湘南宝山铜铅锌多金属矿床闪锌矿元素地球化学特征及其对成矿的制约

位于钦杭成矿带和南岭成矿带叠合部位的湘南地区是我国重要的W、Sn、Cu、Pb、Zn、Ag多金属矿集区,宝山Cu、Pb、Zn、Ag多金属矿床是湘南地区代表性的矿床。相比中部矽卡岩型矿体,西部和北部脉状矿体研究程度较低。本文拟通过电子探针(EPMA)和激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)原位微区分析技术,对比研究矽卡岩型矿体和脉状矿体的微量元素赋存状态、成矿环境及矿床成因。分析结果显示,宝山矿区不同类型矿体中的闪锌矿均富含Fe、Mn和In,亏损Ga、Ge、Te和Tl等元素,Fe、Mn、Cd和In等元素主要以类质同象的形式赋存于闪锌矿中;矽卡岩型矿体形成于中—高温度环境,脉状矿体形成于中温环境。综合分析认为,宝山铜铅锌银矿床为形成于中—高温环境下的广义矽卡岩型矿床。值得注意的是,Cd含量达到了伴生工业品位的数百倍,具有很高的综合利用价值。     

自适应有限元不同网格间力学结果传递方法及程序实现

对于依赖于加载历史的自适应有限元分析问题,不同网格间力学结果的传递过程起着重要作用。基于按距离加权平均的改进插值方法,研究分步加载时自适应有限元不同网格间力学结果的继承问题。为使传递结果合理并减小计算工作量,插值方法采取选择邻近数据点、考虑方向影响、适当提高结果场的光滑性并使其通过全部已知数据点等措施;针对开挖过程中结构介质不断改变、开挖工作面不断移动及不同开挖步引入的介质之间场变量不连续等特点,采取分区划分网格并插值方式,构造不同网格间应力及位移结果的传递过程。所述传递过程,能为自适应有限元模拟多步骤开挖及弹塑性增量荷载分析等各种分步加载计算问题的解决提供有利条件。最后,给出2个算例以验证传递过程的可靠性。按增量荷载初应力方法对厚壁筒弹塑性分析表明,其结果与理论解吻合;模拟多步开挖的工程实例计算结果亦展示出所述传递方法的有效性。     

Atmospheric pollution for trace elements in the remote high-altitude atmosphere in central Asia as recorded in snow from Mt. Qomolangma (Everest) of the Himalayas

A series of 42 snow samples covering over a one-year period from the fall of 2004 to the summer of 2005 were collected from a 2.1-m snow pit at a high-altitude site on the northeastern slope of Mt. Everest. These samples were analyzed for Al, V, Cr, Mn, Co, Ni, Cu, Zn, As, Rb, Sr, Cd, Sb, Pb, and Bi in order to characterize the relative contributions from anthropogenic and natural sources to the fallout of these elements in central Himalayas. Our data were also considered in the context of monsoon versus non-monsoon seasons. The mean concentrations of the majority of the elements were determined to be at the pg g(-1) level with a strong variation in concentration with snow depth. While the mean concentrations of most of the elements were significantly higher during the non-monsoon season than during the monsoon season, considerable variability in the trace element inputs to the snow was observed during both periods. Cu, Zn, As, Cd, Sb, and Bi displayed high crustal enrichment factors (EF(c)) in most samples, while Cr, Ni, Rb, and Pb show high EF(c) values in some of the samples. Our data indicate that anthropogenic inputs are potentially important for these elements in the remote high-altitude atmosphere in the central Himalayas. The relationship between the EF(c) of each element and the Al concentration indicates that a dominant input of anthropogenic trace elements occurs during both the monsoon and non-monsoon seasons, when crustal contribution is relatively minor. Finally, a comparison of the trace element fallout fluxes calculated in our samples with those recently obtained at Mont Blanc, Greenland, and Antarctica provides direct evidence for a geographical gradient of the atmospheric pollution with trace elements on a global scale.     

大尺度线性遗产区域景观特征识别——以北京长城文化带为例

在国家文化公园建设背景下,国家对于大尺度线性遗产所在区域的保护工作日益重视,但对大尺度线性遗产所在的带状区域景观特征识别的研究尚属空白。以北京长城文化带为研究区域,基于景观特征评估(LCA)理论,借助地理信息系统(GIS)技术,围绕长城防御、屯垦和军情3个历史功能,构建由长城边墙、城堡和烽火台组成的文化遗产要素识别框架,探索大尺度线性遗产区域景观特征识别的技术路径和实现手段。在对自然景观要素和文化遗产要素进行分类、融合的基础上形成31种景观特征类型,针对不同的景观特征类型进行关键特征识别,深入研究自然景观与文化遗产的耦合关系及其形成机制,以期对中国的大尺度线性文化遗产区域总体评估和保护利用提供借鉴与参考。     

Influence of soil properties on trace element availability and plant accumulation in a Mediterranean salt marsh polluted by mining wastes: implications for phytomanagement

The aims of this study were to determine the factors which control metal and As phytoavailability in the different microenvironments (Sand Dunes, Salt Flat, Dry River and Shrubs) present at a Mediterranean salt marsh polluted by mining wastes. We performed a field study following a plot sampling survey. The analyses of soil parameters (pH, electrical conductivity (EC), organic carbon contents, etc.), total metal and As concentrations and their phytoavailability assessed with EDTA were related to each microenvironment and the corresponding plant species uptake. The averages of pH and EC were slightly alkaline (pH ≈ 7.5) and saline (≈ 2.2 to 17.1 dS m⁻¹) respectively. The soil samples from the Salt Flat subzone showed the highest metal concentrations (e.g. 51 mg kg⁻¹ Cd, 11,600 mg kg⁻¹ Pb) while for As, the highest concentrations occurred in the Dry River (380 mg kg⁻¹ As). The total metal and EDTA-extractable concentrations occurred as it follows: Salt Flat > Dry River > Degraded Dunes > Shrubs. In relation to plant metal and As accumulation, the highest root concentrations were obtained in the species from the Salt Flat subzone: ~ 17 mg kg⁻¹ As, ~ 620 mg kg⁻¹ Pb, for both, Juncus maritimus and Arthrocnemum macrostachyum. However the highest metal and As shoot concentrations occurred in species from the Sand Dunes: ~ 23 mg kg⁻¹ As ~ 270 mg kg⁻¹ Pb for Dittrichia viscosa; ~ 23 mg kg⁻¹ As, ~ 390 mg kg⁻¹ Zn for Crucianella maritima. The occurrence of edaphic gradients including salinity and texture determined the vegetation distribution. However, it cannot be concluded that there was a disturbance due to metal(loid)s soil concentrations in terms of vegetation composition except in the Degraded Dunes and Dry River. The higher EDTA-extractable concentrations were coincidental with the most saline soils but this did not result in higher metal(loid)s plant accumulation.     

“三稀”和铂族元素测试方法的应用

文章以保存的化探副样为基础,利用ICP-MS、X射线荧光、原子荧光等大型分析仪器为手段,通过对方法的对比和探讨,建立了"三稀"和铂族元素的测试方法。对检测数据质量监控的各项技术指标(检出限和报出率,国家一级标准物质合格率,重复性检验和异常点合格率等)参数均符合DZ/T0130.4-2006地质矿产实验室测试质量管理规范中(1∶200 000)区域地球化学调查样品化学成分分析规定的质量要求。分析数据对地球化学填图的成图效果较好,为基础地质、环境地质及其他领域应用提供地球化学依据。     

空间摆盘机构副元素分离预测

从空间机构学理论出发,抽象出摆盘机构的动力学模型,导出了无间隙时连杆与摆盘铰接处的运动副反力及其方向变化率,以此获得了方向变化率与运动副反力模的比值;根据比值的绝对值变化,给出了空间摆盘机构运动副元素的分离准则,得到了在主轴转角处于特定位置副元素将分离的结论。研究结果为鱼雷摆盘发动机的振动与噪声控制提供参考,并为进一步发展含间隙鱼雷摆盘机构的动力优化综合理论提供了分析方法。     

Load characterization and power conditioner synthesis using higher-order elements

It is shown that virtually all nonlinear and/or time-varying loads that generate harmonic current distortion can be characterized in terms of so-called higher-order circuit elements. The most relevant higher-order elements exploited in this paper are the memristor, meminductor, and memcapacitor. Such elements naturally arise by introducing constitutive relationships in terms of higher-order voltage and current differentials and integrals. Consequently, the power conditioner necessary to compensate for the load current distortions is synthesized similarly. The new characterization and compensation synthesis is applied to the half-wave rectifier and the controlled bridge converter.     

老年智能服装的功能设计研究

从老年智能服装的需求及用途出发,阐述了老年智能服装的定义,分别剖析了健康监测、保健治疗、防走失、防跌倒、蓄热保暖5种老年智能服装的功能性及工作原理,并对老年智能服装的设计要素进行了分析,指出设计关键点,明确了老年智能服装的开发应充分融合现代新科技、新工艺和新技术,拓展了老年智能服装设计的新思路,并为智能服装研究者提供了一定的理论参考依据。     

Equivalent circuit models using CPE for impedance spectroscopy of electronic ceramics

Complex immittance (Impedance Z, Modulus M, Admittance Y, Permittivity ?) spectra for some equivalent circuit models involving resistances, capacitances and constant phase angle elements (CPE) are calculated for different ratios of the parameters. A comparison of experimentally obtained complex immittance plots with these diagrams greatly facilitates the search for the most appropriate equivalent circuit representing the electrical properties of electronic ceramics. An equivalent circuit for Ba_1-xSr_xTiO₃ (x = 0.35) ceramic system is developed by using these simulated plots.