Algorithm for 2D irregular-shaped nesting problem based on the NFP algorithm and lowest-gravity-center princlple

The nesting problem involves arranging pieces on a plate to maximize use of material. A new scheme for 2D irregular-shaped nesting problem is proposed. The new scheme is based on the NFP （No Fit Polygon） algorithm and a new placement principle for pieces. The novel placement principle is to place a piece to the position with lowest gravity center based on NFP. In addition, genetic algorithm （GA） is adopted to find an efficient nesting sequence. The proposed scheme can deal with pieces with arbitrary rotation and containing region with holes, and achieves competitive results in experiment on benchmark datasets.     

高职机制专业金工实习改革实践与探讨

高职机制专业金工实习的主要任务是培养适应机械制造企业生产第一线职业岗位需要的通用的核心能力。为此，笔提出了在金工实习教学中培养具有质量、成本、效益、安全、创新意识，适应企业岗位要求的人才的具体措施，并取得了较为满意的实践教学效果。     

烯烃复分解反应--2005年诺贝尔化学奖综述

烯烃复分解反应是指在金属卡宾化合物的催化作用下,烯烃里的碳—碳双键被拆散、交换、重组,形成新分子的过程。法国的肖万提出了烯烃复分解反应的基本机制;美国的施罗克和格拉布二人继承和发展了肖万的烯烃复分解反应机制,研制出了有效、实用的催化剂。新的合成过程更简单快捷,生产效率更高,副产品更少,产生的有害废物也更少,有利于保护环境,每天都惠及人类。     

提高薄壁件内孔加工精度方法的研究

对影响薄壁件内孔的加工精度的因素进行了分析,找出了主要的影响因素,并从工艺上采取有效的改进措施,解决了薄壁件内孔加工误差大的难题,从而提高了薄壁件内孔的加工精度.     

热电子对多孔金属物态方程贡献的数值计算

沿等压路径计算了热电子对物态方程贡献的大小。证明了热电子对压力的贡献与热电子对体积的贡献二者不成严格线性变化关系，结果显示有必要对热电子对金属物态方程贡献的计算方式作进一步的研究。     

金属卤化物的结构-活性/性质的研究

本文提出一种新的描述金属卤化物标准生成焓H的键参数函数，即用电荷数z与半径r之比、电负性x、主量子数n研究了它们与金属卤化物标准生成焓H的相关性，用MATLAB语言算得相关系数为R=0．9910．结果表明金属卤化物生成焓与z／r、x、n有很好的线性关系，其线性回归方程如下：△H=696.6372 45.4539[z1/r1/0.77)^2 z2/(r2/0.77)^2] 25.8218n^1/3-453.5393x     

An extended chemical analysis of gallstone

Chemical composition of gall stones is essential for aetiopathogensis of gallstone disease. We have reported quantitative chemical analysis of total cholesterol bilirubin, calcium, iron and inorganic phosphate in 120 gallstones from haryana. To extend this chemical analysis of gall stones by studying more cases and by analyzing more chemical constituents. A quantitative chemical analysis of total cholesterol, total bilirubin, fatty acids, triglycerides, phospholipids, bile acids, soluble proteins, sodium potassium, magnesium, copper, oxalate and chlorides of biliary calculi (52 cholesterol, 76 mixed and 72 pigment) retrieved from surgical operation of 200 patients from Haryana state was carried out. Total cholesterol as the major component and total bilirubin, phospholipids, triglycerides, bile acids, fatty acids (esterified), soluble protein, calcium, magnesium, iron, copper, sodium, potassium, inorganic phosphate, oxalate and chloride as minor components were found in all types of calculi. The cholesterol stones had higher content of total cholesterol, phospholipids, fatty acids (esterified), inorganic phosphate and copper compared to mixed and pigment stones. The mixed stones had higher content of iron and triglycerides than to cholesterol and pigment stones. The pigment stones were richer in total bilirubin, bile acids, calcium, oxalate, magnesium, sodium, potassium, chloride and soluble protein compared to cholesterol and mixed stones. Although total cholesterol was a major component of cholesterol, mixed and pigment gall stone in Haryana, the content of most of the other lipids, cations and anions was different in different gall stones indicating their different mechanism of formation.     

氰化物预处理方法的研究

该文采用吡啶—巴比妥酸分光光度法对水样中的总氰化物进行测定,探讨了氰化物测定的各预处理体系,选用了9种预处理体系分别对八种金属氰络合物进行了实验研究,并使金属氰络合物与游离氰含量比为1:1的条件下考察其游离情况.实验表明,除3种预处理体系外,其它预处理体系均获得了满意的结果.     

抉剔其类 发其隐情——《斩鬼传》讽刺手法探析

《斩鬼传》是《儒林外史》之前的一部特色鲜明的寓意类讽刺小说。作者运用了多种讽刺手法,将讽刺的锋芒直指人类的道德缺陷和丑恶癖性,使众多"人鬼"穷形尽相。小说善于运用对比、衬托的讽刺手法,在衬比之中彰显讽刺对象;作者秉持冷静的态度,不加半点评述,让人物尽情地表演,在冷静客观中呈现人物的言行、刻画讽刺对象。此外,小说还使用了主观直斥和合理夸张等讽刺手法,讥刺了人类诸多弱性。《斩鬼传》的讽刺艺术和风格,对后世讽刺性小说产生了一定影响。     

多目标猫群算法求解切削参数优化问题

针对车床切削过程的复杂性,在充分考虑加工过程约束条件的基础上,建立了生产率、刀具耗损寿命和表面粗糙度的切削参数优化问题的数学模型。推导和分析发现,目标函数和和分析切削参数约束条件都是关于进给量、切削速度和背吃刀量的方程和不等式,为优化奠定了良好的基础。采用改进的多目标猫群算法进行优化,结果表明,该算法能有效求解切削参数优化问题。