利用工艺尺寸链综合计算工序余量,工序尺寸及公差

本文介绍了从零件加工工艺过程角度出发，利用工艺尺寸链作综合分析和计算，合理地确定加工过程中各工序余量、工序尺寸及公差，为工艺设计提供了更加经济、合理的工艺参数，较好地解决了ＣＡＰＰ系统中有关尺寸链计算的问题．     

齿条型链轮传动及加工方法

齿条齿形的链轮传动作为一种新型传动形式,除具有普通链轮传动的特点外,还有传动平稳、精度高、制造简单等优点。针对批量的大小可以采用成形铣削、展成滚齿等方法加工齿形,并可依据齿廓啮合原理设计通用滚刀。对齿条型链轮传动进行了运动学和动力学分析,给出了齿条型链轮的齿形计算公式,并根据链轮齿形确定了滚刀齿形。经实际加工验证,所加工的链轮装机后,运转正常,性能稳定。     

丙三醇对玉米醇溶蛋白流变性和黏结性的影响

为了探明改性玉米醇溶蛋白的流变性和黏结性及其相互关系,研究了丙三醇、温度、剪切速率等对玉米醇溶蛋白流变性和黏结性的影响。结果表明,丙三醇改性的玉米醇溶蛋白具有假塑性流体特性,呈现"剪切变稀"现象。丙三醇含量、剪切温度和剪切速率对玉米醇溶蛋白的流变性有显著影响。随丙三醇含量的增加,玉米醇溶蛋白的黏度明显增加;随剪切温度的增加,黏度呈先下降后增加的趋势,当温度为308 K时,黏度最低;随剪切速率的增加,黏度呈下降趋势。随丙三醇含量的增加,改性玉米醇溶蛋白对竹颗粒的黏结性呈先增加后下降的趋势,当丙三醇体积分数为10%时,黏结性较佳。改性玉米醇溶蛋白的黏度逐渐增加时,其黏结性呈先增加后减小趋势。     

纤维素基生物材料在细胞培育肉生产中的应用

随着细胞培育肉研究的兴起,应用于细胞培育肉生产的可食用支架受到高度关注。纤维素具有丰富易得、可食用、非动物源、成本低、可商业化生产等特点,这些都展示了纤维素用于细胞培育肉的重要潜力。本综述首先介绍了不同种类纤维素（植物纤维素、细菌纤维素）的基本理化性质,其次围绕支架的一系列特定结构（多孔、定向、球形结构、天然精密结构、可定制结构）,提出了针对纤维素基细胞培育肉支架的制备方法,最后讨论了纤维素应用于细胞培育肉支架中的主要挑战,并提供了可能的解决方案,以期为低成本、连续化生产纤维素基支架以及良好培育肌肉、脂肪细胞提供参考。     

钢筋混凝土用热轧带肋钢筋标准历次修订情况介绍

介绍了我国钢筋研制、生产、使用基本情况,阐述了我国热轧钢筋标准自１９５２年颁布执行以来所经历的８次修订,将热轧钢筋标准的演变与发展划分为四个阶段。     

车辆底盘自动集中润滑系统故障检测装置的设计

通过对车辆底盘自动集中润滑系统进行分析,研究故障检测的方法与装置设计。     

Influence of potassium permanganate pretreatment on mechanical properties and thermal behavior of moso bamboo particles reinforced PVC composites

To illustrate the mechanism of oxidizer treatment on wood cellulose reinforced plastic composites, moso bamboo particles were modified with potassium permanganate aqueous solutions and then filled in polyvinyl chloride (PVC) matrix. Mechanical properties and thermal behaviors of moso bamboo particles reinforced PVC composites (BPPC) were investigated. Results showed that tensile strength of BPPC achieved its maximum value of 13.79 MPa with 0.5% potassium permanganate treatment while modulus of rupture and modulus of elasticity reached their highest values of 30.36 MPa and 3261.89 MPa, respectively, at 0.2% concentration. Potassium permanganate treatment enhanced elongation at break and flexural deformation of BPPC. The melting temperature reached 190.8°C with 0.5% potassium permanganate treatment and the melting enthalpy of crystallization was reduced to 69.82 J/g with 0.2% potassium permanganate treatment. A uniform dispersion of moso bamboo particles in PVC matrix was obtained after potassium permanganate treatment. Low concentration potassium permanganate would oxidize hydroxyl groups of moso bamboo cellulose while too high concentration would degrade moso bamboo cellulose. POLYM. COMPOS., 35:1460–1465, 2014. © 2013 Society of Plastics Engineers     

关于剖切面及其剖切方法划分的标准化

根据逻辑学关于褐示概念外延的划分原理,剖析了现行机械制图国家标准关于剖切面及其剖切方法分类的逻辑错误,提出了剖切面及其剖切方法严密,完整,清楚的划分方法。     

Far-infrared and microwave drying of peach

Little detailed information is available for the far-infrared and microwave drying characteristics on peach and far-infrared combined with microwave drying on other food products. Experiments were conducted to study microwave and far-infrared dehydration characteristics and two-stage drying process involving far-infrared following microwave drying on peach. As microwave drying power and infrared drying power increased, dehydration rate of peach increased and whole drying energy consumption decreased. Peach experienced two falling rate periods when dried with microwave drying or far-infrared drying, and the first falling rate period under moisture content of peach more than 1.7 (dry basic, d. b.), the second falling rate period under less than moisture content 1.7 (d. b.). The same water loss will consume more energy and the steeper curve of energy versus moisture content were obtained when the moisture content is less than 1.7 (d. b.). However, differed from microwave drying, an accelerating dehydration rate period existed in the initial period of far-infrared drying. The effects of infrared drying power, microwave drying power and exchanging moisture content at former far-infrared drying converting into latter microwave drying (three factors) on energy consumption rate and sensory quality (two indices) are significant. The interaction effect of infrared drying power and exchanging moisture content on two indices is significant. The effects of second-order of microwave drying power and of interaction between infrared drying power and microwave drying power on energy consumption rate were not significant. The effects of second-order of exchanging moisture content and of interaction between exchanging moisture content and microwave drying power on sensory quality were not significant.     

Dual-thread Speculation: A Simple Approach to Uncover Thread-level Parallelism on a Simultaneous Multithreaded Processor

As chip multiprocessors with simultaneous multithreaded cores are becoming commonplace, there is a need for simple approaches to exploit thread-level parallelism. In this paper, we consider thread-level speculation as a means to reap thread-level parallelism out of application binaries. We first investigate the tradeoffs between scheduling speculative threads on the same core and on different cores. While threads contend for the same resources using the former approach, the latter approach is plagued by the overhead for inter-core communication. Despite the impact of resource contention, our detailed simulations show that the first approach provides the best performance due to lower inter-thread communication cost. The key contribution of the paper is the proposed design and evaluation of the dual-thread speculation system. This design point has very low complexity and reaps most of the gains of a system. The work was carried out while Fredrik Warg was a graduate student at Chalmers University of Technology.