湖光岩拮抗菌的研究

采用涂布法、划线分离法以及形态学和生理生化特性分析,对湛江湖光岩微生物进行了分离纯化及部分性质研究;同时用平板菌落计数法对其异养细菌、真菌和弧菌等的数量进行初步统计。采用牛津杯法,对拮抗细菌进行筛选和培养特性研究。结果表明,微生物数量与种类在水平分布上具有显著差异。底泥异养菌总量为（1．3—8．6）×10^8 cfu／g,真菌总量为（0．1—5．7）×10^7 cfu／g。而水体细菌总量为（0．5—6．7）×10^5 cfu／ml,真菌总量为（0．4-1．1）×10^3 cfu／ml。共分离纯化到148株细菌,经筛选发现16株细菌对溶藻弧菌（Vibrio alginolyticus）具有明显的抑制作用,占细菌总数的10．8％,其中菌株DH078和DH113对溶藻弧菌的拈抗作用最明显。结果还表明,细菌DH078在营养肉汤中培养4d抑菌活性最强,其产生抗菌活性物质的最佳条件是稀释2倍的营养肉汤、蛋白胨0．6％、牛肉膏0．6％、酵母膏0．2％、盐度0和pH7．0。可见湖光岩微生物资源较为丰富,本研究可为保护和充分开发利用湖光岩微生物提供科学依据。     

大辽河口溶解态重金属的变化特征及影响因素研究

分别于2009年7月和2010年4月在大辽河口采集表层水样,测定了水体中溶解态Cu、Pb、Zn、Cd和Cr的含量,并对其分布特征及影响因素进行探讨。结果表明:除2010年4月Cu,及个别站位Pb、Zn含量较高外,表层水重金属含量均达到国家一类海水水质标准。2010年4月表层水中Cu、Pb、Zn、Cr的浓度大于2009年7月,2航次Cu、Cd、Cr的含量由河向海呈逐渐上升趋势,2010年4月Pb、Zn的含量表现为河口段高于口外海滨。重金属的含量和分布主要受径流量、潮汐作用以及风浪扰动的影响。     

溶藻弧菌外膜蛋白对凡纳滨对虾免疫功能的影响

应用溶藻弧菌外膜蛋白(Outer membrane protein,OMP)注射凡纳滨对虾Penaeus vannamei,测定其对凡纳滨对虾免疫指标的影响以及对凡纳滨对虾的免疫保护作用。注射OMP0.5、1.0和1.5mg.ml-1后3个实验组的凝集效价均显著高于对照组(p<0.05),但实验组之间差异不显著,而血清溶菌活力在注射后急剧上升,在6h时达到最高,随后下降,到96h时基本恢复正常。0.5和1.0 mg.ml-1OMP组的抗菌活力在12h时达到最高值,且在12—72 h之间均明显高于对照组和1.5 mg.ml-1组(p<0.05)。血清溶血活力在注射后3h达到最高值,在1—96h内,实验组的溶血活力维持较高水平,均高于对照组。0.5、1.0和1.5mg.ml-13个OMP实验组对凡纳滨对虾的免疫保护率分别为65.9%、75.6%和70.7%。     

卵形鲳鲹结节病病原的分离与鉴定

从湛江港、阳江闸坡海水网箱养殖的患结节病卵形鲳鲹(Trachinotus ovatus)中分离一株细菌,回归感染结果证明该菌是引起卵形鲳鲹结节病的病原,对卵形鲳鲹半致死浓度为45 g-1。该菌株呈革兰阳性,好氧,具有弱抗酸性,菌体呈短杆状或细长分枝状,过氧化氢酶阳性,氧化酶阴性,还原硝酸盐,不水解酪素、黄嘌呤、酪氨酸、淀粉、明胶,以柠檬酸盐为唯一碳源生长。对其16S rDNA序列作Blast分析,构建系统进化树。结果表明,该菌株与诺卡氏菌属的菌株亲缘关系最近,且与鰤鱼诺卡氏菌(Nocardia seriolea JCM 3360T)的16S rDNA序列同源性高达99%。综合患病鱼的症状及病原菌形态、生理生化特性及16S rDNA序列的结果,该菌被鉴定为鰤鱼诺卡氏菌(N.seriolea)。     

Google Maps组件二次开发与应用

随着Web平台逐渐成熟,在互联网上服务的新技术陆续出现,促使地理信息系统(GIS)的功能强大、应用广泛。目前,基于浏览器应用程序的开发技术,结合Google Maps和Joomla框架的组件无疑是最引人注目的技术之一。本文分析了Google Maps在Joomla构站中的现实应用,设计了一套Google Maps在Joomla中集成的解决方案,并且阐述了组件四个功能模块的实现过程。此组件基于Google Maps API与Joomla框架,利用PHP和JavaScript脚本语言进行开发,提供了Google Maps在Joomla网站中的一种简易安装方式,实现添加标记,画线等简单应用,并对其在复杂组件环境中的应用作了初步研究。     

Development of grouting materials with application to the protection of the geological relics of the Weng'an Biota

The Weng'an Biota, a fossil KonservatLagerst?tte in South China that is c. 570 – 609 myr old, preserves the world's oldest zoolite and provides a unique empirical record for studying animal origins and early evolution. Due to geological disasters caused by the exploitation of the local phosphate mine, part of the fossilized records and the geological sections of the Weng'an Biota have been seriously damaged. Protection of this unique fossil area is urgently required. In this research, an innovative scheme for the protection of the geological relics of the Weng'an Biota is proposed by backfilling the mine cavity with specially formulated grouting materials. In view of the shortcomings of the current grouting materials, such as the high proportion of water separation, the low stone percentage and high cost, newly developed grout materials consisting of mixtures of cement-fly ash-expansion agent(C-F-E) were systematically studied by a combined method of theoretical analysis and experimental study. Firstly, new grouting materials(C-F-E) were developed using selected proportions of(1) Portland cement(P·O 32.5),(2) external admixture(Fly ash),(3) expansion agent(NV) and(4) admixture(DFZ). Then, the properties of new grouting materials(C-F-E), such as stability, stone percentage, rheology, fluidity, setting time and compressive strength were evaluated by laboratory tests. Finally, a new model of the hydration process was proposed for these newly developed grouting materials based on a detailed scanning electron microscopy(SEM) study of their microstructural development. These research results will provide an effective solution to the protection of the geological relics of the Weng'an Biota. Additionally, these grouting materials may prove suitable for solving similar problems in the management of most mine cavities requiring stabilization in the future.     

四川东北部“9·20”暴雨落区预报误差分析及思考

利用常规气象资料、卫星云图及雷达资料、自动气象站资料及NCEP1°×1°逐6h再分析资料,对2018年9月19—20日四川盆地东北部一次暴雨落区预报误差进行分析。结果表明:副高快速东退南压,配合低层强北风,加快了低层切变线和急流东退南压;西南气流偏西分量增强,偏南分量减弱,加快降水系统的东移,使得降水系统主要停滞在四川东北部的广安及达州中南部区域,造成该区产生暴雨和大暴雨。数值预报场上副高、切变线和急流东退南压速度均明显慢于实况,导致此次过程暴雨预报落区较实况误差较大。由卫星云图、地面流场和露点锋区分析可以看出,通过暖湿气流中具备抬升作用的位置可以判断1~3h内云团的演变趋势,确定强降水落区,为短临预报提供较好参考。通过多普勒雷达垂直风廓线产品(VWP)分析700hPa附近引导气流的转换来判断系统移动的速度和移出的时间。数值预报具有自身的误差和不稳定性,在实际业务中应以数值预报为基础,综合分析多种观测资料订正数值预报才能提高暴雨落区预报准确率。     

基于桩-锚结构造价的锚索拉力计算模型研究

桩-锚结构的计算包括锚索拉力计算和桩身内力计算,通过锚索拉力计算桩身内力,再通过桩身内力计算结构造价,锚索拉力将影响桩-锚结构造价的计算,因此,锚索拉力计算对桩-锚结构设计尤为重要。通过对桩-锚结构造价与锚索拉力之间的关系进行分析研究,从桩-锚结构造价与锚索拉力的关系曲线、多项式拟合以及优化的变形协调条件3个方面建立与桩-锚结构造价相匹配的锚索拉力的计算模型。结合桩身内力计算的m法和K法以及结构力学中的虚功原理和图乘法理论,编写Visual C++计算程序,通过不同的滑坡工程实例对不同锚索拉力作用下的桩-锚结构造价进行计算,获得锚索拉力与桩-锚结构造价的关系图。计算结果表明:桩-锚结构造价是随着锚索拉力的增大先减小后增加的。关系曲线模型和多项式拟合模型计算的与桩-锚结构最低造价相匹配的锚索拉力与优化的变形协调条件计算的锚索拉力十分接近,可选择其中任意一种计算方法计算得到的锚索拉力作为最终锚索拉力计算值。此时,桩身弯矩的正负极值并不相等,这也表明桩身正负弯矩的极值相等时的锚索拉力并不一定是最优的锚索拉力,因为此时桩身所处的受力状态虽然比较理想,但造价可能较高,经济效益不佳。     

The variation of evaporation over South China and its relationships to precipitation

The evaporation rate over South China is estimated based on the Climate Prediction Center Merged Analysis of Precipitation(CMAP)data and the NCEP/DOE reanalysis II data from 1979 to 2007. The temporal variation of evaporation over South China and its relationship to precipitation are discussed. Climatologically,the evaporation rate over South China is the largest in July and smallest in March.In spring and summer,the evaporation rate is approximately one half of the precipitation rate.However,the evaporation rate is approximately equal to the precipitation rate in fall and winter.The year-to-year variation of the evaporation rate over South China is quite in phase with that of the precipitation rate in the period from February to May but out of phase with that of the precipitation rate in early winter.Over South China there is a pronounced decreasing trend in the evaporation in colder seasons and a positive correlation between the evaporation variation and the rainfall variation in spring.In summer,the abnormality of rainfall over South China is closely related to the anomalous evaporation over the northeastern part of the South China Sea and its eastern vicinity.In winter,the rainfall variation in South China has a close linkage with the evaporation variation in a belt area covering the eastern Arabian Sea,the Bay of Bengal,the southeastern periphery of the Plateau,the southern part of South China Sea and the central part of Indonesia.     

高精度磁测正常场改正和高度改正精度

地球磁场强度存在沿纬度方向和高度方向上的变化,在开展高精度磁测工作时,必须进行高度改正和正常场改正。目前普遍使用的改正方法是根据高斯球谐表达式的13级近似式、十级近似式以及一级近似式进行改正的。经计算发现,与高斯球谐表达式的13级近似式相比,当测点与基点的南北方向距离为30 km时,使用十级近似式计算的正常场改正误差为-0.21 nT;使用一级近似式计算的正常场改正的误差随测点与基点的南北方向距离增大而增大,当测点与基点的南北方向的距离大于4 km时,正常场改正误差大于1 nT;使用一级近似式计算的高度改正的误差随测点与基点高度差增大而增大,当测点与基点高度差大于300 m时,误差大于1 nT。