梁的刚度设计的二因子法

针对筒支架、外伸梁及多跨连续梁变形分析的种种困难，提出了拟固定端的概念，并且给出确定拟固定端的位置的方法，进而把所有的梁全部转化为拟悬臂梁，把所有的荷载转化为集中力或由集中力得到的结果，由此便可由悬臂梁的结果PI^3/3EI及PI^2/2EI依悬臂梁的方法解所有梁的变形极值，这将对梁的刚度设计具有重要意义，对于计算的程序化，特别是连续梁的计算具有相当的优势。     

DTM350／600型球磨机端盖开裂原因分析及对策

福建省电帽福建无烟煤的８台ＤＴＭ３５０＝６００型磨机投产后，磨煤机端盖长则５￣６ａ，短则２ａ，均行后发生了不同程度的开裂并逐步发展，以致引起烧瓦 ，经专题研究，设计研制出改进型盖改进型端盖投运至今已有４ａ多，端盖完好无损。，     

Microstructural characteristics and mechanical properties of carbon nanotube reinforced aluminum alloy composites produced by ball milling

The influence of milling time on the structure, morphology and thermal stability of multi-walled carbon nanotubes (MWCNTs) reinforced EN AW6082 aluminum alloy powders has been studied. After structural and microstructural characterization of the mechanically milled powders micro- and nano-hardness of the composite powder particles were evaluated. The morphological and X-ray diffraction studies on the milled powders revealed that the carbon nanotubes (CNTs) were uniformly distributed and embedded within the aluminum matrix. No reaction products were detected even after long milling up to 50 h. Nanotubes became shorter in length as they fractured under the impact and shearing action during the milling process. A high hardness of about 436 ± 52 HV is achieved for the milled powders, due to the addition of MWCNTs, after milling for 50 h. The increased elastic modulus and nanohardness can be attributed to the finer grain size evolved during high energy ball milling and to the uniform distribution of hard CNTs in the Al-alloy matrix. The hardness values of the composite as well as the matrix alloy compares well with that predicted by the Hall–Petch relationship.     

Impact of durum wheat milling on deoxynivalenol distribution in the outcoming fractions

The milling behaviour of two naturally infected samples of durum wheat grain with contrasting levels of mycotoxins was studied. Although the two samples showed a similar milling behaviour, an increase of ～20% in deoxynivalenol (DON) levels was found in semolina from the sample containing the higher level of mycotoxin. However, even if the highest concentration of DON was found in fractions originating from the grain outer layers, the mycotoxin contamination in semolina and flours were not related to the amount of two compounds (ash or phytic acid) used to monitor these external tissues. The presence of the trichothecene-producing fungi in the inner-most semolina fraction was also shown using specific DNA primers and PCR amplification. Comparison of DON concentrations in the feed stock and corresponding output at each milling step or grinding of semolina fractions followed by sizing showed that concentration of mycotoxin occurs in the finest particles at the first processing steps. Therefore, DON contamination of milling fractions is not simply due to the presence of peripheral grain tissues.     

桑椹天然植物染料的稳定性能

研究了桑椹天然植物染料在不同条件下的稳定性能.通过测试染液可见吸收光谱来探讨酸碱、温度、光照以及金属离子对桑椹天然植物染液的影响.结果显示:桑椹天然植物染液可见吸收光谱在紫外区域出现新的吸收峰且峰形尖锐,随pH提高而出现吸收峰红移现象(逐渐减弱并消失),染料适合在酸性浴(pH≤4)或碱性浴(pH≥8)中染色;在80℃以下稳定性良好,但耐光性较差,长时间的光照使染液色泽灰暗,鲜艳度下降:Al<'3+>使染液表现出明显的增色效应和轻微的吸收峰红移现象,Mg<'2+>对染液颜色影响很小、Cu<'2+>有轻微增色效应,加入Fe<'3+>染液吸收峰红移(逐渐减弱消失并在紫外光区域出现末端吸收效应).     

The path to a paradigm shift in hemodialysis

About 1 out of 4 American conventional dialysis patients die in the first year and 3 out of 5 die within 5 years with no favorable trend in sight. Largely ignored in practice is the evidence accumulated over decades that longer, more frequent dialysis can immediately slash this grim result in half or more. Pierratos has called for a paradigm shift—a disruptive change—in dialysis practice from conventional treatment to daily nocturnal dialysis, performed at home, to realize this dramatic improvement. We examine here how such a paradigm shift might be brought about and suggest that changes in 3 perspectives must occur. First, new dialysis guidelines must be recast from the old goal of minimally adequate to a new goal of best possible . Second, the body of dialysis research must be interpreted through the lens of best possible patient survival and well being, and the near-impossibility of demonstrating dialysis survival advantage through randomized clinical trials must be acknowledged. Finally, dialysis modality must be seen as, most importantly, a survival and well-being choice, not merely a "Lifestyle" choice; hence, it must be the nondelegatable responsibility of the physician, not dialysis center personnel, to advise and prescribe. Many old perspectives, which might stand in the way of this sorely needed paradigm shift are also examined. These old perspectives make up a fabric of excuses that has delayed—and, if not discarded, will continue to delay—progress toward a survival and well-being outlook for dialysis patients just as favorable as might be achieved through kidney transplant.     

不同工况下爆炸切割浅海废弃油井的安全性探讨

海洋资源开采后,废弃油井给海上交通及环境造成巨大安全隐患,因此在油井退役后需要将其去除.由于海上输油管一般采用多层防护套管并于中间添加水泥层,普通方法难于短时间将油井切断,因而常采用爆炸切割的方法.利用大型爆炸切割器进行拆除作业时,增大炸药量,切割能力增强,但对外界的冲击破坏作用增大,不安全因素相应增多.对不同工况下废...     

纵剪机切边刀盘热处理工艺研究

切边刀盘是纵剪机上的关键件,其材质和技术要求的特殊性导致刀盘热处理出现裂纹、变形等缺陷.在借鉴专利技术的基础上,应用“传导温差与层界面及材料的导温系数”原理,研制出了“感应快速加热、快速冷却局部淬火、糖葫芦”式的工频热处理工艺技术,提出了热处理工艺措施,满足了产品性能要求.