尺寸镀铬零件镀前加工和镀铬形位偏差补偿法

前言零件镀铬由于几何因素和电化学因素的影响,零件表面上的镀层厚度往往不均匀,从而使镀铬的零件产生形位偏差。轴或孔镀铬后通常容易产生不园度、螺纹和枪炮管内膛阳线镀铬后在其棱角处产生镀层堆积,使螺纹的形状和阳线的轮廓改变。在生产中为了保证零件镀铬后的形位公差,通常采用以下方法:(1)辅助阴极;(2)仿形阳极;(3)     

单件生产中零件配合公差的确定

介绍了单件生产中零件配合公差的确定方法。从理论上分析了大量生产时零件能满足配合性能的原因。提出了按中值公差加工零件的措施，并在实践中取得了较好的效果。     

铸铁涨圈松孔镀铬工艺研究

依据航标及零件的工况,采用镀铬方法,通过对试片及试验件的施镀,成功地对封严涨圈端面进行了松孔镀铬,满足了设计要求。并且针对该材料镀层的硬度、结合力,以及通过两厂生产的试件进行摩擦磨损、网纹等情况的对比性能试验。结果表明,封严涨圈在端面进行松孔镀铬的工艺可行,松孔镀铬层与铸铁基体的结合力良好,硬度、厚度、网纹类型和深度均满足航标的要求。     

内孔镀铬夹具的设计及应用

针对液压外筒的结构特点及工艺要求,阐述了液压外筒的内孔镀铬夹具的设计及应用。通过装夹方式的改变,采用象形阳极、保护阴极及上下绝缘定位板的合理设计,有效的解决了零件内孔尺寸镀铬厚度不均匀、零件变形、上端口镀层超过标准厚度等弊病,提高了产品的合格率。     

电镀零件设计工艺性及配合公差的探讨

一、前言机件零件镀上一层或几层金属(镀层厚度一般δ≈100微米)后,在配合时会发生超差或过紧现象(镀后使孔径减小,轴径增大)使原设计的动配合件发生“咬死”,或经常要调换的易损件不能甚至难以拆装,因此必须将电镀前的零件配合较松(对镀前还须拋磨加工的拉光件除外),使零件电镀后仍能符合原设计的公差配合尺寸。零件间的配合性质,合理的加工余量及尺寸公差取决于设计及机械加工水平;合理的镀层厚度及厚度工艺公差的选择取决于使用场合和合理选用;镀层分布的均匀性及公差的控制取决于电镀工艺水平     

某型飞机襟翼滑轨电镀铬工艺分析与工装设计

本文研究的对象为某型飞机襟翼滑轨,此零件属于易损件,在工作中经常会产生磨损及工作面铬镀层脱落.在使铬镀层恢复到设计状态时,为了降低维修成本和缩短维修周期,通过设计特殊的电镀铬工装配合合适的电镀铬工艺,直接在襟翼滑轨表面沉积厚度和表面粗糙度同时符合设计状态的铬镀层,该零件的维修成功,对其他异型零件电镀铬工装象形阳极设计和...     

论工艺因素对氧化铝陶瓷零件形位公差尺寸的影响

本文尝试运用材料学过程理论对陶瓷制造过程进行了分析,进而总结分析了影响95%氧化铝陶瓷零件形位公差尺寸的工艺因素,讨论了陶瓷制造过程的能量分配问题和统筹兼顾问题。     

机械加工中光滑极限量规检验时的加工工艺

本文从大批量加工表面比较光滑的轴和孔的生产中利用光滑极限量规进行检验，而在光滑极限的量规的设计中存在着缩小一定量的生产公差的情况中加以分析，提出了一些加工工艺的改进方法，避免由于用量规检验缩小了生产公差而造成了一些合格零件的误判，避免加工的浪费，提高生产效率，节约加工成本。     

活塞杆镀硬铬装挂方式的改进

用传统方法对中短型活塞杆镀硬铬,镀层厚度时常出现局部超厚。在磨床上加工时容易产生偏差,影响使用寿命。新产品的活塞杆比较长,镀层厚度的均匀性要求高,要求直接镀出合格的均匀性镀层,不超厚,不磨削加工。经过分析研究,创新了水平旋转装卡镀铬法。对较长的活塞杆镀出了不产生局部超厚和锥度及椭圆度等的均匀性镀层。     

提高TC6钛合金零件镀铬层结合力的方法

钛及钛合金是非常活泼的金属,表面容易生成一种自然的氧化膜,电镀时很难获得结合力良好的镀层。某型号飞机起落架TC6钛合金零件在镀铬后铬层经常出现起皮、鼓泡等现象,严重影响了产品的正常交付。通过对影响镀铬层结合力的因素进行分析,总结出了几种提高钛合金零件镀铬层结合力的常用方法,并对铬层的结合力检测方法作了简要的介绍。     

锌离子对自絮凝酵母乙醇耐性和絮凝颗粒大小的影响

研究了6种金属离子在合成培养基中对摇瓶培养的自絮凝酵母乙醇耐性的影响,发现锌离子对高浓度乙醇冲击下的酵母细胞活性有保护作用,并进一步研究了乙醇连续发酵过程中锌的添加对自絮凝酵母乙醇耐性的影响。发酵培养基中分别添加0.01、0.05 和 0.1 g·L^-1的硫酸锌时,自絮凝酵母颗粒平均粒度减小,同时乙醇耐性和高温耐性都得到明显提高,并且发现细胞活性的提高与酵母细胞内麦角固醇和海藻糖的增加密切相关。对酵母细胞内锌的含量的分析表明,3个添加组胞内锌的积累量基本相似,比对照组均增加了6倍。相关性分析表明,酵母胞内锌含量与酵母细胞的胁迫耐性密切相关并显著影响其胁迫耐性。各添加组的乙醇产量均有提高,其中添加0.05 g·L^-1的硫酸锌时乙醇产量最高,比对照组高8.4%。以上研究结果表明,调控连续乙醇发酵过程中培养基中锌离子浓度,是提高酵母细胞乙醇耐受性、高温度耐受性和乙醇产量的有效途径。     

AM／AMPS／DMDAAC共聚物合成及其降滤失性能研究

以丙烯酰胺、2-丙烯酰胺基-2-甲基丙磺酸、二烯丙基氯化铵为原料,采用氧化-还原引发体系合成了耐温、耐盐的钻井液降滤失剂。讨论了引发剂加量、二烯丙基氯化铵加量和反应温度对聚合物降滤失性能的影响。当引发剂加量为0．15％、二烯丙基氯化铵加量为10％、反应温度为45℃时,合成的聚合物在高温、高含盐条件下具有优良的降滤失性能。     

Color tolerance prediction for recycled paper based on consumers' awareness

Consumers' tolerance of the color of recycled paper was evaluated by the visual assessment of such paper by 30 Japanese university students. The assessment was performed to measure color tolerance using 266 color samples in eight conditions specifying the situation of paper as (1) “either paper is recycled or not recycled,” (2) “whether you will buy/use,” and (3) “use for office paper or for workbook paper.” The responses of the subjects were sorted out quantitatively in terms of the colorimetric values of color samples and then correlated with International Organization for Standardization (ISO) brightness and CIE whiteness. Both the ISO brightness and CIE whiteness were found to be dependent on hue factors and also to be restricted for use in direct representation of the consumers' responses to paper quality. Since the consumers' evaluation of paper quality is due to visual whiteness, we propose a new equation to predict the consumers' tolerance of paper color, in which the equation contains two factors concerning the color distance from the white point and the hue impact. The new tolerance equation was confirmed to predict the consumers' tolerance successfully, particularly when the consumers are aware that the paper is recycled. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011     

Comparative and Systematic Omics Revealed Low Cd Accumulation of Potato StMTP9 in Yeast: Suggesting a New Mechanism for Heavy Metal Detoxification

The metal tolerance protein (MTP) family is a very old family with evolutionary conservation and less specific amplification. It seems to retain the original functions of the ancestral genes and plays an important role in maintaining metal homeostasis in plant cells. We identified the potato MTP family members for the first time, the specific and conservative StMPTs were discovered by using systematic and comparative omics. To be surprised, members of the StMTP family seem to have mutated before the evolution of dicotyledon and monocotyledon, and even the loss of the entire subfamily (subfamily G6, G7). Interestingly, StMTP9 represents the conserved structure of the entire subfamily involved in toxic metal regulation. However, the gene structure and transmembrane domain of StMTP8 have undergone specific evolution, showing that the transmembrane domain (Motif13) located at the NH₂ terminal has been replaced by the signal peptide domain, so it was selected as the control gene of StMTP9. Through real-time fluorescence quantitative analysis of StMTPs under Cd and Zn stress, a co-expression network was constructed, and it was found that StMTP9 responded significantly to Cd stress, while StMTP8 did the opposite. What excites us is that by introducing StMTPs 8/9 into the ∆ycf1 yeast cadmium-sensitive mutant strain, the functional complementation experiment proved that StMTPs 8/9 can restore Cd tolerance. In particular, StMTP9 can greatly reduce the cadmium content in yeast cells, while StMTP8 cannot. These findings provide a reference for further research on the molecular mechanism of potato toxic metal accumulation.     

涂漆方法种种

涂装行业发展过程中，随着涂料新品种的不断涌现，各种有效的涂漆方法和施工技巧纷纷出现。不同涂漆方法各有其优势和局限性，应视具体情况选择涂漆方法。本期介绍了高压无气喷涂的优点、施工安全，空气辅助高压无气喷涂，双组分高压无气喷涂的特点和静电喷涂技术。     

Aluminium phytotoxicity

Breeding for Al tolerance is considered a useful way to improve crop performance on acid soils. However, a successful selection of Al-tolerant genotypes, which will render high yields on acid soils, requires the development of screening methods based on the knowledge of Al-toxicity and Al-tolerance mechanisms. In this paper the present stage of knowledge on Al phytotoxicity and tolerance is comprehensively reviewed. Special emphasis will be made on primary mechanisms of Al toxicity, the interactions of Al with membranes, and the role of Ca in the Al-toxicity syndrome.     

Candidate Genes and Pathways in Rice Co-Responding to Drought and Salt Identified by gcHap Network

Drought and salinity stresses are significant abiotic factors that limit rice yield. Exploring the co-response mechanism to drought and salt stress will be conducive to future rice breeding. A total of 1748 drought and salt co-responsive genes were screened, most of which are enriched in plant hormone signal transduction, protein processing in the endoplasmic reticulum, and the MAPK signaling pathways. We performed gene-coding sequence haplotype (gcHap) network analysis on nine important genes out of the total amount, which showed significant differences between the Xian/indica and Geng/japonica population. These genes were combined with related pathways, resulting in an interesting mechanistic draft called the ‘gcHap-network pathway’. Meanwhile, we collected a lot of drought and salt breeding varieties, especially the introgression lines (ILs) with HHZ as the parent, which contained the above-mentioned nine genes. This might imply that these ILs have the potential to improve the tolerance to drought and salt. In this paper, we focus on the relationship of drought and salt co-response gene gcHaps and their related pathways using a novel angle. The haplotype network will be helpful to explore the desired haplotypes that can be implemented in haplotype-based breeding programs.     

一种新型驱油剂AM-VP-AMPS共聚物的研究

以丙烯酰胺 (AM)、N 乙烯基 2 吡咯烷酮 (VP)和 2 丙烯酰胺基 2 甲基丙磺酸 (AMPS)为单体 ,以水作为溶剂 ,在反应温度 6 0～ 6 5℃ ,pH值为 8左右 ,反应时间为 8h的条件下合成了AM-VP -AMPS共聚物。用IR、13 CNMR对共聚物结构进行了表征 ,研究了共聚物溶液的耐温抗盐性能。结果表明 :少量的阳离子会导致共聚物的水溶液黏度急剧下降 ,当阳离子量达到一定值后 ,继续增加阳离子量对共聚物的水溶液黏度影响不大 ,共聚物的标准盐溶液在温度 (90± 1 )℃无氧的条件下老化 1 30天 ,其溶液黏度的绝对值仍然在 6 0mPa·s以上。     

储氢方法

介绍了三种储氢方法；金属氢化物储存，有机物储存以及吸附储存，并对各种方法进行评述，指出：把碳纳米材料和储氢合金两者的优势结合起来。制备出新型的复合储氢材料将是一个十分有理论意义和实际意义的重要研究课题。     

醇类污染物的监测方法

文章着重介绍了现阶段对水体和大气环境中醇类污染物质监测的几种方法。为定量定性分析环境中的醇类污染物提供了方法。