Ultrasonic-assisted condensation of chitosan with salicylaldehyde

In order to synthesize an improved adsorbent for heavy metal ions, we studied the condensation reaction of chitosan with salicylaldehyde in ethanol to form a Schiff base. The effect irradiating the reaction using an ultrasonic liquid processor was contrasted with conventional methods. The IR spectra of condensed chitosan prepared by the two methods showed that their molecular structures were identical. The reaction conditions, including solvents, ultrasonic power density and irradiation time, pH, and reactant ratio, were optimized by orthogonal design. A shorter reaction time and a higher product yield were obtained using ultrasonic-assisted synthesis compared with the traditional method. A condensation degree of 89.63% was achieved using the optimized conditions: i.e. ultrasonic irradiation at 180 W for 60 min; 95% ethanol as the solvent, pH 4.0, and salicylaldehyde:chitosan ratio of 6:1.     

青藏高原典型植被生长季遥感模型提取分析

物候变化是衡量全球气候变化最直接、敏感的指示器,针对青藏高原这个独特地域单元上特殊的高寒植被进行关键物候期遥感提取模型及植被物候时空变化的研究具有重要的意义。本文首先以反距离加权空间插值算法与Savitzky-Golay滤波算法相结合的数据重建模型获得高质量2003-2012年青藏高原MODIS归一化植被指数(NDVI)数据。在此数据基础上,分别利用动态阈值法、最大变化斜率法、logistic曲线拟合法3种遥感植被生长季提取模型,对青藏高原地区两种典型植被的生长季(SOS生长季开始期,EOS生长季结束期,LOS生长季长度)进行提取。通过对3种模型提取结果的对比分析,并结合日均温模型对提取结果的验证发现,动态阈值法为青藏高原地区典型植被生长季的最优遥感提取模型。该模型对近10 a的高分辨率典型高寒植被物候参量的反演及时空变化特征分析表明,受青藏高原水热及海拔梯度的影响,青藏高原植被物候变化呈现出从东南向西北的空间分异规律,随春季温度的升高,近10 a来青藏高原高寒草地总体呈现生长季开始期(SOS)提前(0.248 d/a)的趋势。     

Lithofacies features and mechanism of formation of “Zihe-type” time- and strata-bound iron ore deposits in central Shandong province

The Lower Palaeozoic system is a series of iron-bearing rocks consisting mainly of shallow sea-fades carbonates. On the basis of microfacies analysis of the carbonate rocks, the Lower Palaeozoic sedimentary sea basin is divided into two broad sedimentary-tectonic regions of four sedimentary facies and eight subfacies. The original iron-rich carbonates were deposited in saltlakes, lagoons, etc. of the restricted basins. Over the long geological history, the original iron formations were reconstructed to various extents by late tectonic processes. Geological observations and studies on the equilibrium mechanism of oxygen/sulfur isotopic fractionation and the composition and temperature of fluid inclusions in the minerals indicate that thermal brines played an important role in reworking of the original iron-rich carbonate rocks, which led to the formation of sedimentary-reworked strata-bound ore deposit.     

Tectonic Dynamic Metallization of Silver-GoldHydrothermal Fluids in Proterozoic GneissTerrene Shear Zones, Suichang, Zhejiang, China

-,The well-known Suichang silvengold field is located inZhejiang Province of SOutheast China. It is the largest silver-gold deposit associated with copper and zinc in the Cathaysianmetallogenic province.There are a series of silver-gold dePOsits in the shear zonesof Proterozoic gneiss terrene, Suichang region. The volcanicapparatus at Mesozoic has complicated rpineralization. Respectively, there are two pieces of understanding on the origin ofore-formigg nuid: (l ) metamorphic fluid (Lia…     

广西芒场锡-多金属矿田叠加褶皱构造及趋势面分析研究

本文利用传统构造地质学中小构造要素统计方法,从空间上恢复并确定了芒场锡-多金属矿田内印支早期北北西向芒场复背斜和燕山晚期北北东向褶皱;利用趋势面分析方法给出了两期褶皱的叠加部位及其控矿模型。根据叠加褶皱具等距性控矿特点,笔者预测了已知矿床外围的两个未知矿点,经野外验证和工程揭露表明,上述矿点均见有锑、银矿化。     

湖北交通运输大数据存储应用平台设计与实现

针对当前湖北省交通运输数据的存储管理与应用瓶颈,结合目前大数据技术的发展背景,本文基于Hadoop生态体系设计与实现了针对湖北交通运输业务的大数据存储分析平台。文中从总体架构、存储结构、扩展架构、数据接入与治理、分布式任务调度的设计实现到平台的应用场景进行了论述,并使用10年的高速公路数据与具体业务场景对平台进行了存储与效率实验。实验结果表明,相比传统关系型数据库,该平台在数据存储、查询计算方面均具有非常明显的优越性。     

不等视距水准测量应用及精度分析

在水准测量作业过程中,为减小视距差引起的系统误差,相关规范对水准测量前后视距差及视距累积差进行了严格的控制,而在实际的工作中对前后视距差的控制又极大地限制了水准测量的应用领域以及工作效率。针对此问题,该文提出将i角当作系统参数进行平差的方法,平差结束即可得到i角值以及经过i角误差改化后的高程平差值。对比分析了附加系统参数平差法与条件函数法,实例表明附加系统参数平差法具有更好的高效性和稳健性。     

黄河三角洲浅层地下水盐分来源及咸化过程研究

黄河三角洲地下水咸化已成为区域最突出的生态环境问题之一。识别地下水补给及盐分来源是有效控制和改善地下水咸化问题的关键。本研究采集了研究区浅层地下水、地表水和海水等不同类型水样,利用离子比、Piper三线图、吉布斯图等方法对八大离子浓度、δD和δ¹⁸O 组成、Br和Sr 浓度等进行地下水补给研究与盐分来源辨析。结果表明:(1)黄河三角洲浅层地下水以总溶解性固体(TDS)为338 g/L的咸水为主,地下水水化学类型较为单一,主要为Cl-Na型。(2)三角洲区域地下水以大气降水补给为主,并且在补给过程中经历了不同程度的蒸发作用的影响,黄河现行流路区域地下水主要来源于河水侧渗补给,但浅层地下水含水层水平渗透性较差限制了黄河侧渗补给范围。(3)海洋是黄河三角洲浅层地下水盐分的主要来源,黄河现行流路区域及近岸地下水盐分来源于海水混合,三角洲北部刁口河等古河道区域地下水盐分主要来源于海相蒸发盐淋滤溶解。     

Fabric evolution and liquefaction resistance in multiple-liquefaction process: a micromechanical study using DEM-clump

Acta Geotechnica - Recent earthquake case histories in Japan and New Zealand revealed that soil sites can experience liquefaction multiple times under a sequence of earthquake shaking. Field...     

基于SEM的湖南省暴雨气象防灾减灾服务公众满意度评估

以湖南省暴雨气象防灾减灾服务为研究视角,首先对湖南省气象局暴雨气象防灾减灾服务效益评估研究组抽样调查得到的7 478份问卷数据进行无效问卷剔除,在此基础上,从暴雨预报的准确性、预警发布的及时性、信息发布的频次、获取信息的便捷性、内容的通俗性及防御建议的有效性六个方面,分析公众暴雨气象防灾减灾服务满意度。采用结构方程模型,评估各个因素对暴雨气象防灾减灾服务公众满意度的影响。最后利用所得到的各个路径系数建立暴雨气象防灾减灾服务公众满意度评估模型,代入调查问卷采集到的数据后得到湖南省暴雨气象防灾减灾服务公众满意度为88.02%。