流动注射安培检测废水中梯恩梯的研究

采用流动注射分析(FIA)可以快速检测废水中的梯恩梯(TNT)。本文设计了应用碳糊作电极的简易喷壁安培检测池,组装了流动注射分析装置,选择pH=9.5伯瑞坦-罗宾森(Britton-Robinson)缓冲液作为载体,载体流速3.9ml/min,用N_2除O_2;电位-0.60V(SCE),进样体积100μl,连接管长50cm。在所选定的上述条件下,TNT在0.1-70mg/1之间有良好的线性关系,样品回收率在94.4-102.7%之间;进样频率96样/小时。     

企业联盟的动因及其政策动态一致性的博弈分析

本文运用博弈论分析了企业联盟的动因 .在此基础上 ,提出了联盟的动因模型 ;然后进一步分析了联盟形成后政策的动态一致性问题 ,提出了满足联盟政策动态一致性的条件 ,并对其进行了深入讨论 .     

氢在铁中偏克原子应变场的测定

利用特殊的四边形夹具可分别施加等值的拉、压载荷,同时测出拉、压应力引起的相对稳态氢渗透通量的变化就可求出氢的应变场。结果表明,氢在铁中的应变场是非球对称的,且;ε_1>0,ε_2=ε_3<0。 实验表明,氢的表观偏克原子应变场和表观偏克原子体积均随体内氢浓度的增加而下降。用最小二乘法可获得氢浓度趋于零时的真实值,分别为ε_1=0.37,ε_2=ε_3=-0.11,V_H=2.49cm~3/mol。实验还表明,外加应力大小对应变场没有影响。     

关于绍兴印山大墓墓主问题的探讨--兼说绍兴306号墓的国属问题

绍兴印山大墓出土遗物的年代约在春秋晚期至战国前期之间.在目前已知的同时代的南方墓葬中,印山大墓的体量最大,气势最为雄伟,结构最为奇特与复杂.结合越国历史,它绝对不可能是春秋时期的允常之墓,而只能是战国时期某位越王之墓,具体王名尚难确定.若参考诸位越王的传世铜器情况,以者旨于赐之墓的可能性较大.绍兴306号墓形制与印山大墓迥异,应该是徐墓,不是越墓.     

低损耗阶跃型聚合物光纤制备工艺的研究

介绍了制备低损耗阶跃型聚合物光纤的工艺流程，研究发现随着链转移剂质量分数的增加，聚合物的相对分子质量相应降低，聚合物光纤的力学性能也随之改变，加入改性单体丙烯酸乙酯或丙烯酸丁酯后，提高了聚合物光纤的柔韧性，但降低了聚合物光纤的透光率，包层工艺对光纤损耗也有较大影响。通过原料精馏提纯、材料改性和共挤工艺等措施制备出低损耗聚合物光张样品，其光损耗小于200dB/km(波长650nm)。     

Coxsackievirus B4 infection of spinal sympathetic ganglion

Summary Coxsackievirus B₄ infection of a spinal sympathetic ganglion of a squirrel monkey is described. Chromatolysis and neuronophagia were extensive. It is suggested that such viral sympathetic ganglial infections may be responsible for dysfunction of organ systems.Supported by the Cardiovascular Research Fund, the Rowell A. Billups Fund for Research in Heart Disease, the Feazel Laboratory and grant No. RR-00164-17 from the Animal Resources Branch, Division of Research Resources of NIH.     

Characteristics of dynamic membrane filtration: structure,operation mechanisms,and cost analysis

Dynamic membrane technology represents a promising substitution for conventional membrane bioreactor system,which owns the merits of flexible and comparably cheap materials,easy for backwash,good antifouling property,etc.It has been over half a century since the principle of dynamic membranes was first reported,whereas the development and popularization are still limited.This paper makes a review on characteristics of dynamic membranes,including development and application,mechanism,structure and materials,operation conditions,membrane fouling,dynamic membrane cleaning,and cost analysis,attempting to give clues on promotions and perspectives exhibited of this technology.     

Tracing the stepwise oxygenation of the Proterozoic ocean

Biogeochemical signatures preserved in ancient sedimentary rocks provide clues to the nature and timing of the oxygenation of the Earth's atmosphere. Geochemical data suggest that oxygenation proceeded in two broad steps near the beginning and end of the Proterozoic eon (2,500 to 542 million years ago). The oxidation state of the Proterozoic ocean between these two steps and the timing of deep-ocean oxygenation have important implications for the evolutionary course of life on Earth but remain poorly known. Here we present a new perspective on ocean oxygenation based on the authigenic accumulation of the redox-sensitive transition element molybdenum in sulphidic black shales. Accumulation of authigenic molybdenum from sea water is already seen in shales by 2,650 Myr ago; however, the small magnitudes of these enrichments reflect weak or transient sources of dissolved molybdenum before about 2,200 Myr ago, consistent with minimal oxidative weathering of the continents. Enrichments indicative of persistent and vigorous oxidative weathering appear in shales deposited at roughly 2,150 Myr ago, more than 200 million years after the initial rise in atmospheric oxygen. Subsequent expansion of sulphidic conditions after about 1,800 Myr ago (refs 8, 9) maintained a mid-Proterozoic molybdenum reservoir below 20 per cent of the modern inventory, which in turn may have acted as a nutrient feedback limiting the spatiotemporal distribution of euxinic (sulphidic) bottom waters and perhaps the evolutionary and ecological expansion of eukaryotic organisms. By 551 Myr ago, molybdenum contents reflect a greatly expanded oceanic reservoir due to oxygenation of the deep ocean and corresponding decrease in sulphidic conditions in the sediments and water column.     

心理旅游的市场细分研究

心理旅游是一项新兴的特色旅游活动,短短5年的发展历史,正逐渐得到经营者的认可和旅游者的认同,其市场发展空间十分广阔.本文通过分析心理旅游的发展历程、概念理解和特点认识,根据旅游者的不同心理特征进行市场细分研究.     

Study of the varve record from Erlongwan maar lake, NE China, over the last 13 ka BP

In a sediment sequence from Erlongwan maar lake that spans the last 13 ka BP, two main varve types can be recognized： biogenic varves （from the present to -11.2 ka BP, 0-632 cm） and clastic varves （from -11.2 to -12.7 ka BP, 632-700 cm）. Based on the dominant types of algae contained in the sediment, the biogenic varves can be classified into dinocyst-biogenic varves （0-63 cm） and mixed （dinocyst and diatom）-biogenic varves （214-632 cm）. In this paper, the formation process and components of the varve are described, the possible reason for the types of varve changing throughout the record is discussed and a high-resolution varve chronology is established spanning the last 13 ka BP. Although further varve counting and error assessment are needed, the results presented here represent a solid foundation for studying the palaeoclimate record of Erlongwan maar lake.