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| 1 | 微震监测技术在矿井岩层破裂监测中的应用显示文摘介绍了澳大利亚联邦科学工业研究院勘探采矿局 (CSIRO)开发的用于岩层破裂监测的微震监测系统 ,为能将之应用于中国深井灾害的监测 ,提出了对软硬件改造和开发井下智能化、自动化和可视化微震监测系统的初步方案 。 | 姜福兴 XUN Luo | 2002 | 岩土工程学报2002,24,2: | 186 |
| 2 | Intelligent Manufacturing in the Context of Industry 4.0: A Review显示文摘 | Ray Y. Zhong Xun Xu Eberhard Klotz Stephen T. Newman | 2017 | Engineering2017,3,5: | 130 |
| 3 | Sodium oligomannate therapeutically remodels gut microbiota and suppresses gut bacterial amino acids-shaped neuroinflammation to inhibit Alzheimer's disease progression显示文摘Recently,increasing evidence has suggested the association between gut dysbiosis and Alzheimer's disease(AD)progression,yet the role of gut microbiota in AD pathogenesis remains obscure.Herein,we provide a potential mechanistic link between gut microbiota dysbiosis and neuroinflammation in AD progression.Using AD mouse models,we discovered that,during AD progression,the alteration of gut microbiota composition leads to the peripheral accumulation of phenylalanine and isoleucine,which stimulates the differentiation and proliferation of pro-inflammatory T helper 1(Thl)cells.The brain-infiltrated peripheral Th1 immune cells are associated with the Ml microglia aaivation,contributing to AD-associated neuroinflammation.Importantly,the elevation of phenylalanine and isoleucine concentrations and the increase of Th1 cell frequency in the blood were also observed in two small independent cohorts of patients with mild cognitive impairment(MCI)due to AD.Furthermore,GV-971,a sodium oligomannate that has demonstrated solid and consistent cognition improvement in a phase 3 clinical trial in China,suppresses gut dysbiosis and the associated phenylalanine/isoleucine accumulation,harnesses neuroinflammation and reverses the cognition impairment.Together,our findings highlight the role of gut dysbiosis-promoted neuroinflammation in AD progression and suggest a novel strategy for AD therapy by remodelling the gut microbiota. | Xinyi Wang Guangqiang Sun Teng Feng Jing Zhang Xun Huang Tao Wang Zuoquan Xie Xingkun Chu Jun Yang Huan Wang Shuaishuai Chang Yanxue Gong Lingfei Ruan Guanqun Zhang Siyuan Yan Wen Lian Chen Du Dabing Yang Qingli Zhang Feifei Lin Jia Liu Haiyan Zhang Changrong Ge Shifu Xiao Jian Ding Meiyu Geng | 2019 | Cell Research2019,29,10: | 192 |
| 4 | 采场覆岩空间破裂与采动应力场的微震探测研究显示文摘介绍了用微地震定位监测技术揭示的采场覆岩空间破裂与采动应力场的关系。认为存在 4种由采动引起的岩体破裂类型。展示了 3种典型采动边界条件下覆岩破裂与采动应力场的关系。提出了由微震事件分布推断区段煤柱稳定性的方法。 | 姜福兴 XUN Luo 杨淑华 | 2003 | 岩土工程学报2003,25,1: | 141 |
| 5 | 微地震监测揭示的采场围岩空间破裂形态显示文摘中澳联合课题组采用微地震定位监测技术,观测和研究了煤矿长壁工作面围岩的空间破坏规律,分析得出:地层进入充分采动阶段前,岩层的破裂高度近似为采空区短边长度的一半;证实了采空区'见方'时顶板破裂高度达到最大值,且采场顶板容易来大压(异常压力),解释了国内外部分综采、综放采场支架压坏的岩层运动机理;根据微地震监测结果,提出了工作面长度为200~250m时底板破裂深度的估计曲线以及岩层离层与破裂的微地震显现的差异;初步描述了采场围岩空间破裂的形态,即在采空区周围顶、底板及四周煤体破裂后形成的三维空间破裂形态. | 姜福兴 杨淑华 XUN Luo | 2003 | 煤炭学报2003,28,4: | 158 |
| 6 | Antitumor effect of matrine in human hepatoma G2 cells by inducing apoptosis and autophagy显示文摘AIM: To study the antitumor effect of matrine in human hepatoma G2 (HepG2) cells and its molecular mechanism involved in antineoplastic activities. METHODS: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect viability of HepG2 cells. The effect of matrine on cell cycle was detected by flow cytometry. Annexin-V-FITC/PI double staining assay was used to detect cellular apoptosis. Cellular morphological changes were observed under an inverted phase contrast microscope. Transmission electron microscopy was performed to further examine ultrastructural structure of the cells treatedwith matrine. Monodansylcadaverine (MDC) staining was used to detect autophagy. Whether autophagy is blocked by 3-methyladenine (3-MA), an autophagy inhibitor, was evaluated. Expression levels of Bax and Beclin 1 in HepG2 cells were measured by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR).RESULTS: Matrine signif icantly inhibited the proliferation of HepG2 cells in a dose- and time-dependent manner, and induced G1-phase cell cycle arrest and apoptosis of HepG2 cells in a dose-dependent manner. The total apoptosis rate was 0.14% for HepG2 cells not treated with matrine. In contrast, the apoptosis rate was 28.91%, 34.36% and 38.80%, respectively, for HepG2 cells treated with matrine at the concentration of 0.5, 1.0 and 2.0 mg/mL. The remarkable morphological changes were observed under an inverted phase contrast microscope. Abundant cytoplasmic vacuoles with varying sizes were observed in HepG2 cells treated with matrine. Furthermore, vacuolization in cytoplasm progressively became larger and denser when the concentration of matrine was increased. Electron microscopy demonstrated formation of abundant autophagic vacuoles in HepG2 cells after matrine treatment. When the specif ic autophagic inhibitor, 3-MA, was applied, the number of autophagic vacuoles greatly decreased. MDC staining showed that the fluorescent density was higher and the number of MDC-labeled particles in HepG2 cells was greater in matrine treatment group than in control group. Fewer autophagic vacuoles were observed in the combined 3-MA and matrine treatment group when 3-MA was added before matrine treatment, indicating that both autophagy and apoptosis are activated when matrine-induced death of hepatoma G2 cells occurs. Real-time quantitative RT-PCR revealed that the expression levels of Bax gene, an apoptosis-related molecule, and Beclin 1 gene which plays a key role in autophagy were higher in matrine treatment group than in control group, indicating that Beclin 1 is involved in matrineinduced autophagy and the pro-apoptotic mechanismof matrine may be related to its upregulation of Bax expression. CONCLUSION: Matrine has potent antitumor activities in HepG2 cells and may be used as a novel effective reagent in treatment of hepatocellular carcinoma. | Zhang, Jun-Qiang Li, Yu-Min Liu, Tao He, Wen-Ting Chen, Ying-Tai Chen, Xiao-Hui Li, Xun Zhou, Wen-Ce Yi, Jian-Feng Ren, Zhi-Jian | 2010 | World Journal of Gastroenterology2010,16,34: | 61 |
| 7 | Comparative Analysis of Codon Usage Patterns Among Mitochondrion, Chloroplast and Nuclear Genes显示文摘 | Wen-Juan Zhang Jie Zhou Zuo-Feng Li Li Wang Xun Gu Yang Zhong | 2007 | Journal of Integrative Plant Biology2007,49,2: | 55 |
| 8 | Regulation of glucose and lipid metabolism in health and disease显示文摘Glucose and fatty acids are the major sources of energy for human body. Cholesterol, the most abundant sterol in mammals, is a key component of cell membranes although it does not generate ATP. The metabolisms of glucose, fatty acids and cholesterol are often intertwined and regulated. For example, glucose can be converted to fatty acids and cholesterol through de novo lipid biosynthesis pathways. Excessive lipids are secreted in lipoproteins or stored in lipid droplets. The metabolites of glucose and lipids are dynamically transported intercellularly and intracellularly, and then converted to other molecules in specific compartments. The disorders of glucose and lipid metabolism result in severe diseases including cardiovascular disease, diabetes and fatty liver. This review summarizes the major metabolic aspects of glucose and lipid, and their regulations in the context of physiology and diseases. | Ligong Chen Xiao-Wei Chen Xun Huang Bao-Liang Song Yan Wang Yiguo Wang | 2019 | Science China(Life Sciences)2019,62,11: | 40 |
| 9 | Reprogramming of ovine adult fibroblasts to pluripotency via drug-inducible expression of defined factors显示文摘在 enucleated 鸡蛋的体的房间的 Reprogramming 做了多丽,绵羊,在 1996 的第一个成功地克隆的哺乳动物。然而,绵羊的机制体的房间 reprogramming 还没被探讨了。而且,绵羊胚胎的茎(ES ) 细胞仍然不是可得到的,它限制精确修改基因的绵羊的产生。在这研究,我们报导体的房间能是的那只绵羊直接 reprogrammed 到导致的 pluripotent 用定义因素(Oct4, Sox2, c-Myc, Klf4, Nanog, Lin28, SV40 大 T 和 hTERT ) 的茎(iPS ) 房间。我们的观察显示从绵羊的体的细胞比从另外的种,在 iPS,细胞被报导了的体的细胞对改编更困难。我们证明绵羊 iPS 房间表示 ES 房间标记,包括碱的磷酸酶, Oct4, Nanog, Sox2, Rex1,阶段特定的胚胎的 antigen-1, TRA-1-60, TRA-1-81 和 E-cadherin。绵羊 iPS 房间展出了正常 karyotypes 并且能在 vitro 并且在 teratomas 区分进所有三细菌层。我们的学习可以帮助在绵羊揭示体的房间 reprogramming 的机制并且提供一个平台为绵羊 ES 房间探索文化条件。而且,绵羊 iPS 房间可以直接被用来产生精确修改基因的绵羊。 | Lei Bao Lixiazi He Jijun Chen Zhao Wu Jing Liao Lmgdun Rao Jiangtao Ren Hui Li Hui Zhu Lei Qian Yijun Gu Huimin Dai Xun Xu Jinqiu Zhou Wen Wang Chun Cui Lei Xiao | 2011 | Cell Research2011,21,4: | 32 |
| 10 | Prevalence of HPV Infection And Cervical Intraepithelial Neoplasia And Attitudes towards HPV Vaccination among Chinese Women Aged 18-25 in Jiangsu Province显示文摘Objective:Few data are available on the epidemiology of HPV and cervical cancer among Chinese women younger than 25 years old.This study aimed to estimate the HPV infection rate and the prevalence of cervical intraepithelial neoplasia(CIN) in women aged 18-25,as well as their knowledge of and attitudes towards HPV vaccination.Methods:A population-based cervical cancer screening study was conducted on women aged 18-25 in Jiangsu province in 2008.Participants provided socio-demographic,reproductive and behavioral information and completed a survey about their knowledge of and attitudes towards HPV vaccination.Women then underwent a gynecologic exam to provide two cervical exfoliated cell samples for high risk HPV DNA testing and liquid-based cytology(LBC) as well as visual inspection with acetic acid(VIA).Women testing positive for any test were referred to colposcopy and biopsy.The gold standard for diagnosis of cervical lesions was directed or random biopsies.Results:Within the sample of 316 women,3.4% of them were diagnosed with CIN grade 2 or worse lesions and 17.1% were found to be positive for HPV DNA.Among these young women,extra-marital sexual behavior of them(OR=2.0,95%CI:1.1-3.8) or their husbands(OR=2.6,95%:1.4-4.7) were associated with an increased risk of HPV positivity.Although overall HPV awareness was low,after a brief educational intervention,98.4% reported they would electively receive HPV vaccination and would also recommend that their daughters be vaccinated.However,most urban and rural women reported their ideal maximum out-of-pocket contribution for HPV vaccination to be less than 500 RMB and 50-100 RMB,respectively.Conclusion:Our study indicates cervical disease burden is relatively high among sampled Chinese women aged 18-25.Appropriate educational interventions for female adolescents and strategies to subsidize vaccine costs are definitely needed to ensure the effectiveness of vaccination campaigns in China. | Shang-ying Hu Ying Hong Fang-hui Zhao Adam K. Lewkowitz Feng Chen Wen-hua Zhang O.in-jing Pan Xun Zhang Cindy Fei Hui Li You-lin Qiao | 2011 | Chinese Journal of Cancer Research2011,23,1: | 31 |
| 11 | Distribution 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 | 2019 | Chinese Journal of Cancer Research2019,31,4: | 30 |
| 12 | Human umbilical cord mesenchymal stem cells promote peripheral nerve repair via paracrine mechanisms显示文摘Human umbilical cord-derived mesenchymal stem cells(h UCMSCs) represent a promising young-state stem cell source for cell-based therapy. h UCMSC transplantation into the transected sciatic nerve promotes axonal regeneration and functional recovery. To further clarify the paracrine effects of h UCMSCs on nerve regeneration, we performed human cytokine antibody array analysis, which revealed that h UCMSCs express 14 important neurotrophic factors. Enzyme-linked immunosorbent assay and immunohistochemistry showed that brain-derived neurotrophic factor, glial-derived neurotrophic factor, hepatocyte growth factor, neurotrophin-3, basic fibroblast growth factor, type I collagen, fibronectin and laminin were highly expressed. Treatment with h UCMSC-conditioned medium enhanced Schwann cell viability and proliferation, increased nerve growth factor and brain-derived neurotrophic factor expression in Schwann cells, and enhanced neurite growth from dorsal root ganglion explants. These findings suggest that paracrine action may be a key mechanism underlying the effects of h UCMSCs in peripheral nerve repair. | Zhi-yuan Guo Xun Sun Xiao-long Xu Qing Zhao Jiang Peng Yu Wang | 2015 | Neural Regeneration Research2015,10,4: | 26 |
| 13 | Malate transported from chloroplast to mitochondrion triggers production of ROS and PCD in Arabidopsis thaliana显示文摘规划房间死亡(PCD ) 是一个基本生物过程。在马赛克死亡 1 的缺乏(MOD1 ) ,质体局部性的 enoyl-ACP reductase,导致反应的氧种类(ROS ) 和 PCD 的累积,它能被 mitochondrial 建筑群压制我变化,从叶绿体显示一个信号到线粒体。然而,这个信号尚待被阐明。在这研究,通过克隆并且分析一系列 mod1 suppressors,我们揭示调整 mitochondrial ROS 和扳机 PCD 的产生的一条全面细胞器通讯小径。我们证明在 PLASTIDIAL NAD 依赖的 MALATE 脱氢酶(plNAD-MDH ) 的变化, chloroplastic DICARBOXYLATE TRANSPORTER 1 (DiT1 ) 并且(mMDH1 ) MITOCHONDRIAL MALATE 脱氢酶 1 能各在 mod1 救 ROS 累积和 PCD 显型,经由 malate 梭从叶绿体表明直接通讯到线粒体。进一步的研究证明这些元素在不同光周期条件下面在氧化还原作用动态平衡和植物生长起关键作用。而且,我们表明 ROS 水平和 PCD 显著地在房间,它能是戏剧性地稀释了由的对待 malate 的 HeLa 被增加人的基因 MDH2 击倒, Arabidopsis mMDH1 的 ortholog。这些结果揭开在植物和动物系统的一条保存导致 malate 的 PCD 小径,革命化我们在细胞器之间的通讯的理解。 | Yannan Zhao Lilan Luo Jiesi Xu Peiyong Xin Hongyan Guo Jian Wu Lin Bai Guodong Wang Jinfang Chu Jianru Zuo Hong Yu Xun Huang Jiayang Li | 2018 | Cell Research2018,28,4: | 24 |
| 14 | On the tuning of electrical and thermal transport in thermoelectrics: an integrated theory–experiment perspective显示文摘During the last two decades,we have witnessed great progress in research on thermoelectrics.There are two primary focuses.One is the fundamental understanding of electrical and thermal transport,enabled by the interplay of theory and experiment;the other is the substantial enhancement of the performance of various thermoelectric materials,through synergistic optimisation of those intercorrelated transport parameters.Here we review some of the successful strategies for tuning electrical and thermal transport.For electrical transport,we start from the classical but still very active strategy of tuning band degeneracy(or band convergence),then discuss the engineering of carrier scattering,and finally address the concept of conduction channels and conductive networks that emerge in complex thermoelectric materials.For thermal transport,we summarise the approaches for studying thermal transport based on phonon–phonon interactions valid for conventional solids,as well as some quantitative efforts for nanostructures.We also discuss the thermal transport in complex materials with chemical-bond hierarchy,in which a portion of the atoms(or subunits)are weakly bonded to the rest of the structure,leading to an intrinsic manifestation of part-crystalline part-liquid state at elevated temperatures.In this review,we provide a summary of achievements made in recent studies of thermoelectric transport properties,and demonstrate how they have led to improvements in thermoelectric performance by the integration of modern theory and experiment,and point out some challenges and possible directions. | Jiong Yang Lili Xi Wujie Qiu Lihua Wu Xun Shi Lidong Chen Jihui Yang Wenqing Zhang Ctirad Uher David J Singh | 2016 | npj Computational Materials2016,,1: | 24 |
| 15 | Therapeutic effects of endoscopic therapy combined with enteral nutrition on acute severe biliary pancreatitis显示文摘背景尖锐严重胆汁的胰腺炎(ASBP ) 是严重、致命的疾病,并且开销是巨大的,治疗学的效果仍然不是令人满意的。试图改进治疗学的效果并且减少 105 个病人与 ASBP 诊断了的 ASBP treatment.Methods 的开销的这研究被指我们从 2004 年 1 月的部门到 2009 年 7 月。诊断基于外科的中国社会的 2007 个标准。病人们被划分成二个组;E 组:经历了的 50 个病人内视镜后退 choledochopancreatography (ERCP )+ 内视镜的 sphincterotomy (EST )+ 内视镜的 lithotripsy 篮子(ESR )+endoscopic 后退胆汁的排水(ERBD ) 和 enteral 营养(在) ,并且 R 组:没有 ERCP,经历了传统的治疗的 55 个病人。随后,主观症状,症状,生物化学的分析,浆液内毒素,肿瘤坏死因素一,由计算断层摄影术(CT ) 的等级,住院的费用和一些停留在二 groups.Results 之间被比较所有注册病人与所有治疗学的政体应允了很好。联合了在的内视镜的治疗能显著地改进症状,临床的符号,实验室价值,肿瘤坏死因素 and 内毒素当显著地减少时,医院的医院开销和长度留下来。试验性的调查结果表明与内视镜的治疗与结合了的 R group.Conclusions 相比在 E 组有明显的优点在是 ASBP 的有效、安全、经济的治疗学的政体。 | ZHOU Wen-ce LI Yu-min ZHANG Hui LI Xun ZHANG Lei MENG Wen-bo ZHU Ke-xiang ZHANG Quan-bao HE Min-yan | 2011 | Chinese Medical Journal2011,,19: | 22 |
| 16 | Atomically dispersed Au_1 catalyst towards efficient electrochemical synthesis of ammonia显示文摘Tremendous efforts have been devoted to explore energy-efficient strategies of ammonia synthesis to replace Haber–Bosch process which accounts for 1.4% of the annual energy consumption. In this study,atomically dispersed Au_1 catalyst is synthesized and applied in electrochemical synthesis of ammonia under ambient conditions. A high NH_4^+ Faradaic efficiency of 11.1% achieved by our Au_1 catalyst surpasses most of reported catalysts under comparable conditions. Benefiting from efficient atom utilization, an NH_4^+ yield rate of 1,305 lg h^(-1) mg_(Au)^(-1) has been reached, which is roughly 22.5 times as high as that by supported Au nanoparticles. We also demonstrate that by employing our Au_1 catalyst, NH4+can be electrochemically produced directly from N_2 and H_2 with an energy utilization rate of 4.02 mmol kJ^(-1). Our study provides a possibility of replacing the Haber–Bosch process with environmentally benign and energy-efficient electrochemical strategies. | Xiaoqian Wang Wenyu Wang Man Qiao Geng Wu Wenxing Chen Tongwei Yuan Qian Xu Min Chen Yan Zhang Xin Wang Jing Wang Jingjie Ge Xun Hong Yafei Li Yuen Wu Yadong Li | 2018 | Science Bulletin2018,63,19: | 22 |
| 17 | Cationic nanocarriers induce cell necrosis through impairment of Na^+/K^+-ATPase and cause subsequent inflammatory response显示文摘有积极表面费用的 Nanocarriers 以他们限制了他们的临床的应用的毒性著名。位于他们的毒性下面的机制例如煽动性的反应的正式就职,仍然保持大部分未知。在我们发现了 cationic nanocarriers 的那注射的现在的学习,包括 cationic liposomes, PEI,和 chitosan,导致了坏死的房间的快速的外观。cationic nanocarriers 导致的房间坏死依赖于他们的积极表面费用,但是不要求 RIP1 和 Mlkl。相反,细胞内部的 Na + 超载被发现伴随房间死亡。在文化媒介或有 Na +/K+-ATPase 阳离子绑定地点禁止者 ouabain 的房间的预告的处理的 Na + 的弄空,从房间坏死的保护的房间。而且,有 cationic nanocarriers 的处理在 vitro 并且在 vivo 禁止了 Na +/K+-ATPase 活动。计算模拟证明 cationic 搬运人能与 Na +/K+-ATPase 的阳离子绑定地点交往。有 ouabain 的小剂量的老鼠 pretreated 在 cationic nanocarriers 的致命的剂量的注射以后显示出改进幸存。进一步的分析建议 cationic nanocarriers 和 mitochondrial DNA 的产生的漏导致的那房间坏死能在 vivo 触发严重发炎,它被包含 TLR9 并且 MyD88 发信号的一条小径调停。一起拿,我们的结果揭示由此的新奇机制 cationic nanocarriers 通过和 mitochondrial 的随后的暴露的和 Na +/K+-ATPase, 的相互作用导致尖锐房间坏死是的联系损坏的分子的模式调停的一个关键事件煽动性的回答。我们的学习为评估 nanocarriers 的 biocompatibility 并且为药交货设计更好、更安全的有重要含意。 | Xiawei Wei Bin Shao Zhiyao He Tinghong Ye Min Luo Yaxiong Sang Xiao Liang Wei Wang Shuntao Luo Shengyong Yang Shuang Zhang Changyang Gong Maling Gou Hongxing Deng Yinglan Zhao Hanshuo Yang Senyi Deng Chengjian Zhao Li Yang Zhiyong Qian Jiong Li Xun Sun Jiahuai Han Chengyu Jiang Min Wu Zhirong Zhang | 2015 | Cell Research2015,25,2: | 21 |
| 18 | Theoretical and experimental investigation on bridge-borne noise under moving high-speed train显示文摘Bridge-borne noise pollution caused by train-induced bridge vibration has attracted more and more attentions due to its low-frequency characteristic.In order to investigate the numerical simulation technique of bridge-borne noise and noise reduction methods,a simply supported prestressed concrete (PC) box-girder bridge is adopted for study.Based on train-track-bridge interaction theory,the dynamic response of the bridge under a moving high-speed train is calculated in time-domain and assumed as the sound source of bridge-borne noise.Then bridge-borne noise is estimated according to boundary element method (BEM) in frequency-domain.The time-frequency transform is conducted by fast Fourier transformation (FFT).The validity of the numerical simulation technique is verified through comparison with field measurement results.Furthermore,noise reduction methods are proposed and corresponding effects are discussed.Results show that the proposed numerical simulation method is feasible and accurate in assessing bridge-borne noise.The dominant frequencies of bridge vibration and bridgeborne noise range from 40 Hz to125 Hz and from 31.5 Hz to 100 Hz,respectively.The peak frequency of bridge-borne noise near the bottom plate is 63 Hz.Increasing the thickness of deck plate,adjusting the inclination of webs to 0°-12°,strengthening the boundary constraints and adding a longitudinal clapboard are very effective noise control measures. | ZHANG Xun LI XiaoZhen LIU QuanMin WU JinFeng LI YaDong | 2013 | Science China(Technological Sciences)2013,56,4: | 20 |
| 19 | Collision Tectonics between the Tarim Block(Basin)and the Northwestern Tibet Plateau:New Observations from a Multidisciplinary Geoscientific Investigation in the Western Kunlun Mountains显示文摘New results from deep seismic reflection profiling, wide-angle reflection-refraction profiling and broadband seismic experiments reveal that a series of south-dipping reflectors occur on the southern margin of the Tarim block (basin). However, it is these south-dipping structures that are intercepted by another series of north-dipping reflectors at depths from 30 to about 150 km beneath the foreland of the W Kunlun Mountains. No evidence from the above geophysical data as well as geochemical and surface geological data indicate the southward subduction of the Tarim block beneath the W Kunlun Mountains (NW Tibet plateau), forming the so-called “two-sided subduction” model for the Tibet plateau as proposed by previous studies. So the authors infer that the tectonic interaction between the Tarim block and the W Kunlun block was chiefly affected by a “horizontal compression in opposite directions”, which brought about “face-to-face contact” between these two lithospheric blocks and led to the thickening, shortening and densifying of the lithosphere. Hence a “delamination” was formed due to the gravitational instability created by the thickening and densifying; then alkaline basic volcanic rocks (mainly shoshonite series) was erupted along the northern margin of the Tibet plateau owing to the delamination. This inference for the formation of the alkaline basic volcanics has been confirmed by recent geochemical and petrological studies in Tibet, indicating that different contacts control different magmatic activities: the alkali basalts are always developed in the “horizontal shortening boundary (contact)” on the northern margin of the Tibet plateau, while the muscovite granite and two-mica granite (leucogranite) in the “subductional contact” on the southern margin of the Tibet plateau. | XIAO Xuchang LIU Xun GAO Rui Houn KAO LUO Zhaohua | 2001 | Acta Geologica Sinica(English Edition)2001,75,2: | 19 |
| 20 | Soil Organic Carbon,Carbon Fractions and Nutrients as Affected by Land Use in Semi-Arid Region of Loess Plateau of China显示文摘Cropland (CP),native grassland (NG) and two shrub land treatments which were converted from cropland in 1985:seabuckthorn (Hippophae rhamnoides L.) (ST),and branchytamarisk (Tamarix ramosissima) (BT) were investigated to evaluate effects of land use conversion on soil organic carbon (SOC) and soil nutrients in the semi-arid region of the Loess Plateau of China.Total organic carbon (TOC),light fraction organic carbon (LFOC),heavy fraction organic carbon (HFOC),total N (TN),nitrate nitrogen (NO 3-N) and nitrite nitrogen (NO 2-N),ammonium nitrogen (NH + 4-N),total P,and available P (AP) were measured.The results showed that SOC in NG,ST and BT were 12.7%,27.7% and 34.8% higher than that of the cropland,respectively.LFOC,light fraction (LF) dry matter,ratio of TOC to TN (C/N) and the ratio of TOC to AP (C/P) were higher in the shrub land or native grassland than in the cropland.Cropland had the highest TN,the sum of NO 3-N and NO 2-N,TP and AP due to the use of chemical fertilizers.TOC significantly correlated with LFOC,HFOC and C/N.LFOC significantly correlated with dry matter of the LF and C/N.TN,the sum of NO 3-N and NO 2-N and AP were significantly negatively correlated with TOC and LFOC.Therefore,land use conversion from cropland to shrub land,or maybe grassland,contributed to SOC sequestration and improved soil nutrients stabilization. | LIU Xun,LI Feng-Min,LIU Da-Qian and SUN Guo-Jun Key Laboratory of Arid and Grassland Ecology of the Ministry of Education,School of Life Sciences,Lanzhou University,Lanzhou 730000 (China) | 2010 | Pedosphere2010,20,2: | 19 |