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近20年兰西城市群生态系统服务价值对土地利用转型的时空响应

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环境科学 2024年第6期45卷 3329-3340页

作者：梁膑月曹春李锦超唐千惠吴育垚肖潇饶玉良王继伟杨丽琴西北师范大学地理与环境科学学院甘肃省绿洲资源环境与可持续发展重点实验室兰州730070

快速城市化和人类活动加剧了对现代城市群中各种生态系统服务退化的威胁,探索城市群尺度下的生态安全状况具有重要意义.以兰西城市群为研究区,选择2000、2005、2010、2015和2020年土地利用数据,引入景观生态风险指数,运用土地利用转移... 详细信息

快速城市化和人类活动加剧了对现代城市群中各种生态系统服务退化的威胁,探索城市群尺度下的生态安全状况具有重要意义.以兰西城市群为研究区,选择2000、2005、2010、2015和2020年土地利用数据,引入景观生态风险指数,运用土地利用转移矩阵、单位面积价值当量因子法和双变量空间自相关分析法,分析兰西城市群土地利用变化特征,阐明土地利用转型引起的生态风险变化对生态系统服务价值的影响.结果表明:①2000~2020年间兰西城市群土地利用类型主要以草地、耕地和林地为主.建设用地面积扩张明显,主要来源于耕地和草地;6种土地利用类型交叉转化较强,土地利用变化总面积为6646.05 km^(2);②从空间变化上来看,兰西城市群生态系统服务价值空间格局未发生明显转变,但区域差异性显著,总体呈现西北高、东南低的分布特征;③从时间变化上来看,兰西城市群生态系统服务价值呈逐年增长的趋势,总价值流向从1864.59亿元增长为1921.56亿元,总增值56.97亿元;④兰西城市群近20年生态风险指数整体呈上升的趋势,生态风险区以低生态风险区和较低生态风险区占主导地位;生态系统服务价值与生态风险指数有显著的正向空间相关性.本文旨在揭示土地利用方式对生态系统服务价值和生态风险影响的认识,为区域生态风险管理和土地利用政策制定提供重要参考,进而促进黄河流域生态环境高质量发展.

关键词：兰西城市群土地利用变化生态系统服务价值生态风险时空演变

Left Multiplication Mappings on Operator Spaces

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Journal of Mathematical Research and Exposition 2010年第3期30卷 487-494页

作者： yu wu yao Department of Mathematics & Physics Hefei University Anhui 230601 P. R. China

Let X be a separable infinite dimensional Banach space and B（X） denote its operator algebra, the algebra of all bounded linear operators T ： X → X. Define a left multiplication mapping LT ： B（X）→B（X） by LT（V） → TV, V ∈ B（X）. We investigate the connections between hypercyclic and chaotic behaviors of the left multiplication mapping LT on S（Z） and that of operator T on X. We obtain that LT is SOT-hypercyclic if and only if T satisfies the Hypercyclicity Criterion. If we define chaos on B（X） as SOT-hypercyclicity plus SOT-dense subset of periodic points, we also get that LT is chaotic if and only if T is chaotic in the sense of Devaney.

关键词： Hypercyclicity Criterion topological transitivity operator space chaos.

Direct, real-time PCR （MethyLight） assay for methylation of O6-methylguanine-DNA methyltransferase promoter in glioma

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Chinese Medical Journal 2009年第11期122卷 1342-1345页

作者： CHEN Gong wu Xing yao yu ZHOU Liang-fu MAO Ying Department of Neurosurgery Huashan Hospital Fudan University Shanghai 200040 China

O6-Methylguanine-DNA methyltransferase （MGMT） is a cellular DNA repair protein that rapidly reverses alkylation （e.g. methylation） at the O6 position of guanine, thereby neutralizing the cytotoxic effects of alkylating agent therapy such as temozolomide （TMZ） and carmustine. It has been shown that epigenetic silencing of the MGMT gene by promoter methylation shuts down gene transcription and reflects a common alteration in primary human tumors leading to MGMT deficiency. Epigenetic silencing of the MGMT gene has been shown to correlate with improved survival in several studies of glioma patients treated with the alkylating agent therapy and has been substantiated in two clinical trials.

关键词： O6-methylguanine-DNA-methyltransferase real-time PCR methylation-specific PCR glioma drug resistance

Conversion to sirolimus immunosuppression in liver transplantation recipients with hepatocellular carcinoma:Report of an initial experience

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World Journal of Gastroenterology 2006年第19期12卷 3114-3118页

作者： Jian Zhou Jia Fan Zheng Wang Zhi-Quan wu Shuang-Jian Qiu Xiao-wu Huang yao yu Jian Sun Yong-Sheng Xiao Yi-Feng He yu-Qi Wang Zhao-You Tang Liver Cancer Institute and Zhongshan Hospital Fudan University Shanghai 200032 China

AIM： To report a retrospective analysis of preliminary results of 36 patients who received sirolimus （SRL, Rapamune, rapamycin） in a consecutive cohort of 248 liver allograft recipients. METHODS： Thirty-six liver transplant patients with hepatocellular carcinoma （HCC） who were switched to SRL- based immunosuppression therapy from tacrolimus were enrolled in this study. The patients who were diagnosed as advanced HCC before orthotopic liver transplantation （OLT） were divided into group A （n = 11）, those who were found to have HCC recurrence and/or metastasis after OLT were assigned to group B （n = 18）, and those who developed renal insuffidency caused by caldneurin inhibitor （CNI） were assigned to group C （n = 7） after OLT. RESULTS： The patients were followed up for a median of 10.4 mo （range, 3.8-19.1 mo） after conversion to SRL therapy and 12.3 mo （range, 5.1-34.4 too） after OLT. Three patients developed mild acute cellular rejection 2 wk after initiating SRL therapy, which was fully reversed after prednisolone pulse therapy. In group A, only 1 patient was found to have HCC recurrence and metastasis 12 mo after OLT. In group B, 66.7% （12/18） patients （2 with progressive tumor, 7 with stable tumor and 3 without tumor） were still alive due to conversing to SRL and/ or resection for HCC recurrence at the end of a median follow-up of 6.8 mo post conversion and 10.7 mo posttransplant. In group C, no HCC recurrence was demonstrated in 7 patients, and renal function became normal after SRL therapy. Thrombocytopenia （n = 2）, anemia （n = 8）, and oral aphthous ulcers （n = 7） found in our cohort were easily manageable. CONCLUSION： The conversion to SRL-based immunosuppression may inhibit the recurrence and metastasis of HCC and improve CNI-induced renal insufficiency in OLT patients with HCC.

关键词： Sirolimus Orthotopic liver transplantation Hepatocellular carcinoma

Facilitating prelithiation of silicon carbon anode by localized high-concentration electrolyte for high-rate and long-cycle lithium storage

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Carbon Energy 2024年第6期6卷 216-233页

作者： yuanxing Zhang Borong wu Jiaying Bi Xinyu Zhang Daobin Mu Xin-yu Zhang Ling Zhang yao Xiao Feng wu School of Materials Science and Engineering Beijing Institute of TechnologyBeijingChina Chongqing Innovation Center Beijing Institute of TechnologyChongqingChina College of New Energy Xi′an Shiyou UniversityXi′anChina Institute for Carbon Neutralization College of Chemistry and Materials EngineeringWenzhou UniversityWenzhouChina Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjinChina

The commercialization of silicon-based anodes is affected by their low initial Coulombic efficiency(ICE)and capacity decay,which are attributed to the formation of an unstable solid electrolyte interface(SEI)***,a feasible and cost-effective prelithiation method under a localized highconcentration electrolyte system(LHCE)for the silicon-silica/graphite(Si-SiO_(2)/C@G)anode is designed for stabilizing the SEI layer and enhancing the *** thin SiO_(2)/C layers with-NH_(2) groups covered on nano-Si surfaces are demonstrated to be beneficial to the prelithiation process by density functional theory calculations and electrochemical *** SEI formed under LHCE is proven to be rich in ionic conductivity,inorganic substances,and flexible organic ***,faster Li+transportation across the SEI further enhances the prelithiation effect and the rate performance of Si-SiO_(2)/C@G *** also leads to uniform decomposition and high stability of the SEI with abundant organic *** a result,the prepared anode shows a high reversible specific capacity of 937.5 mAh g^(-1)after 400 cycles at a current density of 1 *** 811‖Li-SSGLHCE full cell achieves a high-capacity retention of 126.15 mAh g^(-1)at 1 C over 750 cycles with 84.82%ICE,indicating the great value of this strategy for Si-based anodes in large-scale applications.

关键词： localized high-concentration electrolytes prelithiation SEI layer silicon anode

On the thermodynamics of plasticity during quasi-isentropic compression of metallic glass

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Matter and Radiation at Extremes 2024年第2期9卷 74-89页

作者： Kaiguo Chen Bo Chen Yinan Cui yuying yu Jidong yu Huayun Geng Dongdong Kang Jianhua wu yao Shen Jiayu Dai College of Science National University of Defense TechnologyChangsha 410073People’s Republic of China Hunan Key Laboratory of Extreme Matter and Applications National University of Defense TechnologyChangsha 410073People’s Republic of China Applied Mechanics Laboratory Department of Engineering MechanicsSchool of AerospaceTsinghua UniversityBeijing 100084People’s Republic of China Institute of Fluid Physics China Academy of Engineering PhysicsMianyangPeople’s Republic of China Department of Material Science and Technology Shanghai Jiao Tong UniversityShanghaiPeople’s Republic of China

Entropy production in quasi-isentropic compression (QIC) is critically important for understanding the properties of materials under extremeconditions. However, the origin and accurate quantification of entropy in this situation remain long-standing challenges. In this work, a framework is established for the quantification of entropy production and partition, and their relation to microstructural change in QIC. Cu50Zr50is taken as a model material, and its compression is simulated by molecular dynamics. On the basis of atomistic simulation-informed physicalproperties and free energy, the thermodynamic path is recovered, and the entropy production and its relation to microstructural change aresuccessfully quantified by the proposed framework. Contrary to intuition, entropy production during QIC of metallic glasses is relativelyinsensitive to the strain rate ˙γ when ˙γ ranges from 7.5 × 10^(8) to 2 × 10^(9)/s, which are values reachable in QIC experiments, with a magnitudeof the order of 10^(−2)kB/atom per GPa. However, when ˙γ is extremely high (>2 × 10^(9)/s), a notable increase in entropy production rate with˙γ is observed. The Taylor–Quinney factor is found to vary with strain but not with strain rate in the simulated regime. It is demonstrated thatentropy production is dominated by the configurational part, compared with the vibrational part. In the rate-insensitive regime, the increase inconfigurational entropy exhibits a linear relation to the Shannon-entropic quantification of microstructural change, and a stretched exponential relation to the Taylor–Quinney factor. The quantification of entropy is expected to provide thermodynamic insights into the fundamentalrelation between microstructure evolution and plastic dissipation.

关键词： entropy metallic regime

Helmholtz decomposition with a scalar Poisson equation in elastic anisotropic media

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Petroleum Science 2024年第3期21卷 1597-1610页

作者： Xin-yu Fang Gang yao Qing-Qing Zheng Ping-Min Zhang Di wu Feng-Lin Niu State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China Unconventional Petroleum Research Institute China University of Petroleum(Beijing)Beijing102249China Department of Mathematics College of ScienceChina University of Petroleum(Beijing)Beijing102249China College of Geophysics China University of Petroleum(Beijing)Beijing102249China Department of Earth Environmental and Planetary SciencesRice UniversityHoustonTX77005UA

P-and S-wave separation plays an important role in elastic reverse-time *** can reduce the artifacts caused by crosstalk between different modes and improve image *** addition,P-and Swave separation can also be used to better understand and distinguish wave types in complex *** present,the methods for separating wave modes in anisotropic media mainly include spatial nonstationary filtering,low-rank approximation,and vector Poisson *** of these methods require multiple Fourier transforms or the calculation of large matrices,which require high computational costs for problems with large *** this paper,an efficient method is proposed to separate the wave mode for anisotropic media by using a scalar anisotropic Poisson operator in the spatial *** 2D problems,the computational complexity required by this method is 1/2 of the methods based on solving a vector Poisson ***,compared with existing methods based on pseudoHelmholtz decomposition operators,this method can significantly reduce the computational *** examples also show that the P and S waves decomposed by this method not only have the correct amplitude and phase relative to the input wavefield but also can reduce the computational complexity significantly.

关键词： Anisotropic media Scalar anisotropic Poisson equation Improved elastic wavefield decomposition

Enhancement of catalytic activity for hydrogenation of nitroaromatic by anionic metal-organic framework

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Chinese Chemical Letters 2024年第3期35卷 144-148页

作者： Qi wu Anyang Li Ruibo He Yaxi wu Lei Hou Guoping Yang Wenyan Zhang yao-yu Wang Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry&Materials ScienceNorthwest UniversityXi'an 710127China

Nitroaromatic hydrogenation catalysis without precious metals remains a longstanding *** rate of electron transfer is the crucial factor affecting hydrogenation ***,an ionic Cd-based metal-organic framework(I-Cd-MOF)exhibiting a unique structure with one-dimensional(1D)opening nanochannels and good electron transfer ability was synthesized for catalyzing hydrogenation of 4-nitrophenol(4-NP).The catalytic activity of the unique I-Cd-MOF without noble metals is detected,which is higher than most reported noble metal ***,the reaction rate of I-Cd-MOF(4.28 min^(-1))is about 47.6 times higher than that of the Cd-based neutral MOF(N-Cd-MOF)with the similar crystalline *** chromatograph mass spectrometer(LC-MS)and theoretical results demonstrate that 4-NP and five intermediates are stabilized in the channels of I-Cd-MOF,which increases the possibility of contact with H^*and H_(2)g enerated at the Cd *** I-Cd-MOF was extended to other nitroaromatic hydrogenation catalysis,which still displays excellent *** importantly,the I-MOF@Filter membrane was successfully constructed for continuous hydrogenation catalytic reactions,which maintains a high catalytic performance after 7 cycles of recycling without *** work fills in the application of the I-MOFs in hydrogenation catalytic reactions and provides an effective way for the rapid and green degradation of nitroaromatic compounds.

关键词： Anions Metal-organic frameworks Catalysis Electron transfer Hydrogen production

Dissolution kinetics and reaction mechanism of Al_(2)O_(3) in molten CaF_(2)-CaO-Al_(2)O_(3) slag

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Journal of Iron and Steel Research International 2024年第4期31卷 861-869页

作者： yao-xin Du Yan-wu Dong Zhou-hua Jiang Ganna Stovpchenko yu-shuo Li Jun Huang Xin-wei Wang yu-xiao Liu School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina Key Laboratory of Ecological Metallurgy of Multimetallic Mineral Northeastern UniversityShenyang 110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina E.O.Paton Electric Welding Institute of the National Academy of Science of Ukraine Kiev 03115Ukraine

The dissolution behavior of Al_(2)O_(3) in molten CaF_(2)-CaO-Al_(2)O_(3) slag,a basic slag system of electroslag remelting process,was investigated by rotating cylinder method using corundum rods to simulate Al_(2)O_(3) inclusions in *** experimental results show that the dissolution rate of Al_(2)O_(3);rods in CaF_(2)-CaO-Al_(2)O_(3) slag increases with the increase in rotating speed and temperature,and the rate-controlling step is the mass transfer in the *** dissolution rate of Al_(2)O,in CaF_(2)-CaO-Al_(2)O_(3) slag increases with the increase in the ratio of CaO to Al_(2)O_(3),which is due to the increase in dissolution driving force and the decrease in slag *** apparent activation energy of the mass transfer of AlOs in slag C is calculated to be 222.86 kJ mol^(-1).During the dissolution of Al_(2)0,inclusions in the slag,it reacts with F in liquid slag at first,then reacts with CaO to form the intermediate compounds of xCaO-yAl_(2)O_(3) system,and finally dissolves in molten *** dissolution rate of Al_(2)O_(3) inclusions in CaF_(2)-CaO-Al_(2)O_(3) slag for electroslag remelting is positively correlated with the ratio of the dissolution driving force and slag viscosity,and the correlation coeficient is 2.487×10^(-11).

关键词： Inclusion Electroslag remelting Mass transfer:Dissolution rate-Dissolution driving force