用一种方法同时检测水产品中的多种致病性弧菌

建立了水产品中12种致病性弧菌的同一检测方法。确定了增菌、分离培养基、培养温度等关键参数。新方法有较好的特异性，简便、快速，灵敏度＜0.4个／g；对200份水产品的检测结果显示，新方法的检测结果同常规培养法的结果完全相符。     

In-Situ Observation of Fluid Mud in the North Passage of Yangtze Estuary, China

Observations of fluid mud were made in the lower North Passage of the Yangtze Estuary in February 2000, on 10 -11 August 2000, on 30 - 31 August 2000 (after two strong typhoons), on 21 - 24 August 2000 (neap tide) and on 3 -6 September 2000 (mean tide) respectively. In situ data show that the fluid mud in this area consists of fine cohesive sediment (median size 7.23 μm). The formation and movement of fluid mud varied during the neap-spring and flood-ebb tidal cycle. Observations suggest that fluid mud phenomena in this area may be categorised in a three-fold manner as slack water, storm and saltwedge features. The thickness of the fluid mud layer of slack water during the neap tide ranged from 0.2 to 0.96 m, whereas during the mean tide, the thickness ranged from 0.17 to 0.73 m, and the thickness of the fluid mud layer was larger during slack water than at the flood peak. Shoals cover an area of 800 km^2 with a water depth smaller than 5 m. Erosion of these extensive intertidal mudflats due to storm action provides an abundant sediment source. This is particularly significant in this estuary when the tidal level is lower than 5 m. The lower North Passage is a typical zone of saltwater wedging, so the saltwedge fluid mud has the most extensive spatial range in the estuary.     

基于坐标归一化和奇异值分解的直接线性变换解法

直接线性变换方法是数字摄影测量和计算机视觉领域最常用的解析处理方法之一,特别适用于未检校数码相机的三维测量,但直接线性参数间的相关性、物方控制的约束和设计矩阵元素数量级的较大差异,均可导致法矩阵严重病态,从而影响解的稳定性。本文借鉴改进的八点基本矩阵估计算法,采用基于坐标归一化和奇异值分解的解法,即首先将像点和物点坐标进行相似变换得到归一化坐标后组成法矩阵,其次利用矩阵奇异值分解方法代替常规的最小二乘方法,模拟和真实数据表明,此方法可以有效提高解算精度和稳定性。     

Carbon and oxygen isotopic composition of car- bonate cements of different phases in terrigenous siliciclastic reservoirs and significance for their origin： A case study from sandstones of the Triassic Yanchang Formation, southwestern Ordos Basin, China

Early carbonate cements in the Yanchang Formation sandstones are composed mainly of calcite with relatively heavier carbon isotope （their δ^18O values range from -0.3‰- -0.1‰） and lighter oxygen isotope （their δ^18O values range from -22.1‰- -19.5‰）. Generally, they are closely related to the direct precipitation of oversaturated calcium carbonate from alkaline lake water. This kind of cementation plays an important role in enhancing the anti-compaction ability of sandstones, preserving intragranular volume and providing the mass basis for later disso- lution caused by acidic fluid flow to produce secondary porosity. Ferriferous calcites are characterized by relatively light carbon isotope with δ^13C values ranging from -8.02‰ to -3.23‰, and lighter oxygen isotope with δ^18O values ranging from -22.9‰ to -19.7‰, which is obviously related to the decarboxylation of organic matter during the late period of early diagenesis to the early period of late diagenesis. As the mid-late diagenetic products, ferriferous cal- cites in the study area are considered as the characteristic authigenic minerals for indicating large-scaled hydrocarbon influx and migration within the clastic reservoir. The late ankerite is relatively heavy in carbon isotope with δ^13C values ranging from -1.92‰ to -0.84‰, and shows a wide range of variations in oxygen isotopic composition, with δ^18O values ranging from -20.5‰ to -12.6‰. They are believed to have nothing to do with decarboxylation, but the previously formed marine carbonate rock fragments may serve as the chief carbon source for their precipitation, and the alkaline diagenetic environment at the mid-late stage would promote this process.     

成都平原区水稻土成土剖面Cd形态分布特征及影响因素研究

成土过程中不同形态镉(Cd)迁移转化的影响因素研究对于了解Cd的地球化学行为具有非常重要的意义。以四川省成都平原区农田生态系统水稻土剖面中不同形态Cd分布特征为例,探讨成土过程中不同形态Cd的迁移转化影响因素及其生态危害性。结果表明:总量Cd、离子交换态Cd和碳酸盐Cd均表现出表层富集,深层含量稳定的特征;岷江流域和沱江流域水稻土Cd含量的背景值分别为0.147,0.215mg·kg-1。外源输入耕层土壤中Cd主要为活动态,其增加量占Cd总量增加量的60.71%~90.52%,向下垂向迁移能力非常弱。成土过程随着土壤中Cd总量增加,稳定态Cd含量显著增加,而活动态Cd含量明显降低。土壤的pH值主要对碳酸盐态Cd含量有影响,pH值越大,其含量越高;随着土壤成熟度增高,粉粒和粘粒含量增加的同时,残渣态Cd含量显著降低,而有机结合态Cd含量显著增高。耕层土壤中Cd的生物有效性系数高达0.59~0.65,已经严重地影响到农作物安全。     

西藏雄村铜(金)矿地质灾害危险性综合分区评价

将勘探开发区划分为小区块评价单元,从地质灾害基础因子、响应因子、诱发因子分析入手,选定地形地貌、植被、岩性、地质构造及周边地震活动、地质灾害现状、预测地质灾害的危险性、人类工程活动为雄村铜(金)矿地质灾害综合分区定量评估因子,由此求得各区块的灾害因子综合量值.按危险性分区阀值将各评价区块最终归并为地质灾害危险性大、中等和小3个级别分区.     

斯通利波和渗透率的关系分析

理论和实际资料证明,在渗透性地层,低频斯通利波出现的频散和能量衰减与地层渗透率有关,因此可利用斯通利波的传播速度和能量衰减等特性来估算地层渗透率。斯通利波的能量和渗透率负相关。因为斯通利波能量代表了斯通利波的有关信息,因此可以认定斯通利波和渗透率负相关。     

GPS接收机专用芯片组技术发展

在总结国外现有的完整GPS接收机专用芯片组最新情况的基础上，结合典型的芯片产品，阐述了GPS接收机专用芯片组从分立式器件到片上系统、再到单片式接收机的技术发展过程、现状和趋势。     

2001年全球重大气候事件概述

全球气候仍持续偏暖。亚洲大部出现异常冷冬，许多地区遇到数十年未见的风雪严寒；美国冬季也连续遭受暴风雪袭击。东亚、南亚、中亚有西亚发生了大范围的持久干旱，南亚、东南亚夏季暴雨频繁，造成严重洪涝灾害。欧洲、非洲及南美洲的许多国家和地区降水异常偏多，导致不同程度的洪水，俄罗斯西伯利亚地区发生百年不遇的大洪水。北大西洋飓风较常年显著偏多，西北太平洋台风也给沿海地区带来严重灾害。     

初论古文化类型演替与传承模式的区域分异——以西拉沐沦河流域和汶泗流域为例

西拉沐沦河流域地处中国地貌大势三大台阶之中台阶与低台阶的过渡区。该区的中度抬升和下切,造成了西拉沐沦河流域考古文化遗址在空间上的垂向迁移;频繁的迁移也导致了考古遗址在堆积形态上主要表现为单一型,体现了不同考古文化之间“间断”的,不稳定的传承方式。位于中国地貌大势之低台阶上的汶泗流域,属自下古生代以来就十分稳定的剥蚀区,这些自然条件造成了汶泗流域遗址在堆积形态上主要表现为叠置型,考古文化在时空上,很少随着时间做空间上的改变,基本上在同一水平空间稳定不动,体现了不同考古文化之间“连续”、稳定的传承方式。两个流域的对比研究说明,不同地域、不同的自然条件,可以造成考古文化演替与传承模式的区域分异