Physiological acclimation strategies of riparian plants to environment change in the delta of the Tarim River,China

The occurrence and development of riparian forests, which were mainly dominated by mesophytes species related closely with surface water. Since there was no water discharged to the lower reaches of Tarim River in the past three decade years, the riparian forests degrade severely. The groundwater table, the saline content of the groundwater, as well as the content of free proline, soluble sugars, plant endogenous hormones (abscisic acid (ABA), and cytokinins (CTK)) of the leaves and relative rates of sap flow of the Populus euphratica Oliv. (arbor species), Tamarix ramosissima Ldb. (bush species), and Apocynum venetum L. (herb species) were monitored and analyzed at the lower reaches of the Tarim River in the study area where five positions on a transect were fixed at 100 m intervals along a sampling direction from riverbank to the sand dunes before and after water release. The physiological responses and acclimation strategies of three species to variations in water and salinity stress were discussed. It was found that A. venetum population recovered to groundwater table ranging from −1.73 to −3.56 m, and when exposed to saline content of the groundwater ranging from 36.59 to 93.48 m mol/L; P. euphratica appeared to be more sensitive to the elevation of groundwater table than the A. venetum and T. ramosissima at groundwater table ranging from −5.08 to −5.80 m, and when exposed to saline content of the groundwater ranging from 42.17 to 49.55 m mol/L. T. ramosissima tended to be the best candidate species for reclamation in this hyper-arid area because it responded to groundwater table ranging from −1.73 to −7.05 m, and when exposed to saline content of the groundwater ranging from 36.59 to 93.48 m mol/L. These results explained the distribution patterns of desert vegetation in the lower reaches of the Tarim River. Understanding the relationships among ecological factors variables, physiological response and acclimation strategies of plant individuals could provide guidance to sustainable management, reclamation and development of this and similar regions.     

似水准椭球

提出了“似水准椭球”概念,给出了“似水准椭球”的“匀质分层”、“整体纬向”和“内匀外纬”3种模式的密度分布方式。针对“似水准椭球”密度分布的合理性和稳定性问题,初步提出了求解“似水准椭球”的拉格朗日函数和哈密顿积分的设想。     

多维地震作用下偏心结构的磁流变阻尼器半主动控制

理论研究与震害经验表明,地震时结构会产生不可忽略的平动与扭转耦合的空间振动。本文提出了基于线性最优控制理论的部分状态反馈次优控制策略和基于遗传算法的控制策略,以Marlab和Simulink为平台,采用磁流变阻尼器对双向水平地震作用下的偏心结构平．扭耦联反应进行半主动控制。对-6层双向偏心框架结构进行控制效果仿真分析的结果证明,本文提出的2种控制策略是有效的。     

凡纳滨对虾(Litopenaeus vannamei)体重、存活性状的遗传参数和基因型与环境互作效应

利用7个凡纳滨对虾(Litopenaeus vannamei)引进群体,通过双列杂交和巢式交配设计构建家系,建立育种基础群体,估计体重、存活性状的遗传参数和基因型与环境互作效应(genotype by environment interactions,G×E)。结果表明,凡纳滨对虾基础群体体重和存活性状的遗传力估计值范围分别在(0.19±0.09)—(0.43±0.09),(0.27±0.04)—(0.45±0.06),均属于中高遗传力水平,并且统计检验显著(P<0.05)。Z-score检验表明,体重和存活性状遗传力估计值在河北黄骅(HBHH)和青岛鳌山(QBAS)两个测试场间差异均不显著。体重和存活性状的表型和遗传相关系数分别为0.007和0.008,表现为低度线性负相关。对于体重和存活性状,HBHH和QBAS场间的遗传相关分别为0.83±0.04和0.40±0.11。体重性状的G×E效应不显著(K<0.5),但存活性状存在显著的G×E效应(K>0.5)。上述结果显示,凡纳滨对虾基础群体体重和存活性状的遗传变异丰富,多代选择可获得较大的遗传进展。     

冰封期水动力水质模型在松花江水污染事件中的应用

根据研究流域特点建立了冰封期水动力水质模型,结合冰封期水位测量的特点,对水位模拟结果进行了修正,分别利用2006和2007年水文监测数据对模型进行了率定和验证,利用模型对2005年松花江硝基苯水污染事件进行模拟。计算结果表明:建立的冰封期水动力水质模型能够很好地适用于该地区,部分断面硝基苯质量浓度峰值的相对误差为5%~13%,峰值出现时间的绝对误差为2~3 h。利用模型预测了上游边界流量增加20%及减少5%对水质的影响,结果表明:流量增加导致污染团峰值提前22 h到达摆渡河断面,硝基苯质量浓度峰值降低了15%,流量减少导致峰值延迟6 h到达摆渡河断面,质量浓度峰值升高了4.6%。     

济阳坳陷沾化凹陷罗家地区古近系沙河街组页岩储集特征分析*

利用岩石薄片和扫描电镜分析等测试技术, 可以将济阳坳陷罗家地区古近系沙河街组页岩段储集空间分为孔隙和裂缝两大类。孔隙又可以分为黏土矿物晶间孔、碳酸盐矿物晶间孔、黄铁矿晶间微孔、碎屑颗粒溶孔和砂质粒间微孔5个亚类;裂缝分为成岩裂缝和构造裂缝两大类, 成岩裂缝又可以分为层间裂缝和粒缘裂缝两类。裂缝与基质孔隙之间, 存在一个微米尺度的重合带, 反映了储集空间发育继承性的特点, 油气聚集在以层间裂缝为中心, 粒缘裂缝等次级裂缝和较大的碳酸盐晶间孔为骨架, 以各类晶间孔隙、黏土微孔和溶蚀孔隙为基质的储集空间网络中。储集空间发育与岩性关系密切, 纹层状泥质灰岩物性较好, 相应的页岩物性具有基质渗透率极低和裂缝导流能力较强的特点。     

砂砾岩水力压裂裂缝扩展规律的数值模拟分析

砂砾岩储层一般具有岩性和渗透性变化大、孔隙度低、连通性差、孔隙结构复杂和非均匀性严重等特点,因此,在水力压裂过程中,裂缝扩展形态难以控制,大规模改造难度大。针对国内某典型砂砾岩油藏特征,采用数值计算方法对砂砾岩压裂裂缝的扩展规律进行了研究,包括地应力场、砾石含量和粒径等对裂缝扩展形态及压裂压力的影响。研究表明,砾石的存在增加了压裂裂纹扩展的复杂性,裂纹主要有止裂、偏转、穿透和吸附4种表现模式,但主应力差严格控制着裂纹的走向,随着主应力差的增大,裂纹由总体绕砾扩展转变为总体穿砾扩展,失稳压力随着主应力差的增大而明显减小;砾石含量的多少体现了砂砾岩试样宏观的非均匀性,含量越高均匀性越差,随着砾石含量的提高,裂纹与砾石的相互作用占据主导地位,失稳压力随砾石含量的增加而增大;当砾石体积含量一定时,砾石粒径对压裂压力的影响主要取决于砾石排列的随机性,失稳压力随砾石粒径的增大而略有增大。     

Comparison in copper accumulation and physiological responses of Gracilaria lemaneiformis and G. lichenoides (Rhodophyceae)

Heavy metal pollution has become a worldwide problem in aquaculture. We studied copper (Cu2+ ) accumulation and physiological responses of two red algae Gracilaria lemaneiformis and Gracilaria lichenoides from China under Cu2+ exposure of 0-500 μg/L in concentration. Compared with G. lemaneiformis, G. lichenoides was more capable in accumulating Cu2+ , specifically, more Cu2+ on extracellular side (cell wall) than on intracellular side (cytoplasm) and in cell organelles (especially chloroplast, cell nucleus, mitochondria, and ribosome). In addition, G. lichenoides contained more insoluble polysaccharide in cell wall, which might promote the extracellular Cu2+ -binding as an efficient barrier against metal toxicity. Conversely, G. lemaneiformis was more vulnerable than G. lichenoides to Cu 2+ toxin for decreases in growth, pigment (chlorophyll a, chlorophyll b, phycobiliprotein, and β-carotene) content, and photosynthetic activity. Moreover, more serious oxidative damages in G. lemaneiformis than in G. lichenoides, in accumulation of reactive oxidative species and malondialdehyde, and in electrolyte leakage, because of lower antioxidant enzyme (superoxide dismutase and glutathione reductase) activities. Therefore, G. lichenoides was less susceptible to Cu2+ stress than G. lemaneiformis.     

面向网页文本的地理要素变化检测

地理要素变化检测已成为国家地理信息"十二五"规划和全国地理国情普查的重要组成部分。网页文本中蕴含海量的地理要素信息,尤其是新闻、政府、社交平台等网站的网页文本更新频繁,可为地理要素变化检测提供现势性的数据源。本文针对网页文本中地理要素变化的语言描述特点,构建了表达地理要素变化的语义知识库,设计了搜索引擎和通用主题相结合的网页爬虫,实现了相关网页文本的高效获取;采用规则模型和条件随机场模型,分别进行网页文本中地理要素变化信息抽取,包括地理要素名称、位置(地名)、时间和属性等。实验结果显示,本文设计的网页爬虫具有较高的相关网页文本获取能力,地理要素变化信息抽取的准确率能够达到70%以上,但是,语义知识库的完备程度对于信息抽取性能具有较大影响。研究成果表明,以网页文本为数据源的地理要素变化信息获取方法,能提供一种快速检测地理要素变化的新途径,与实地调绘和遥感影像检测等方法结合应用具有较好的优势互补性,可作为有力的辅助手段解决地理要素的持续更新和实时更新问题。     

基于MapX和VC++的地理信息监控系统的设计与实现

在VC++开发环境下,利用GIS开发工具Mapinfo的MapX组件,设计地理信息监控系统。通过电瓶车信息采集系统客户端软件的实际运用证明了这种方法的实用性,实现了传输数据、地图控制、数据管理等主要功能。