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1Regional Tectonic Transformation in East Kunlun Orogenic Belt in Early Paleozoic: Constraints from the Geochronology and Geochemistry of Helegangnaren Alkali-feldspar Granite显示文摘The Helegangnaren feldspar granite exposed in the eastern part of East Kunlun, is characterized by high concentrations of SiO2 and alkaline, low abundances of Fe, Mg and Ca, metaluminous-weak peraluminous. Trace elements analysis shows that the granite is depleted extremely in Ba, Sr and Eu, and rich in some large-ion lithophile elements and high field strength elements. Besides, the granite has high Ga contents, the values of 104 (Ga/Al) vary from 2.50 to 2.77, which is mainly greater than the lower limit of A-type granites (2.6), and is higher than the I-and S-type granites' average (2.1 and 2.28, respectively). Rare earth element (REE) is characterized by relatively high fractionations of light REE (LREE) and heavy REE (HREE) (LREE/HREE=9.3-13.60, (La/Yb)N =10.92-18.02), pronounced negative Eu anomalies (δEu=0.08-0.13), and exhibits right-dipping gull pattern. Major elements, rare elements and trace elements features show the granite is ascribed to A-type granite and A2 subtype in tectonic genetic type. They are plotted into post-collision or within-plate area in a variety of tectonic discriminations. Geological and geochemical data comprehensively suggest that the granite is formed in a post-collision extensive tectonic setting. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb dating yields a weighted mean age of 425 Ma, belonging to Middle Silurian, which is similar to the age of the post-collision geological events in the region. The differences of magmatic rocks in formation age, rocks assemblage and rocks series systematically indicate that the regional tectonic stress regime in the East Kunlun orogenic belt experienced a major transformation from compress to extension in Middle Silurianin, and the Helegangnaren feldspar granite intruded in the early stage of tectonic transformation.LI Ruibao PEI Xianzhi LI Zhuochen SUN Yu PEI Lei CHEN Guochao CHEN Youxin LIU Chengjun WEI Fanghui 2013Acta Geologica Sinica(English Edition)2013,87,2:35
2Distribution of high-risk human papillomavirus genotype prevalence and attribution to cervical precancerous lesions in rural North China显示文摘Objective: Precise prevention is more desired for cervical cancer due to the huge population, high prevalence of human papillomavirus(HPV) infection in China and the vision of screen-and-treat strategies in low-and middleincome countries(LMICs). Considerations of combining type-specific prevalence and attribution proportion to high-grade cervical intraepithelial neoplasia are informative to more precise and effective region-specific cervical cancer prevention and control programs. The aim of the current study was to determine the genotype distribution of HPV and attribution to cervical precancerous lesions among women from rural areas in North China.Methods: A total of 9,526 women participated in the cervical cancer screening project in rural China. The samples of women who tested positive for HPV were retested with a polymerase chain reaction(PCR)-based HPV genotyping test. The attribution proportion of specific high-risk human papillomavirus(HR-HPV) types for different grades of cervical lesions was calculated by using the type contribution weighting method.Results: A total of 22.2%(2,112/9,526) of women were HR-HPV positive and HPV52(21.7%) was the most common HR-HPV genotype, followed by HPV58(18.2%), HPV53(18.2%) and HPV16(16.2%). The top three genotypes detected in HR-HPV-positive cervical intraepithelial neoplasia(CIN)1 were HPV16(36.7%), HPV58(20.4%), HPV56(15.3%). Among CIN2+, the most frequent genotypes were HPV16(75.6%), HPV52(17.8%),HPV58(16.7%). HPV16, 56, 58, 53, 52, 59, 68, and 18 combined were attributed to 84.17% of all CIN1 lesions,and HPV16, 58, and 52 combined were attributed to 86.98% of all CIN2+ lesions.Conclusions: The prevalence of HR-HPV infection among women from rural areas in North China was high and HPV16, HPV58, HPV52 had paramount attributable fraction in CIN2+. Type-specific HPV prevalence and attribution proportion to cervical precancerous lesions should be taken into consideration in the development of vaccines and strategy for screening in this population.Shuang Zhao Xuelian Zhao Shangying Hu Jessica Lu Xianzhi Duan Xun Zhang Feng Chen Fanghui Zhao 2019Chinese Journal of Cancer Research2019,31,4:30
3Geochemistry and regional distribution of ophiolites and associated volcanics in Mianlüe suture, Qinling-Dabie Mountains显示文摘Systematic studies of the ophiolites and associated volcanics stretching more than 1500 km from the Derni-Nanping-Pipasi-Kangxian area in the west to the Qingshuihe area of the south Dabie Mountains in the east indicate the existence of a suture zone (the Mianl黣 suture) and a vanished paleo-ocean basin (the Mianl黣 paleo-ocean basin) in the region. From west to east, ophiolitic mlange associations distribute discontinuously along the suture. Rock assem-blages include ophiolite, island arc and oceanic island rock series. The Mianl黣 paleo-ocean basin experienced its major formation and expending episode during the Carboniferous-Permian period. The finding of the suture zone and the paleo-ocean basin is tectonically significant in timing the collision between the North China-Qinling and Yangtze blocks and determining the formation and evolution of the Qinling orogenic belt.LAI Shaocong, ZHANG Guowei, DONG Yunpeng, PEI Xianzhi & CHEN Liang Key Laboratory of Continental Dynamics, Ministry of Education and Department of Geology, Northwest University, Xian 710069, China 2004Science China Earth Sciences2004,47,4:25
4Northernmost paleo-tethyan oceanic basin in Tibet:Geo-chronological evidence from ^(40)Ar/^(39)Ar age dating of Dur'ngoi ophiolite显示文摘Whole rock 40Ar/39Ar age dating has been conducted on a basalt sample from Dur’ngoi ophiolite, Qinghai Province, which was reported to be the northernmost pa-leo-tethyan oceanic basin in Tibet. A high temperature pla-teau age (345.3±7.9 Ma) with an isochorn age (336.6±7.1 Ma) has been obtained, representing the eruption time of oceanic crust Considering related geological settings, the new age provides constraints on the northernmost pa-leo-tethyan suture zone in Tibet and the tectonic evolution of Paleo-tethys in Northeast Tibet and adjacent areas.CHEN Liang, SUN Yong, PEI Xianzhi, GAO Ming, FENG Tao, ZHANG Zhongqing & CHEN Wen1. Laboratory of Continental Dynamics, Northwest University, Xi’an 710069, China 2. Department of Geology, Northwest University, Xi’an, 710069, China 3. Institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037, China 2001Chinese Science Bulletin2001,46,14:24
5An Ammonia-Hydrogen Energy Roadmap for Carbon Neutrality:Opportunity and Challenges in China显示文摘1.Opportunities and a bottleneck in the hydrogen energy industry Hydrogen(H_(2))is a carbon-free energy carrier with a wide range of application scenarios that was first emphasized in the Report on the Work of the Government in 2019 in China.In March 2021,President Xi Jinping reiterated that China pledges to achieve the goals of peak carbon emissions by 2030 and carbon neutrality by 2060.Lilong Jiang Xianzhi Fu 2021Engineering2021,7,12:20
6The LA-ICP-MS zircons U-Pb ages and geochemistry of the Baihua basic igneous complexes in Tianshui area of West Qinling显示文摘Baihua meta-igneous complex consists mainly of pyroxenite-gabbro(diorite)-diorite-quartz diorite. They form a complete comagmatic evolutionary series. The geochemical characteristics of basic-interme- diate basic igneous rocks indicate that they belong to a tholeiite suite. The REE distribution pattern is nearly flat type and LREE is slightly enriched type, and their primitive mantle-normalized and MORB-normalized trace element spider diagrams are generally similar; the LIL elements (LILE) Cs, Ba, Sr, Th and U are enriched, but Rb, K and the HFSEs Nb, P, Zr, Sm, Ti and Y are relatively depleted. All these show comagmatic evolution and origin characteristics. The tectonics environment discrimination of trace element reveals that these igneous complexes formed in an island-arc setting. The LA-ICP-MS single-zircons U-Pb age of Baihua basic igneous complex is 434.6±1.5 Ma (MSWD = 1.3), which proves that the formation time of the island-arc type magmatite in the northern zone of West Qinling is Late Ordovician or Early Silurian, also reveals that the timing of subduction of paleo-ocean basin represented by the Guanzizhen ophiolite and resulting island-arc-type magmatic activities is probably Middle-Late Ordovician to Early Silurian.PEI XianZhi DING SaPing ZHANG GuoWei LIU HuiBin LI ZuoChen LI GaoYang LIU ZhanQing MENG Yong 2007Science China Earth Sciences2007,50,z2:15
7A human herpesvirus miRNA attenuates interferon signaling and contributes to maintenance of viral latency by targeting IKKε显示文摘类型我发信号的干扰素(IFN ) 是调停的主要反应抗病毒的天生的免疫。IFN 抄写依赖于抄写因素 IRF3/IRF7 和 NF-B 的激活。许多病毒的蛋白质作为能够防碍 IFN 发信号从主人便于避免被显示出天生的有免疫力的反应。这里,我们报导那病毒的 miRNA, miR-K12-11,由 Kaposi 的联系肉瘤的 herpesvirus (KSHV ) 编码了为 IFN 通过指向 I-kappa-B kinase epsilon (IKK ) 发信号和行为的调整是批评的。miR-K12-11 的宫外的表示导致了减少的 IKK 表示,当 miR-K12-11 的抑制被发现在感染 KSHV 的房间恢复 IKK 表示时。重要地, miR-K12-11 的表示稀释了由减少的调停 IKK 的 IRF3/IRF7 phosphorylation 并且由禁止刺激基因(ISG ) 的 IKK 依赖的 IFN 的激活发信号的 IFN,允许抗病毒的免疫的 miR-K12-11 抑制。我们的数据建议由 miR-K12-11 指向的 IKK 是 KSHV 利用调制在 KSHV 生命周期期间发信号的 IFN 的重要策略,特别在潜伏。我们也证明 IKK 能与 12-O-tetradecanoylphorbol 13 醋酸盐的处理 synergistically 提高 KSHV 复活。而且, miR-K12-11 的抑制提高了小囊的口炎病毒感染导致的 KSHV 复活。一起拿,我们的调查结果也建议 miR-K12-11 能由指向 IKK 贡献 KSHV 潜伏的维护。Deguang Liang Yuan Gao Xianzhi Lin Zhiheng He Qinglan Zhao Qiang Deng Ke Lan 2011Cell Research2011,21,5:15
8Paleo-Tethyan Oceanic Crust Subduction in the Eastern Section of the East Kunlun Orogenic Belt:Geochronology and Petrogenesis of the Qushi'ang Granodiorite显示文摘The Qushi'ang granodiorite(QSG) is located at the central east of the ophiolitic melange belt in the East Kunlun Orogenic Belt(EKOB) in the northern margin of the Qinghai-Tibetan Plateau. LA-MC-ICP-MS zircon U–Pb dating suggests that the granodiorite and mafic microgranular enclaves(MMEs) crystallized 246.61±0.62 and 245.45±0.9 Ma ago, respectively. Granodiorite, porphyritic diorite, and MMEs are metaluminous and medium-K calk-alkaline series, with island-arc magma features, such as LILE enrichment and HFSE depletion. The porphyritic diorite has high Cr(13.50 ppm to 59.01 ppm), Ni(228.53 ppm to 261.29 ppm), and Mg~#(46–54). Granodiorite and porphyritic diorite have similar mineral compositions and evolved major and trace elements contents, particularly Cr and Ni, both of which are significantly higher than that in granites of the same period. The crystallization age of MMEs is close to that of granodiorite, and their major and trace elements contents are in-between porphyritic diorite and granodiorite. The results suggest that the original mafic magma, which was the product of mantle melting by subduction process, intruded into the lower crust(Kuhai Rock Group), resulting in the formation of granodiorite. Countinous intrusion of mafic magma into the unconsolidated granodiorite formed MMEs and porphyritic diorite. The granodiorite reformed by late-stage strike-slip faulting tectonic event indicates that the strike-slip fault of Middle Kunlun and the collision of the Bayanhar block with East Kunlun were later than 246 Ma. Therefore, the formation of the QSG not only indicates the critical period of evolution of East Kunlun but also represents the tectonic transition from oceanic crust subduction to slab breaking.CHEN Guochao PEI Xianzhi LI Ruibao LI Zuochen LIU Chengjun CHEN Youxin PEI Lei WANG Meng LI Xiaobing 2017Acta Geologica Sinica(English Edition)2017,91,2:14
9Geochemical Features, Age, and Tectonic Significance of the Kekekete Mafic-ultramafic Rocks, East Kunlun Orogen, China显示文摘The Kekekete mafic-ultramafic rocks are exposed in the Kekesha-Kekekete-Dawate area,which are in the eastern part of the East Kunlun Orogenic Belt.It outcrops as tectonic slices intruding tectonically in the Paleoproterozoic Baishahe Group and the Paleozoic Nachitai Group.The Kekekete mafic and ultramafic rocks is located near the central fault in East Kunlun and lithologically mainly consists of serpentinite,augite peridotite,and gabbro.The LA-ICP-MS zircon U-Pb age of the gabbro is 501±7 Ma,indicating that Kekekete mafic-ultramafic rocks formed in the Middle Cambrian.This rock assemblage is relatively poor in SiO2 and(Na2 O+K2 O) but rich in MgO and SFeO.The chondrite-normalized REE patterns of the gabbro dip slightly to the right;the primitive mantle and MORBnormalized spidergrams of trace elements show enrichment of large-ion lithophile elements(Cs,Rb,Ba,etc.) and no differentiation of high field strength elements.The general dominance of E-MORB features and the geochemical characteristics of OIB suggest that the Kekekete mafic-ultramafic rocks formed in an initial oceanic basin with slightly enriched mantle being featured by varying degrees of mixing of N-MORB depleted mantle and a similar-OIB-type source.From a comprehensive study of the previous data,the author believes that the tectonic history of the East Kunlun region was controlled by a geodynamic system of rifting and extension in the late stages of the Neoproterozoic to early stages of the Early Paleozoic and this formed the paleo-oceanic basin or rift system now represented by the ophiolites along the central fault in East Kunlun,the Kekekete mafic-ultramafic rocks and Delisitan ophiolite.LI Ruibao PEI Xianzhi LI Zuochen SUN Yu FENG Jianyong PEI Lei CHEN Guochao LIU Chengjun CHEN Youxin 2013Acta Geologica Sinica(English Edition)2013,87,5:13
10Geochemistry of the ophiolite and oceanic island basalt in the Kangxian-Pipasi-Nanping tectonic mélange zone, South Qinling and their tectonic significance显示文摘Detailed studies indicate that Kangxian-Pipasi-Nanping tectonic zone is a complicated mélange zone which includes many tectonic slabs of different origins. Ophiolite (MORB-type basalt), oceanic island tholeiite and alkaline basalt have been identified. Moreover, this tectonic mélange zone is eastward connected with the Mianlüe suture zone. The deformation characteristics, consisting components and volcanic rock geochemical features for the Kangxian-Pipasi-Nanping tectonic mélange zone are much similar to those of the Mianlüe suture zone and Deerni ophiolite. Therefore, the Kangxian-Pipasi-Nanping tectonic mélange zone should be the westward extension part of the Mianlüe suture zone. It indicates that the Mianlüe suture zone had extended to the Nanping area.LAI Shaocong ZHANG Guowei PEI Xianzhi YANG Haifeng 2004Science China Earth Sciences2004,47,2:13
11Algorithm and experiments of six-dimensional force/torque dynamic measurements based on a Stewart platform显示文摘Stewart platform(SP) is a promising choice for large component alignment, and interactive force measurements are a novel and significant approach for high-precision assemblies. The designed position and orientation(P&O) adjusting platform, based on an SP for force/torquedriven(F/T-driven) alignment, can dynamically measure interactive forces. This paper presents an analytical algorithm of measuring six-dimensional F/T based on the screw theory for accurate determination of external forces during alignment. Dynamic gravity deviations were taken into consideration and a compensation model was developed. The P&O number was optimized as well.Given the specific appearance of repeated six-dimensional F/T measurements, an approximate cone shape was used for spatial precision analysis. The magnitudes and directions of measured F/Ts can be evaluated by a set of standards, in terms of accuracy and repeatability. Experiments were also performed using a known applied load, and the proposed analytical algorithm was able to accurately predict the F/T. A comparison between precision analysis experiments with or without assembly fixtures was performed. Experimental results show that the measurement accuracy varies under different P&O sets and higher loads lead to poorer accuracy of dynamic gravity compensation. In addition, the preferable operation range has been discussed for high-precision assemblies with smaller deviations.Wen Ke Du Fuzhou Zhang Xianzhi 2016Chinese Journal of Aeronautics2016,29,6:13
12Genome-wide Scan for Seed Composition Provides Insights into Soybean Quality Improvement and the Impacts of Domestication and Breeding显示文摘优秀特点的复杂基因建筑学妨碍了努力在大豆修改种子营养素。染色体宽的协会研究为种子作文被进行,包括蛋白质,油,丰满的酸,和氨基酸,用有一个高密度的 SNP 数组的 313 多样的大豆 germplasm 就职 genotyped。87 个 chromosomal 区域的一个总数被识别与种子作文被联系,解释基因变化的 8%-89% 。已知的功能的候选人基因 GmSAT1, AK-HSDH, SACPD-C,和 FAD3A,和通常认为的 MtN21 nodulin, FATB,和 steroid-5 -- 涉及 N 2 固定,氨基酸生合成,和丰满的酸新陈代谢的 reductase 在主要效果的 loci 被发现。另外的 germplasm 就职的进一步的分析显示这些主要效果的 loci 受到了驯服或现代繁殖选择,并且突变而产生之遗传的变体和分布与地理区域相关。我们也表明与种子重量有关并且到全部的蛋白质的氨基酸集中有一个不同基因基础。这帮助揭开在种子之中的复杂关系的深入的基因机制加重。因此,我们的学习不仅为大豆营养素改进提供珍贵基因和标记,份量上和品质上,而且进在驯服期间优秀、引起的大豆的改变的提议卓见。Jiaoping Zhang Xianzhi Wang Yaming Lu Siddhi J. Bhusal Qijian Song Perry B. Cregan Yang Yen Michael Brown Guo-Liang Jiang 2018Molecular Plant2018,11,3:12
13A Survey on Expert Recommendation in Community Question Answering显示文摘Xianzhi Wang Chaoran Huang Lina Yao Boualem Benatallah Manqing Dong 2018Journal of Computer Science & Technology2018,33,4:10
14Plate tectonic control on the formation and tectonic migration of Cenozoic basins in northern margin of the South China Sea显示文摘The tectonic evolution history of the South China Sea(SCS) is important for understanding the interaction between the Pacific Tectonic Domain and the Tethyan Tectonic Domain,as well as the regional tectonics and geodynamics during the multi-plate convergence in the Cenozoic.Several Cenozoic basins formed in the northern margin of the SCS,which preserve the sedimentary tectonic records of the opening of the SCS.Due to the spatial non-uniformity among different basins,a systematic study on the various basins in the northern margin of the SCS constituting the Northern Cenozoic Basin Group(NCBG) is essential.Here we present results from a detailed evaluation of the spatial-temporal migration of the boundary faults and primary unconformities to unravel the mechanism of formation of the NCBG.The NCBG is composed of the Beibu Gulf Basin(BBGB),Qiongdongnan Basin(QDNB),Pearl River Mouth Basin(PRMB) and Taixinan Basin(TXNB).Based on seismic profiles and gravity-magnetic anomalies,we confirm that the NE-striking onshore boundary faults propagated into the northern margin of the SCS.Combining the fault slip rate,fault combination and a comparison of the unconformities in different basins,we identify NE-striking rift composed of two-stage rifting events in the NCBG:an early-stage rifting(from the Paleocene to the Early Oligocene) and a late-stage rifting(from the Late Eocene to the beginning of the Miocene).Spatially only the late-stage faults occurs in the western part of the NCBG(the BBGB,the QDNB and the western PRMB),but the early-stage rifting is distributed in the whole NCBG.Temporally,the early-stage rifting can be subdivided into three phases which show an eastward migration,resulting in the same trend of the primary unconformities and peak faulting within the NCBG.The late-stage rifting is subdivided into two phases,which took place simultaneously in different basins.The first and second phase of the early-stage rifting is related to back-arc extension of the Pacific subduction retreat system.The third phase of the earlystage rifting resulted from the joint effect of slab-pull force due to southward subduction of the proto-SCS and the back-arc extension of the Pacific subduction retreat system.In addition,the first phase of the late-stage faulting corresponds with the combined effect of the post-collision extension along the Red River Fault and slab-pull force of the proto-SCS subduction.The second phase of the late-stage faulting fits well with the sinistral faulting of the Red River Fault in response to the Indochina Block escape tectonics and the slab-pull force of the proto-SCS.Pengcheng Wang Sanzhong Li Yanhui Suo Lingli Guo Guangzeng Wang Gege Hui M.Santosh Ian D.Somerville Xianzhi Cao Yang Li 2020Geoscience Frontiers2020,11,4:10
15U–Pb Zircon Geochronology and Geochemistry of the Neoproterozoic Liujiaping Group Volcanics in the Northwest Margin of the Yangtze Block:Implications For the Breakup of the Rodinia Supercontinent显示文摘Investigation of the petrogenesis and the origin of zircons from the volcanic rocks of the Liujiaping Group of the back-Longmenshan tectonic belt in the northwest margin of the Yangtze Block is conducted by analysis of U–Pb geochronology and geochemistry. Results show that selected zircons are characterized by internal oscillatory zonings and high Th/U ratios(0.43–1.18), indicating an igneous origin. Geochronological results of LA–ICP–MS U–Pb dating of the Liujiaping Group zircons yield an age of 809 ± 11 Ma(MSWD = 2.2), implying that the volcanic rocks were formed in the Late Neoproterozoic. Geochemical analysis shows that the rocks are calc-alkaline, supersaturated in Al, and metaluminous to weakly peraluminous. Rare-earth elements are present at high concentrations(96.04–265.48 ppm) and show a rightward incline and a moderately negative Eu anomaly, similar to that of continental rift rhyolite. Trace element geochemistry is characterized by evident negative anomalies of Nb, Ta, P, Th, Ti, inter alia, and strong negative anomalies of K, Rb, Sr, et al. We conclude that the Liujiaping Group volcanic rocks resulted from typical continental crust source petrogenesis and were formed in a continental margin setting, which had no relation to subduction, and thus, were the products of partial melting of the lower crust due to crustal thickening caused by active continental margin subduction and arc–continent collision orogeny in the northwestern Yangtze Block and were triggered by the breakup of the Rodinia supercontinent during the Neoproterozoic.LI Zuochen PEI Xianzhi LI Ruibao PEI Lei LIU Chengjun CHEN Youxin XU Tong YANG Jie WEI Bo 2015Acta Geologica Sinica(English Edition)2015,89,4:8
16Tests and analysis of mechanical behaviours of rock bolt componentsfor China's coal mine roadways显示文摘A series of laboratory tests were performed to study the mechanical behaviours of newly developed high strength rock bolt components, including rebar, thread, plate, and domed washer. The characteristics of deformation and damage of each component were presented. The stress distribution of plate and domed washer was investigated through fi nite element modelling. The numerical results show that the yield and tensile strengths of the developed high strength rebar are 33.6%e58.3% and 17.2%e28.7% greater than those of the conventional rebar, respectively. The increase in yield strength was higher than that in tensile strength, suggesting an increase in yield to tensile strength ratio and a decrease in elongation. It is well-known that the thread processing may not be of high precision and accuracy as expected, which is characterised as rough thread surface, non-identical tooth height, toe stripping, and cracks in the surface.Hardening during thread processing tends to increase the thread yield and tensile strengths. In this paper, the typical deformation process of arch-shaped plate is classi fi ed into fi ve stages. The tested plates exhibited distinct deformation characteristics and bearing capacities due to variations in shape, size,material and presence of washer. It was observed that uneven bottom surface, low bearing arch and large radius of the transitional arc connecting bearing arch and bottom surface were the major reasons accounting for low load-bearing capacity of plates. The performance of domed washer has a close relation with the shape, size, strength, and deformation compatibility with plate. Stress concentration was observed on the periphery of the contact surface between domed washer and plate, which is signi fi cantly in fl uenced by the strength of domed washer and is considered to be 20%e30% higher than that of plate.Finally, a case study in the Datong coal mining district was presented, and the support pattern and effect of the developed rock bolt were described.Hongpu Kang 2015岩石力学与工程学报2015,34,1:7
17Settling behavior of non-spherical particles in power-law fluids:Experimental study and model development显示文摘Solid-particle settling occurs in many natural and industrial processes, such as in the transportation of drilling cuttings and fracturing proppant. Knowledge of the drag coefficient and settling velocity of cuttings and proppant is of significance to hydraulics design, wellbore cleanout, and fracture optimization. We conducted 553 tests to investigate the settling characteristics of spherical and non-spherical particles in power-law fluids. Three major particle shapes (spherical, cubic, and cylindrical) and eight different particle sphericities were used to simulate cuttings and proppant, and power-law fluids were applied to simulate drilling and fracturing fluids. Based on the data analysis, a new drag coefficient-particle Reynolds number correlation was developed to determine the drag coefficient in a power-law fluid for spherical and non-spherical particles. The drag coefficient increases as the sphericity decreases for the same particle Reynolds number. For a specific particle shape, the drag coefficient decreases as the particle Reynolds number increases, but the decreasing trend is reduced at high particle Reynolds number conditions. An explicit settling-velocity equation was proposed to calculate the settling velocity of spherical and non-spherical particles in power-law fluids by considering the effect of sphericity. A suitable range for the proposed model is 0.0001 < Re <200, 0.471 <φ< 1, and 0.505 < n < 1. An illustrative example is presented to show how to calculate the drag coefficient and settling velocity in power-law fluids with given particle and fluid properties.Zhengming Xu Xianzhi Song Gensheng Li Zhaoyu Pang Zhaopeng Zhu 2019Particuology2019,17,5:6
18Meso-Cenozoic Evolution of Earth Surface System under the East Asian Tectonic Superconvergence显示文摘The East Asian geological setting has a long duration related to the superconvergence of the Paleo-Asian, Tethyan and Paleo-Pacific tectonic domains. The Triassic Indosinian Movement contributed to an unified passive continental margin in East Asia. The later ophiolites and I-type granites associated with subduction of the Paleo-Pacific Plate in the Late Triassic, suggest a transition from passive to active continental margins. With the presence of the ongoing westward migration of the Paleo-Pacific Subduction Zone, the sinistral transpressional stress field could play an important role in the intraplate deformation in East Asia during the Late Triassic to Middle Jurassic, being characterized by the transition from the E-W-trending structural system controlled by the Tethys and Paleo-Asian oceans to the NE-trending structural system caused by the Paleo-Pacific Ocean subduction. The continuously westward migration of the subduction zones resulted in the transpressional stress field in East Asia marked by the emergence of the Eastern North China Plateau and the formation of the Andean-type active continental margin from late Late Jurassic to Early Cretaceous(160-135 Ma), accompanied by the development of a small amount of adakites. In the Late Cretaceous(135-90 Ma), due to the eastward retreat of the Paleo-Pacific Subduction Zone, the regional stress field was replaced from sinistral transpression to transtension. Since a large amount of late-stage adakites and metamorphic core complexes developed, the Andean-type active continental margin was destroyed and the Eastern North China Plateau started to collapse. In the Late Cretaceous, the extension in East Asia gradually decreased the eastward retreat of the Paleo-Pacific subduction zones. Futhermore, a significant topographic inversion had taken place during the Cenozoic that resulted from a rapid uplift of the Tibet Plateau resulting from the India-Eurasian collision and the formation of the Bohai Bay Basin and other basins in the East Asian continental margin. The inversion caused a remarkable eastward migration of deformation, basin formation and magmatism. Meanwhile, the basins that mainly developed in the Paleogene resulted in a three-step topography which typically appears to drop eastward in altitude. In the Neogene, the basins underwent a rapid subsidence in some depressions after basin-controlled faulting, as well as the intracontinental extensional events in East Asia, and are likely to be a contribution to the uplift of the Tibetan Plateau.DMITRIENKO Liudmila V. WANG Pengcheng LI Sanzhong CAO Xianzhi Ian SOMERVILLE ZHOU Zaizheng HU Mengying SUO Yanhui GUO Lingli WANG Yongming LI Xiyao LIU Xin YU Shengyao ZHU Junjiang 2018Acta Geologica Sinica(English Edition)2018,92,2:6
19Mechanisms and field test of solution mining by self-resonating cavitating water jets显示文摘Rapid solution mining is the key to cavern construction in salt formations. Rapid solution mining technology with self-resonating cavitating water jets is described in this paper. It can generate three main physical effects: helical flow dissolution, self-resonating cavitating jet erosion, and ultrasonic waves. A self-resonating cavitating nozzle was also designed with the principles based on theory of fluid transients and hydro-acoustics. Under ambient pressure, the experimental results show that the impulse amplitude of pressure reaches a peak at a standoff distance of 5-13 times the nozzle outlet diameter and the cutting ability of self-resonating cavitating jets is twice that of conventional jets under the same conditions. Compared with the conventional mining method, the field test indicates that rapid solution mining technology with self-resonating cavitating jets can speed the construction by more than 2 times at the pocket stage of cavern development.Song Xianzhi Li Gensheng Yuan Jinping Tian Zhonglan Shen Ruichen Yuan Guangjie Huang Zhongwei 2010Petroleum Science2010,7,3:5
20Magma Mixing and Mingling for Xiangjiananshan Granitic batholith at eastern area of the East Kunlun Orogenic Belt显示文摘The East Kunlun Orogenic Belt(EKOB)in northeast margin of the Qinghai-Tibetan Plateau is an important part of the Central Orogenic System(COS).During the long-time geological evolution,complicatedCHEN Guochao PEI Xianzhi LI Ruibao LI Zuochen LIU Chenjun CHEN Youxin PEI Lei 2017Acta Geologica Sinica(English Edition)2017,91,S1:5
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