9 resultados para Jade.

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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The geochemical and U-series isotopic characteristics of hydrothermal sulfide samples from the Jade site (127A degrees 04.5'E, 27A degrees 15'N, water depth 1300-1450 m) at Jade site in the Okinawa Trough were analyzed. In the hydrothermal sulfide samples bearing sulfate (samples HOK1 and HOK2), the LREEs are relatively enriched. All the hydrothermal sulfide samples except HOK1 belong to Zn-rich hydrothermal sulfide. In comparison with Zn-rich hydrothermal sulfides from other fields, the contents of Zn, Pb, Ag, Cd, Au and Hg are higher, the contents of Fe, Al, Cr, Co, Ni, Sr, Te, Cs, Ti and U lower, and the Pb-210 radioactivity ratios and Pb-210/Pb ratios very low. In the hydrothermal sulfide mainly composed of sphalerite, the correlations between rare elements Hf and U, and Hf and Mn as well as that between dispersive elements Ga and Zn, are strongly positive; also the contents of Au and Ag are related to Fe-sulfide, because the low temperature promotes enrichment of Au and Ag. Meanwhile, the positive correlations between Fe and Bi and between Zn and Cd are not affected by the change of mineral assemblage. Based on the Pb-210/Pb ratios of hydrothermal sulfide samples (3.99x10(-5)-5.42x10(-5)), their U isotopic composition (U-238 content 1.15-2.53 ppm, U-238 activity 1.07-1.87 dpm/g, U-234 activity 1.15-2.09 dpm/g and U-234/U-238 ratio 1.07-1.14) and their Th-232 and Th-230 contents are at base level, and the chronological age of hydrothermal sulfide at Jade site in the Okinawa Trough is between 200 and 2000 yr.

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Helium, neon and argon isotope compositions of fluid inclusions have been measured in massive sulfide samples from the Jade hydrothermal field in the central Okinawa Trough. Fluid-inclusion He-3/He-4 ratios are between 6.2 and 10.1 times the air value (Ra), and with a mean of 7.8Ra, which are consistent with the mid-ocean ridge basalt values [He-3/He-4 approximate to (6Rasimilar to 11Ra)]. Values for Ne-20/Ne-22 are from 10.7 to 11.3, which are significantly higher than the atmospheric ratio (9.8). And the fluid-inclusion Ar-40/Ar-36 ratios range from 287 to 334, which are close to the atmosperic values (295.5). These results indicate that the noble gases of trapped hydrothermal fluids in massive sulfides are a mixture of mantle- and seawater-derived components, and the helium of fluid inclusions is mainly from mantle, the nelium and argon isotope compositions are mainly from seawater.

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利用质子激发X射线荧光(PIXE)、X射线衍射(XRD)、扫描电子显微镜(SEM)以及激光拉曼光谱(LRS)技术对几个来自中国新疆、俄罗斯、加拿大和新西兰等地的软玉样品的进行了岩石矿物学特征分析,从成分组成和微观织构方面比较了各地软玉的不同特征.实验结果显示了软玉作为透闪石质玉石,随着Fe2O3含量的增加,逐步向阳起石过渡.中国和田玉以其特有的毛毡状纤维交织结构,形成了均匀细腻、油脂光泽的表面特征.无破损成分分析方法为研究贵重的古玉样品提供了技术支持.

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为研究安阳市新出土殷墟玉器的质地和来源,利用外束质子激发X射线荧光(PIXE)、X射线衍射(XRD)以及激光拉曼光谱(LRS)技术对玉器进行了矿物学特征分析,从成分、矿相和结构研讨它们的质地和来源。实验结果显示,安阳市新出土殷墟玉器中80%为透闪石型软玉,且来自同一矿区,质地较好。个别样品属蛇纹石类型玉石和白云石岩。本研究证实了激光Raman光谱对古玉器鉴别的应用前景。

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蛇纹石玉是我国利用最早的玉石之一。采用外束质子激发x射线荧光(PIXE)、x射线衍射(XRD)和拉曼光谱(Raman)技术对我国出土的古玉器以及辽宁省岫岩县出产的蛇纹石玉石进行矿物特征分析。通过对古玉器和玉石的对比研究,成功地对古玉器中的蛇纹石质玉器进行了无损鉴定,总结得出了蛇纹石质古玉器的无损鉴别方法,对于深化我国古玉器的研究具有重要意义。微量元素特征分析有助于探索古玉器玉料的来源。

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河南南阳独山玉的开采历史可以追溯到新石器时代,在我国玉文化中占有重要地位。鉴于当前对独山玉进行无损鉴别的方法较少,利用质子激发X荧光技术(proton induced X-ray emission,PIXE)、X射线衍射(X-ray diffraction,XRD)、激光Raman光谱(laser Raman spectroscopy,LRS)和扫描电子显微镜(scanning electron microscope,SEM)等技术对河南南阳独山玉料进行岩石矿物学分析。结果表明:独山玉主要由钙长石矿物构成,晶粒细小且结合紧密的显微结构与独山玉具有极高的稳定性有较大关系。PIXE,XRD和Raman技术作为无损分析方法为鉴定独山玉提供了准确有效的方法,为研究贵重的古玉样品提供了技术支持。

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九寨沟自然保护区地处四川盆地北部岷山山脉南段,属川西高原气候中的暖温带。保护区内分布着118 个串珠状排列的高山湖泊,核心景区共有湖泊20 个(组),集中在海拔2000 米到3000 米之间。水资源是九寨沟的灵魂,保护水生生态系统是九寨沟生态旅游可持续发展的立足之本。本研究以九寨沟湿地生物多样性保护项目为依托,于2007 年5 月~2008 年4 月对九寨沟核心景区湖泊水体硅藻植物进行调查,分析了其密度与环境因子的相互关系,旨在为九寨沟湖泊生态系统保护提供科学依据和基础资料。主要有以下几点结论: (1)九寨沟硅藻植物丰富,调查统计为2 纲6 目10 科35 属159 种(包括变种和变型),水体硅藻中真性浮游种类较少,着生种类多,羽纹纲的脆杆藻属、舟形藻属、桥弯藻属、异极藻属、曲壳藻属的种类最多,常为优势属组成湖泊硅藻群落,只在长海是小环藻属占绝对优势。 (2)九寨沟水体中硅藻细胞密度不大,多在4×104~30×104 个/L,长海最高,五花海最低。在年变化上,不同的湖泊水体中硅藻的生长高峰季节不尽相同,在夏季、秋末和冬末春初均有可能出现高密度。在空间上,整体看来密度与海拔有一定的正相关,但由于水温不是单一主导因素,密度受多种环境因子影响,在海拔梯度上呈现一定的波浪状变化。 (3)影响九寨沟湖泊水体硅藻细胞密度较重要的环境因子是海拔、水温和pH。硅藻细胞密度年变化幅度大的湖泊水体,年平均细胞密度大。因此,环境因素不太稳定的湖泊水体,更可能出现高的硅藻细胞密度。11 月份响应于水量剧烈的减少,细齿菱形藻大量出现在五彩池成为优势种群,造成水体硅藻细胞密度的大幅增加。 (4)九寨沟湖泊水体水质几乎达到国家地表水I 类标准,但是,硅藻商指数以及代表多样性的Cairns 指数计算的结果不能反映水质的情况,这是由于水质状况不是决定九寨沟湖泊水体中硅藻生存的种类和数量的主要因素。因此在用各种指数分析水质的时候,都应该先判断计算该指数的参数是否主要由水质状况决定,然后再综合理化性质等其他指标分析和比较。 (5)人类的活动对九寨沟湖泊水生态系统有一定的影响。一方面,在低海拔景点人类活动的干扰比海拔高处相对要大,干扰引起低海拔景点湖泊硅藻Cairns指数较高;另一方面,旺季的影响比淡季大,水体中出现了典型富营养种类。因此,应加强低海拔景点和旺季的管理,并限制淡季的人类活动以保证九寨沟生态系统的自我恢复。 Jiuzhaigou nature reserve is located in north Sichuan, at the south section of Minshan Mountain, having a warm temperate climate which belongs to West Sichuan plateau climate. It includes 118 mountain lakes, and 20 of them between 2000 and 3000 altitude degree constitute the core area of Jiuzhaigou. The water is Jiuzhaigou's soul, so it is the basis of sustainable tourism development of Jiuzhaigou to protect the water ecological environment. Research depends on Jiuzhaigou wetland biodiversity protection program in this paper, invested the diatom plants in 17 lakes at the core area from May 2007 to April 2008. The composition and the correlation of diatom density and the environment were studied, which could provide scientific and basic information for the protection of the ecological environment of Jiuzhaigou. The main conclusions were: 1 The diatom species were in abundance, investigation showed that there were 159 species belong to 10 families and 35 genera. Most diatoms were benthos, euplankton were less. Genera Fragilaria, Navicula, Cymbella, Gomphonema and Achnanthes had the most species, which always were the dominant genera. Only in The Long Lake genus Cyclotella possessed a predominant status. 2 The diatom cell density was not very high, always between 4×104 cell/L and 30×104 cell/L, highest in The Long Lake and lowest in The Colorful Lake. In one year's time, diatom in different lakes had different growth type. The maximum could be in summer, late autumn and late winter early spring. The cell density showed a positive correlation to altitude in the whole, but fluctuated in details along altitude because of comprehensive influence by many environmental factors. 3 Altitude, water temperature and pH were the more important factors to determine the cell density. There was a positive correlation between the range of cell density in one year and the average cell density. So high annual cell average density probably will appear in lakes which has an unstable environmental condition. The boom of Denticula elegans in The Jade-Colored Lake in November was corresponding to the large decrease in water quantity. 4 The water quality of Jiuzhaigou was near the National Surface Water Standard rank I, but the Diatom Quotient and the Cairns Index didn't reflect the water quality accordingly. It was because the water quality wasn't the most important factor here which determined the species number and species quantity, so the index based on these items would not reflect it. Therefore, it is recommended that, when we use indices to evaluate the water quality, we should know first whether the water quality is the main determinative factor inflects the items used to compute the indices, and then combined with other chemical indices to analyze and do comparison. 5 The tourists' activities had influenced the water ecosystem of Jiuzhaigou. On the one hand, disturbance was relatively high at the lower altitude, it resulted in higher Cairns index; on the other hand, influence in high season was more severe than in low season, some typical species indicating eutrophication were observed in the water. It is suggested that the management at lower altitude and in high season must be strengthen, and less people activity in low season is necessary to fulfill the recovery of the water ecosystem.

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为了实现可重构装配系统的快速重构能力,在分析了传统控制结构的基础上,结合分层递阶和分布式控制的优点,提出了基于多智能体系统的混合控制体系结构。这种结构具有低复杂性、强鲁棒性、易维护性、可扩展性以及可重用性等特点,能够适应重构系统的要求。在遵守智能物理代理基金会规范的前提下,以Java智能体开发平台进行了装配系统中各层智能体的实例开发。

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本文的研究内容是围绕国家“973”计划支持项目“基于智能制造单元的可重构装配生产线基础理论与实现方法研究”展开的。本研究以汽车减速箱装配生产线为实际背景,主要工作由四部分组成:对汽车减速箱的产品结构、装配工艺特征深入分析的基础上,提出了主干线和装配模块相结合的组织结构建模方法;利用网络法进行分析装配系统的三个重构过程,提出了适用于增容性、鲁棒性、适应新产品重构的优化算法;建立了基于多Agent系统的混合控制体系结构,利用JADE台进行具体软件编程,实现了可重构装配生产线的控制系统;最后将组织结构建模、控制结构建模、重构优化算法有效的结合成统一整体,通过对Agent之间协商机制的研究,最终实现了可重构装配系统的实时重构、调度和控制,初步形成基于智能制造单元的汽车减速箱可重构装配系统的基本理论框架和方法体系。首先对汽车减速箱的产品结构、装配工艺特征进行了深入分析,从而形成了基于功能对象的产品族划分方法。在此基础上,根据模块化的设计思想,提出了主干线和装配模块相结合的可重构装配系统的开放式组织结构。通过引入缓冲区和多功能工作站,使得装配系统具有能力柔性、鲁棒性、功能扩展能力等特点,并能够通过模块的局部调整快速响应市场的需求。利用随机过程的基本原理,在建立缓冲区状态数学模型的基础上,以缓冲区被充满概率最小化为目标,通过递进算法确定缓冲区容量。讨论了可重构装配系统的两个规划问题:负荷平衡和多品种排序。阐述了混合模型产品的装配任务优先图和优先矩阵的合并,建立负荷平衡问题的数学模型,并总结了目前存在的求解方法。在归纳投产排序的优化模型和目标函数的基础上,介绍了生产比倒数法、试探法、循环改进法等优化方法。重构过程的优化是可重构装配系统研究的一个重要方面。利用网络法的基本原理,针对扩大生产能力、设备故障和新产品到达的三种系统重构要求,给出了相应的重构算法。通过装配操作向多功能工作站的转移以实现装配系统的增容;以工期延长最短为优化目标,利用网络法中的组织优化原则实现系统的鲁棒性重构;以最大候选原则的基本原理为基础,提出了基于固定设备约束的重构算法用于系统适应新产品的重构。在分析传统控制系统体系结构的基础上,根据可重构装配系统组织结构的特征,提出了基于多Agent系统的混合控制体系结构,它结合了递阶结构和分布式控制的优点,使得更有利于实现可重构装配系统的实时控制、调度和重构。为了对Agent进行建模和实现,在遵守FIPA规范的前提下,以汽车减速箱装配系统为背景,利用JADE发平台,进行了各层Agent的实例开发,包括Agent属性描述、行为定义、通讯机制以及交互界面设计和Agent具体功能的编程实现。可重构装配系统重构过程的实现机理体现为多Agent之间的有效协商。在对现有Agent协商模型深入分析的基础上,针对鲁棒性、增容性、适应新产品的装配系统三个重构问题,提出了多Agent系统的协商机制,主要包括协商问题的形式化描述、协商模型、协商策略,结合相应的重构算法实现装配系统的重构。给出了Agent协商过程中存在的主要冲突和消解方法。通过多Agent系统协商实现可重构装配系统重构、调度和控制,充分体现了控制系统集中规划与分布式求解相结合的优点。