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Dynamics of Saline-alkali Land and Its Ecological Regionalization in Western Songnen Plain, China

Chinese Geographical Science 2010年第2期20卷 159-166页

作者： YANG Jiuchun zhang Shuwen LI Ying BU Kun zhang yubo CHANG Liping zhang Yangzhen Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Software College Jilin University Changchun 130012 China

As the important reserve land resources for food production,saline-alkali land should play a significant role to ensure the national food security in the context of global food crisis. The western Songnen Plain is one of main distribution regions of saline-alkali land in China,with great potential in agricultural development. In this study,the extent,transformation,spatial distribution and temporal change of saline-alkali land in the western Songnen Plain during 1954–2005 were investigated by using remote sensing and GIS spatial analysis methods. Saline-alkali land change was detected from a temporal series of topographic maps in 1954,satellite images of Landsat MSS in 1976,Landsat TM/ETM in 1988,2000 and 2005 through artificial visual interpretation. The results indicated a significant expansion in saline-alkali land area and aggravation in salinization. The area of saline-alkali land had increased from 401.48×103 ha in 1954 to 1 097.45×103 ha in 2005. While the ratio of light,moderate and serious salinized land areas changed from 6.72︰2.92︰1.00 to 1.25︰1.06︰1.00 in the study period. Grassland,cropland,swampland and water body were the major land use and land cover types from which saline-alkali land transformed. And the secondary salinization occured mainly in Da′an City,Tongyu County,Changling County,Daqing City,Dorbod Mongolian Autonomous County and Zhaoyuan County. Finally,seven large ecoregions and 14 corresponding sub-ecoregions were delineated out based on spatio-temopral dynamic characteristics of saline-alkali land and geo-relational environmental attributes. According to the results,measures of amelioration and ways of development of saline-alkali land in the western Songnen Plain were put forward.

关键词： saline-alkali land salinization ecological regionalization food security Songnen Plain

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Experimental Investigation on the Mechanical Properties of Natural Fiber Reinforced Concrete

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Journal of Renewable Materials 2022年第5期10卷 1307-1320页

作者： Ismail Shah Jing Li Shengyuan Yang yubo zhang Aftab Anwar School of Architecture and Civil Engineering Yunnan Agricultural UniversityKunming650000China Key Laboratory of Crop Growth and Intelligent Agriculture of Yunnan Province Yunnan Agricultural UniversityKunming650000China

Recently,addition of various natural fibers to high strength concrete has aroused great interest in the field of building *** is because natural fibers are much cheaper and locally available,as compare to synthetic *** in view,this current research conducted mainly focuses on the static properties of hybridized(sisal/coir),sisal and coir fiber-reinforced *** types of natural fibers sisal and coir were used in the experiment with different lengths of 10,20 and 30 mm and various natural fiber concentrations of 0.5%,1.0%,and 1.5%by mass of cement,to investigate the static properties of sisal fiber reinforced concrete(SFRC),coir fiber reinforced concrete(CFRC)and hybrid fiber reinforced concrete(HFRC).The results indicate that HFRC has increased the compressive strength up to 35.98%with the length of 20 mm and with 0.5%concentration,while the CFRC and SFRC with the length of 10 mm and with 1%concentration have increased the compressive strength up to 33.94%and 24.86%,*** another hand,the split tensile strength was increased by HFRC with the length of 20 mm and with 1%concentration,CFRC with the length of 10 mm and with 1.5%concentration,and SFRC with the length of 30 mm and with 1%concentration have increased up to 25.48%,24.56%and 11.80%,respectively,while the HFRC with the length of 20 mm and with 0.5%concentration has increased the compressive strength of concrete but has decreased the split tensile strength up to 2.28%compared to ***,using the HFRC with the length of 20 mm and with 1%concentration provide the maximum output in terms of split tensile strength.

关键词： Sisal fiber reinforced concrete coir fiber reinforced concrete hybrid fibers compressive and tensile strength

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Prediction of protected band edge states and dielectric tunable quasiparticle and excitonic properties of monolayer MoSi_(2)N_(4)

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npj Computational Materials 2022年第1期8卷 1216-1222页

作者： Yabei Wu Zhao Tang Weiyi Xia Weiwei Gao Fanhao Jia yubo zhang Wenguang Zhu Wenqing zhang Peihong zhang Department of Materials Science and Engineering and Shenzhen Institute for Quantum Science&engineering Southern University of Science and TechnologyShenzhenGuangdong518055China Guangdong Provincial Key Lab for Computational Science and Materials Design and Shenzhen Municipal Key Lab for Advanced Quantum Materials and DevicesSouthern University of Science and TechnologyShenzhenGuangdong518055China ICQD Hefei National Laboratory for Physical Science at the MicroscaleKey Laboratory of Strongly-Coupled Quantum Matter PhysicsChinese Academy of SciencesDepartment of Physicsand Synergetic Innovation Center of Quantum Information and Quantum PhysicsUniversity of Science and Technology of ChinaHefeiAnhui230026China Department of Physics University at BuffaloState University of New YorkBuffaloNY14260USA Department of Physics Dalian University of TechnologyDalianLiaoning116024China International Centre for Quantum and Molecular Structures Materials Genome InstituteDepartment of PhysicsShanghai University99 Shangda RoadShanghai200444China

The electronic structure of two-dimensional(2D)materials are inherently prone to environmental perturbations,which may pose significant challenges to their applications in electronic or optoelectronic devices.A 2D material couples with its environment through two mechanisms:local chemical coupling and nonlocal dielectric screening *** local chemical coupling is often difficult to predict or control *** dielectric screening,on the other hand,can be tuned by choosing the substrates or layer thickness in a controllable ***,a compelling 2D electronic material should offer band edge states that are robust against local chemical coupling *** it is demonstrated that the recently synthesized MoSi_(2)N_(4)is an ideal 2D semiconductor with robust band edge states protected from capricious environmental chemical coupling *** many-body perturbation theory calculations are carried out to illustrate how the band edge states of MoSi_(2)N_(4)are shielded from the direct chemical coupling effects,but its quasiparticle and excitonic properties can be modulated through the nonlocal dielectric screening *** unique property,together with the moderate band gap and the thermodynamic and mechanical stability of this material,paves the way for a range of applications of MoSi_(2)N_(4)in areas including energy,2D electronics,and optoelectronics.

关键词： dielectric protected quasi

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Landscape Dynamics and Driving Factors in Da’an County of Jilin Province in Northeast China During 1956-2000

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Chinese Geographical Science 2008年第2期18卷 137-145页

作者： WANG Zongming zhang yubo zhang Bai SONG Kaishan GUO Zhixing LIU Dianwei LI Fang Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China Software College of Jilin University Changchun 130026 China

The landscape pattern of Da’an County, Northeast China has undergone significant changes since the 1950s as a result of climatic change and human activities. The aim of this paper is to quantitatively study landscape pattern and its spatial dynamics of Da’an County at the landscape level over the nearly 50-year span. Patch dynamics were examined ac-cording to land use and land cover change processes built from a series of images, as well as topographic maps, and tem-poral patterns built from landscape pattern metrics. The transition matrix of landscape patch types and changes of various landscape metrics were applied. The results showed that, from 1956 to 2000, the landscape within the study area had un-dertaken a complicated evolution in landscape structure and composition. The outstanding characteristic is that sa-line-alkali land increased and grassland decreased. As some smaller patches amalgamated, the heterogeneity of patch de-creased. All those changes were the synthetic result of both climatic and anthropogenic influences, but the predominant factor was different in different parts. In the southern part of the study area, the landscape pattern changes resulted from the modification of climate obviously, while in the northern part, the landscape pattern changes were mainly caused by human activities, such as the conversion between farmland and saline-alkali land. This phenomenon showed that human activities played more important role in the north than in the south of Da’an County.

关键词： landscape evolution land use change saline-alkali land Da'an County Northeast China

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Metallurgy Failure Analysis for an Early Fracture Engine Intake Valve Made of 85Cr18Mo2V

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稀有金属材料与工程 2012年第S1期41卷 148-151页

作者： zhang yubo Xu Binshi Wang Haidou Yang Daxiang Lina, Zhu Acad Armored Forces Engn Natl Key Lab Remfg Beijing 100072 Peoples R China

By means of analysis technique such as scanning electron microscopy(SEM)equipped with energy dispersive spectroscopy(EDS),and transmission electron microscopy(TEM),deep metallurgy failure analysis for an early fracture engine intake valve made of the martensite material of 85Cr18Mo2V was performed through macroscopical and microcosmic as well as chemical composition *** to the result of SEM,this valve belonged to fatigue *** crack sources of dense micro-holes near the surface of intake valve and SiO2 impurity are the direct reasons to cause the valve *** EDS analysis for the fatigue source region approved that superfluous Si,O and Al impurity *** TEM observation of the slice cut from the region closing to the fracture surface showed that deep areas near the surface of valve were oxidized *** material structure got brittle due to the generation of *** will be produced in these oxidation areas under high cycle fatigue ***,the synthetical action of various factors finally caused the fracture of valve.

关键词： intake valve fatigue fracture 85Cr18Mo2V failure analysis interior oxidation

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Effect of nerve growth factor on angiogenesis in a rat model of sciatic nerve regeneration

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Neural Regeneration Research 2009年第2期4卷 139-143页

作者： yubo zhang Yamin Wu Lei Liu Chuan Song Zaiyun Long the 324 Hospital of Chinese PLA Chongqing 400020 China Research Institute of Field Surgery Daping Hospital Third Military Medical University of Chinese PLA Chongqing 400042 China

BACKGROUND： It remains to be determined whether nerve growth factor （NGF） can promote angiogenesis in regenerating peripheral nerves during repairing peripheral nerve injury. OBJECTIVE： To evaluate the effects of NGF on angiogenesis, and to analyze the influencing mechanisms of NGF, according to the expression patterns of CD34, von Willebrand factor （vWF）, vascular endothelial cell growth factor （VEGF）, and the NGF receptor TrkA in proliferating vascular endothelial cells from a rat model of sciatic nerve injury. DESIGN, TIME AND SETTING： Randomized, controlled study performed at the Research Institute of Field Surgery, Daping Hospital affiliated to the Third Military Medical University of Chinese PLA, between October 2003 and July 2005. MATERIALS： Forty-five healthy, adult, Wistar rats underwent sciatic nerve injury. The rats were randomly divided into four groups： NGF ＋ chitosan （n = 15）, NGF ＋ chitosan ＋ anti-VEGF （n = 10）, chitosan （n = 10）, and physiological saline （n = 10）. METHODS： A 1 -cm defected sciatic nerve was bridged with a silica gel conduit. NGF ＋ chitosan group： 100 μ L chitosan and 5 μ L NGF （20 mg/L） were injected into the silica gel conduit; NGF ＋ chitosan ＋ anti-VEGF group： an additional 5μ L anti-VEGF monoclonal antibody （1 g/L） was injected into the silica gel conduit; chitosan group： 100μL chitosan and 5 μL physiological saline were injected into the silica gel conduit; physiological saline group： only 5μL physiological saline was injected into the silica gel conduit. MAIN OUTCOME MEASURES： CD34 and vWf were used to label blood capillaries and large-diameter blood vessels in the regenerating peripheral nerves, respectively. At day 14 following surgery, immunohistochemistry was used to detect and semi-quantitatively analyze expressions of CD34, vWf, VEGF, and TrkA in proliferating vascular endothelial cells in the regenerating sciatic nerve. A confocal laser microscope was used to determine co-expression. RESULTS： Expressions of TrkA,

关键词： nerve growth factor sciatic nerve angiogenesis endothelial cell vascular endothelial cell growth factor co-expression

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Anti-inflammatory sesquiterpene polyol esters from the stem and branch of Tripterygium wilfordii

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Chinese Journal of Natural Medicines 2023年第3期21卷 233-240页

作者： HU Yalin XU Tianqi YIN Wenjing CHENG Huaiyu zhang Xia LIU Ying zhang yubo ZHOU Guangxiong Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research Institute of Traditional Chinese Medicine and Natural ProductsCollege of PharmacyJinan UniversityGuangzhou 511436China Department of Pharmacology School of MedicineGuangdong Clinical Translation Center for Targeted DrugJinan UniversityGuangzhou 511436China

The stem and branch extract of Tripterygium wilfordii(Celastraceae)afforded seven new dihydroagarofuran sesquiterpene polyesters[tripterysines A‒G(1‒7)]and eight known ones(8‒15).The chemical structures of these new compounds were established based on combinational analysis of HR-ESI-MS and NMR *** absolute configurations of tripterysines A‒C(1‒3)and E‒G(5‒7)were determined by X-ray crystallographic analysis and circular dichroism *** the compounds were screened for their inhibitory effect on inflammation through determining their inhibitory effect on nitric oxide production in LPS-induced RAW 264.7 cells and the secretion of inflammatory cytokines TNF-αand IL-6 in LPS-induced BV2 *** 9 exhibited significant inhibitory activity on NO production with an IC50 value of 8.77μmol·L−***,compound 7 showed the strongest inhibitory effect with the secretion of IL-6 at 27.36%.

关键词： Tripterygium wilfordii Sesquiterpene polyester Tripterysine Anti-inflammation

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TIPS治疗肝硬化伴或不伴门静脉血栓临床对比研究

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介入放射学杂志 2024年第10期33卷 1101-1106页

作者：李如春胡继红潘文秋卓松波张玉博田梽甫昆明医科大学第一附属医院医学影像科临沧市人民医院介入科

目的分析TIPS治疗肝硬化伴或不伴门静脉血栓形成（portal vein thrombosis, PVT）的临床特点及疗效。方法回顾性分析2018年10月至2022年10月在昆明医科大学第一附属医院接受TIPS治疗的肝硬化伴消化道出血患者193例，按术前有无PVT分为... 详细信息

目的分析TIPS治疗肝硬化伴或不伴门静脉血栓形成（portal vein thrombosis, PVT）的临床特点及疗效。方法回顾性分析2018年10月至2022年10月在昆明医科大学第一附属医院接受TIPS治疗的肝硬化伴消化道出血患者193例，按术前有无PVT分为非PVT组118例，PVT组75例。分别于术后1、3、6个月及之后每6个月随访，观察PVT对肝硬化患者临床特征及TIPS术后疗效的影响。结果两组患者手术成功率均为100%。PVT组行脾脏切除或行分脾动脉栓塞术占26.7%（20/75）,高于非PVT组的13.6%（16/118）,差异有统计学意义（χ2=5.192,P=0.023）。PVT组患者术前Child-Pugh评分、MELD评分和MELD-Na+评分分别为（8.1±1.9）分、（9.2±8.0）分、（9.2±8.0）分，均高于非PVT组的（7.4±1.9）分、（7.7±5.8）分、（7.7±5.8）分，差异有统计学意义（P0.05）。结论 TIPS用于治疗肝硬化PVT伴消化道出血安全、有效；PVT患者的肝功能更差，TIPS术后显性肝性脑病发生率更高。

关键词：肝硬化门静脉血栓形成消化道出血经颈静脉肝内门体分流术

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考虑风口回旋区影响的高炉热风分配模拟

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材料与冶金学报 2024年第4期23卷 314-320页

作者：罗志国张瑀博史本慧刘洪升刘炳南邹宗树东北大学多金属共生矿生态化冶金教育部重点实验室沈阳110819 海洋装备用金属材料及其应用国家重点实验室辽宁鞍山114009 鞍钢集团钢铁研究院辽宁鞍山114009

以鞍钢新5号高炉为研究对象,对比分析了空喷及考虑风口回旋区这两种工况下高炉热风的周向分配情况.结果表明:当风口参数相同时,空喷与考虑风口回旋区这两种工况下的热风分配规律相同,即在高炉圆周0°,90°,180°和270°方位的风口风量... 详细信息

以鞍钢新5号高炉为研究对象,对比分析了空喷及考虑风口回旋区这两种工况下高炉热风的周向分配情况.结果表明:当风口参数相同时,空喷与考虑风口回旋区这两种工况下的热风分配规律相同,即在高炉圆周0°,90°,180°和270°方位的风口风量和鼓风动能较大,45°,135°,225°和315°方位的风口风量和鼓风动能较小;空喷和考虑风口回旋区这两种工况下的风量极差分别为3.65 m^(3)/min和7.29 m^(3)/min,标准差分别为1.32和2.71;空喷和考虑风口回旋区这两种工况下的鼓风动能极差分别为9.93 kJ/s和19.90 kJ/s,标准差分别为3.62和7.41;与空喷工况相比,考虑风口回旋区工况下热风和鼓风动能分配的不均匀性更为明显,热风分配结果更准确.

关键词：高炉风口回旋区热风分配风量鼓风动能

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Effect of ultrasonic treatment and Sr addition on microstructure of Al-20%Si alloy

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China Foundry 2013年第4期10卷 213-216页

作者： Miao Long Lu Yiping zhang yubo Fu Ying Li Tingju School of Materials Science EngineeringDalian University of Technology

Many investigations have revealed that transition of melt structure can effectively influence the final solidification microstructures. In this study, ultrasonic treatment was applied to AI-20%Si melt and Sr-modified AI-20%Si melt at 720 ℃ （i.e. above liquidus of about 690℃） for 60 s, and then the melt was quickly quenched to room temperature. Experimental results show that ultrasonic treatment can refine the primary Si phase and a-AI of AI-20%Si alloy; strontium can make the morphology of Si phase spheroidized and refined as Sr addition changes the faceted growth characteristic of Si phase; however, the refinement effect of ultrasonic treatment on the primary Si phase and α-AI is weakened by Sr addition.

关键词： ultrasonic treatment nucleation rate liquidus strontium modification quenching

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