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    题名 作者 年代 出处 被引量
1Spatial and temporal trends of climate change in Xinjiang, China显示文摘在 65 个气象学的车站的从 1961 ~ 2005 的系列数据集被用来揭示气候的空间、时间的趋势的温度和降水时间在 Xinjiang 变化,中国。年度、季节的吝啬的空气温度和全部的降水用 Mann-Kendall (MK ) 测试被分析,反的距离加权(IDW ) 插值,和 R/S 方法。结果显示那:(1 ) 在过去的 45 年里增加的温度和降水,而是温度的增加比降水的更明显;(2 ) 为温度增加,更高纬度并且更高举起更快增加,不过,纬度在增加以后有更大的影响。北 Xinjiang 显示出比南部的 Xinjiang 的更快的温暖,特别在夏天;(3 )降水的增加在南部的 Xinjiang 主要在冬季发生在北 Xinjiang 并且在夏天。Ili,在 Xinjiang 有大多数降水,显示出降水的弱增加;(4 ) 尽管温度和降水一般来说增加了,增加在 Xinjiang 内是不同的;(5 ) 林中小丘索引(H) 分析显示那个气候变化将继续当前的趋势。LI Qihu CHEN Yaning SHEN Yanjun LI Xingong XU Jianhua 2011Journal of Geographical Sciences2011,21,6:41
2Genome-wide identification, expression analysis of auxin-responsive GH_3 family genes in maize(Zea mays L.) under abiotic stresses显示文摘Auxin is involved in different aspects of plant growth and development by regulating the expression of auxinresponsive family genes. As one of the three major auxinresponsive families, GH3(Gretchen Hagen3) genes participate in auxin homeostasis by catalyzing auxin conjugation and bounding free indole-3-acetic acid(IAA) to amino acids.However, how GH3 genes function in responses to abiotic stresses and various hormones in maize is largely unknown.Here, the latest updated maize(Zea mays L.) reference genome sequence was used to characterize and analyze the Zm GH3 family genes from maize. The results showed that 13 Zm GH3 genes were mapped on fi ve maize chromosomes(total10 chromosomes). Highly diversi fi ed gene structures and tissue-speci fi c expression patterns suggested the possibility of function diversi fi cation for these genes in response to environmental stresses and hormone stimuli. The expression patterns of Zm GH3 genes are responsive to several abiotic stresses(salt, drought and cadmium) and major stress-relatedhormones(abscisic acid, salicylic acid and jasmonic acid)Various environmental factors suppress auxin free IAA contents in maize roots suggesting that these abiotic stresses and hormones might alter GH3-mediated auxin levels. The respon siveness of Zm GH3 genes to a wide range of abiotic stresses and stress-related hormones suggested that Zm GH3 s are involved in maize tolerance to environmental stresses.Shangguo Feng Runqing Yue Sun Tao Yanjun Yang Lei Zhang Mingfeng Xu Huizhong Wang Chenjia Shen 2015Journal of Integrative Plant Biology2015,57,9:17
3Great flood in the middle-lower Yellow River reaches at 4000 a BP inferred from accurately-dated stalagmite records显示文摘Recently,Wu et al.[1]suggested an earthquake-induced landslide dam outburst flood on the eastern Tibetan Plateau at 1920BCE(3870 a BP,BP denotes year before 1950 CE)caused the Great Flood in the middle-lower Yellow River reaches,and resulted in the founding of Xia Dynasty at 3850 a BP.This age is$150–300younger than the previously estimated age of the Xia Dynasty[2].While the geological evidence of the outburst flood。Liangcheng Tan Chuan-Chou Shen Yanjun Cai Hai Cheng R.Lawrence Edwards 2018Science Bulletin2018,63,4:16
4Trend in pan evaporation and its attribution over the past 50 years in China显示文摘Trends in pan evaporation are widely relevant to the hydrological community as indicators of hydrological and climate change. Pan evaporation has been decreasing in the past few decades over many large areas with differing climates globally. This study analyzes pan evaporation data from 671 stations in China over the past 50 years in order to reveal the trends of it and the corresponding trend attribution. Mann-Kendall test shows a significant declining trend in pan evaporation for most stations, with an average decrease of 17.2 mm/10a in China as a whole, the rate of decline was the steepest in the humid region (29.7 mm/10a), and was 17.6 mm/10a and 5.5 mm/10a in the semi-humid/semi-arid region and arid region, respectively. Complete correlation coefficients of pan evaporation with 7 climate factors were computed, and decreases in diurnal temperature range (DTR), SD (sunshine duration) and wind speed were found to be the main attributing factors in the pan evaporation declines. Decrease in DTR and SD may relate to the increase of clouds and aerosol as well as the other pollutants, and decrease in wind speed to weakening of the Asian winter and summer monsoons under global climate warming.LIU Min SHEN Yanjun ZENG Yan LIU Changming 2010Journal of Geographical Sciences2010,20,4:11
5Characteristics of Boundary Layer Structure during a Persistent Haze Event in the Central Liaoning City Cluster, Northeast China显示文摘The characteristics of boundary layer structure during a persistent regional haze event over the central Liaoning city cluster of Northeast China from 16 to 21 December 2016 were investigated based on the measurements of particulate matter(PM) concentration and the meteorological data within the atmospheric boundary layer(ABL). During the observational period, the maximum hourly mean PM_(2.5) and PM10 concentrations in Shenyang, Anshan, Fushun, and Benxi ranged from 276 to 355 μg m–3 and from 378 to 442 μg m–3, respectively, and the lowest hourly mean atmospheric visibility(VIS) in different cities ranged from 0.14 to 0.64 km. The central Liaoning city cluster was located in the front of a slowly moving high pressure and was mainly controlled by southerly winds. Wind speed(WS) within the ABL(< 2 km) decreased significantly and WS at 10-m height mostly remained below 2 m s–1 during the hazy episodes, which was favorable for the accumulation of air pollutants. A potential temperature inversion layer existed throughout the entire ABL during the earlier hazy episode [from 0500 Local Time(LT) 18 December to 1100 LT 19 December], and then a potential temperature inversion layer developed with the bottom gradually decreased from 900 m to 300 m. Such a stable atmospheric stratification further weakened pollutant dispersion. The atmospheric boundary layer height(ABLH) estimated based on potential temperature profiles was mostly lower than 400 m and varied oppositely with PM_(2.5) in Shenyang. In summary, weak winds due to calm synoptic conditions, strong thermal inversion layer, and shallow atmospheric boundary layer contributed to the formation and development of this haze event.The backward trajectory analysis revealed the sources of air masses and explained the different characteristics of the haze episodes in the four cities.Xiaolan LI Yangfeng WANG Lidu SHEN Hongsheng ZHANG Hujia ZHAO Yunhai ZHANG Yanjun MA 2018Journal of Meteorological Research2018,32,2:10
6Spatiotemporal Variations and Regional Transport of Air Pollutants in Two Urban Agglomerations in Northeast China Plain显示文摘Characteristics of air pollution in Northeast China(NEC) received less research attention in the past comparing to other heavily polluted regions in China.Spatiotemporal variations of six criteria air pollutants(PM10, PM2.5, SO2, NO2, O3 and CO) in Central Liaoning Urban Agglomeration(CLUA) and Harbin-Changchun Urban Agglomeration(HCUA) in NEC Plain were analyzed in this study based on three-year hourly observations of air pollutants and meteorological variables from 2015 to 2017.The results indicated that the annual mean concentrations of air pollutants are generally higher in the middle and southern regions in NEC Plain and lower in the northern region.Megacities such as Shenyang, Harbin and Changchun experience severe air pollution, with a three-year averaged air quality index(AQI) larger than 80, far exceeding the daily AQI standard at the first-level of 50 in China.The annual mean PM and SO2 concentrations decrease most significantly in NEC urban agglomerations from 2015 to 2017, followed by CO and NO2, while O3 shows a slight increasing trend.All the six pollutants exhibit obvious seasonal and diurnal variations, and these variations are dictated by local emission and meteorological conditions.PM2.5 and O3 concentrations in NEC urban agglomerations strongly depend on wind conditions.High O3 concentrations at different cities usually occur in presence of strong winds but are independent on wind direction(WD), while high PM2.5 is usually accompanied by weak winds and poor dispersion condition, and sometimes also occur when the northerly or southerly winds are strong.Regional transport of air pollutants between NEC urban agglomerations is common.A severe haze event on November 1–4, 2017 is examined to demonstrate the role of regional transport on pollution.LI Xiaolan HU Xiaoming SHI Shuaiyi SHEN Lidu LUAN Lan MA Yanjun 2019Chinese Geographical Science2019,29,6:9
7Acupuncture and moxibustion reduces neuronal edema in Alzheimer's disease rats显示文摘To examine the possible correlation of aberrant Wnt signaling and pathological changes in Alzheimer's disease, we established a rat model of Alzheimer's disease and measured axin and β-catenin expression in the hippocampus. Rats were pretreated with moxibustion or electroacu-puncture, or both, at Baihui(GV20) and Shenshu(BL23). Axin expression was lower, β-catenin expression was greater, and neuronal cytoplasmic edema was visibly prevented in the rats that had received the pretreatments. Our results suggest that the mechanism underlying the neuro-protective effect of acupuncture and moxibustion in Alzheimer's disease is associated with axin and β-catenin expression in the Wnt signal transduction pathway.Hua Zhou Guojie Sun Lihong Kong Yanjun Du Feng Shen Shuju Wang Bangguo Chen Xiaoling Zeng 2014Neural Regeneration Research2014,9,9:8
8Modeling demand/supply of water resources in the arid region of northwestern China during the late 1980s to 2010显示文摘水需求与一张增加的人口和经济开发连续地增加。作为结果,水供应和需求之间的差别成为一个重要问题,特别在干旱区域。在西北的中国( ARNWC )的干旱区域弄明白水资源的利用,并且也在未来使用提供方法论预言水,三个模型在这研究被建立计算农业灌溉,在到 2010 的从1980年代末的 ARNWC 的工业、国内的水使用。在河盆水平在水资源的区域,供应和需求基于河分泌物被分析。结果显示农业灌溉需求在 ARNWC 占据超过 90% 全部的水使用。全部的水需求从 31.97 km 增加了 < 啜 class= “ a-plus-plus ” > 在到 48.19 km 的 1980 年代末的 3 < 啜 class= “ a-plus-plus ” > 在 2010 的 3 。在这个干旱区域的大多数河盆在媒介和高水位线应力下面。严重风险的河盆例如 Shiyang 河盆和 Tianshan 山的北山麓的东方部分,在这个区域被发现。水供应从 4 月变得批评到 5 月,这被揭示,它是由比较每月的水消费决定了的最低的水供应的季节。LIU Xingran SHEN Yanjun GUO Ying LI Shuo GUO Bin 2015Journal of Geographical Sciences2015,25,5:7
9Isorhapontigenin protects against doxorubicin-induced cardiotoxicity via increasing YAP1 expression显示文摘As an effective anticancer drug, the clinical limitation of doxorubicin(Dox) is the time-and dose-dependent cardiotoxicity. Yes-associated protein 1(YAP1) interacts with transcription factor TEA domain 1(TEAD1) and plays an important role in cell proliferation and survival. However, the role of YAP1 in Dox-induced cardiomyopathy has not been reported. In this study, the expression of YAP1 was reduced in clinical human failing hearts with dilated cardiomyopathy and Dox-induced in vivo and in vitro cardiotoxic model. Ectopic expression of Yap1 significantly blocked Dox-induced cardiomyocytes apoptosis in TEAD1 dependent manner. Isorhapontigenin(Isor) is a new derivative of stilbene and responsible for a wide range of biological processes. Here, we found that Isor effectively relieved Doxinduced cardiomyocytes apoptosis in a dose-dependent manner in vitro. Administration with Isor(30 mg/kg/day, intraperitoneally, 3 weeks) significantly protected against Dox-induced cardiotoxicity in mice. Interestingly, Isor increased Dox-caused repression in YAP1 and the expression of its target genes in vivo and in vitro. Knockout or inhibition of Yap1 blocked the protective effects of Isor on Dox-induced cardiotoxicity. In conclusion, YAP1 may be a novel target for Dox-induced cardiotoxicity and Isor might be a new compound to fight against Dox-induced cardiotoxicity by increasing YAP1 expression.Panxia Wang Minghui Wang Yuehuai Hu Jianxing Chen Yanjun Cao Cui Liu Zhongkai Wu Juan Shen Jing Lu Peiqing Liu 2021Acta Pharmaceutica Sinica B2021,11,3:7
10Warm temperature compromises JA-regulated basal resistance to enhance Magnaporthe oryzae infection in rice显示文摘Changes in global temperatures profoundly affect the occurrence of plant diseases.It is well known that rice blast can easily become epidemic in relatively warm weather.However,the molecular mechanism remains unclear.In this study,we show that enhanced blast development at a warm temperature(22C)compared with the normal growth temperature(28C)is rice plant-determined.Comparative transcriptome analysis revealed that jasmonic acid(JA)biosynthesis and signaling genes in rice could be effectively induced by Magnaporthe oryzae at 28C but not at 22C.Phenotypic analyses of the osaoc1 and osmyc2 mutants,OsCOI1 RNAi lines,and OsMYC2-OE plants further demonstrated that compromised M.oryzaeinduced JA biosynthesis and signaling lead to enhanced blast susceptibility at the warm temperature.Consistent with these results,we found that exogenous application of methyl jasmonate served as an effective strategy for improving blast resistance under the warm environmental conditions.Furthermore,decreased activation of JA signaling resulted in the downregulated expression of some key basal resistance genes at 22C when compared with 28C.Among these affected genes,OsCEBiP(chitin elicitorbinding protein precursor)was found to be directly regulated by OsMYB22 and its interacting protein OsMYC2,a key component of JA signaling,and this contributed to temperature-modulated blast resistance.Taken together,these results suggest that warm temperature compromises basal resistance in rice and enhances M.oryzae infection by reducing JA biosynthesis and signaling,providing potential new strategies for managing rice blast disease under warm climate conditions.Jiehua Qiu Junhui Xie Ya Chen Zhenan Shen Huanbin Shi Naweed I.Naqvi Qian Qian Yan Liang Yanjun Kou 2022Molecular Plant2022,15,4:5
11Finite-time control of linear parameter-varying systems with norm-bounded exogenous disturbance显示文摘In this paper, a new approach is presented for finite-time control problems for linear systems subject to time-varying parametric uncertainties and exogenous disturbance. The disturbance is assumed to be time varying and bounded. Sufficient conditions are obtained for the existence of a linear parameter-dependent state feedback gain, which can ensure that the closed-loop system is finite-time bounded (FTB). The conditions can be reduced to feasibility problems involving LMIs. Numerical examples show the validity of the proposed methodology.Yanjun SHEN 2008控制理论与应用(英文版)2008,6,2:5
12Electro-conductive Nanocrystalline Cellulose Film Filled with TiO_2-ReducedGraphene Oxide Nanocomposite显示文摘Imparting electro-conductive properties to nanocellulosebased products may render them suitable for applications in electronics,optoelectronics, and energy storage devices. In the present work, an electroconductive nanocrystalline cellulose(NCC) film filled with TiO2-reducedgraphene oxide(TiO2-RGO) was developed. Initially, graphene oxide(GO) was prepared using the modified Hummers method and thereafter photocatalytically reduced using TiO2 as a catalyst. Subsequently, an electro-conductive NCC film was prepared via vacuum filtration with the as-prepared TiO2-RGO nanocomposite as a functional filler. The TiO2-RGO nanocomposite and the NCC/TiO2-RGO film were systematically characterized. The results showed that the obtained TiO2-RGO nanocomposite exhibited reduced oxygen-containing group content and enhanced electroconductivity as compared with those of GO. Moreover, the NCC film filled with TiO2-RGO nanocomposite displayed an electro-conductivity of up to 9.3 S/m and improved mechanical properties compared with that of the control. This work could provide a route for producing electro-conductive NCC films, which may hold significant potential as transparent flexible substrates for future electronic device applications.RuoNan Zhao YanJun Tang XiaoChuang Shen XingHua Hong YiMing Zhou 2018Paper And Biomaterials2018,3,4:5
13Inconsistency of changes in uniaxial compressive strength and P-wave velocity of sandstone after temperature treatments显示文摘It is generally accepted that the uniaxial compressive strength(UCS)and P-wave velocity of rocks tend to decrease simultaneously with increasing temperature.However,based on a great number of statistical data and systematic analysis of the microstructure variation of rocks with temperature rising and corresponding propagation mechanism of elastic wave,the results show that(1)There are three different trends for the changes of UCS and P-wave velocity of sandstone when heated from room temperature(20C or 25C)to 800C:(i)Both the UCS and P-wave velocity decrease simultaneously;(ii)The UCS increases initially and then decreases,while the P-wave velocity decreases continuously;and(iii)The UCS increases initially and then fluctuates,while the P-wave velocity continuously decreases.(2)The UCS changes at room temperaturee400C,400Ce600C,and 600Ce800C are mainly attributed to the discrepancy of microstructure characteristics and quartz content,the transformation plasticity of clay minerals,and the balance between the thermal cementation and thermal damage,respectively.(3)The inconsistency in the trends of UCS and P-wave velocity changes is caused by the change of quartz content,phase transition of water and certain minerals.Jinyuan Zhang Yanjun Shen Gengshe Yang Huan Zhang Yongzhi Wang Xin Hou Qiang Sun Guoyu Li 2021Journal of Rock Mechanics and Geotechnical Engineering2021,13,1:5
14Patient-derived non-small cell lung cancer xenograft mirrors complex tumor heterogeneity显示文摘Objective:Patient-derived xenograft(PDX)models have shown great promise in preclinical and translational applications,but their consistency with primary tumors in phenotypic,genetic,and pharmacodynamic heterogeneity has not been well-studied.This study aimed to establish a PDX repository for non-small cell lung cancer(NSCLC)and to further elucidate whether it could preserve the heterogeneity within and between tumors in patients.Methods:A total of 75 surgically resected NSCLC specimens were implanted into immunodeficient NOD/SCID mice.Based on the successful establishment of the NSCLC PDX model,we compared the expressions of vimentin,Ki67,EGFR,and PD-L1 proteins between cancer tissues and PDX models using hematoxylin and eosin staining and immunohistochemical staining.In addition,we detected whole gene expression profiling between primary tumors and PDX generations.We also performed whole exome sequencing(WES)analysis in 17 first generation xenografts to further assess whether PDXs retained the patient heterogeneities.Finally,paclitaxel,cisplatin,doxorubicin,atezolizumab,afatininb,and AZD4547 were used to evaluate the responses of PDX models to the standard-of-care agents.Results:A large collection of serially transplantable PDX models for NSCLC were successfully developed.The histology and pathological immunohistochemistry of PDX xenografts were consistent with the patients’tumor samples.WES and RNA-seq further confirmed that PDX accurately replicated the molecular heterogeneities of primary tumors.Similar to clinical patients,PDX models responded differentially to the standard-of-care treatment,including chemo-,targeted-and immuno-therapeutics.Conclusions:Our established PDX models of NSCLC faithfully reproduced the molecular,histopathological,and therapeutic characteristics,as well as the corresponding tumor heterogeneities,which provides a clinically relevant platform for drug screening,biomarker discovery,and translational research.Xuanming Chen Cheng Shen Zhe Wei Rui Zhang Yongsheng Wang Lili Jiang Ke Chen Shuang Qiu Yuanli Zhang Ting Zhang Bin Chen Yanjun Xu Qiyi Feng Jinxing Huang Zhihui Zhong Hongxia Li Guowei Che Kai Xiao 2021Cancer Biology & Medicine2021,18,1:5
15Acupoint combinations used for treatment of Alzheimer's disease: A data mining analysis显示文摘OBJECTIVE: To identify the acupoint combinations used in the treatment of Alzheimer's disease(AD).METHODS: The clinical literature regarding acupuncture and moxibustion for AD was searched and collected from databases including Chinese Biomedical Medicine, China National Knowledge Infrastructure, Wanfang Database and PubMed. The database of acupuncture and moxibustion prescriptions for AD was established by using Excel software so as to conduct the descriptive analysis, association analysis on the data.RESULTS: Baihui(GV 20), Sishencong(EX-HN 1),Shenmen(HT 7), Zusanli(ST 36), Neiguan(PC 6),Fengchi(GB 20), Taixi(KI 3), Dazhui(GV 14), Shenshu(BL 23), Sanyinjiao(SP 6), Shenting(GV 24), Fenglong(ST 40), Xuanzhong(GB 39), Shuigou(GV 26)and Taichong(LR 3) were of higher frequency in the treatment of AD with acupnucture and moxibustion. Most acupoints were selected from the Governor Vessel. The commonly used acupoints were located on the head, face, neck and lower limbs. The combination of the local acupoints with the distal ones was predominated. The crossing points among the specific points presented the advantage in the treatment. The association analysis indicated that the correlation among Fengchi(GB 20)-Baihui(GV 20) was the strongest, followed by combinations of Dazhui(GV 14)-Baihui(GV 20), Shenshu(BL 23)-Baihui(GV 20) and Neiguan(PC 6)-Baihui(GV 20) and indicated the common rules of the clinical acupoint selection and combination for AD.CONCLUSION: Our findings provide a reference for acupoints selection and combination for AD in clinical acupuncture practice.Yu Chaochao Wang Li Kong Lihong Shen Feng Ma Chaoyang Du Yanjun Zhou Hua 2018Journal of Traditional Chinese Medicine2018,38,6:4
16Comparison of winter wheat yield sensitivity to climate variables under irrigated and rain-fed conditions显示文摘庄稼模拟模型提供决定庄稼产量的敏感到气候变化的其他、不太费时间、划算的工具。在这研究,二个动态机械学的模型,谷神星(庄稼环境资源合成)和 APSIM (农业生产系统模拟器),被用来在灌溉的井( CFG )下面模仿小麦( Triticum aestivum L.)的收益并且喂雨( YY )在北方中国平原( NCP )在与不同气候变量的关系调节。学习测试了冬季小麦收益敏感到温度,放射,降水,和大气的二氧化碳的不同层次(在在在 NCP 的 Luancheng Agro 生态系统试验性的车站的 CFG 和 YY 条件下面的公司 2) 集中。从 CERES 和 APSIM 小麦庄稼模型的结果大部分是一致的并且建议在气候变量的变化在 NCP 影响了小麦谷物产量。也在到在不同的水(CFG 和 YY ) 下面的气候变量的产量调节的冬季小麦的敏感有重要变化。当时 2 湩漠桴牥瀠潥汰 e 的温度增加?Dengpan XIAO Yanjun SHEN He ZHANG Juana P. MOIWO Yongqing QI Rende WANG Hongwei PEI Yucui ZHANG Huitao SHEN 2016Frontiers of Earth Science2016,10,3:4
17Searching for the Nano-Hertz Stochastic Gravitational Wave Background with the Chinese Pulsar Timing Array Data ReleaseⅠ显示文摘Observing and timing a group of millisecond pulsars with high rotational stability enables the direct detection of gravitational waves(GWs).The GW signals can be identified from the spatial correlations encoded in the times-of-arrival of widely spaced pulsar-pairs.The Chinese Pulsar Timing Array(CPTA)is a collaboration aiming at the direct GW detection with observations carried out using Chinese radio telescopes.This short article serves as a“table of contents”for a forthcoming series of papers related to the CPTA Data Release 1(CPTA DR1)which uses observations from the Five-hundred-meter Aperture Spherical radio Telescope.Here,after summarizing the time span and accuracy of CPTA DR1,we report the key results of our statistical inference finding a correlated signal with amplitude logA_(c)=-14.4_(-2.8)^(+1.0)for spectral index in the range ofα∈[-1.8,1.5]assuming a GW background(GWB)induced quadrupolar correlation.The search for the Hellings–Downs(HD)correlation curve is also presented,where some evidence for the HD correlation has been found that a 4.6σstatistical significance is achieved using the discrete frequency method around the frequency of 14 n Hz.We expect that the future International Pulsar Timing Array data analysis and the next CPTA data release will be more sensitive to the n Hz GWB,which could verify the current results.Heng Xu Siyuan Chen Yanjun Guo Jinchen Jiang Bojun Wang Jiangwei Xu Zihan Xue RNicolas Caballero Jianping Yuan Yonghua Xu Jingbo Wang Longfei Hao Jingtao Luo Kejia Lee Jinlin Han Peng Jiang Zhiqiang Shen Min Wang Na Wang Renxin Xu Xiangping Wu Richard Manchester Lei Qian Xin Guan Menglin Huang Chun Sun Yan Zhu 2023Research in Astronomy and Astrophysics2023,23,7:3
18Evaluating urban expansion and land use change in Shijiazhuang, China, by using GIS and remote sensing显示文摘Jieying Xiao Yanjun Shen Jingfeng Ge Ryutaro Tateishi Changyuan Tang Yanqing Liang Zhiying Huang 2005Landscape and Urban Planning2005,,1:3
19Scattered Rural Settlements and Development of Mountainous Regions in Western Sichuan,China显示文摘Making rural settlements of Mountainous Regions in Western Sichuan as the study objects and using symbolic statistical methods,then combining the case study of Daofu County,the paper analyzes the negative impact of the scattered rural settlements on infrastructure construction,farm-ers' income increase and mountain ecological reconstruction in mountainous regions of western Sichuan. The results indicate that economic density is posi-tively related to both rural settlements density(R2=0.73) and rural population density(R2=0.77) ,and it is the same for relationship between towns density and rural settlements density(R2=0.88) and between towns density and eco-nomic density(R2=0.71) ,and the scattered distribution pattern of the rural settlements and shortage of economic centers is a major factor to the lagged socioeconomic development. On the eco-economic zoning to Daofu County,the paper indicates the spatial distribution model and the industrial develop-ment model of the rural settlements need to be changed,and rural population should be concentrated in larger rural settlements with development of off-farm industries while infrastructure construction is to reinforced.GAO Yanjun CHEN Guojie SHEN Maoying 2007Wuhan University Journal of Natural Sciences2007,12,4:3
20Sandstone-concrete interface transition zone (ITZ) damage and debonding micromechanisms under freeze-thaw显示文摘The sufficient bond between concrete and rock is an important prerequisite to ensure the effect of shotcrete support. However, in cold regions engineering protection system, the bond condition of rock and concrete surface is easily affected by freeze-thaw cycles, resulting in interface damage, debonding and even supporting failure. Understanding the micromechanisms of the damage and debonding of the rock-concrete interface is essential for improving the interface protection.Therefore, the micromorphology, micromechanical properties, and microdebonding evolution of the sandstone-concrete interface transition zone(ITZ) under varying freeze-thaw cycles(0, 5, 10, 15, 20) were studied using scanning electron microscope, stereoscopic microscope, and nano-indentation. Furthermore, the distribution range and evolution process of ITZ affected by freeze-thaw cycles were defined. Major findings of this study are as follows:(1) The microdamage evolution law of the ITZ under increasing freeze-thaw cycles is clarified, and the relationship between the number of cracks in the ITZ and freeze-thaw cycles is established;(2) As the number of freeze-thaw cycles increases, the ITZ's micromechanical strength decreases, and its development width tends to increase;(3) The damage and debonding evolution mechanisms of sandstone-concrete ITZ under freeze-thaw cycles is revealed, and its micromechanical evolution model induced by freeze-thaw cycles is proposed.YanJun Shen Huan Zhang JinYuan Zhang HongWei Yang Xu Wang Jia Pan 2021Research in Cold and Arid Regions2021,13,2:3
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