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Determination of the load bearing capacity of pre-stressed expandable props for ground support in underground mines

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矿业科学技术学报:英文版 2023年第8期33卷 977-990页

作者： Kunmeng Li Kaiyuan Jiang Yuanhui Li Xin Wang Kai Liu Shuai Xu Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines School of Resources and Civil EngineeringNortheastern UniversityShenyang 110819China Key Laboratory of Liaoning Province on Deep Engineering and Intelligent Technology School of Resources and Civil EngineeringNortheastern UniversityShenyang 110819China China-Canada Centre of Deep Mining Innovation Key Laboratory of Ministry of Education on Safe Mining of Deep Metal MinesSchool of Resources and Civil EngineeringNortheastern UniversityShenyang 110819China Department of Engineering Science University of OxfordOxford OX13PJUnited Kingdom

This paper aims to determine the load bearing capacity of pre-stressed expandable props with different geometries and load eccentricities for flexible support in underground mining or excavation.It is deduced that the expandable device could have much higher strength(>89 MPa)by laboratory tests,and the load bearing capacity of the expandable prop may depend on the stability of the supporting steel pipe structure.A good agreement was found between the laboratory test and numerical results in terms of the load bearing capacity and the final macro-bending failure pattern for expandable props with heights of 1.5 and 2.7 m,and the theoretical calculation for the strength of traditional steel structures is not directly suitable for the expandable props.Moreover,additional numerical simulations were performed for the expandable props with different normalized slenderness ratiosλ_(n)and loading eccentric distances e.The variation of stability coefficient of the expandable prop is in line with the Perry-Robertson equation and its correlation coefficients are fitted as a of 0.979 and b of 0.314.For estimating the load bearing capacity of the expandable props,the strength equation for traditional steel structures is improved by introducing a bending magnification factor and by modifying the normalized slenderness ratio to a converted slenderness ratio.Based on the underground field monitoring for the strength of expandable props with different heights,the empirical eccentric distances were back calculated,and a safety factor is introduced to obtain the designed strength of the expandable prop.In addition,a four-step design procedure is proposed for the expandable prop.

关键词： Pillar stability Load bearing capacity Expandable prop Slenderness ratio Eccentric distance

RNA helicase MTR4 drives tumorigenesis of nasopharyngeal carcinoma by regulating the expression of key cell cycle genes

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Protein & Cell 2023年第2期14卷 149-152页

作者： Lili Yu Lei jiang Meng Wu Wenlong Dou kaiyuan Ji Jianlong Zhou Jinchul Kim Yang Xu Department of Cardiology Cardiovascular Key Lab of Zhejiang ProvinceThe Second Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310009China Department of Medical Oncology Key Laboratory of Cancer Prevention and InterventionMinistry of EducationThe Second Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310009China Cancer Center Zhejiang UniversityHangzhou 310058China School of Basic Medical Sciences Southern Medical UniversityGuangzhou 510515China Ageing Research Center Korea Research Institute of Bioscience and BiotechnologyDeajeon 34141Korea

Dear Editor,The pathogenesis of nasopharyngeal carcinoma(NPC)is closely associated with the infection of Epstein Barr virus(EBV)(Hau et al.,2020).However,the mechanisms underlying NPC tumorigenesis remain unclear,leading to a lack of therapeutic targets to effectively treat NPC.RNA helicase MTR4,which is a compo-nent of the virus-induced cofactor complex linking viral RNA to exosome for degradation,is overexpressed in NPCs of patients.The expression levels of MTR4 are inversely correlated with the prognosis of NPC patients.

关键词： nasopharyngeal tumorigenesis

Decorating ketjen black with ultra-small Mo_(2)C nanoparticles to enhance polysulfides chemisorption and redox kinetics for lithium-sulfur batteries

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Journal of Energy Chemistry 2020年第12期29卷 207-215页

作者： Nan jiang Guangyu jiang Dechao Niu Jiayi Mao Meiwan Chen kaiyuan Li Yongsheng Li Lab of Low-Dimensional Materials Chemistry Key Laboratory for Ultrafine Materials of Ministry of Education.School of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China

The low sulfur utilization and fast capacity fading resulting from the sluggish redox reaction and abominable polysulfides shuttle greatly hinder the practical applications of lithium-sulfur(Li-S) batteries.Herein, we develop a facile "in-situ growth" method to decorate ultra-small Mo2 C nanoparticles(USMo2 C) on the surface of Ketjen Black(KB) to functionalize the commercial polypropylene(PP) separators,which can accelerate the redox kinetics of lithium polysulfides conversion and effectively increase the utilization of sulfur for Li-S batteries. Importantly, the US-Mo2 C nanoparticles have abundant sites for chemical adsorption towards polysulfides and the conductive carbon networks of KB have cross-linked pore channels, which can promote electron transport and provide physical barrier and volume expansion space for polysulfides. Due to the combined effects of the US-Mo2 C and KB, Li-S cells employing the multifunctional PP separators modified with KB/US-Mo2 C composite(KB/US-Mo2 C@PP) exhibit a high specific capacity(1212.8 mAh g^(-1) at 0.2 C), and maintain a reversible capacity of 1053.3 m Ah g^(-1) after 100 cycles.More importantly, the KB/US-Mo2 C@PP cells with higher sulfur mass loading of 4.9 mg cm^(-2) have superb areal capacity of 2.3 mAh cm^(-2). This work offers a novel and promising perspective for high-performance Li-S batteries from both the shuttle effect and the complex polysulfides conversion.

关键词： in-situ growth Ultra-small Mo_(2)C Catalytic effect Chemisorption Multifunctional separator Lithium-sulfur batteries

Provenance and tectonic setting transition as recorded in the Neoproterozoic strata, western jiangnan Orogen:Implications for South China within Rodinia

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Geoscience Frontiers 2019年第5期10卷 1823-1839页

作者： Jiawei Zhang Taiping Ye Yaran Dai Jianshu Chen Hui Zhang Chuangu Dai Guohua Yuan Kaiyuan Jiang Guizhou Geological Survey Bureau of Geology and Mineral Exploration and Development of Guizhou ProvinceGuiyang 550081China Chinese Academy of Land and Resources Economics Beijing 101149China Key Laboratory of Carrying Capacity Assessment for Resources and Environment Ministry of Land and ResourcesBeijing 101149China Guizhou Central Laboratory of Geology and Mineral Resources Bureau of Geology and Mineral Exploration and Development of Guizhou ProvinceGuiyang 550018China

The Neoproterozoic Tonian strata (ca.870-725 Ma) in the western jiangnan Orogen archive the records of sedimentary provenance and tectonic setting which can be used to understand the geological evolution of the South China Continent.These strata are separated into the basement and cover sequences by a regional angular unconformity.The basement sequence can be subdivided into the lower and the upper parts by the widespread interbedded ca.840 Ma basalt with pillow structure.In the present work,234 concordant detrital zircon analyses are obtained from three Tonian sandstone samples in the Fanjingshan district,Guizhou Province.Combined with previous results,a total of 1736 analyses of detrital zircon U-Pb ages derived from 12 formations of Tonian strata in the western jiangnan Orogen are used to decipher the integrated sedimentary and tectonic histories.The zircons from the lowermost part of the basement sequence (the Yujiagou Formation) show oval morphology and display two Paleoproterozoic age peaks at 2325 Ma and 1845 Ma which are similar with the detrital zircon age peaks from the Late Paleoproterozoic to Early Mesoproterozoic Dongchuan/Dahongshan/Hekou groups,suggesting a passive margin basin in which the sediments were mainly sourced from the southwestern Yangtze Block.However,the zircon age population of the lower part of the basement sequence (the Xiaojiahe,Huixiangping formations and their equivalents) indicates the sedimentary derivation from bidirectional sources (the ca.870 Ma arc materials in the south and the old detritus from the southwestern Yangtze Block) which is consistent with a back arc setting for the deposition of the sediments.Zircons from the upper part of the basement sequence (the Duyantang Formation and its equivalent) show euhedral and subangular morphology and display a unimodal age peak at ca.835 Ma.This sequence was possibly deposited in a convergent setting and the detritus were came from the locally distributed syn-collisional igneous rocks.The lower part of the cover sequence (the Xi

关键词： Detrital zircon Fanjingshan Sibao Back arc basin Precambrian Tonian

Sulfur and Oxygen Isotopes of Sulfate Extracted from Early Cambrian Phosphorite Nodules： Implications for Marine Redox Evolution in the Yangtze Platform

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Journal of Earth Science 2016年第2期27卷 170-179页

作者： Wenlang Qiao Xianguo Lang Yongbo Peng Kaiyuan Jiang Wu Chen Kangjun Huang Bing Shen Guizhou Geological Survey Guiyang Guizhou Province 550018 China Key Laboratory of Orogenic Belts and Crustal Evolution MOE & School of Earth and Space Sciences Peking University Beijing 100871 China Department of Geology and Geophysics Louisiana State University Baton Rouge LA 70803 USA

Phosphorite nodule beds are discovered in the black shale of basal Niutitang Formation throughout the Yangtze Platform in South China, recording an important phosphorite-generation event. Platform-wide phosphorite precipitation requires special oceanographic and geochemical conditions, thus the origin of the Niutitang phosphorite nodules may provide valuable information about the ocean chemistry in the Early Cambrian. In this study, we measured sulfur and oxygen isotopic compositions of sulfate extracted from phosphorite nodules collected from the basal Niutitang Formation. Phosphorite associated sulfate（PAS） is a trace amount of sulfate that incorporates into crystal lattice during phosphorite precipitation, accordingly PAS records the geochemical signals during phosphorite nodule formation. Sulfur isotopic composition of PAS（δ^（34）S_（PAS）） ranges from-1.16‰ to ＋24.48‰（mean=＋8.19‰, n=11）, and oxygen isotopic value（δ^（18）O_（PAS）） varies between-5.3‰ and ＋26.3‰（mean=＋7.0‰, n=8）. Most phosphorite nodules have low δ^（34）SPAS and low δ^（18）O_（PAS） values, suggesting PAS mainly derived from anaerobic oxidation of H_2S within suboxic sediment porewater. We propose that phosphate was delivered to the Yangtze Platform by a series of upwelling events, and was scavenged from seawater with the precipitation of FeOOH. The absorbed phosphate was released into suboxic porewater by the reduction of FeOOH at the oxic-suboxic redox boundary in sediments, and phosphorite nodule precipitated by the reaction of phosphate with Ca^（2＋） diffused from the overlying seawater. The platform-wide deposition of phosphorite nodules in the basal Niutitang Formation implies the bottom water might be suboxic or even oxic, at least sporadically, in Early Cambrian. We speculate that the intensified ocean circulation as evident with frequent occurrences of upwelling events might be the primary reason for the episodic oxidation of the Yangtze Platform in Early Cambrian.

关键词： phosphorite nodules Niutitang Formation phosphorite associated sulfate sulfurisotope oxygen isotope.

Flight Characteristics Analysis Based on QAR Data of a Jet Transport During Landing at a High-altitude Airport

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Chinese Journal of Aeronautics 2012年第1期25卷 13-24页

作者： C.Edward Lan WU kaiyuan YU jiang Department of Aerospace Engineering The University of KansasKansas 66045USA China Aerodynamics Research and Development Center Mianyang 622661China Scientific Research Base Civil Aviation Flight University of ChinaGuanghan 618307China

Flight data of a twin-jet transport aircraft in revenue flight are analyzed for potential safety problems. Data from the quick access recorder （QAR） are first filtered through the kinematic compatibility analysis. The filtered data are then organized into longitudinal- and lateral-directional aerodynamic model data with dynamic ground effect. The dynamic ground effect requires the radio height and sink rate in the models. The model data are then refined into numerical models through a fuzzy logic algorithm without data smoothing in advance. These numerical models describe nonlinear and unsteady aerodynamics and are used in nonlinear flight dynamics simulation. For the jet transport under study, it is found that the effect of crosswind is significant enough to excite the Dutch roll motion. Through a linearized analysis in flight dynamics at every instant of time, the Dutch roll motion is found to be in nonlinear oscillation without clear damping of the amplitude. In the analysis, all stability derivatives vary with time and hence are nonlinear functions of state variables. Since the Dutch roll motion is not damped despite the fact that a full-time yaw damper is engaged, it is concluded that the design data for the yaw damper is not sufficiently realistic and the contribution of time derivative of sideslip angle to damping should be considered. As a result of nonlinear flight simulation, the vertical wind acting on the aircraft is estimated to be mostly updraft which varies along the flight path before touchdown. Varying updraft appears to make the descent rate more difficult to control to result in a higher g-load at touchdown.

关键词： jet transport unsteady aerodynamics nonlinear aerodynamics flight dynamics flight safety quick access recorder data

转化手术在cT4b期食管癌中的临床应用研究进展

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中华胸心血管外科杂志 2022年第9期38卷 572-576页

作者：姜凯元田东川北医学院附属医院胸外科南充637000

由于食管不存在浆膜层,cT4b期食管癌易侵犯气管、肺、主动脉等重要脏器并伴有肿瘤转移,整体预后极差。这部分晚期不可切除食管癌患者的根治性化疗或放化疗结果并不理想。近年来,随着转化手术的提出,即针对晚期不可切除食管癌患者,通过... 详细信息

由于食管不存在浆膜层,cT4b期食管癌易侵犯气管、肺、主动脉等重要脏器并伴有肿瘤转移,整体预后极差。这部分晚期不可切除食管癌患者的根治性化疗或放化疗结果并不理想。近年来,随着转化手术的提出,即针对晚期不可切除食管癌患者,通过诱导治疗实现肿瘤降期后再进行手术切除,部分研究报道了其可行性和有效性。然而关于诱导治疗方案和术后生存率,各研究报道不一。本文就食管癌转化手术的发展、诱导治疗方式、手术疗效及预后作一综述,旨在总结近年来转化手术在临床上的应用情况,为进一步制订该模式的治疗策略提供一定理论基础。

关键词：诱导治疗食管癌患者术后生存率治疗策略肿瘤转移不可切除疗效及预后放化疗

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多方安全计算研究综述

信息安全研究 2021年第12期7卷 1161-1165页

作者：蒋凯元国家公共信用信息中心北京100045

随着互联网的快速发展,数据资源已经成为各行业的重要竞争力,但由于数据的拥有者和使用者无法统一,数据安全和个人隐私等问题日益加剧,因而产生了“数据孤岛”现象.多方安全计算技术能够同时确保数据输入的隐私性和数据计算的正确性,并... 详细信息

随着互联网的快速发展,数据资源已经成为各行业的重要竞争力,但由于数据的拥有者和使用者无法统一,数据安全和个人隐私等问题日益加剧,因而产生了“数据孤岛”现象.多方安全计算技术能够同时确保数据输入的隐私性和数据计算的正确性,并且在无第三方的情况下通过协议保证参与计算的参与方输入的数据不泄露,有望解决以上类似问题.从多方安全计算的定义和特点出发,介绍多方安全计算的研究现状、组成模型和应用场景.

关键词：多方安全计算安全模型个人隐私密码学分布式计算

Prognostic implications of epidermal growth factor receptor variant Ⅲ expression and nuclear translocation in Chinese human gliomas

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Chinese Journal of Cancer Research 2019年第1期31卷 188-202页

作者： kaiyuan Yang Xiaohui Ren Liyuan Tao Peipei Wang Haihui jiang Li Shen Yiming Zhao Yong Cui Mingxiao Li Song Lin Neurosurgery Beijing Tiantan HospitalCapital Medical UniversityBeijing 100070China China National Clinical Research Center for Neurological Diseases Beijing 100070China Beijing Neurosurgical Institution Capital Medical UniversityBeijing 100050China Research Center of Clinical Epidemiology Peking University Third HospitalBeijing 100191China Department of Cell Biology Peking University Health Science Center Peking University Stem Cell Research Center Beijing 100191China

Objective: To determine the prognostic implications and clinical significance of epidermal growth factor receptor variant Ⅲ(EGFRvⅢ) expression and EGFRvⅢ nuclear translocation in Chinese human gliomas.Methods: We retrospectively examined EGFRvⅢ expression and EGFRvⅢ nuclear translocation using immunohistochemistry in specimens of 240 Chinese patients with glioma, including 84 World Health Organization(WHO) II gliomas, 84 WHO Ⅲ gliomas and 72 glioblastomas(WHO IV). Factors that correlated with EGFRvⅢ and EGFRvⅢ nuclear translocation expression were analyzed by the Chi-square test. Kaplan-Meier methodology and Cox regression were used for the survival analysis.Results: Log-rank tests showed that patient age, Karnofsky performance scale(KPS) score, tumor grade,EGFRvⅢ expression, EGFRvⅢ nuclear translocation, 1 p/19 q codeletion, isocitrate dehydrogenase(IDH)mutation, Ki-67 labeling index and O6-methylguanine-DNA methyltransferase(MGMT) status(P<0.05) were significantly correlated with overall survival(OS) time. Multivariate Cox regression analysis revealed that patient age, tumor grade, EGFRvⅢ nuclear translocation, 1 p/19 q codeletion, and IDH mutation(P<0.05) were significantly correlated with OS. Patients with a high level of EGFRvⅢ nuclear translocation(≥7%) had both significantly shorter OS [hazard ratio(HR): 1.920, 95% confidence interval(95% CI): 1.228-3.003, P=0.004] and progression-free survival(PFS) times(HR: 1.661, 95% CI: 1.116-2.471, P=0.012) than those with a low level of EGFRvⅢ nuclear translocation(<7%).Conclusions: A high level of EGFRvⅢ nuclear translocation in glioma is an independent factor indicating a poor prognosis, but EGFRvⅢ expression is not an independent clinical prognostic factor. The level of EGFRvⅢ nuclear translocation maybe a novel and crucial prognostic biomarker in glioma.

关键词： Glioma EGFRvⅢ expression EGFRvⅢ nuclear translocation biomarker prognosis