X荧光光谱分析技术在测定安徽月山矿床铁铜矿石中Fe、Cu的应用研究

为建立符合安徽月山矿区的X荧光光谱(XRF)分析方法,针对矿区铁矿、铜矿的特点,用铁、铜矿石的国家标准物质制作系列校准样片,通过粉末压片和玻璃熔融两种制样方法,波长色散X荧光光谱法测定主矿体样品中的Fe、Cu等主量元素,并将测定结果与传统化学方法分析结果进行比较。结果显示,熔片法-XRF的测定结果与化学容量法测定结果一致,试样在850℃灼烧,按40∶1大稀释比熔融制样,解决了样品在高温熔融过程中对铂黄坩埚的腐蚀,适用于月山矿区铁铜矿样品中Fe、Cu的测定。粉末压片法不能克服矿物效应和粒度效应的影响,测定结果与化学容量法结果比对偏差较大,不适用于月山地区铁铜矿中Fe、Cu的测定。     

Potential water sources for Late Quaternary Megalake Jilantai-Hetao,China, inferred from mollusk shell <Superscript>87</Superscript>Sr/<Superscript>86</Superscript>Sr ratios

Lake Jilantai-Hetao, a megalake, was formed some time before 60–50 ka, along the Great North Bend of the Yellow River. The basin is now dry, with most of the area covered by aeolian sand. We are investigating this profound hydrologic change using a number of research approaches. Paleoshorelines of this megalake are best preserved in the Jilantai area in the southwestern portion of the megalake basin. We collected aquatic mollusk shells from littoral sediments at different altitudes around Jilantai and measured their strontium isotope compositions. ⁸⁷Sr/⁸⁶Sr ratios in shell carbonates are different between the high lake phase (~1,080–1,050 m altitude) and the low lake phase (~1,044–1,030 m altitude), with a small shift in average strontium ratios to more radiogenic values during the low lake phase. Based on regional hydrology and physical geography, we conclude that water from the Yellow River was the dominant water source supplying this megalake. ⁸⁷Sr/⁸⁶Sr ratios of modern water samples suggest the Yellow River was the dominant water source during the high lake phase, but that the relative contribution of Yellow River water to the megalake was reduced, and that the relative contributions of local precipitation and groundwater increased, during the low lake phase.     

Structural damage detection using the optimal weights of the approximating artificial neural networks

This work presents a novel neural network‐based approach to detect structural damage. The proposed approach comprises two steps. The first step, system identification, involves using neural system identification networks (NSINs) to identify the undamaged and damaged states of a structural system. The partial derivatives of the outputs with respect to the inputs of the NSIN, which identifies the system in a certain undamaged or damaged state, have a negligible variation with different system errors. This loosely defined unique property enables these partial derivatives to quantitatively indicate system damage from the model parameters. The second step, structural damage detection, involves using the neural damage detection network (NDDN) to detect the location and extent of the structural damage. The input to the NDDN is taken as the aforementioned partial derivatives of NSIN, and the output of the NDDN identifies the damage level for each member in the structure. Moreover, SDOF and MDOF examples are presented to demonstrate the feasibility of using the proposed method for damage detection of linear structures. Copyright © 2001 John Wiley & Sons, Ltd.     

Protracted oogenesis and annual reproductive periodicity in the deep‐sea pennatulacean Halipteris finmarchica (Anthozoa,Octocorallia)

Halipteris finmarchica is one of the most common species of deep‐sea pennatulacean corals in the Northwest Atlantic; it was recently determined to act as a biogenic substrate for other species and as a nursery for fish larvae. Its reproductive cycle was investigated in colonies sampled in 2006 and 2007 along the continental slope of Newfoundland and Labrador (Canada). Halipteris finmarchica exhibits large oocytes (maximum diameter of 1000 μm), which are consistent with lecithotrophic larval development. Female potential fecundity based on mature oocytes just before spawning was ~6 oocytes · polyp^?1 (500–6300 oocytes · colony^?1); male potential fecundity was 16 spermatocysts · polyp^?1 (5500–57,400 spermatocysts · colony^?1). Based on statistical analysis of size‐probability frequency distributions, males harboured one cohort of spermatocysts that matured inside 8–11 months, whereas females harboured two distinct cohorts of oocytes; a persistent pool of small ones (≤400 μm) and a small number (~20%) of larger ones that grew from ~400 to >800 μm over a year. Despite this difference in the tempo of oogenesis and spermatogenesis, a synchronic annual spawning was detected. A latitudinal shift in the spawning period occurred from south (April in the Laurentian Channel) to north (May in Grand Banks and July–August in Labrador/Lower Arctic), following the development of the phytoplankton bloom (i.e. sinking of phytodetritus). Prolonged oogenesis with the simultaneous presence of different oocyte classes in a given polyp is likely not uncommon in deep‐sea octocorals and could hamper the detection of annual/seasonal reproduction when sample sizes are low and/or time series discontinued or brief.     

Biodegradation of Crude Oil by Individual Bacterial Strains and a Mixed Bacterial Consortium Isolated from Hydrocarbon Contaminated Areas

A preliminary study was undertaken to determine the optimal conditions for the biodegradation of a crude oil. Among 57 oil‐degrading bacterial cultures isolated from oil‐contaminated soil samples, Bacillus sp. IOS1‐7, Corynebacterium sp. BPS2‐6, Pseudomonas sp. HPS2‐5, and Pseudomonas sp. BPS1‐8 were selected for the study based on the efficiency of crude oil utilization. Along with the selected individual strains, a mixed bacterial consortium prepared using the above strains was also used for degradation studies. The mixed bacterial consortium showed more growth and degradation than did individual strains. At 1% crude oil concentration, the mixed bacterial consortium degraded a maximum of 77% of the crude oil. This was followed by 69% by Pseudomonas sp. BPS1‐8, 64% by Bacillus sp. IOS1‐7, 45% by Pseudomonas sp. HPS2‐5, and 41% by Corynebacterium sp. BPS2‐6. The percentage of degradation by the mixed bacterial consortium decreased from 77 to 45% as the concentration of crude oil was increased from 1 to 12%. Temperature of 35°C and pH 7 were found to be optimum for maximum degradation.     

阿拉善地块北缘雅干花岗岩体地球化学、地质年代学及其对区域构造演化制约

位于阿拉善北部中蒙边境地区的雅干花岗岩体以二长花岗岩为主,岩体的锆石离子探针U-Pb年龄为283.2±2.2Ma (n=14,MSWD=0.016).该花岗岩体具有相对较低的SiO2含量(66.96％～70.71％),和较高的A12O3(15.05％～16.05％)和(Na2O+ K2O)含量(7.24％～9.19％),且岩体钠含量稍高(Na2O/K2O＞1).雅干花岗岩体总体上表现为高钾钙碱性及偏铝质-过铝质的特征.岩体稀土元素总合量为101.9×10-6～133.1 ×1O-6,在稀土元素配分模式图中,岩体表现为轻-重稀土元素中等程度-强烈分异,同时具有明显的负Eu异常(δEu =0.59 ～0.77);在微量元素原始地幔标准化蛛网图中,岩体表现为亏损Nb、Ta、P、Ti,富集Ba、Rb、Cs、Th、K等大离子亲石元素;岩体同位素特征则表现为具有高的(87 Sr/86 Sr)i值(0.707654 ～0.710235)以及负εNd(t)值.根据雅干花岗岩体的形成时代、地球化学特征以及相关的沉积建造特征,可推断该岩体形成于后碰撞环境,表明古亚洲洋在阿拉善地块北缘北部地区的分支于早二叠世(283.2 ±2.2Ma)之前已经闭合.     

A note on the algorithm of symplectic integrators

For a Hamiltonian that can be separated into N+1(N\geq 2) integrable parts, four algorithms can be built for a symplectic integrator. This research compares these algorithms for the first and second order integrators. We found that they have similar local truncation errors represented by error Hamiltonian but rather different numerical stability. When the computation of the main part of the Hamiltonian, H ₀, is not expensive, we recommend to use S ^* type algorithm, which cuts the calculation of the H ₀ system into several small time steps as Malhotra(1991) did. As to the order of the N+1 parts in one step calculation, we found that from the large to small would get a slower error accumulation. This revised version was published online in July 2006 with corrections to the Cover Date.     

FITS数据文件的检索和访问

普适图像传输系统(Flexible Image Transport System,FITS)是天文学领域应用最广泛的数据格式.自从20世纪80年代FITS格式被国际天文联合会(IAU)正式公布为国际标准以来,大部分的天文数据都是以FITS文件的形式在世界各地的数据中心和天文学家手中保存和交换.采用文件系统方式保存管理的FITS数据文件,很难适应程序化的检索和定位需求.随着FITS文件数量的不断增加以及虚拟天文台技术的发展,为这些以文件形式保存的天文数据提供检索功能的需求越来越迫切.FITS头以关键词值对的形式确切定义了所属FITS文件的结构,还提供了数据本身诸多特性的重要信息.FITS头中保存的这些信息可以满足大部分FITS数据文件查询检索的需求.将FITS头中的信息利用数据库来保存和管理,可以极大的方便对FITS文件的检索和定位.FITS头归档入库系统(FitHAS)是中国虚拟天文台项目开发的一个简单实用的FITS头信息归档入库工具,能够方便的将单个或者多个FITS文件的主FITS头信息导入到数据库中,为FITS数据文件的查询检索奠定基础,进而为虚拟天文台等更高层次的数据访问服务部署创造条件.本文介绍FITS数据格式,FITS头的基本结构;探讨虚拟天文台环境下FITS数据文件检索定位的实现方式;阐述FitHAS的功能特点、设计开发和使用方法.     

土地利用结构与社会经济结构——基于中国不同用地类型区域的实证分析

应用简单相关分析、典型相关分析以及聚类分析等方法,选取1999-2007年中国31个省市(除港澳台地区)的面板数据,对全国及不同用地类型区域的土地利用结构与社会经济结构的关系进行实证分析.研究表明,我国土地利用结构与社会经济结构的相互影响关系显著,产业结构的升级以及土地利用结构的优化相互作用,并对中国社会经济发展具有显著贡献:土地利用结构与社会经济结构的关系具有显著的区域差异性,基于不同用地类型区域的分析有助于二者量化关系规律的进一步显化:相应的政策含义是,土地宏观调控政策应与产业政策相协调,并兼具宏观政策和区域政策的双重特点.     

A Review on Researches of Active Tectonics——History, Progress and Suggestions1

This paper reviews the history and progress of research on active tectonics in China and overseas. By giving a brief introduction on the history of active tectonic research in China and other countries, the paper sums up the process and development of quantitative investigation of active tectonics since the 1980s. The focus is on the main efforts and progress made in China on certain aspects of research, such as basic surveys and applied investigation of active tectonics, the study of theories related to regional active tectonics and their kinematics and geodynamics, surveys on coupling relations between deep and shallow structures, active fault surveys and prospecting and seismic hazard assessment in urban areas, as well as the efforts made using Quaternary geochronology. Furthermore, the paper looks back on Chinese quantitative investigation of active tectonics in China and sums up cognitions derived from studies on the determination of several basic and measurable parameters of active tectonics. These parameters include the length of fault and fault segmentation, coseismic slip and cumulative slip, fault slip rate, the sequence of paleoearthquake events and the time elapsed since the most recent event. At the same time, efforts and progress made in China on assessing the long-term seismic potential for active faults and evaluating the risk from potential active fault movement have been reviewed by summarizing research on developing theories, models, methods and the application of time-dependent seismic potential to prohabilistic assessment, magnitude estimation for potential earthquakes on active faults, and the forecast of potential risk caused by active fault movement. Finally, in consideration of the realities and problems in the research of active tectonics in China, the authors put forward several suggestions for issues worthy of more attention for further investigation in the future.