内燃机车柴油机飞车事故的分析及预防

介绍了飞车发生的现象，分析了内燃机车柴油机飞车事故的原因，提出了飞车事故的处理方法和预防措施。     

晶种分解过程αk的变化

对烧结法和拜尔法种分槽的αk与△αk的变化过程进行了概述。αk和△αk的变化对氢氧化铝晶体长大有显著的影响，因此控制种分槽αk和△αk变化非常重要。     

一类中立型偏微分方程的振动性

研究一类中立型偏微分方程（１）解的振动性，获得方程（１）在不同边界条件下的所有解振动的充分条件，并给出这些充分条件应用的实例。     

Perusing Piezoelectric Head Performance in a New 3-D Printing Design

Rapid prototyping (RP) is a computerized fabrication technology that additively builds highly complex three-dimensional physical objects layer by layer using data generated by computer, for example CAD or digital graphic. Three-dimensional printing (3DP) is one of such technologies that employ ink-jet printing technology for processing powder materials. During fabrication, a printer head is used to print a liquid on to thin layers of powder following the object’s profile as generated by the system computer. This work looks at redesigning 3DP machine, using piezoelectric demand-mode technology head in order to improve accuracy, surface finishing and color quality of constructed models. The layers created with aforesaid system are between 25 to 150 μm (steps of 25 μm).     

The trophic fingerprint of marine fisheries

Biodiversity indicators provide a vital window on the state of the planet, guiding policy development and management. The most widely adopted marine indicator is mean trophic level (MTL) from catches, intended to detect shifts from high-trophic-level predators to low-trophic-level invertebrates and plankton-feeders. This indicator underpins reported trends in human impacts, declining when predators collapse ("fishing down marine food webs") and when low-trophic-level fisheries expand ("fishing through marine food webs"). The assumption is that catch MTL measures changes in ecosystem MTL and biodiversity. Here we combine model predictions with global assessments of MTL from catches, trawl surveys and fisheries stock assessments and find that catch MTL does not reliably predict changes in marine ecosystems. Instead, catch MTL trends often diverge from ecosystem MTL trends obtained from surveys and assessments. In contrast to previous findings of rapid declines in catch MTL, we observe recent increases in catch, survey and assessment MTL. However, catches from most trophic levels are rising, which can intensify fishery collapses even when MTL trends are stable or increasing. To detect fishing impacts on marine biodiversity, we recommend greater efforts to measure true abundance trends for marine species, especially those most vulnerable to fishing.     

Alperin－Burry意义下Brauer对应的一个结果

在这篇文章中，我们得到了下列主要结果：定理Ａ设ＨＧ，Ｂ，ｂ分别是ＲＧ，ＲＨ的块，其块元分别为的方群Ｄ满足，则下列等价：（１）；（２）；（３）；（４）任给，则Ｘ￣Ｇ的所有不可约分量都属于Ｂ。