42CrMo钢销轴QPQ处理后的组织与性能

通过常规力学性能试验、金相分析和中性盐雾测试,比较了QPQ处理42Cr Mo钢销轴与目前镀硬铬处理销轴的性能。结果表明,QPQ处理销轴的综合性能优于镀硬铬处理销轴,QPQ处理销轴表层组织为弥散分布的氮化物与回火索氏体的混合物,心部组织为回火索氏体,镀硬铬处理销轴的表层为回火马氏体,心部为回火索氏体;QPQ处理能在销轴表面形成致密而均匀的保护层,抗腐蚀能力优于镀硬铬工艺。综上所述,QPQ处理技术可取代镀硬铬用于销轴表面防护处理。     

富铬发芽糙米的研制

以不同浓度的三氯化铬水溶液浸泡糙米并培养发芽，研究糙米的富铬效果。结果表明，铬浓度对糙米的发芽及其铬含量有影响。80mg/kg的铬溶液浸泡糙米12h，35℃恒温培养至芽长0．5～1．0mm可获得富铬发芽糙米。其总铬和有机铬的含量分别约是普通发芽糙米的4倍和11倍。     

皮革及鞣液中铬的化学发光法测定

本文系统研究了鲁米诺—Ｃｒ（Ⅲ）—Ｈ２Ｏ２化学发光反应体系的最佳条件，考察了溴和氯离子对痕量铬催化、过氧化氢氧化鲁米诺的化学发光信号的增强作用。将该方法用于测定皮革及铬鞣液中的含铬量，结果令人满意。     

Adipose tissue metabolism and production responses to calcium propionate and chromium propionate

The objective was to determine action of calcium propionate and chromium propionate on lipogenesis and lipolysis in adipose tissue, dry matter (DM) intake, milk production and composition, and serum glucose and free fatty acids in Holstein dairy cattle treated from 21 d prepartum to 35 d postpartum. Twelve multiparous animals were assigned to each treatment: control (C), calcium propionate (CaP, 0.125 kg/d), chromium propionate (CrP, 10 mg of trivalent Cr/d), and both. All animals were switched to control at 36 days in milk (DIM) and the trial continued to 90 DIM. Biopsies of adipose tissue were taken at −7, 14, 28, and 56 d from calving. Control intake prepartum was 10.6 ± 2 kg/d. Calcium propionate increased DM intake 11% prepartum and 13% postpartum; CrP increased DM intake 7 and 16%; and the combination treatment had no effect. Milk yield was 44.2 kg/d for controls and 46.8 kg/d for d 1 to 90 for CrP-treated cows. Adipose tissue lipogenesis in cows treated with either CaP or CrP was 1.25 to 78 times as fast as controls from 14 to 56 d and had returned to prepartum rates by 56 d. From 14 to 28 d, basal lipolysis in CaP- or CrP-treated cows ranged from 27 to 102% of control, whereas stimulated lipolysis was 61 to 113% of control. Milk fat yield was 92 to 95% of control on calcium and chromium propionate; the difference was similar to the net reduction in adipose lipolysis. Milk lactose, protein, and solids-not-fat did not differ among treatments. Providing a small amount of gluconeogenic precursors may reduce net lipolysis, allowing increased feed intake and milk production. The effect is thought to be through chromium acting to increase glucose flux into adipocytes.     

铬鞣的新视角

从碱式硫酸铬溶液的耐碱性能出发,逐步阐述了铬粉的种类与质量,碱化剂的种类与质量以及应用的方法对生产高质量蓝革的重要性。另外,简短回顾了鞣制技术对于蓝革质量的影响。     

Performance of dairy cows as affected by prepartum dietary carbohydrate source and supplementation with chromium throughout the transition period

Holstein cows (n = 72) entering second or later lactation were used to determine whether productive performance and dry matter intake (DMI) are affected by carbohydrate source in the prepartum diet and chromium-L-methionine (Cr-Met) supplementation throughout the periparturient period. Cows were fed either a TMR with the concentrate portion based on starch-based cereals [high nonfiber carbohydrate (NFC); 1.59 Mcal/kg of net energy for lactation (NEL), 14.4% crude protein (CP), 40.3% NFC] or a TMR with the concentrate portion based on nonforage fiber sources (low NFC; 1.54 Mcal/kg NEL, 14.5% CP, 33.6% NFC) from 21 d before expected parturition until parturition. After parturition all cows were fed a lactation TMR (1.74 Mcal/kg NEL, 16.5% CP, 40.0% NFC). The Cr-Met was supplemented once daily via gelatin capsule at dosages of 0, 0.03, or 0.06 mg of Cr/kg of metabolic body weight. Thus, treatments were in a 2 (carbohydrate source) x 3 (Cr-Met) factorial arrangement. Neither prepartum nor postpartum DMI was affected by prepartum dietary carbohydrate source. Administering increasing amounts of Cr-Met linearly increased milk yield and, subsequently, postpartum DMI. Prepartum carbohydrate source did not affect postpartum milk yield; however, cows fed the low NFC diet tended to yield milk with a lower content of total solids. These data indicate that prepartum carbohydrate source has little influence on performance during the immediate peripartal period, and that increases in milk yield for cows supplemented with Cr-Met are independent of prepartum dietary carbohydrate source.     

降糖奶粉基料的中试工艺研究及产品特性分析

采用吡啶甲酸铬、乳酸锌和可溶性膳食纤维等作为功能成分制备辅助调节血糖的保健奶粉。生产过程采用微胶囊技术，将膳食纤维、吡啶甲酸铬和乳酸锌作为功能成分，酪蛋白、糊精和膳食纤维为壁材，植物油(富含油酸、亚油酸)为芯材，经喷雾干燥得到降糖奶粉基料，与脱脂奶粉干法混和得到一种功能保健食品——高纤、有机铬、锌、降糖奶粉。实验摸索了降糖奶粉中试生产的工岂条件，讨论了影响乳酸锌乳化液稳定性的因素，并利用火焰原了吸收法对产品中铬、锌的分布情况进行了分析。     

新型与普通镀锌钝化工艺效果对比分析

与原工艺相比,采用镀锌钝化新工艺后,不但提高了防腐性能,而且减少了有毒物质六价铬的使用和排放,从而减轻了对人类健康和环境的危害。     

等温淬火温度对CADI组织及性能的影响

针对含一定碳化物等温淬火球墨铸铁(CADI),研究了等温淬火温度对贝氏体相形貌、残余奥氏体量、力学性能及耐磨性能的影响,分析了冲击断裂机理。结果表明,对于铸态组织为75%珠光体+铁素体+10%碳化物试样,经920℃×1.5 h奥氏体化后,在240℃、280℃及320℃进行等温淬火处理2 h,随着等淬温度的提高,贝氏体的形貌由针状变粗至羽毛状,残余奥氏体量增加,硬度减低,冲击韧度提高,相对耐磨性降低。最佳等温淬火温度为280℃,此热处理工艺后组织为贝氏体+22.33%残余奥氏体+10%碳化物,硬度HRC 50.9,冲击韧度32.72 J/cm2,断口呈混合断裂特征,相对耐磨性比320℃时增加11%。     

铝合金铸件三价铬本色钝化工艺

介绍了一种用于铝合金铸件三价铬本色钝化液及其钝化工艺.简述了钝化的机理、工艺流程、槽液管理、钝化条件及对表调、水洗、烫干、吹水等工序的控制,同时也介绍了商品化压铸铝合金三价铬本色钝化液的选择.