塔里木河流域土地利用监测适宜尺度选择方法

Optimal scale is one of the important issues in ecology and geography. Based on land-use data of the Tarim River Basin in Xinjiang of China in the 1950s, regarding the area of land use types as the parameter in scale selecting, the histograms of the patches in area are charted. Then, by reinforcing the normalized scale variances (NSV) with 3 landscape indices, the scale characteristics of land use in the Tarim River Basin can be summarized. (1) NSV in the Tarim River up to a maximum at scale of 1:50,000 which is considered appropriate for the Tarim River. (2) Diversity indices of saline land are consistent with NSV’s. Diversity indices and NSV of sandy land showed that the appropriate scale is in the same scale domain. There is a significant difference between diversity indices and NSV of forestland and shrubland. (3) Fractal dimension of sandy land and saline land showed a hierarchical structure at a scale of 1:10,000. Fractal dimension of forestland and shrubland are distributed under the same hierarchical structure in the region. Foundation: National Natural Science Foundation of China, No.40571030; No.40730633 Author: Zhao Jin (1980–), Ph.D, specialized in study of scale effect.     

安徽省数字化形变仪器及观测资料的综合分析

从仪器运行情况,影响形变观测的主要因素,观测精度和映震能力等方面,对安徽省淮北,泾县,泗县数字化形变观测台站的监测能力进行了综合分析,得到了安徽省数字化形变前兆观测的基本情况,对安徽省形变台网观测资料的应用和未来台站建设具有一定的参考意义。     

The relationship between methylated chromans and maturity of organic matter in the source rocks from Jianghan hypersaline basin

The distribution, the relative composition, and their variation of methylated chromans (MTTC) with maturation of organic matter in the source rocks from Mingjia 1 well, Jianghan hypersaline basin, have been analyzed and studied. There is a close relationship between the distribution of methylatd chromans and paleosalinity of depositional environment. In the Eq ₁–Eq ₃ source rocks deposited under hypersaline environment with lower Pr/Ph ratio, higher gammacerane index and abundant organic sulfur-containing compounds, methyl MTTC and dimethyl MTTC are main components, but in the Eq ₄ source rocks deposited non-hypersaline environment with relatively higher Pr/Ph ratio, lower gammacerane index and organic sulfur-containing compounds, trimethyl MTTC is a major compound in methylate chromans. Obviously, the distributions and the compositions of methylated chromans in the source rocks are in harmony with biomarker indicators indicating the paleaosalinity and redox of depositional environment. The relationship between the ratio of 5,8-dimethyl MTTC to 7,8-dimethyl MTTC (dimethyl MTTC ratio) and the maturity of organic matter in the source rocks from Mingjia 1 well has been discussed. The results show that dimethyl MTTC ratio increased with the burial depth and the maturation of organic matter in the source rocks, especially in immature level. It is noteworthy that this ratio is very susceptible to small variation in the maturity of organic matter in the source rocks when vitrinite reflectance R _o is less than 0.65%. It may imply that this ratio is a good and susceptible aromatic maturity indicator for the relative maturity of organic matter in immature source rocks.     

郑开下穿越工程非饱和土土-水特征曲线室内试验研究

利用气相法和渗吸法,对郑州至开封下穿越工程降水施工引起的非饱和砂质粉土和粉质黏土的土-水特征曲线进行了室内试验研究。研究结果表明,非饱和砂质粉土和粉质黏土的进气值约为2 kPa和250 kPa,残余饱和度对应的吸力值约为15 MPa和28 MPa,两种非饱和土的减饱和过程都具有明显的阶段特征。通过该工程非饱和土土土-水特征曲线的分段性研究,对于工程降水施工以及掌子面加固等有重要的指导意义。     

主成分分析在农田土壤环境评价中的应用

本文尝试利用主成分分析方法对农田土壤污染物进行识别,并对土壤环境质量进行分级。结果表明,利用主成分分析可以有效地识别土壤污染物中的主要成分,揭示土壤污染物的数据结构和相互间的关系。主成分分析方法可用于定量化的土壤复合污染研究或对历史数据较为缺乏的地区进行土壤环境质量评价。在污染物检测指标数量较大时,可以在一定程度上简化农田土壤重点污染物的定量化识别过程。     

云南盐津2006地震群的强震动应急观测研究

2006年7月22日09时10分21.6秒,云南省昭通市盐津县境内(28°01′N,104°08′E)发生Ms5.1地震,震源深度9km.极震区烈度为Ⅵ度,个别Ⅶ破坏点,等震线形状呈椭圆形,长轴走向北东向.地震造成22人死亡,13人重伤,35428户、151168人受灾.2006年8月25日13时51分41.1秒,盐津县(28°03′N,104°07′E)再次发生5.1级地震,震源深度7km,较7月22日地震略浅.微观震中由722地震位置向西北偏移约4km.由于震中位置基本相同,故地震灾害相互叠加,出现灾害加重现象和灾情范围扩大趋势,地震造成2人死亡,重伤7人,1万多户、4.5万多人需要紧急转移安置,房屋倒塌1500多间,其中170所学校的校舍不同程度受损.     

Genetic algorithm for seismic topology optimization of lifeline network systems

Lifeline systems, such as water distribution and gas supply networks, usually cover large areas. For these systems, seismic design is always a difficult problem because of the complexity of large‐scale networks. In this paper, a topology optimization technology for lifeline networks is established. Firstly, in order to speed up the convergence of optimization process, an element investment importance analysis is carried out to evaluate the importance of components to the lifeline network. Then a topology optimization model is established. The aim of the model is to find the least‐cost network topology while the seismic reliability between the sources and each terminal satisfies prescribed reliability constraints. For this optimization problem, a genetic algorithm, which takes network topologies as the individuals of its population, is used to search for the optimal solutions by suitable operators, including selection, crossover and mutation operators. The capacity of the proposed algorithm is illustrated by its applications to a simple example network consisting of 10 nodes and an actual network with 391 nodes located in a large city of China. Copyright © 2008 John Wiley & Sons, Ltd.     

基于实测的采空区稳定性数值模拟分析

准确掌握采空区的三维形态和空间位置是进行采空区稳定性数值模拟的关键。介绍了空区三维激光探测系统（cavity monitoring system,CMS）的基本构成、工作原理及探测方法。结合冬瓜山铜矿采空区的实际情况,在采用CMS准确探测采空区的基础上,应用Surpac建立采空区三维模型和矿区地学三维模型,提出采用数据转换的耦合模式将Surpac与Phase2耦合构建数值计算模型,进行数值模拟计算,根据模拟计算结果对采空区的围岩稳定性进行了分析。研究结果表明,将CMS,Surpac和Phase2三者的优势结合起来,可为岩土工程的稳定性数字模拟研究提供一条新的有效途径。     

日本盘鲍×皱纹盘鲍子代杂种优势的RAPD分析

本文通过对日本盘鲍 (D)、皱纹盘鲍 (H)及其二者的正反杂交子代 D♀× H♂ (DH)、D♂× H♀ (HD)四样本的基因组 DNA进行 RAPD标记分析。探讨了杂种优势产生的分子遗传机制。从 4 0个随机引物 (OPK,OPV系列 )中筛选出 12个引物进行扩增 ,共得到 113条清晰稳定的扩增带 ,多态率占 4 3.3%。其中四群体各有其特异扩增位点。另外 D与 DH,H与 HD及 D与 DH,HD等间亦存在共享片段。四群体内相似性指数各自为 0 .798(H)、0 .799(D)、0 .777(HD)、0 .788(DH)。可见正反杂交子代群体内相似性指数皆低于两亲本 ,这表明杂种子代基因组发生的变异更大些。皱纹盘鲍与其正反杂交子代的相对遗传距离分别为 0 .0 76 ,0 .0 95,而日本盘鲍与其正反杂交子代的相对遗传距离分别为 0 .0 31,0 .0 33,前者明显大于后者 ,这表明杂交子代与两亲本的遗传距离不是对等的 ,而是更偏向日本盘鲍。     

长江口上升流海区的生态环境特征

根据 1 985年 8月的调查资料 ,讨论了长江口上升流海区的生态环境特征。研究表明 ,在长江口外 ,大约在 1 2 2°2 0′— 1 2 3°1 0′E、31°0 0′— 32°0 0′N海区存在着明显的下层高盐冷水的抬升现象 ;伴随这种上升运动 ,于 5— 1 0m层 ,在上述高盐冷水区明显地存在一个低溶解氧、高营养盐区。资料表明 ,该低氧、高营养盐海水不是直接来自表层的长江冲淡水 ,而是来自深底层的变性后的台湾暖流水。分析表明 ,长江口外的浮游植物高值区的分布位置与上升流区基本一致 ,两者比较浮游植物高值区略向东南方向偏移约 1 5— 2 0km。作者认为形成这种偏离现象的原因可能与上升流中心区水温偏低有关