Google Earth Engine支持下的江苏省夏收作物遥感提取

江苏省是农作物种植大省,国家统计局统计数据显示,江苏省近10年冬小麦、冬油菜的总播种面积分列全国第五、第七,快速准确地获取冬小麦和冬油菜的空间分布对于该省的农业发展具有重意义。基于单机的传统遥感分类能够准确获取农作物的空间分布信息,但是耗时较长。随着地理大数据与云平台、云计算的发展,Google Earth Engine（GEE）作为一个基于云平台的全球尺度地理空间分析平台,为快速遥感分类带来了新的机遇。本文基于GEE,使用Sentinel-2数据快速提取了江苏省2017年冬小麦与冬油菜的空间分布。首先,利用GEE获得覆盖江苏省119景无云质优的Sentinel-2影像;其次,在此基础上分别计算了遥感指数、纹理特征、地形特征,并完成原始特征的构建与优化;最后,分别试验了朴素贝叶斯、支持向量机、分类回归树和随机森林4种分类器,比较了各分类器的分类精度,并提取了冬小麦与冬油菜的空间分布信息。得出以下结论：①GEE能够快速完成覆盖江苏省影像数据的去云、镶嵌、裁剪及特征构建等预处理,较本地处理具有明显优势;②J-M距离值位于前两位且大于1将特征数量从28个压缩到11个,有效压缩了原始特征空间;③光谱+纹理+地形特征组合训练,朴素贝叶斯、支持向量机、分类回归树、随机森林的平均验证精度分别为61%、87%、89%、92%。     

杭州市伏、秋旱灾害风险区划

根据杭州市1959-2010年降水资料、自然环境以及社会经济要素,综合致灾因子、孕灾环境、承灾环境及防灾减灾能力,构建区域干旱灾害风险评价模型。通过ArcGIS空间分析技术结合模糊综合评价法,编制以100 m＆#215;100 m栅格为基本评价单元的杭州市伏、秋旱灾害风险区划图。区划结果表明,淳安西北部、建德中南部、桐庐中部、富阳南部、临安东部以及余杭、主城区,伏旱、秋旱灾害风险均较高。     

THE STUDY AND DISCUSSION ON “DIGITAL QINGHAI—TIBET PLATEAU”

THE STUDY AND DISCUSSION ON “DIGITAL QINGHAI—TIBET PLATEAU”     

Algicidal activities of secondary metabolites of marine macroalgal-derived endophytic fungi

Red tide occurrs frequently and causes signi?cant damage to the environment and human health. As a result, development of new effcient and environment friendly red-tide microalgae inhibitors has gained increasing attention in recent times. Algicolous endophytic fungi with unique habitats are promising sources for active agents owing to their abundant secondary metabolites and distinguished activities. In this study, the algicidal activities of 49 marine macroalgal-derived endophytic fungi against phytoplankton Alexandrium tamarense, Prorocentrum donghaiense, Heterosigma akashiwo, and Chattonella marina were examined using 96-well microplate. Four fungal strains, including Aspergillus wentii(pt-1), A. ustus(cf-42),and A. versicolor(dl-29, pt-20), exhibited potent algicidal activities. A total of 32 pure compounds isolated from these fungi were noted to possess dif ferent degrees of algicidal activities. Of those, 11 compounds comprising ?ve anthraquinones, two terpenoids, and four steroids showed high 24-h inhibition rates for the four red tide algae, with 24 h EC_(50) values ranging from 0.01 to 14.29 μg/mL. Among them, compound1(1,5-dihydroxy-3-methoxy-7-methylanthraquinone) presented the strongest activity against H. akashiwo,and could decrease its chlorophyll a(Chl a) and superoxide dismutase contents and increase the soluble protein, malondialdehyde, and peroxidase contents. These results suggested that the identi?ed anti-algal compound might inhibit the growth of red tide algae by weakening photosynthesis(reducing Chl a content),destroying cell membrane, and damaging the antioxidant system.     

北京市地理市情普查内业作业的设计及实现

按照国家要求,北京市组织开展了全市第一次地理国情普查工作。本文重点探讨了北京市地理市情普查内容与指标、作业流程、资料使用、内业采集与编辑整理、质量控制的设计及实现。这些内容的研究和探讨对现有的作业方式和作业内容有一定规范作用,可为今后开展常态化监测提供参考,对其他省市的省市情普查监测的开展有一定借鉴意义。     

Analgesis and wound healing effect of chitosan and carboxymethyl chitosan on scalded rats

Analgesis and wound healing effect of chitosan and carboxymethyl chitosan on scalded rats were investigated. A II degree scald model was established in rats, which was subsequently treated with chitosan and carboxymethyl chitosan solution, respectively. The concentration of bradykinin and 5-hydroxytryptophan was detected by assaying enzyme-linked immunosorbent. Healing condition was observed and pathological sections were made to determine the healing effect of chitosan and carboxymethyl chitosan. Results showed that the concentration of bradykinin and 5-hydroxytryptophan peaked at the third hour post-wound in all groups, while the concentration of hydroxyproline peaked at the seventh day post-wound in both chitosan and carboxymethyl chitosan group. The concentration of bradykinin and 5-hydroxytryptophan of carboxymethyl chitosan group was significantly lower than that of control (P < 0.05), while that of chitosan group was similar to that of control (P > 0.05). These findings indicated that carboxymethyl chitosan reduced the concentration of algogenic substances, resulting in analgesia. During the whole recovery process, the hydroxyproline concentration in chitosan and carboxymethyl chitosan group on day 3 and 7 was significantly higher than that of control (P < 0.01); however the significance of such a highness decreased on day 14 (P < 0.05). These findings indicated that chitosan and carboxymethyl chitosan accelerated tissue repair. Meanwhile, chitosan performed better in healing than carboxymethyl chitosan in both decrustation and healing time. In conclusion, carboxymethyl chitosan showed significant analgesis and wound-healing promotion effect, but chitosan only showed wound-healing promotion effect.     

基于多层神经网络与Sentinel-2数据的大豆种植区识别方法

大豆作为全球最重要的油料作物,是中国进口的大宗农产品,对其种植区的精准识别是决策制定、种植结构调整基础,对国家粮食安全有重要意义。本文利用Sentinel-2作为数据源,利用多层神经网络方法与对大豆进行提取,并与随机森林、决策树、支持向量机等机器学习进行对比,发现F1-Socre指标显示多层神经网络的分类精度最高,为93.53%,其次为随机森林、支持向量机、决策树。将神经网络分类结果与SLIC面向对象分割聚合之后,结果既忽略了同一地块的微小差别,又区分出了不同地块的作物差异,很好的体现了大豆的分布。Sentinel-2数据是进行大尺度大豆种植监测的绝佳数据源,大豆与玉米等其他作物在第二个红边波段的反射率有较为明显的差异。多层神经网络方法在图像分类任务中表现出色,结合图像分割算法精度可达到95.51%,可以满足大豆种植面积监测的需求。     

冬季亚澳季风环流的低频耦合过程

利用1982—1983年和1984—1985年两个冬季的欧洲中期预报中心格点资料研究了冬季东亚西风急流与澳大利亚夏季风在低频尺度上的相互作用与可能的传播方式。结果表明,我国北部上空的西风急流(及相应的锋区)与澳大利亚的夏季风的低频变化有很好的一致性。它们的联系和相互作用表现为:东亚西风急流通过改变西北太平洋地区的越赤道气流影响澳大利亚夏季风的低频变化,而澳大利亚夏季风则通过增强或减弱的高空辐散向北气流影响东亚西风急流。将这种相互作用称为亚澳季风环流的“低频耦合过程”。     

西秦岭江里沟钨铜钼多金属矿床地质特征及辉钼矿Re-Os同位素年龄

近些年探明的江里沟大型钨(铜钼)多金属矿床位于青海省同仁县,地处秦岭造山带西段勉-略缝合带以北岗察复式岩体西北缘,属斑岩-矽卡岩型钨铜钼多金属矿床。矽卡岩型钨(铜钼)矿体主要赋存于江里沟花岗岩体与下二叠统大关山群的大理岩和下三叠统隆务河群凝灰质细粉砂岩的接触带矽卡岩中,呈似层状、透镜状和豆荚状产出。云英岩型钨矿体和斑岩型钼矿体赋存于江里沟花岗岩体中。本次研究选取16件矽卡岩型和斑岩型辉钼矿样品,采用ICP-MS法进行Re-Os同位素定年,获得模式年龄介于215.0±3.0~219.0±3.7 Ma,加权平均年龄为216.85±0.77 Ma,等时线年龄为217±1 Ma(MSWD=1.4)。矿床形成于晚三叠世,属秦岭造山带印支期后碰撞伸展环境构造-岩浆-流体成矿的产物。     

青藏高原雨季降水凝结潜热的估算研究

利用美国NOAA系列卫星观测的青藏高原区(75°~105°E,25°~40°N)水平分辨率为2.5°×2.5°经纬度网格,共91个网格点的1974年6月—2005年12月的月平均射出长波辐射(简称OLR)资料,青藏高原93个常规气象站的1961—2005年的月降水资料,在研究降水量与OLR关系及其气候分区的基础上,分区、分网格建立了利用OLR估算降水量,进而估算降水凝结潜热的数学模型。利用所得模型计算出青藏高原雨季1961—2005年历年逐月的降水凝结潜热。结果表明,高原东部多年平均降水量为401.5 mm,凝结潜热为18.55×1020J。近45年高原东部的降水凝结潜热有所增大,其递增率为0.218×1020J/10a,相当于每10年增加1.2%。高原总体的降水凝结潜热及其变率略大于高原东部。