamental research into turbulent combustion. The characteristics of controllable active thermo-atmosphere (CATA) of a vitiated coflow combustor are investigated. The results show that the oxygen mole frac- tion of vitiated coflow flames between 0% and 21% yield coflow temperature between 700 and 1500 K, and there is a constant temperature space as a cylinder with a radius of 40 mm. These features of the vitiated coflow indicate the exis- tence of a controllable active thermo-atmosphere, which benefits the basic study on the autoignition of a combustible mixture in a homogeneous charge compression ignition (HCCI) combustion. 展开更多
关键词 协流 燃烧器 热量 空气 燃料 温度
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Surplus Space Method: A New Numerical Model for Prediction of Shallow-seated Magmatic Bodies 被引量:8
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作者 dengjun HUANGDinghua +4 位作者 WANGQingfeit WANLi YAOLingqing GAOBangfei LiuYan 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第6期1245-1249,共5页
Based on the data of field measurement and drilling in the Tongling area, a series of numerical simulations are carried out by using the 'Surplus Space Method' (SSM), which is first put forward in this paper a... Based on the data of field measurement and drilling in the Tongling area, a series of numerical simulations are carried out by using the 'Surplus Space Method' (SSM), which is first put forward in this paper and applied to predict the shallow-seated magmatic bodies. The results of the numerical simulations show the existence and the 3-D shape of a conical magmatic structure at a depth of-1000 m beneath the center of the area: its top offsets southwards and bifurcates to several branches, while its lower part stretches northeastwards and contracts rapidly to a point at about -1000 m depth. This point is reckoned to be a 'sink' of magma system, transferring ore materials and heat energy from the deep magma chamber to the sub-surface apophyses. The preliminary application of the SSM proves that it may be developed as a new detection means for determining the existence of shallow-seated magmatic bodies and analyzing their three-dimensional features. 展开更多
关键词 Tongling area shallow-seated magmatic bodies surplus space method numerical simulation
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Late Paleozoic Sequence-Stratigraphic Frameworks and Sea Level Changes in Dianqiangui Basin and Its Adjacent Areas with Systematic Revision of Regional Unconformities 被引量:7
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作者 MeiMingxiang MaYongsheng +3 位作者 dengjun MengQingfen YiDinghong LiDonghai 《Journal of China University of Geosciences》 SCIE CSCD 2004年第1期55-68,共14页
The formation process of the Dianqiangui basin, a special basin, occurred after the Caledonian orogeny, in the south of Guizhou, the west of Guangxi and the southeast of Yunnan, experienced three periods: it began ... The formation process of the Dianqiangui basin, a special basin, occurred after the Caledonian orogeny, in the south of Guizhou, the west of Guangxi and the southeast of Yunnan, experienced three periods: it began in the Devonian, persisted in the Carboniferous, and became fiercer in the Permian. Controlled by syndepositional fault-zones, varieties of isolated carbonate platforms, large and small, were developed in the background of a deep-water basin, namely, an inter-platform ditch. And a special paleogeographical Late Paleozoic pattern marked by “platform-basin-hill-trough” was produced in both the Dianqiangui basin and its adjacent areas. Affected by regional tectonic activities and the global changes in the sea level, the platform carbonates and coal measures superimposed each other cyclically on the attached platform. The reef-building on the isolated platform and the margin of the attached platform corresponds to the development of the shale succession in the deep-water basin. All of these elementary characteristics reflect a regular and sophisticated filling succession of the Dianqiangui basin, a result of the dual controls of the regionally tectonic activities and the eustacy. Based on the two elementary features of the third-order sequences, i.e. the regularity of sedimentary-facies succession in space and the simultaneity of environmental changes in time, 25 third-order sequences could be discerned in the Upper Paleozoic strata in the Dianqiangui basin and its adjacent areas. On the basis of the two kinds of facies-changing surfaces and the two kinds of diachronisms in stratigraphic records, the regional Late Paleozoic sequence-stratigraphic framework in the Dianqiangui basin and its adjacent areas can be established. There are two types of facies-changing surfaces and two types of diachronisms in stratigraphic records: the static type, a result of the change in sedimentary facies in space, and the dynamic type, a result of the change in time. These two types of facies-changing surfaces led 展开更多
关键词 sequence-stratigraphic frameworks Late Paleozoic revision of unconformities Dianqiangui basin and its adjacent areas.
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Lx2-32c,a novel semi-synthetic taxane,exerts antitumor activity against prostate cancer cells in vitro and in vivo 被引量:6
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作者 Guangyao Lv dengjun Sun +7 位作者 Jingwen Zhang Xiaoxia Xie Xiaoqiong Wu Weishuo Fang Jingwei Tian Chunhong Yan Hongbo Wang Fenghua Fu 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2017年第1期52-58,共7页
Tubulin has been shown to be an effective target for the development of cytotoxic agents against prostate cancer. Previously, we reported that Lx2-32 c is an anti-tubulin agent with high binding affinity to tubulin. I... Tubulin has been shown to be an effective target for the development of cytotoxic agents against prostate cancer. Previously, we reported that Lx2-32 c is an anti-tubulin agent with high binding affinity to tubulin. In this study, we investigated the potential of Lx2-32 c to act as an effective cytotoxic agent in the treatment of prostate cancer. MTT assays showed that Lx2-32 c was cytotoxic to all tested prostate cancer cell lines. The Lx2-32c-treated cells typically exhibited a rounded morphology associated with the onset of apoptosis, as evidenced by immunocytochemical staining. Human prostate cancer cell lines treated with Lx2-32 c arrest in the G2/M phase of the cell cycle and the treatment is associated with an increased ratio of cells in the sub-G0/G1 phase as determined by flow cytometry. Furthermore, expression of the cleaved form of poly(ADP-ribose) polymerase in prostate cancer cell lines treated with Lx2-32 c was shown by Western blotting assay. Xenograft implants of LNCa P and PC3-derived tumors in nude mice showed that Lx2-32 c treatment significant inhibited tumor growth with effects equivalent to those of docetaxel. These findings demonstrate the potential of Lx2-32 c as a candidate antitumor agent for the treatment of prostate cancer. 展开更多
关键词 Lx2-32c Cephalomannine Prostate cancer MICROTUBULE Cell cycle arrest Apoptosis
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Soil and microbial C:N:P stoichiometries play vital roles in regulating P transformation in agricultural ecosystems:A review
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作者 Guanglei CHEN Jiahui YUAN +4 位作者 Shenqiang WANG Yuting LIANG dengjun WANG Yiyong ZHU Yu WANG 《Pedosphere》 SCIE CAS CSCD 2024年第1期44-51,共8页
Stoichiometry plays a crucial role in biogeochemical cycles and can modulate soil nutrient availability and functions. In agricultural ecosystems,phosphorus(P) fertilizers(organic or chemical) are often applied to ach... Stoichiometry plays a crucial role in biogeochemical cycles and can modulate soil nutrient availability and functions. In agricultural ecosystems,phosphorus(P) fertilizers(organic or chemical) are often applied to achieve high crop yields. However, P is readily fixed by soil particles, leading to low P use efficiency. Therefore, understanding the role of carbon:nitrogen:P stoichiometries of soil and microorganisms in soil P transformation is of great significance for P management in agriculture. This paper provides a comprehensive review of the recent research on stoichiometry effect on soil P transformation in agricultural ecosystems. Soil microorganisms play an important role in the transformation of soil non-labile inorganic P to microbial biomass P by regulating microbial biomass stoichiometry. They also mobilize soil unavailable organic P into available P by changing ecoenzyme stoichiometry. Organic materials, such as manure and straw, play an important role in promoting the transformation of insoluble P into available P as well. Additionally, periphytic biofilms can reduce P loss from rice field ecosystems. Agricultural stoichiometries are different from those of natural ecosystems and thereby should receive more attention due to the influences of anthropogenic factors. Therefore, it is necessary to conduct further stoichiometry research on the soil biochemical mechanisms underlying P transformation in agricultural ecosystems. In conclusion, understanding stoichiometry impact on soil P transformation is crucial for P management in agricultural ecosystems. 展开更多
关键词 ecoenzyme microbial biomass microbial community MICROORGANISM P availability periphytic biofilm soil P transformation
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Review of ultraviolet ageing mechanisms and anti-ageing methods for asphalt binders 被引量:3
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作者 Yuanyuan Li Jianlin Feng +10 位作者 Shaopeng Wu Anqi Chen Dongliang Kuang Tao Bai Yangming Gao Jizhe Zhang Linglin Li Liyao Wan Quantao Liu Zongwu Chen dengjun Gu 《Journal of Road Engineering》 2022年第2期137-155,共19页
Asphalt binder is inevitably aged by ultraviolet(UV)light during its service period.UV ageing can significantly decrease the technical properties of asphalt binder.The sensitivity of asphalt to UV ageing and thermal-o... Asphalt binder is inevitably aged by ultraviolet(UV)light during its service period.UV ageing can significantly decrease the technical properties of asphalt binder.The sensitivity of asphalt to UV ageing and thermal-oxidative ageing differs,such that the UV ageing performance cannot be determined based on the thermal-oxidative ageing performance.Previous researches mainly focused on the chemical composite and technical performance changes of asphalt binder during UV ageing,and the UV light parameters effect on the ageing rate of asphalt binder.However,the theory for characterizing and explaining the development of UV ageing depth does not get too much attentions,and the UV ageing mechanism of asphalt binder is not very clear.Therefore,it cannot guide to develop or select the good methods or anti-UV ageing additives for asphalt binders.This paper focuses on the latest researches of the mechanisms and anti-ageing methods of asphalt binders.With the increase of UV ageing time,the UV ageing of asphalt binder develops gradually from the surface to inner part.There are various methods,such as low-penetration grade asphalt,less air void ratio,UV stabilizers and UV light absorbers,that can improve the UV ageing resistance of asphalt binders.A new theory of sensitive wavelengths of asphalt UV ageing is proposed,which can enrich the basic theory of asphalt UV ageing.Depending on this theory,different wavelengths of UV light have different ageing effects on asphalt binder.The composite anti-UV ageing additives with barrier and specific absorption effects on UV light is proposed,and may have better improvement effect on the anti-UV ageing performance of asphalt binder. 展开更多
关键词 Road engineering Asphalt pavement Asphalt binder UV ageing Anti-UV ageing method
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Quantification of the redox properties of microplastics and their effect on arsenite oxidation
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作者 Lin Chen dengjun Wang +5 位作者 Tianran Sun Tingting Fan Song Wu Guodong Fang Min Yang Dongmei Zhou 《Fundamental Research》 CAS CSCD 2023年第5期777-785,共9页
Microplastics have attracted global concern.The environmental-weathering processes control their fate,transport,transformation,and toxicity to wildlife and human health,but their impacts on biogeochemical redox proces... Microplastics have attracted global concern.The environmental-weathering processes control their fate,transport,transformation,and toxicity to wildlife and human health,but their impacts on biogeochemical redox processes remain largely unknown.Herein,multiple spectroscopic and electrochemical approaches in concert with wet-chemistry analyses were employed to characterize the redox properties of weathered microplastics.The spectroscopic results indicated that weathering of phenol-formaldehyde resins(PFs)by hydrogen peroxide(H2O2)led to a slight decrease in the content of phenol functional groups,accompanied by an increase in semiquinone radicals,quinone,and carboxylic groups.Electrochemical and wet-chemistry quantifications,coupled with microbial-chemical characterizations,demonstrated that the PFs exhibited appreciable electron-donating capacity(0.264-1.15 mmol e-g^(-1))and electron-accepting capacity(0.120-0.300 mmol e-g^(-1)).Specifically,the phenol groups and semiquinone radicals were responsible for the electron-donating capacity,whereas the quinone groups dominated the electron-accepting capacity.The reversible redox peaks in the cyclic voltammograms and the enhanced electron-donating capacity after accepting electrons from microbial reduction demonstrated the reversibility of the electron-donating and-accepting reactions.More importantly,the electron-donating phenol groups and weathering-induced semiquinone radicals were found to mediate the production of H2O2 from oxygen for arsenite oxidation.In addition to the H2O2-weathered PFs,the ozone-aged PF and polystyrene were also found to have electron-donating and arsenite-oxidation capacity.This study reports important redox properties of microplastics and their effect in mediating contaminant transformation.These findings will help to better understand the fate,transformation,and biogeochemical roles of microplastics on element cycling and contaminant fate. 展开更多
关键词 Microplastics WEATHERING Redox property Semiquinone radicals Electron-donating and-accepting capacity Arsenite oxidation
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Metallogenic Systems on the Paleocontinental Margin of the North China Craton 被引量:3
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作者 ZHAIYusheng dengjun +5 位作者 TANGZhongli XIAORongge SONGHonglin PENGRunmin SUNZhongshi WANGJianping 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第2期592-603,共12页
The North China Craton (NCC) is one of the largest blocks composing the continent. Different types of continental margins well developed around the NCC, along with lots of metallogenic systems of different metals and ... The North China Craton (NCC) is one of the largest blocks composing the continent. Different types of continental margins well developed around the NCC, along with lots of metallogenic systems of different metals and different times. Based on the study on the structural evolution of the NCC, the authors made a new division of tectonic units of the NCC. Through an analysis of the data of 1:25000 geochemical survey on stream sediments, regional geochemical features of main ore-forming elements including Au, Ag, Cu, Pb, Zn, W, Ni, Co and Mo of the NCC are discussed in the paper. Then different metallogenic systems and their forming processes and geodynamics are discussed in detail. At last, temporal and spatial distribution regularities are summarized and ten favorable ore-control factors on the paleocontinental margins are put forward, including (1) abundance of ore sources; (2) rendezvous of ore-forming fluids; (3) high thermo-dynamic anomaly; (4) remarkable Earth crust-mantle interaction; (5) cluster of macroscopic structures and their long activities; (6) diversity of ore-forming environments; (7) long geohistory; (8) multiforms of critical transitional ore-forming mechanisms; (9) multi-staged and superimposed ore-formation; and (10) suitable preservation condition. 展开更多
关键词 North China Craton Paleocontinental margin metallogenic systems metallogenic evolution
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Long-term biochar addition significantly decreases rice rhizosphere available phosphorus and its release risk to the environment 被引量:1
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作者 Hao Chen Jiahui Yuan +6 位作者 Guanglei Chen Xu Zhao Shenqiang Wang dengjun Wang Lei Wang Yujun Wang Yu Wang 《Biochar》 SCIE 2022年第1期281-295,共15页
Phosphorus(P)availability,diffusion,and resupply processes can be altered by biochar addition in flooded rice rhizosphere,which controls the risk of P release to the environment.However,there are few in-situ investiga... Phosphorus(P)availability,diffusion,and resupply processes can be altered by biochar addition in flooded rice rhizosphere,which controls the risk of P release to the environment.However,there are few in-situ investigations of these rhizospheric processes and effects.To explore the effects of biochar addition on soil P availability,high-resolution dialysis(HR-Peeper),diffusive gradients in thin films(DGT),and zymography techniques were used to provide direct evidence in the rice rhizosphere at the sub-millimeter scale.Long-term(9-years)field and greenhouse pot experiments demonstrated that biochar addition notably decreased the soluble/labile P and Fe concentrations in rice rhizosphere(vs.no biochar addition;CK)based on the results of Peeper,DGT,and two-dimensional imaging of labile P fluxes.DGT-induced fluxes in the soil/sediment(DIFS)model and sediment P release risk index(SPRRI)further indicated that biochar addition decreased the diffusion and resupply capacity of P from soil solid to the solution,thereby decreasing P release risk to the environment.These processes were dominated by Fe redox cycling and the hydrolysis of Al(hydro)oxides that greatly increased the unavailable P(Ca-P and residual-P).Additionally,greenhouse pot experiments(without additional biochar)showed that the previous long-term biochar addition significantly increased soil phosphatase activity,due to an adaptive-enhancing response to P decrease in the rhizosphere zone.The in-situ study on the biogeochemical reactions of P in the rice rhizosphere may provide a new and direct perspective to better evaluate the biochar addition and potential benefits to agricultural soils. 展开更多
关键词 BIOCHAR Rice rhizosphere Phosphorus availability DGT DIFS SPRRI
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Characteristics of the Composite Metallogenic System along the Jilin Paleocontinental Margin and the Evolution of Continental Dynamic Regimes 被引量:1
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作者 SUNZhongshi JIANGYanguo +2 位作者 dengjun CHEYingfang WANGJianping 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2004年第2期571-582,共12页
In view of the existing problems about the metallogenic epoch and origin of the complex along the Jilin paleocontinental margin, we propose the composite metallogenic system of the Jilin old land, based on the theory ... In view of the existing problems about the metallogenic epoch and origin of the complex along the Jilin paleocontinental margin, we propose the composite metallogenic system of the Jilin old land, based on the theory of metallogeny and from the continental dynamics and comprehensive analysis on the metallogenic characteristics. Its scientific theory is demonstrated by the following aspects: (1) Screening and analysis of the multi-stage super-imposition and sequences. The composite ore-forming system consists mainly of three types: the divergent-type epicontinental metallogenic system on the southern margin, the convergent-type epicontinental metallogenic system on the northern margin and the strike-slip-type epicontinental metallogenic system on the northeastern margin. Their major metallogenic epochs are Archean-Proterozoic, Variscan and Yanshanian respectively. (2) Comprehensive analysis of the genetic relations of the complicated deposits. The above-mentioned three types all indicate a consanguinity among granites, vein rocks and gold deposits, correspondence with geochemical elements, and unicity showing the same activities of mantle derived fluids and multi-source origin of ore-forming substances. (3) As to the mechanisms for mineral concentration, in addition to the sources, we also focus on the co-actions of permeability, vibration, gas-liquid state alternation and abrupt changes of flow velocity during the movement of ore-forming liquids, as well as the extraction and communication of multi-sequence circulating liquids. (4) It is helpful for establishing the relationship between metallogeny and the evolution of continental dynamic regimes, i.e., the ore-controlling correlations between the ore-forming elements-metallogenic series-metallogenic systems-composite metallogenic system and ore-controlling structural features (stratabound, primary and branching types)-regional faulting or secondary continental extension and collision-transformation of different continental dynamic types (divergent, convergent an 展开更多
关键词 composite metallogenic system continental dynamic mechanism Jilin paleocontinental margin
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A mechanistic study of ciprofloxacin adsorption by goethite in the presence of silver and titanium dioxide nanoparticles
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作者 Jie Tang Yun Wang +5 位作者 Qiang Xue Fei Liu Kenneth CCarroll Xiaohua Lu Taogeng Zhou dengjun Wang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2022年第8期46-56,共11页
The adsorption behaviors of ciprofloxacin(CIP),a fluoroquinolone antibiotic,onto goethite(Gt)in the presence of silver and titanium dioxide nanoparticles(AgNPs and TiO_(2)NPs)were investigated.Results showed that CIP ... The adsorption behaviors of ciprofloxacin(CIP),a fluoroquinolone antibiotic,onto goethite(Gt)in the presence of silver and titanium dioxide nanoparticles(AgNPs and TiO_(2)NPs)were investigated.Results showed that CIP adsorption kinetics in Gt with or without NPs both followed the pseudo-second-order kinetic model.The presence of AgNPs or TiO_(2)NPs inhibited the adsorption of CIP by Gt.The amount of inhibition of CIP sorption due to AgNPs was decreased with an increase of solution pH from 5.0 to 9.0.In contrast,in the presence of TiO_(2)NPs,CIP adsorption by Gt was almost unchanged at pHs of 5.0∼6.5 but was decreased with an increase of pH from 6.5 to 9.0.The mechanisms of AgNPs and TiO_(2)NPs in inhibiting CIP adsorption by Gt were different,which was attributed to citrate coating of AgNPs resulting in competition with CIP for adsorption sites on Gt,while TiO_(2)NPs could compete with Gt for CIP adsorption.Additionally,CIP was adsorbed by Gt or TiO_(2)NPs through a tridentate complex involving the bidentate inner-sphere coordination of the deprotonated carboxylic group and hydrogen bonding through the adjacent carbonyl group on the quinoline ring.These findings advance our understanding of the environmental behavior and fate of fluoroquinolone antibiotics in the presence of NPs. 展开更多
关键词 CIPROFLOXACIN GOETHITE Silver nanoparticles Titanium dioxide nanoparticles ADSORPTION
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Research on Superimposed Metallogenic System
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作者 ZhaiYusheng WangJianping dengjun PengRunmin 《Journal of China University of Geosciences》 SCIE CSCD 2004年第1期9-14,共6页
As located in the junction of three tectonic plates (the Eurasian plate, the Indian plate and the west Pacific plate), the China continent shows complex regional metallogenic features due to tectonic evolution of “mi... As located in the junction of three tectonic plates (the Eurasian plate, the Indian plate and the west Pacific plate), the China continent shows complex regional metallogenic features due to tectonic evolution of “micro-plates, polycycle tectonic movements”. Well developed superimposed metallogenic systems have constituted one of the regional metallogenic features in China. Through the study on superimposed metallogenic system of the middle and lower reaches of the Yangtze River and of the Yuebei basin (northern Guangdong Province), the authors put forward some basic combination pattern of sedimentary-magmatic superimposed metallogenic system and summarize its forming conditions (controlling factors). 展开更多
关键词 metallogenic system SUPERIMPOSITION middle and lower reaches of the Yangtze River Yuebei basin.
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Cloning and Sequence Analysis of IGFBP-7 Gene in Sheep
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作者 Mingliang ZHOU Pinggui YANG +1 位作者 dengjun WU Xiangyu ZHANG 《Agricultural Biotechnology》 CAS 2015年第6期38-42,共5页
In this study, full-length CDS sequence of IGFBP-7 gene was cloned from Liangshan semi-fine wool sheep with RT-PCR method and analyzed with bioinformatics methods. The results showed that the full-length CDS sequence ... In this study, full-length CDS sequence of IGFBP-7 gene was cloned from Liangshan semi-fine wool sheep with RT-PCR method and analyzed with bioinformatics methods. The results showed that the full-length CDS sequence of IGFBP-7 gene in Liangshan semi-fine wool sheep was 846 bp in length, encoding 282 amino acids. The CDS sequence shared 99%, 95% and 90% homology with bovine, human and rat, respectively; the amino acid sequence shared 98%, 93% and 89%, respectively. The GenBank accession number was FJ589640.1. The amino acid molecular weight of IGFBP-7 was 29.0 kD, and the theoretical isoelec- tric point (pl) was 8.25. The result of phylogenetic analysis showed that IGFBP-7 gone in Liangshan semi-fine wool sheep exhibited close phylogenetic relationships with bovine, goat and other mammals, and distant phylogenetic relationships with Danio rerio and Haliotis diversicolor. IGFBP-7 gene had uniformly distributed hy- drophobic and hydrophilic regions, harboring one signal peptide, two transmembrane regions, 16 phosphorylation sites, four N-glycosylation sites and one O-glyco- sylation site. The result of secondary structure analysis showed that the random coil, or-helix and β-sheet regions accounted for 64.89%, 19.86% and 15.25%, respectively. The result of tertiary structure analysis showed that IGFBP-7 harbors an IGFBP_N domain and an Ig-like domain. This study provided scientific basis for further investigating the function of IGFBP-7 gene in sheep. 展开更多
关键词 SHEEP Insulin-like growth factor-binding protein-7 gene (IGFBP-7 gene) CLONING Sequence analysis
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EVALUATION OF NEW COLLEGE ENGLISH (BOOK ONE & TWO ) IN TERMS OF LANGUAGE SKILLS
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作者 dengjun 《中国英语教学:英文版》 2004年第1期35-41,126,共8页
This study sets out to conduct an informed post-useevaluation of a general College English textbook intended forNon-English majors, New College English (Book One & BookTwo), produced by Zhejiang University, with t... This study sets out to conduct an informed post-useevaluation of a general College English textbook intended forNon-English majors, New College English (Book One & BookTwo), produced by Zhejiang University, with the aim ofassessing its effectiveness in promoting language learning. Theevaluation adapts a procedure of three phases: 1 ) an in-depthanalysis of the materials in terms of its content andmethodology, 2 ) a retrospective evaluation by a representativegroup of its student users, and 3 ) suggestions for the possibleadaptations and teaching application based on the significantfindings of the survey and some recent Second Language Teachingand Learning assumptions. 展开更多
关键词 大学 非英语专业 英语教材 教材评估
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