直线位移传感器线性自动测试皆半自动修刻机研发

简述直线位移传感器自动测试与半自动修刻机的研发背景、目标。叙述了该设备主要研发内容,硬件精度、系统精度、工作原理及计算机软件程序控制。作为一种科学技术仪器设备,工作行程600mm,具有高精度与自动控制功能,系统精度高于0.02%,重复定位精度0.01mm,电脑控制自动输出,液晶数字显示线性精度阻值大小和线性特征曲线,接口打印,功能齐全;升级替代了人工计算操作较差的普通生产设备。     

面向飞机蒙皮柔性夹持数控切边的定位仿真系统及应用

针对切边过程中有效定位点动态变化的特征,提出＂X-2-1＂动态定位原理。基于几何约束关系实现了柔性工装对曲面零件的虚拟装夹,精确计算出柔性工装的调形参数。通过协调单元生死顺序和铣削力加载,实现了切边过程有限元仿真分析。选择典型飞机蒙皮零件进行了集成验证试验,试验分析结果表明加工精度满足制造要求。     

浪形保持架整形凹模加工工艺改进

浪形保持架整形凹模在等分车床上加工时,由于加工精度低,达不到使用要求,选择在镗铣加工中心加工,既减少了加工工序,又提高了模具的精度和寿命,提高了生产率。     

Incidence and severity of Arcanobacterium pyogenes injection site abscesses with needle or needle-free injection

Nursery-age pigs (n=198) were used to evaluate the difference in abscess formation at needle-free jet and conventional needle-and-syringe injection sites. Needle-free jet injection was used to administer injections in the neck and ham on one side of the animal whereas needle-and-syringe was used for neck and ham injections on the opposite side. Immediately prior to injection, the injection site surfaces were contaminated with an inoculum of Arcanobacterium pyogenes. Each pig was humanely euthanized 27 or 28days after injections. Histopathological results showed that needle-free jet injection was associated with more abscesses than needle-and-syringe injection at both neck (P=0.0625) and ham (P=0.0313) injection sites. Out of 792 injection sites, only 13 abscesses were observed, with 12 of those present at needle-free jet injection sites. Needle-free jet injection may increase the occurrence of injection site abscesses that necessitate carcass trimming at pork processing plants.     

Bovine claw and limb disorders at claw trimming related to milk yield

As part of a cross-sectional study of Norwegian Red Cattle, associations of lameness, lesions at the tarsus, claw shapes, claw lesions, and claw trimming with milk yield were examined. Fifty-five tie-stall herds and 57 free-stall herds were sampled by computerized systematic selection, and 2,665 cows were trimmed and limb and claw disorders recorded. After exclusions, 2,599 cows were included in this study. Monthly recordings of milk were extracted from the Norwegian Dairy Herd Recording System. Most claw lesions were mild (score 1). The prevalence of moderate and severe lesions (score 2 and 3) did not exceed 5% for any of the lesions. Associations with test-day milk yield were identified using regression analyses (Proc Mixed) with repeated measurements within lactation and herd as random effect. Lactation curves were fit to visualize differences in changes in milk yield throughout the lactation. Milk yield was generally higher in cows with lesions at the tarsus, heel-horn erosions, and hemorrhages of the white line and the sole than in cows without these lesions, whereas cows with dermatitis yielded less than cows without dermatitis. Cows in lactation 1 with corkscrewed claws had reduced milk yield, whereas cows in lactations 2 and above had increased milk yield compared with cows without corkscrewed claws in respective lactations. Cows in lactation 1 yielded 0.47 ± 0.15 kg and cows in later lactations yielded 0.51 ± 0.15 kg more milk on test days after claw trimming than they did before when adjusted for days in milk. In this study, where most disorders were mild, the most evident results were higher milk yield in cows with lesions at the tarsus, heel-horn erosions, and hemorrhages of the white line and the sole than in cows without these lesions. Cows yielded more milk after claw trimming than they did before trimming.     

Production of fermentable media from vine‐trimming wastes and bioconversion into lactic acid by Lactobacillus pentosus

Trimmings of vineshoots, an agricultural waste with little use, were hydrolysed with dilute sulphuric acid (1–5%) in order to obtain sugar solutions suitable as fermentation media. The operational conditions for hydrolysis were selected on the basis of both the generation of hemicellulosic sugars (mainly xylose) and glucose and the concentrations of reaction byproducts affecting fermentation (furfural, hydroxymethylfurfural and acetic acid). Hemicellulosic hydrolysates were supplemented with nutrients and fermented with Lactobacillus pentosus, without any previous detoxification stage, to produce lactic acid. Under the best operational conditions assayed (3% H₂SO₄ and 15 min), 21.8 g lactic acid l^?1 was produced (Q_P = 0.844 g l^?1 h^?1, Y_P/S = 0.77 g g^?1), which represents a theoretical yield of 99.6%. Acetic acid was the primary byproduct formed from xylose, at about 25% of the lactic acid level. Copyright © 2004 Society of Chemical Industry     

Simultaneous lactic acid and xylitol production from vine trimming wastes

Hemicellulosic hydrolyzates from vineshoot trimmings obtained by dilute sulfuric acid hydrolysis were evaluated for xylitol production by Debaryomyces hansenii NRRL Y‐7426. Bioconversion was not efficient, however, since a mixture of products (mainly ethanol) was achieved. Taking into account that hexoses (such as glucose or mannose) can inhibit xylose metabolism by repression and inactivation of the xylose transport system or catabolic enzymes and that these hemicellulosic hydrolyzates are characterized by a high glucose concentration, a novel technology was developed, sequentially transforming glucose into lactic acid by Lactobacillus rhamnosus followed by fermentation of xylose into xylitol by Debaryomyces hansenii after L. rhamnosus removal by microfiltration. Optimal conditions were achieved using detoxified concentrated hemicellulosic hydrolyzates, after CaCO₃ addition in both stages of fermentation and using nitrogen purges after sampling in order to reduce the oxygen dissolved. Under these conditions 31.5 g lactic acid L^?1 (Q_LA = 1.312 g L^?1 h^?1 and Y_LA/S = 0.93 g g^?1) and 27.5 g xylitol L^?1 (Q_Xylitol = 0.458 g L^?1 h^?1 and Y_Xylitol/S = 0.53 g g^?1) were produced. Finally, lactic acid was selectively recovered using the resin Amberlite IRA 400 (0.0374 g of lactic acid g^?1 of dry resin), allowing a further recovery of xylitol by sequential stages of adsorption, concentration, ethanol precipitation, concentration and crystallization to obtain food‐grade xylitol according to a developed process. Copyright © 2007 Society of Chemical Industry     

人工林修枝装置的研究

针对原有修枝设备存在的不足,研制出机电一体化遥控修枝上树装置。     

滚切式双边剪剪刃间隙平行度偏差分析

双边剪剪刃的间隙与钢板厚度关系直接决定剪切钢板边部质量的好坏,文章主要分析剪刃间隙的平行度的不一致对钢板边部质量的影响,提出在生产过程中采取的处理方法和预防措施。     

一种串并结合的多Site熔丝编程算法

随着集成电路产业的迅猛发展,熔丝修调越来越广泛地应用于集成电路测试工序,熔丝段数目随着需要修调参数的增多而逐步增长,传统的串行熔丝编程方案程序存在代码长、可维护性差、执行时间长等缺点,为了改进代码的可读性和可维护性,文章引进了改进型算法,但对测试执行时间没有任何改善。随着测试代工市场竞争日益激烈,多Site测试方案被广泛使用,但是熔丝编程还继续着串行编程的老算法,Site数目越多,熔丝编程时间越长。针对以上,文章提出了一种串并结合的多Site熔丝编程算法,将多Site熔丝编程时间控制在和单Site熔丝串行编程时间几乎一致。