基于韦伯-费希纳定律的营养状态普适韦伯指数公式

在适当设定各营养状态指标"参照值"Cj0的基础上,用相应于"参照值"Cj0的指标"规范值"xj作为基于韦伯-费希纳定律的营养状态指数公式中的刺激量.由于各项指标的同级营养状态标准的"规范值"xjl差异不大,从而可认为各指标的营养状态韦伯指数公式都具有一个共同适用的韦伯常数α,并采用智能解域搜索算法优化α,得出对所有14项营养指标皆适用的营养状态普适韦伯指数公式.将营养状态韦伯指数公式应用于数十个湖泊的富营养化评价,并与其它多种方法的评价结果进行比较,结果表明该公式不但理论依据充分,而且具有简单、适用的特点.     

量热学和热动力学研究进展概况

对量热学的发展历史作了简要介绍,并就近年来利用量热法进行各种反应的热动力学研究的进展进行了概述。根据将微量热新技术引入到地质、地球化学领域研究矿物溶解的阶段性成果,展望了地球化学反应热动力学研究的广阔前景。     

空间直角坐标计算大地坐标的抛物线逼近法

采用抛物线逼近法求解大地纬度和大地高,先计算空间点在椭球面上的子午面坐标,然后求解点的大地纬度和大地高。     

汶川8.0级地震对鄂尔多斯块体西南缘断裂体系影响的数值模拟

利用有限元方法及静态位移解理论,采用前人反演的汶川8.0级地震破裂过程时空参数,定量计算分析汶川地震对鄂尔多斯块体西南缘断裂体系的影响.数值计算表明,具逆冲右旋性质的汶川地震,在汶川-宝鸡-线以东产生顺时针的位移扰动场,以西产生逆时针的位移扰动场,这与该分界两侧附近的活断层整体走滑方向相一致.水平剪切应力场的局部极值区...     

红土型金矿中痕量金分析应用研究

总结红土型金矿运用痕量金分析的理论基础,对不同金标样样品进行准确度、精密度检查,表明痕量金分析可以满足矿点的检查、异常查证的基本要求。与室内法相比,本法有方便、快捷、低成本、高效率及易掌握等特点。     

Numerical Investigation of the Galactic Problem by Computing Families of Periodic Solutions

The galactic dynamical system expressed by a third-order axisymmetric polynomial potential is investigated numerically by computing periodic solutions. We define as Sthe compact set of initial conditions generating bounded motions, and as S ^p , with S ^p ? S, the countable set of all initial conditions generating periodic solutions. Then, we consider the subsets S _s ^p and S _a ^p of S ^p , where S _s ^p ∪ S _a ^p = S ^p , S _s ^p S _a ^p = Ø, the first of which corresponds to symmetric periodic solutions, and the second to asymmetric solutions. Then, we approximate the set S _s ^p , leaving treatment of the set S _a ^p of asymmetric solutions for a future publication. The set S _s ^p is known to be dense in S (‘Last Geometric Theorem of Poincar;’, Birkhoff, 1913). Using a computer programme capable to locate all elements of the set S _s ^p that generate symmetric periodic solutions that re-enter after intersecting the axis of symmetry from 1 to ntimes. The results of the approximation of S _s ^p in the total domain and in the sample sub-domains of zooming, we present in graphical form as family curves in the (x, C) plane. The solutions located with the largest periods re-enter after 440 galaxy revolutions while the families calculated fully (initial conditions, period, energy, stability co-efficient) include solutions that re-enter after 340 galaxy revolutions. To advance further the approximation of the set S _s ^p thus obtained, we applied the same procedure inside eight sub-domains of the domain Sinto which we ‘zoomed’ through selection of finer search steps and double maximum periods. The family curves thus calculated presented in the (x, C) plane do not intersect anywhere in some sub-domains and their pattern resembles that of laminar flow. In other sub-domains, however, we found family curves from which branching families emanate. The concepts of completeand non-completeapproximation of S _s ^p in sub-domains of laminar and sub-domains with branching family curves, respectively, is introduced. Also, the concept of basic family of order1, 2, ..., n, are defined. The morphology of individual periodic solutions of all families is investigated, and the types of envelopes found are described. The approximate set S _s ^p was also checked by computing Poincar; sections for energy values corresponding to the mean energy range of the eight sub-domains of zooming mentioned above. These sections show that most parts of the compact domain in Sgenerating non-periodic but bounded solutions correspond to with well-shaped tori that intersect the x-axis, a fact that implies that dominant to exclusive type of periodic solutions are the symmetric ones with two normal crossings of this axis. The presence of non-symmetric periodic solutions as well as of chaotic regions is encountered. All calculations reported here were performed using the variable step R-K 8th-order direct integration and setting the allowable energy variation Δ C= |C _start? C _end| < 10^?13. The output, consisting of many thousands of families and their properties (initial conditions, morphology, stability, etc.), is stored in a directory entitled ‘Atlas of the Symmetric Periodic Solution of the Galactic Motion Problem’.     

Thermal behavior of ferric selenite hydrates (Fe2(SeO3)3·3H2O,Fe2(SeO3)3·5H2O) and the water content in the natural ferric selenite mandarinoite

Any progress in our understanding of low-temperature mineral assemblages and of quantitative physico-chemical modeling of stability conditions of mineral phases, especially those containing toxic elements like selenium, strongly depends on the knowledge of structural and thermodynamic properties of coexisting mineral phases. Interrelation of crystal chemistry/structure and thermodynamic properties of selenium-containing minerals is not systematically studied so far and thus any essential generalization might be difficult, inaccurate or even impossible and erroneous. Disagreement even exists regarding the crystal chemistry of some natural and synthetic selenium-containing phases. Hence, a systematic study was performed by synthesizing ferric selenite hydrates and subsequent thermal analysis to examine the thermal stability of synthetic analogues of the natural hydrous ferric selenite mandarinoite and its dehydration and dissociation to unravel controversial issues regarding the crystal chemistry. Dehydration of synthesized analogues of mandarinoite starts at 56–87?°C and ends at 226–237?°C. The dehydration happens in two stages and two possible schemes of dehydration exist: (a) mandarinoite loses three molecules of water in the first stage of the dehydration (up to 180?°C) and the remaining two molecules of water will be lost in the second stage (>180?°C) or (b) four molecules of water will be lost in the first stage up to 180?°C and the last molecule of water will be lost at a temperature above 180?°C. Based on XRD measurements and thermal analyses we were able to deduce Fe₂(SeO₃)₃·(6-x)H₂O (x?=?0.0–1.0) as formula of the hydrous ferric selenite mandarinoite. The total amount of water apparently affects the crystallinity, and possibly the stability of crystals: the less the x value, the higher crystallinity could be expected.     

《盐湖研究》合订本征订启事

<正>《盐湖研究》是原国家科委批准的学术类自然科学期刊,由中国科学院青海盐湖研究所主办,科学出版社出版,1993年创刊并在国内外公开发行。《盐湖研究》自公开发行以来,深受广大读者的厚爱,为了便于我刊读者和文献情报服务单位系统收藏,编辑部藏有94-95年、96-97年、98-     

Li2S—B2O3体系玻璃的形成及其稳定性研究

本要用情性气体保护下的高温熔融反应及液氮淬冷技术制备了Li_2S-B_2O_3体系玻璃。采用XRD、ICP及化学滴定法分别确定了产物的形态和化学组成。利用DTA星热法测定了玻璃的转变温度Tg、晶化温度Tc及晶化峰值温度Tp，并根据Tg、Tc-Tg、Tp－Tg、（Tp－Tg）／Tg四种玻璃稳定性判据讨论了Li2S-B2O3玻璃的相对稳定性。实验表明，Li2S-B2O3体系能在Li2S的摩尔分数X≤0．45的浓度范围形成玻璃，且在x=0．25附近玻璃的稳定性最强。     

连通域标识法在FMI图像溶洞信息定量拾取中的应用

溶蚀孔洞在碳酸盐岩储层中是重要的流体储集空间,研究成像测井(FMI)图像孔洞连通域标记及信息定量拾取很有意义.全井眼微电阻率成像测井(FMI)经数据处理后可得到全井壁高分辨率的彩色图像,经图像灰度化、中值滤波处理后,通过阈值分割得到能够反映井壁溶蚀孔洞特征的二值图像,孔洞表现为黑色暗斑.基于等价对处理的图像连通域标记算法具有快速、不重复标记的优点,利用该算法,可准确地从二值图像中标记溶蚀孔洞连通域,进而可对每个连通域进行目标信息拾取,包括孔洞尺寸、连通域面积、圆度等.利用反映溶蚀孔洞发育程度的面孔率曲线对图像进行分层,在此基础上可拾取每一层段溶蚀孔洞面孔率、分选系数及溶洞密度值的分布等非均质信息,能够定量地评价溶蚀孔洞发育、非均质性强的碳酸盐岩储层,也是FMI图像应用于岩石孔洞结构信息定量表征新的尝试.