Analysis of Influencing Factor of Land Price Based on Bootstrap Method

There are a lot of influencing factors of land price. Method of t-test of regression analysis model can be used to conduct the analysis of significance of influencing factor of land price. In the case of small sample or indefinite error distribution, there is a problem of unlikelihood of statistical referrer. So that, introduce Bootstrap method in the model to increase precision of estimated variance of parameters and reliability of statistical referrer of significance of influencing factor. Take an empirical analysis based on the data of land deal of Chongqing. The result indicates that it is very efficient to solve such problem by Bootstrap method.     

60Co-γ射线辐射处理花卉后生理生化特性变化对小气候要素的响应

选择不同花卉品种种子（虞美人）和根茎（球根海棠、大丽菊），用不同剂量^60Co-γ射线急性辐射处理后，设对照组进行种植。在生长盛期用美国产CID301PS光合作用测定系统测定不同花卉叶片的生理指标和小气候要素，并取样进行了过氧化物酶等系列化指标的分析，通过岑回归分析，选取在岑迹稳定后K=0.2时的岑回归系数，寻找小气候要素对气孔导度等生理指标的作用效应和方向。结果表明，几种花卉处理后气孔导度对小气候要素反应不敏感，而对光合速率、蒸腾速率和细胞间隙CO2浓度等的影响则表现不一致。几种酶活性的测定也表明其间存在明显差异。通过研究，对寻找生态环境条件对辐射效应的影响程度，辐射最佳阈值范围的确定，辐射生物学的发展有一定的参考意义。     

多元分析在黄淮冬麦区小麦良种区试中的应用分析

本文将多元分析法应用于小麦良种区域试验,并与Eberhart和Russell法及G.C.C.Tai(1971)法进行了比较。结果表明,多元分析法不仅提供了基因型各生育阶段对环境的反应敏感性强弱的参数V_1、V_2和V_3,而且提供了各环境地区的环境资源优劣的估计值r_1、r_2及r_3。据V_1r_1+V_2r_2+V_3r_3值最大来选各环境地区适宜品种,在生产上更具有实际指导意义。Tai(1975)多元分析法各基因型的复相关系数月均大于0.8,说明该分析是可靠的。并从生产实际中得到了验证。相比之下,Eberhart和Russell法及Tai(1971)法显得较粗放。     

基于GBDT-LR和信息量模型耦合的滑坡易发性评价

[目的]探索准确、快速的滑坡易发性区划方法,为区域安全监测提供参考,为政府治理滑坡灾害提供科学依据。[方法]以安徽省池州市贵池区为研究区域,采用梯度提升决策树—逻辑回归(GBDT-LR)和信息量(I)模型耦合的方法,实现区域滑坡易发性评价。该方法通过对原样本地学习,组合产生新的模拟样本,从而增强易发性评价模型对滑坡的拟合能力;采用Borderline-Smote算法解决样本数据不对称的问题。选用r.slopeunits软件划分的斜坡单元作为最小评价单元,选取坡度、坡向、地形曲率、剖面曲率、平面曲率、地形湿度指数(TWI)、地形起伏度、归一化植被指数(NDVI)、距断裂距离和距水系距离总计10个评价因子。分别从频率比、滑坡灾害点及隐患点密度、ROC曲线3个方面对构建的滑坡易发性模型进行评价。[结果]试验结果表明：耦合模型I-GBDT-LR分别比I,LR,I-LR模型的高易发区频率比所占比例提升约10%,13%,7%,高易发区滑坡灾害点及隐患点密度分别提升约9,11,7,ROC精度提升约10%,9%,5%。[结论]从检验指标综合来看,耦合模型的精度均高于单一模型,所提出耦合模型精度又高于I...     

Canine Transmissible Venereal Tumour: Asessment of Mast Cell Numbers as Indicators of the Growth Phase

Mast cells are immune cells that are involved mainly in type 1 hypersensitivity reactions, and they have been implicated in tumour angiogenesis. In this study we assessed the presence of mast cell numbers and microvessel density during the progression and regression stages of natural spontaneous canine transmissible venereal tumours (CTVT). Mast cells were demonstrated by histochemical staining with toluidine blue, alcian blue and safranin O. Microvessel counts were demonstrated by immunohistochemical labelling with an antibody against the endothelial cell marker factor VIII. Mitotic cells, apoptotic cells and tumour infiltrating lymphocytes were counted from haematoxylin–eosin-stained sections. Tumour fibrosis was evaluated on Masson's trichome-stained sections. The results showed that progressing tumours had significantly higher mast cell counts and microvessel counts at the invasive edges of the tumours than did regressing tumours. In both the progressing and regressing tumours, microvessel counts were significantly positively correlated with mast cell counts. Regressing tumours had significantly higher mast cell counts of the whole tumour than progressing tumours. The results also showed that progressing tumours had significantly higher mitotic rate than regressing tumours, and fibrosis and apoptosis were significantly higher in regressing tumours than progressing tumours. There were no significant differences between the biochemical and haematological values of dogs with progressing and regressing tumours. These results suggests that mast cells play a role in CTVT progression probably by promoting vascularization at the invasion front during the progression phase, and that mast cell count could be used as one of the histological factors to indicate growth stage of CTVT.     

基于增强回归树的麦-玉轮作农田蒸散影响因素分析

为探讨华北典型轮作农田蒸散(ET)变化规律,以山东禹城试验站冬小麦-夏玉米(麦-玉)轮作田为研究对象,基于涡度相关技术实测的8年观测数据与增强回归树方法,分析了农田ET逐日变化特征及其对环境因子的响应。结果表明：研究时段内逐日ET变化范围在0～9.6 mm/d之间,且不同阶段(小麦季、玉米季和农闲期)ET总量存在较大差异。一般而言,每年小麦季ET的峰值和总量均明显高于玉米季,而农闲期ET占全年ET总量的比例不足4%。净辐射是影响麦-玉轮作田不同阶段ET变化的首要因素,对各阶段ET的贡献率由高到低依次为小麦季(81.4%)、玉米季(52.7%)、农闲期(36.8%)。除净辐射外,其他环境因子对ET的影响则具有阶段性差异。饱和水汽压差对小麦季和玉米季ET存在一定的影响,而土壤含水率和风速对农闲期ET的贡献率相对较高。研究可为变化环境下农业水资源高效利用以及作物模型优化等提供科学依据。     

Economic contribution of participatory agroforestry program to poverty alleviation: a case from Sal forests, Bangladesh

In the Forest Department of Bangladesh, a Participatory Agroforestry Program (PAP) was initiated at a denuded Sal forests area to protect the forest resources and to alleviate poverty amongst the local poor population. We explored whether the PAP reduced poverty and what factors might be responsible for poverty alleviation. We used three poverty measurement methods: the Head Count Index, the Poverty Gap Index and the Foster-Greer-Thorbecke index to determine the extent poverty reduction. We used a linear regression model to determine the possible differences among factors in poverty reduction. Data were collected through semi-structured questionnaires and face to face interviews within the study area. PAP proved effective at poverty alleviation, considerably improving the local situation. The linear regression model showed that PAP output explained the income differences in poverty reduction. Participants identified bureaucracy and illegal money demands by forest department officials, an uncontrolled market system, and underdeveloped road infrastructure as the main obstacles to reduction of poverty. Overall, PAP is quite successful in alleviating poverty. So this program might be ofinterest at other degraded forest areas as a tool to alleviate poverty.     

Estimating vertical vegetation density through a SPOT5 imagery at multiple radiometric correction levels

There is growing concern about remote sensing of vertical vegetation density in rapidly expanding peri-urban interfaces.A widely used parameter for such density,i.e.,leaf area index (LAI),was measured in situ in Nanjing,China and then correlated with two vegetation indices (VI) derived from multiple radiometric correction levels of a SPOT5 imagery.The VIs were a normalized difference vegetation index (NDVI) and a ratio vegetation index (RVI),while the four radiometric correction levels were i) post atmospheric correction reflectance (PAC),ii) top of atmosphere reflectance (TOA),iii) satellite radiance (SR) and iv) digital number (DN).A total of 157 LAI-VI relationship models were established.The results showed that LAI is positively correlated with VI (r varies from 0.303 to 0.927,p < 0.001).The R 2 values of "pure" vegetation were generally higher than those of mixed vegetation.The average R 2 values of about 40 models based on DN data (0.688) were higher than that of the routinely used PAC (0.648).Independent variables of the optimal models for different vegetation quadrats included two vegetation indices at three radiometric correction levels,indicating the potential of vegetation indices at multiple radiometric correction levels in LAI inversion.The study demonstrates that taking heterogeneities of vegetation structures and uncertainties of radiometric corrections into account may help full mining of valuable information from remote sensing images,thus improving accuracies of LAI estimation.     

烤烟新品种云烟99及其亲本生长特性研究

为了解烤烟新品种云烟99生长特性,利用Logistic生长模型对云烟99的株高、叶片数、中部叶叶面积生长进行回归分析,并与其父本9147、母本云烟85做比较。结果表明:(1)云烟99及其亲本3个性状共9个Lo-gistic生长模型方程拟合程度均达极显著水平,能较真实地反映云烟99及其亲本的生长特性;(2)云烟99株高比亲本略高,叶片数与亲本相当,中部叶叶面积与父本相当、比母本大;(3)云烟99株高和叶片数的线性生长期与父本相当、比母本长,中部叶叶面积比亲本长;(4)云烟99的3个性状平均生长速率均介于双亲之间,但线性生长速率和最大生长速率存在差异。