中国农业考古资料索引(二十五)——杵臼、碾碓、磨盘

第三编 农业工具 前言 一．本索引按内容分为农作物、农业工具、农田水利、农作图、家禽(附蚕桑、渔业)等五编，每编再分为若干类。本编“农业工具”已在1981年2期至1983年2期、1988年1期至1989年1期、1994年1期至1996年1期发……     

三亚市10年间景观格局变化分析

为了充分了解热带滨海城市发展过程中景观变化特征及其影响因素,利用基于SPOT的影像数据,应用RS、GIS 软件和景观生态学方法,以海南省三亚市作为研究对象,分析了2002—2012 年三亚市土地利用及景观格局的动态变化情况。结果表明：（1）三亚市仍以耕地和阔叶林为主,建设用地大幅度增加,各土地利用类型有相互转移表现,2002—2012 年,水田面积减少了25.75%,水库/坑塘减少6.21%;草丛、建设用地和旱地面积分别增加143.16%、86.89%和10.20%;（2）运用景观格局指数和转移矩阵分析,得出研究区域景观斑块总体数量减少,说明这期间三亚景观破碎化趋势降低,主要由于人类活动的干扰不断加强,城市化进程加快使原来分散的乡镇村落等居民集中地聚集成片,转变为城市化建筑群,从而导致了研究区域景观破碎化程度的下降。     

优质早熟无籽小西瓜迷你红的选育

优质早熟无籽小西瓜迷你红系安徽省农业科学院园艺研究所育种研究室 2 0 0 4年育成的无籽小西瓜新组合。其熟性极早 ,全生育期 80～ 85d ,果实发育期 2 8～ 3 0d。单瓜重 2～ 2 .5kg ,爬地栽培产量 5 .2 5万kg/hm2 左右 ;立架栽培可达 6.0 0万～ 6.75万kg/hm2 左右 ;多茬瓜栽培可达 7.5 0万kg/hm2 以上。植株生长势极强 ,易坐果。果实高圆形 ,花皮 ,红瓤 ,瓤质细嫩多汁酥脆 ,中心含糖量 13 %～14 % ,中边糖梯度小 ,品质及口感极好。     

Rainfall results, 1970-1975: Florida area cumulus experiment

The latest rainfall results of the Florida Area Cumulus Experiment (FACE) are discussed after a review of the background, design, and early results of this experiment. Analysis without the benefit of data stratification and appropriate covariates of the 48 random experimentation days obtained through 1975 provided no evidence that dynamic seeding appreciably altered the rainfall over the fixed target area (1.3 x 10(4) square kilometers). Partitioning of the experimentation days according to whether the convective echoes moved across the Florida peninsula or developed in situ was more informative. Use of this echo motion covariate with five meaningful predictor models of natural rainfall in a stepwise regression program produced persuasive evidence for an effect of seeding in both echo motion categories. For days with moving echoes, there is evidence for a positive, statistically significant treatment effect on the rainfall from the subject clouds (the floating target) and in the overall target area. The results for days with stationary echoes, although considerably more tentative, suggest that seeding produces more rainfall in the floating target but with no net change of the precipitation in the overall target area. The ramifications of this result and a possible explanation are discussed. Corroborative statistical analyses and discussion are presented, including a discussion of the physical bases and history of the echo motion covariate and the meteorological predictors, analysis that is supportive of the rain-gage-adjusted radar measurements of precipitation in FACE and results of relevant cloud physics measurements in Florida.