来自德国的高品质联轴器

SCHMIDT-KUPPLUNG GmbH的新产品,包括两个系列的产品,Semiflex和Schmidt-Kupplung.选择联轴器的过程相当方便.第一个字母代表系列(比如,F=Semiflex标准系列,C=Semiflex紧凑系列).     

气成岩型金矿床

金可以产在氧化物、碳酸盐或硫化物相含铁建造中。气成成因的矿床含有大量的金。沿表生沉积带含有一种“流矿”,是含金似硅华物质,代表喷气作用形成的脉体,分布于条带状含铁建造层内。热卤水能够把大量的金和其他金属呈可溶的络离子搬运到地面上去,循环液可以在沉积后不久从条带状含铁建造中淋滤出金。在脉体附近使金再次沉淀下来或者把它带到海底。在任何地质事件中,金和带状含铁建造总是具有相关性。     

平顶光束激光冲击2024铝合金诱导残余应力场的模拟与实验

对平顶光束激光冲击2024铝合金诱导的残余应力情况进行了有限元模拟与实验研究。改进了平顶光束诱导冲击波的压力分布模型,并将该模型用于残余应力场的有限元模拟。在实验室环境下获得了适合用于激光冲击的高质量平顶光束,并使用该光束进行激光冲击2024铝合金的实验,实验结果和模拟结果基本一致。研究发现平顶光束冲击2024铝合金有如下特点:存在一个阈值,当激光冲击波压力小于该阈值时,影响区内残余应力场近似均匀分布;当冲击波压力大于该阈值时会引起"残余应力洞",但该"残余应力洞"内部近似均匀分布。在深度方向上,塑性影响深度和最大残余应力深度随激光冲击波压力的增加而增加。     

企业履行社会责任不能光靠表面文章

公司为了摆脱套在自己脖子上的各种社会、环境以及道德枷锁．常常会做一些表面文章。这些企图逃避社会责任的行为．只会妨碍企业的可持续发展.[编者按]     

高炉喷吹生物炭研究进展

高炉喷煤可以降低焦比,但同时加剧温室效应和环境污染.近年来人们开始探索可以替代煤粉的新型燃料,如生物炭、兰炭、城市有机废物等,其中生物质因其来源丰富、环境友好而受到广泛关注.生物炭中的碳含量与煤相近,具备替代煤粉用于高炉喷吹的基本条件.对高炉喷煤技术、生物炭的制备和高炉喷吹生物炭的国内外现状进行了论述,并将生物炭的理化...     

Electrospun porous carbon nanofibers derived from bio-based phenolic resins as free-standing electrodes for high-performance supercapacitors

Phenolic resins were employed to prepare electrospun porous carbon nanofibers with a high specific surface area as free-standing electrodes for high-performance supercapacitors. However, the sustainable development of conventional phenolic resin has been challenged by petroleum-based phenol and formaldehyde. Lignin with abundant phenolic hydroxyl groups is the main non-petroleum resource that can provide renewable aromatic compounds. Hence, lignin, phenol, and furfural were used to synthesize bio-based phenolic resins, and the activated carbon nanofibers were obtained by electrospinning and one-step carbonization activation. Fourier transform infrared and differential scanning calorimetry were used to characterize the structural and thermal properties. The results reveal that the apparent activation energy of the curing reaction is 89.21 kJ·mol^–1 and the reaction order is 0.78. The activated carbon nanofibers show a uniform diameter, specific surface area up to 1100 m²·g^–1, and total pore volume of 0.62 cm³·g^–1. The electrode demonstrates a specific capacitance of 238 F·g^–1 (0.1 A·g^–1) and good rate capability. The symmetric supercapacitor yields a high energy density of 26.39 W·h·kg^–1 at 100 W·kg^–1 and an excellent capacitance retention of 98% after 10000 cycles. These results confirm that the activated carbon nanofiber from bio-based phenolic resins can be applied as electrode material for high-performance supercapacitors.     

香菇粉的添加量对面条物理性质的影响

为了研究香菇粉的添加量对面条物理性质的影响,以小麦粉为原料,加入不同比例的香菇粉(5%、10%和15%),对面条的颜色、质构特性、水分分布状态和热力学性质进行了分析。结果表明,香菇粉的加入导致面条颜色变深,弹性、黏聚性和回复性减小,同时改变了水分分布状态,水分子发生了迁移,与面条中其他大分子物质的结合更紧密,但香菇粉的添加量对面条的糊化温度没有显著的影响。     

Population-level modeling to account for multigenerational effects of uranium in Daphnia magna

As part of the ecological risk assessment associated with radionuclides in freshwater ecosystems, toxicity of waterborne uranium was recently investigated in the microcrustacean Daphnia magna over a three-generation exposure (F0, F1, and F2). Toxic effects on daphnid life history and physiology, increasing over generations, were demonstrated at the organism level under controlled laboratory conditions. These effects were modeled using an approach based on the dynamic energy budget (DEB). For each of the three successive generations, DEBtox (dynamic energy budget applied to toxicity data) models were fitted to experimental data. Lethal and sublethal DEBtox outcomes and their uncertainty were projected to the population level using population matrix techniques. To do so, we compared two modeling approaches in which experimental results from F0, F1, and F2 generations were either considered separately (F0-, F1-, and F2-based simulations) or together in the actual succession of F0, F1, and F2 generations (multi-F-based simulation). The first approach showed that considering results from F0 only (equivalent to a standard toxicity test) would lead to a severe underestimation of uranium toxicity at the population level. Results from the second approach showed that combining effects in successive generations cannot generally be simplified to the worst case among F0-, F1-, and F2-based population dynamics.     

Internet连接覆盖到公路

Autonet Mobile公司的车内路由器可让从笔记本到PDA到iPhone的所有设备实现Internet连接。     

高速处理器为3D视觉电视革命铺平了道路

多核微控制器和DSP将提高汽车安全性能,增加娱乐性。不要去理会所谓的摩尔定律已经消失的言论。不管摩尔定律是否存在,电子产品都在以极快的速度更新换代。高速的单核处理器正逐渐被多核处理器取而代之,半导体正不断促进车辆、电视、台式计算机、电话以及其他家用电器的智能化。