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Nonlinear semi-analytical modeling of liquid sloshing in rectangular container with horizontal baffles
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作者 Xun MENG Ying SUN +2 位作者 jiadong wang Ruili HUO Ding ZHOU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2023年第11期1973-2004,共32页
A nonlinear semi-analytical scheme is proposed for investigating the finiteamplitude nonlinear sloshing in a horizontally baffled rectangular liquid container under the seismic excitation.The sub-domain method is deve... A nonlinear semi-analytical scheme is proposed for investigating the finiteamplitude nonlinear sloshing in a horizontally baffled rectangular liquid container under the seismic excitation.The sub-domain method is developed to analytically derive the modal behaviors of the baffled linear sloshing.The viscosity dissipation effects from the interior liquid and boundary layers are considered.With the introduction of the generalized time-dependent coordinates,the surface wave elevation and velocity potential are represented by a series of linear modal eigenfunctions.The infinite-dimensional modal system of the nonlinear sloshing is formulated based on the Bateman-Luke variational principle,which is further reduced to the finite-dimensional modal system by using the NarimanovMoiseev asymptotic ordering.The base force and overturning moment induced by the nonlinear sloshing are derived as the functions of the generalized time-dependent coordinates.The present results match well with the available analytical,numerical,and experimental results.The paper examines the surface wave elevation,base force,and overturning moment versus the baffle parameters and excitation amplitude in detail. 展开更多
关键词 rectangular container nonlinear sloshing baffe sub-domain multi-modal method
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具有独特电子结构的锌掺杂SnO_(2)介导形成氧空位实现高效稳定的光催化降解甲苯 被引量:3
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作者 武慧中 王佳栋 +5 位作者 陈瑞敏 袁潮苇 张锦 张育新 盛剑平 董帆 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 2021年第7期1195-1204,共10页
室内家具和工业生产排放的挥发性有机化合物(VOCs)是典型的空气污染物,对环境和人类健康造成严重威胁.然而,目前广泛应用的二氧化钛(P25)光催化剂在降解VOCs,尤其是降解芳香烃的过程中,存在光催化转化率低,失活快等问题.因此,开发具有... 室内家具和工业生产排放的挥发性有机化合物(VOCs)是典型的空气污染物,对环境和人类健康造成严重威胁.然而,目前广泛应用的二氧化钛(P25)光催化剂在降解VOCs,尤其是降解芳香烃的过程中,存在光催化转化率低,失活快等问题.因此,开发具有高效和稳定性的新型光催化剂来降解VOCs,并将其实际应用是重要的科学问题.SnO_(2)是一种稳定无毒的半导体光催化剂,但电子和空穴的复合率较高.掺杂过渡金属离子后可以提供缺陷态来抑制催化剂电子空穴对的快速复合,促进界面电荷转移.相比其他金属离子,Zn^(2+)与Sn^(4+)的离子半径非常相近,因此Zn^(2+)会很容易掺杂到SnO_(2)晶格中.并且用Zn^(2+)取代Sn^(4+)会形成表面修饰,即形成更多的氧空位(SOVs)来补偿正电荷.氧空位的存在不仅会产生缺陷能级,而且还可以促进大量局域电子的累积.SnO_(2)上氧空位和Zn掺杂结构的协同作用可以弥补单一的外源离子掺杂或产生氧空位的不足.因此,本文采用一种简便的一步法合成催化剂Zn-SnO_(2),即在SnO_(2)上同时实现Zn掺杂和形成SOVs,利用两者对SnO_(2)的协同作用提高电荷转移和分离效率,使其在低或高相对湿度条件下均表现出高效、稳定的光催化降解甲苯性能.采用低温固态电子顺磁共振(EPR)检测了催化剂中的氧空位,在纯SnO_(2)中仅检测到弱的EPR信号,而Zn-SnO_(2)上的EPR信号非常强,表明Zn^(2+)的掺杂诱导产生了大量的氧空位.扫描电镜和透射电镜结果表明,掺杂Zn^(2+)可以有效抑制SnO_(2)纳米粒子的晶体生长和相变,使得掺杂Zn^(2+)的SnO_(2)粒子的粒径显著减小,从而导致SOVs含量增加,此外粒径的减小有利于增大其比表面积,增加活性吸附位点.紫外可见漫反射结果表明,Zn-SnO_(2)拓宽了光吸收范围,这归因于锌掺杂和氧空位的协同作用.在紫外光照射下,Zn-SnO_(2)的光催化降解甲苯性能优于纯SnO_(2)和P25,降解率达到77.5%.ESR光谱结果表明,Zn-SnO_(2)上的电子自旋共振信号强度均强于纯SnO_(2)和P25,说明Zn-SnO_(2)具有较好的氧化能力,也与DFT计算O_(2)和H_(2)O的吸附能结果相吻合,表明了锌掺杂和SOVs对SnO_(2)的协同作用可以显著提高电荷转移和分离效率.最后,通过原位红外光谱和DFT计算方法对甲苯降解的机理进行了研究.结果表明,甲苯的苯环在纯SnO_(2)表面倾向于在苯甲酸阶段打开,在Zn-SnO_(2)表面更倾向于在苯甲醛阶段选择性地开环.可见,Zn-SnO_(2)光催化剂缩短了甲苯的降解路径,并能显著抑制中间毒副产物产生.综上,本工作提供了一种安全,高效和可持续的降解VOCs的光催化剂. 展开更多
关键词 光催化 锌掺杂 表面氧空穴 甲苯 原位红外光谱
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Evolving insights:how DNA repair pathways impact cancer evolution 被引量:1
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作者 jiadong Zhou Xiao Albert Zhou +1 位作者 Ning Zhang jiadong wang 《Cancer Biology & Medicine》 SCIE CAS CSCD 2020年第4期805-827,共23页
Viewing cancer as a large,evolving population of heterogeneous cells is a common perspective.Because genomic instability is one of the fundamental features of cancer,this intrinsic tendency of genomic variation leads ... Viewing cancer as a large,evolving population of heterogeneous cells is a common perspective.Because genomic instability is one of the fundamental features of cancer,this intrinsic tendency of genomic variation leads to striking intratumor heterogeneity and functions during the process of cancer formation,development,metastasis,and relapse.With the increased mutation rate and abundant diversity of the gene pool,this heterogeneity leads to cancer evolution,which is the major obstacle in the clinical treatment of cancer.Cells rely on the integrity of DNA repair machineries to maintain genomic stability,but these machineries often do not function properly in cancer cells.The deficiency of DNA repair could contribute to the generation of cancer genomic instability,and ultimately promote cancer evolution.With the rapid advance of new technologies,such as single-cell sequencing in recent years,we have the opportunity to better understand the specific processes and mechanisms of cancer evolution,and让s relationship with DNA repair.Here,we review recent findings on how DNA repair affects cancer evolution,and discuss how these mechanisms provide the basis for critical clinical challenges and therapeutic applications. 展开更多
关键词 DNA repair cancer evolution intratumor heterogeneity genomic instability drug resistance
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北美水貂和欧亚水獭在东北地区的分布与生态位重叠 被引量:2
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作者 陈敏豪 张超 +3 位作者 王嘉栋 湛振杰 陈君帜 栾晓峰 《生物多样性》 CAS CSCD 北大核心 2023年第1期179-189,共11页
作为入侵物种,北美水貂(Neovison vison)在欧洲引起了一系列生态问题,侵占了欧亚水獭(Lutra lutra)的生态空间,其入侵性对当地生物多样性和生态系统构成了严重威胁。水貂引入我国东北地区已有70多年的历史,然而国内对其野外种群却鲜有... 作为入侵物种,北美水貂(Neovison vison)在欧洲引起了一系列生态问题,侵占了欧亚水獭(Lutra lutra)的生态空间,其入侵性对当地生物多样性和生态系统构成了严重威胁。水貂引入我国东北地区已有70多年的历史,然而国内对其野外种群却鲜有研究。掌握水貂种群的入侵范围、入侵影响因素以及与本地具有相似生态位的欧亚水獭之间的竞争关系,对水貂的入侵管理和东北地区的生物多样性保护具有重要意义。本研究利用实地调查和文献资料获取的分布信息,通过集合模型识别水貂和水獭的潜在分布区,评估水貂对水獭在地理空间上的入侵风险,并通过主成分分析(principal component analysis,PCA)评估其生态位重叠和影响因素。结果表明:(1)我国东北地区水貂的潜在分布区面积为61,944.57 km^(2),水獭的潜在分布区面积为83,590.94 km^(2),两者重叠区域面积为50,544.21 km^(2),占水獭潜在分布区面积的60.47%;(2)从各省分布情况来看,黑龙江省水獭受水貂入侵的风险最高,潜在分布区重叠的比例达到78.94%,其次是吉林省,重叠比例约为53.80%;(3)水貂和水獭生态位存在高度重叠,Schoener’s D值达到0.60。单因子生态位分析结果表明,水獭比水貂对耕地密度更加敏感,集中分布在低耕地密度区;水獭和水貂均倾向选择有林地密度较高的区域,但水貂在有林地密度的选择上更加平滑,对森林的依赖程度比水獭低;水貂相比水獭更倾向选择降水量低的区域;水獭比水貂更倾向选择高海拔的栖息地。根据地理分布特征和生态位分析的结果,我们建议通过控制人为干扰调控水獭和水貂的竞争关系,以抑制水貂在东北地区的入侵。 展开更多
关键词 北美水貂 欧亚水獭 种间竞争 入侵物种 生态位重叠
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Novel perspective in transplantation therapy of mesenchymal stem cells:targeting the ferroptosis pathway 被引量:1
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作者 YUZHU XU PAN FAN +7 位作者 LEI LIU XUANFEI XU LELE ZHANG jiadong wang YUAO TAO XIAOLONG LI XI LI YUNTAO wang 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2023年第2期115-129,共15页
Ex vivo culture-amplified mesenchymal stem cells(MSCs)have been studied because of their capacity for healing tissue injury.MSC transplantation is a valid approach for promoting the repair of damaged tissues and repla... Ex vivo culture-amplified mesenchymal stem cells(MSCs)have been studied because of their capacity for healing tissue injury.MSC transplantation is a valid approach for promoting the repair of damaged tissues and replacement of lost cells or to safeguard surviving cells,but currently the efficiency of MSC transplantation is constrained by the extensive loss of MSCs during the short post-transplantation period.Hence,strategies to increase the efficacy of MSC treatment are urgently needed.Iron overload,reactive oxygen species deposition,and decreased antioxidant capacity suppress the proliferation and regeneration of MSCs,thereby hastening cell death.Notably,oxidative stress(OS)and deficient antioxidant defense induced by iron overload can result in ferroptosis.Ferroptosis may inhibit cell survival after MSC transplantation,thereby reducing clinical efficacy.In this review,we explore the role of ferroptosis in MSC performance.Given that little research has focused on ferroptosis in transplanted MSCs,further study is urgently needed to enhance the in vivo implantation,function,and duration of MSCs. 展开更多
关键词 Mesenchymal stem cells(MSCs) Ferroptosis Oxidative stress(OS) Iron metabolism Lipid peroxidation Glutathione peroxidase 4(GPX4)
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基于DNA宏条形码技术的大兴安岭北部欧亚水獭冬季食性分析
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作者 湛振杰 张超 +4 位作者 陈敏豪 王嘉栋 富爱华 范雨薇 栾晓峰 《生物多样性》 CAS CSCD 北大核心 2023年第6期81-92,共12页
欧亚水獭(Lutra lutra)是淡水生态系统重要的指示种和旗舰种,然而在人为干扰和环境变化的背景下,中国欧亚水獭种群数量大幅下降,部分地区已局部灭绝。目前欧亚水獭主要分布于我国东北地区和西南地区,其中大兴安岭是维持东北地区水獭种... 欧亚水獭(Lutra lutra)是淡水生态系统重要的指示种和旗舰种,然而在人为干扰和环境变化的背景下,中国欧亚水獭种群数量大幅下降,部分地区已局部灭绝。目前欧亚水獭主要分布于我国东北地区和西南地区,其中大兴安岭是维持东北地区水獭种群稳定的关键区域。了解欧亚水獭的食性组成有利于理解其种间关系与生态系统功能,对评估其生存状况、开展保护工作具有重要意义。本研究在大兴安岭北部共采集疑似欧亚水獭粪便样品50份,使用DNA条形码技术对样品进行物种来源鉴定,结果显示其中35份为欧亚水獭粪便。利用DNA宏条形码技术分析粪便中的物种组成,共得到15种鱼类、2种蛙类、5种昆虫共计22种不同的物种类别。所有脊椎动物食物类别中,杂色杜父鱼(Cottus poecilopus)的相对出现频率和相对序列丰度均最高,分别为19.35%和27.32%,其次为黑龙江林蛙(Ranaamurensis),分别为15.48%和21.73%;科水平上,杜父鱼科的相对出现频率和相对序列丰度均显著高于其他鱼类,分别为32.26%和45.72%。结果表明,大兴安岭北部欧亚水獭冬季主要捕食鱼类,其次为蛙类,其中鱼类主要以杜父鱼科为主;此外还在少量水獭粪便中发现有蜻蜓目、襀翅目、毛翅目等水生昆虫,可能来自水獭猎物。本研究结果可为了解水獭种群生存状况、制定相关政策、开展保护工作提供重要参考依据。 展开更多
关键词 欧亚水獭 食性 DNA宏条形码 非损伤性采样 大兴安岭
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东北地区水獭分布格局与保护优先区识别 被引量:2
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作者 张超 陈敏豪 +5 位作者 杨立 庄鸿飞 武曙红 湛振杰 王嘉栋 栾晓峰 《生物多样性》 CAS CSCD 北大核心 2022年第1期48-58,共11页
水獭是水生生态系统重要的指示种和旗舰种,由于强烈的人为干扰,中国的水獭种群数量大幅下降,部分区域已局部灭绝。然而目前国内对水獭的调查和研究非常有限,本底不清的状况已经严重影响到水獭的野外保育工作。本文以东北地区的欧亚水獭... 水獭是水生生态系统重要的指示种和旗舰种,由于强烈的人为干扰,中国的水獭种群数量大幅下降,部分区域已局部灭绝。然而目前国内对水獭的调查和研究非常有限,本底不清的状况已经严重影响到水獭的野外保育工作。本文以东北地区的欧亚水獭指名亚种(Lutra lutra lutra)为研究对象,基于2016-2020年的调查数据,使用组合建模的方法评估了水獭的潜在分布区;利用地理信息系统和系统保护规划软件分析了水獭的保护优先区并计算了各省级行政区内水獭潜在分布区和保护优先区面临的人类压力;结合国家级自然保护区的空间布局分析了水獭的保护现状,并以内蒙古森工集团、大兴安岭林业集团、伊春森工集团三大国有林区为例分析了重点国有林区在水獭保护中的作用。结果表明:(1)水獭潜在分布区和保护优先区面积分别为104,515.04 km^(2)和45,448.99 km^(2),其中大兴安岭的水獭保护优先区集中连片,并与小兴安岭的保护优先区相连,栖息地之间没有明显地理隔离,是维持东北地区水獭种群稳定的重中之重;(2)水獭面临的人类压力大小依次为:辽宁>吉林>黑龙江>内蒙古;(3)研究区内110个国家级自然保护区中有63个包含水獭潜在分布区,覆盖面积为12,168.93 km^(2),仅占水獭潜在分布区面积的11.64%,其中32个国家级自然保护区包含水獭保护优先区,占水獭保护优先区面积的10.88%;(4)三大国有林区涵盖了71.18%的水獭潜在分布区和79.26%的保护优先区(面积分别为74,390.89 km^(2)和36,022.22 km^(2))。由此可见,尽管水獭潜在分布区中国家级自然保护区占比较低,但是在天然林全面禁伐的背景下,重点国有林区可能在未来东北地区的生物多样性保护中发挥更大作用,因此我们建议将重点国有林区中具有重要保护价值的区域逐步纳入以国家公园为主体的自然保护地体系中,以实现生物多样性的系统性和完整性保护。最后,本文结合研究结果和实地调研提出以下保护建议:(1)加强对河流污染物的管理;(2)控制渔民捕鱼强度;(3)开展全面的水獭专项调查并建立长期的监测体系;(4)加大对水獭的科研投入;(5)加强宣传力度,提升公众保护意识。 展开更多
关键词 欧亚水獭 组合模型 分布 保护优先区 国有林区
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Inhibition of the toxic byproduct during photocatalytic NO oxidation via La doping in ZnO 被引量:3
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作者 Chaowei Yuan Wen Cui +5 位作者 Yanjuan Sun jiadong wang Ruimin Chen Jin Zhang Yuxin Zhang Fan Dong 《Chinese Chemical Letters》 SCIE CAS CSCD 2020年第3期751-754,共4页
It is of a great challenge to develop semiconductor photocatalysts with potential possibilities to simultaneously enhance photocatalytic efficiency and inhibit generation of toxic intermediates.In this study,we develo... It is of a great challenge to develop semiconductor photocatalysts with potential possibilities to simultaneously enhance photocatalytic efficiency and inhibit generation of toxic intermediates.In this study,we developed a facile method to induce the La doping and cationic vacancie(V(Zn))on ZnO for the highly efficient complete NO oxidation.The photocatalytic NO removal efficiency increases from 36.2%to 53,6%.Most importantly,a significant suppressed NO2 production also has been realized.According to the DFT calculations,ESR spectra and in situ FTIR spectra,the introduction of La^3+induce the redistribution of charge carriers in La-ZnO,which promote the production of·O2^- and lead to the formation of V(Zn)for the formation of·OH,contributing to the complete oxidation of NO to nitrate.Besides,the conversion pathway of photocatalytic NO oxidation has been elaborated,This work paves a new way to simultaneously realize the photocatalytic pollutants removal and the inhibition of toxic intermediates generation for efficient and safe air purification. 展开更多
关键词 PHOTOCATALYTIC NO oxidation TOXIC BYPRODUCT REACTIVE oxygen species ZNO CATIONIC vacancie
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Maintenance of Genome Stability
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作者 jiadong wang Tomas Lindahl 《Genomics, Proteomics & Bioinformatics》 SCIE CAS CSCD 2016年第3期119-121,共3页
It was ever thought that genomic information is transmitted faithfully from generation to generation. But our current knowledge does not indicate that it is the case. For example, genomic variations can be generated f... It was ever thought that genomic information is transmitted faithfully from generation to generation. But our current knowledge does not indicate that it is the case. For example, genomic variations can be generated from DNA replication infidelity and unequal chromosome segregation. Natural decay of DNA molecules is also a fundamental source of changing genomic information. In addition, cellular and organismal exposure to exogenous genotoxic agents such as ultraviolet (UV) light, oxidative stress, chemical mutagens, and radiation can lead to a variety of modifications on DNA constituents, resulting in genome alterations. Fortunately, cells have evolved several response systems to tackle numerous DNA lesions in order to maintain their genome integrity. Among them, check- point control is probably the most well-known one. For exam- ple, checkpoint responds to replication stress, replication fork stalling, double-strand DNA breaks, and various other types of DNA lesions. Increasing experimental evidence indicates that genomic instability is probably the fundamental reason for carcinogenesis. Genomic instability is also found to be a main etiological factor of neurodegenerative diseases, aging, immunodeficiency, etc. Thus, to understand how cells regulate to maintain their genomic stability is of fundamental importance. 展开更多
关键词 genomic Genome chromosome DNA segregation replication decay eukaryotic ultraviolet transmitted
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