基于TM-NDVI的草地生产力遥感监测研究

采用地面调查与"3S"技术相结合的方法,以三江源玛多县为例,在计算玛多县 TM 影像归一化植物指数(NDVI)分布图的基础上,建立监测样点地上生物量与 NDVI 的遥感模型,结合青海省草地生产力划分等级,得出玛多县草地生产力等级分布图,实现草地生产力监测由点到面扩展.研究表明:①2009 年玛多县草地覆盖面积约 222 万hm<'2>,NDVI 以 0～0.5 为主,占玛多县草地总面积的 88.64%;②监测样点生物量与 NDVI 相关系数达 0.7 以上,呈显著相关关系,模型可定量表达为生物量=552.632×NDVI<'1.137>;③玛多县草地生产力等级以 750～3 000 kg/hm<'2>为主,占玛多县总草地面积 72%;草地生产力最高等级为 4 500～6 000 kg/hm<'2>,但占玛多县总草地面积不到1%.     

基于植被覆盖度遥感反演的国情草地三级分类研究

植被覆盖度遥感反演技术能够科学、合理的对植被覆盖度进行计算,定量描述植被的覆盖度。依托青海省植被覆盖度遥感反演结果,提出青海省地理国情普查植被覆盖度遥感反演使用分类原则。通过其应用,可以弥补青海省地理国情普查高分影像时相不好等不利因素,同时也可以科学、合理的统一青海省各普查单位之间对草地三级分类的认知。     

基于Google Earth Engine的有色金属资源型地区植被覆盖度动态变化分析——以安徽省铜陵市为例

为揭示有色金属资源型城市植被覆盖度变化特征,基于GEE(Google Earth Engine)平台获取2000-2019年MOD13Q1 NDVI数据,采用像元二分模型和一元线性回归法分析铜陵市植被覆盖度时空变化。结果表明：(1)2000-2009年铜陵市植被覆盖度呈下降趋势,2010-2019年呈现上升趋势;(2)铜陵市植被覆盖度等级主要为中高和高植被覆盖度,等级转化主要发生在中、中高和高植被覆盖度之间;(3)植被覆盖度显著改善和显著退化区域所占比例分别为62.38%和28.07%,空间变化趋势以改善为主。研究结果可为铜陵市的植被保护、生态环境质量评价及矿山的绿色发展提供科学参考和依据。     

宁夏草地生态系统服务功能的价值评估

根据草地生态系统单住面积生态服务价值表,对各草地类型生物量订正的基础上,对宁夏天然草地生态系统的服务价值进行了评估,同时也对宁夏人工草地生态系统的服务价值进行了评估.结果表明,①1980年宁夏天然草地生态系统的服务价值为80.67×10<'8>元,1997年为43.96×10<'8>元,2004和2005年分别为21.22×10<'8>和16.28×10<'8>元.②宁夏天然草地主要草地类型生态系统服务的总价值从1980-2005年逐年降低,温性草句草原的生态系统服务价值在2004年有所增加,其余草地类型的生态系统服务价值逐年降低.③宁夏人工草地的生态系统服务价值逐年增加.④宁夏天然草地生态系统服务价值中的经济服务价值所占比例非常小,生态服务价值占的比例较大.⑤1980～1997年草地生态系统服务价值明显下降,2004～2005年没有明显变化,宁夏草地的生态系统服务价值一直在下降,但都比当年的牧业总产值高.     

减轻草地放牧压力变四季放牧为两季放牧

本文简要介绍了新源县天然草地退化现状,通过草地监测、示范带动,提出了天然草地变四季放牧为两季放牧的方法和途径,并为持续的草地资源管理积累了科学数据,在畜牧业的生产实践中起到良好的指导作用.     

玛沁县天然草地生态系统服务功能价值评价

为了研究玛沁县天然草地生态系统服务功能价值,利用7种指标评价玛沁县高寒草地类12种天然草地类型的生态价值,为三江源区尤其是囊谦县生态补偿提供理论依据.     

太原市小返乡典型植被深层土壤干燥化研究

选取太原市小返乡30年枣树林地、30年苹果园地和草地样地,结果表明测量地点轻度甚至重度土壤干层发育.除地形、气候和植被类型外,土壤特性也是影响土壤干层发育的重要因素.因此,生态恢复要根据土壤干层发育情况,并遵循植被演替的自然规律.     

基于CA模型的香格里拉县土地利用变化模拟

以滇西北香格里拉县为例,利用1989、2000年TM(ETM)数据得出土地利用变化信息,利用元胞自动机理论对土地利用变化进行模拟和预测.预测结果经与2003年的调查结果对比,Kappa系数达0.79.与2000年相比,2015年土地利用模拟结果中自然/半自然植被面积减少幅度呈现增大趋势,减少面积占2000年自然/半自然植被总面积的9.32%;人工用地2000～2015年间282.45 hm2/年的速度增长,高于1989～2000年间208.3 hm2/年速度,主要来源是未利用土地、农业用地和自然/半自然植被的减少.农业用地2000～2015年间以1 563.613 hm2/年的速度增加,高于1989～2000年农业用地的1431.614 hm2/年速度,其增加面积主要来源于自然/半自然植被和未利用土地,主要集中在人工用地周围.     

佛山市植被覆盖度的遥感估算及变化分析

选取2000和2007年两个时期的TM数据,利用基于NDVI的像元二分模型,估算佛山市的植被覆盖度,并分析其时空变化的情况.结果 表明,近8年来,佛山市的植被覆盖度总体上呈下降的趋势,并存在区域间不平衡的现象.较高植被覆盖区的面积减少了384.41 km2,变化率为27.26%,而较低植被覆盖区的面积和中度植被覆盖区的面积分别增加了80.55 km2和229.24 km2,变化率分别为14.17%和18.09%.禅城区、南海区和三水区高植被覆盖区和较高植被覆盖区的面积都有所减少,而较低植被覆盖区和中度植被覆盖区的面积都有所增加.顺德区则相反,高植被覆盖区和较高植被覆盖区的面积都有所增加,较低植被覆盖区和中度植被覆盖区的面积都有所减少.33个镇(街)的植被覆盖度变化存在差异,罗村、狮山、大沥的植被覆盖度下降幅度最大,均在10%以上,而伦教、北溶和均安的植被覆盖度则有一定的增加.     

基于MODIS遥感影像的退牧换草工程监测研究——以昭苏县为例

本文选取了昭苏县为研究区域,以2003年8月和2009年8月的MODIS遥感影像为数据源,结合对应时期的地面调查数据,从植被盖度、植物类组成、地上生物量对特克斯县退牧换草工程的实施效果进行了分析.得出2009年禁牧区和休牧区植被盖度分别比2003年高10%-13%和6%-7%,生物量分别比2003年高2.1%-22.8%和1.8%-13.3%.     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.