成型温度对PBX装药内部质量及性能的影响

针对压制成型的PBX炸药装药，选择CT无损检测、巴西实验和扫描电镜检测等技术，对比研究了室温和加热两种温度下压制成型的炸药装药内部质量、静态力学性能和细观破坏形式。结果表明，加热压制有利于改善炸药装药的内部质量，可避免产生初始损伤，且提高了装药的力学性能。细观尺度上，室温压制成型的装药主要发生界面脱黏破坏，加热压制成型装药的主要破坏形式是穿晶断裂。     

矿用提升机盘形制动器制动安全分析

通过解析矿用提升机制动器制动的工作原理,分析影响安全制动的因素,可以在工作中尽快找出影响安全制动的原因,并采用相应的解决方法使提升机在有效制动范围内运行。     

Spurenstoffabtrennung mit keramischen Nanofiltrationsmembranen als Rotationsscheibenfilter

Reducing micropollutant pollution of water bodies is an important objective of water management and an integral part of environmental policy. Ceramic nanofiltration membranes were developed as multichannel membranes of increased membrane area and rotating disk filters. The membranes developed show retention of over 80 % for PEG 400. The membranes are currently being tested for the separation of micropollutants from wastewater contaminated with pharmaceuticals. With the help of a downstream oxidative process, the trace substances remaining in the permeate are degraded.     

Contested landscapes: territorial conflicts and the production of different ruralities in Brazil

ABSTRACT

From the perspective of Brazilian agrarian geography, the conflicts generated by land tenure disputes have as protagonists the families of the Landless Workers’ Movement (Movimento dos Trabalhadores Rurais Sem Terra), traditional landowners, and agribusiness corporations. In this article, we present a reflection on land conflicts and the spatial and territorial production of latifundia, peasant smallholders, and large-scale agribusiness through studies of the landscapes of two municipalities in the state of São Paulo. Among the various tools for analysing territorial disputes, Google Earth can be used for local, regional, and international comparative studies of how landscapes have been transformed. Informed by traditional research, the article analyses a diversity of photographs, from satellite to field shots, as evidence of landscapes that express conflicting social relations in disputes over different models of social and territorial development.     

不同层面倾角下锦屏一级水电站左岸板岩坡体破坏模式及能量特征

为了合理分析锦屏一级水电站左岸坡体的变形,选取坡体板岩进行巴西劈裂试验,分别研究了不同层面倾角下不同饱水率板岩的力学特性及能量特征。结果表明,板岩的抗拉强度随层面倾角的不断增加先减小后增加,其最大降幅达82%;同一层面倾角下,随着饱水程度的增加,板岩抗拉强度逐渐降低,在层面倾角为45°时,抗拉强度从1.64MPa降至0.52MPa,降幅达68%;试样层面倾角0°~90°的破坏受饱水率的影响较小,主要由层面倾角控制,破坏特征分为岩石拉伸型破坏、层面剪切破坏、基质-层面互剪型破坏、层面张拉破坏四种模式;试样破坏的累积能量随饱水程度的增加而不断减小,在相同饱水程度下,累积能量随层面倾角的增大而逐渐减小,累积能量的增长速率与荷载比成非线性关系,在轴向荷载达40%~80%时增长最快。     

The Potential Role of Hepatocyte Growth Factor in Degenerative Disorders of the Synovial Joint and Spine

This paper aims to provide a comprehensive review of the changing role of hepatocyte growth factor (HGF) signaling in the healthy and diseased synovial joint and spine. HGF is a multifunctional growth factor that, like its specific receptor c-Met, is widely expressed in several bone and joint tissues. HGF has profound effects on cell survival and proliferation, matrix metabolism, inflammatory response, and neurotrophic action. HGF plays an important role in normal bone and cartilage turnover. Changes in HGF/c-Met have also been linked to pathophysiological changes in degenerative joint diseases, such as osteoarthritis (OA) and intervertebral disc degeneration (IDD). A therapeutic role of HGF has been proposed in the regeneration of osteoarticular tissues. HGF also influences bone remodeling and peripheral nerve activity. Studies aimed at elucidating the changing role of HGF/c-Met signaling in OA and IDD at different pathophysiological stages, and their specific molecular mechanisms are needed. Such studies will contribute to safe and effective HGF/c-Met signaling-based treatments for OA and IDD.     

冷轧带钢切边圆盘剪装置的优化与改进

针对冷轧带钢切边后产生的边部梗压印缺陷,结合切边圆盘剪的剪切原理,设计了一种圆盘剪复合衬套,其采用100Cr钢质内圈和MC尼龙外圈复合结构组成,取代原纯钢质衬套,使圆盘剪在剪切带钢过程中由钢性接触转变为弹性接触,从而避免了带钢边部梗压印缺陷的产生,提高了切边质量与剪切里程数,降低了圆盘剪备件成本,提高了生产效率。     

A simple improvement of a tip loss model for actuator disc simulations

The loading of a wind turbine decreases towards the blade tip because of the velocities induced by the tip vortex. This tip loss effect has to be taken into account when performing actuator disc simulations, where the single blades of the turbine are not modeled. A widely used method applies a factor on the axial and tangential loading of the turbine. This factor decreases when approaching the blade tip. It has been shown that the factor should be different for the axial and tangential loading of the turbine to model the rotation of the resulting force vector at the airfoil sections caused by the induced velocity. The present article contains the derivation of a simple correction for the tangential load factor that takes this rotation into account. The correction does not need any additional curve fitting but just depends on the local airfoil characteristics and angle of attack. Actuator disc computations with the modified tip loss correction show improved agreement with results from actuator line, free wake lifting line, and blade element momentum simulations.     

Food insecurity and nutrition index: Disaggregation and evidence for Brazilian states

Food security and nutrition is a multidimensional theme consisting of three pillars: food access, availability, and sufficiency. Given food security and nutrition's extent, its measures are usually limited. To address these limitations, this paper proposes the creation of a disaggregated food insecurity index for Brazilian states, with the three dimensions in mind. The results show that while food availability elevates the average of the index, the sufficiency still is a problem. Even though the distribution of and access to food in Brazil has increased in the last years, it was not combined with policies that guarantee its safety and quality, reinforcing the need for specific interventions considering regional particularities.