胶体滴定技术中应用的化学试剂及其发展

胶体滴定技术是造纸湿部电荷分析的重要方法。介绍了胶体滴定技术的原理 ,应用的化学试剂———标准聚合电解质、指示剂和基准物 ,以及胶体滴定技术的应用     

聚电解质的测定方法--胶体滴定法

本文详细地介绍了胶体滴定方法，包括原理，所用的标准聚合物，终点判定，结果以及影响因素。并介绍了胶体滴定在聚合物分析等方面的应用。     

电位滴定法测定白液中的总碱、活性碱和有效碱

介绍了自动电位滴定法测定白液中的总碱、活性碱和有效碱,与传统的白液测定方法相比,滴定中不加有毒物质氯化钡和甲醛,直接连续滴定,通过pH值判断滴定终点,操作简便,检测速度快,准确度高.     

Origin 6.0软件在分析化学数据处理中的应用

以分析化学中分析数据的统计性检验、滴定分析中滴定体积计算和标准加入法中浓度计算为例,介绍了用Origin6.0进行数据处理的具体方法.     

利用胶体滴定对纸浆悬浮液进行电荷分析

介绍了利用胶体滴定技术进行电荷分析的方法，对多种纸浆的可溶电荷需求量、表面阴电荷需求量、表面阳电荷需求量和胶体滴定比率进行了测定，研究了纸浆PH值、电导率、浓度和打浆度对胶体滴定测得电荷密度的影响。对利用胶体滴定法进行纸浆悬浮液电荷分析的条件提出了建议。     

自动滴定仪法替代手工滴定方法的优越性

介绍了用梅特勒-T50自动滴定仪测定高锰酸钾的摩尔浓度及其在化学分析检测中的应用。原有方法为手工滴定,现改用自动滴定仪滴定可比普通滴定给出值精确10倍左右,仪器能进行自动滴定,自动滴至终点停止,具有定量进给及动态进给方式,动态进给滴定方式随着电位变化自动调节进给量,有等当点停、体积停两种制停方式,消除人眼误差,使结果更加准确,操作简单,自动化程度高,是值得推荐的方法。     

容量法快速测定白酒中的氰化物

介绍了用试银灵为指示剂，用硝酸银标准溶液滴定白酒中氰化物的快速测定方法。     

白酒生产检验(十六):标准滴定溶液及所用制剂的制备

本期介绍检验方法及试验方法中标准滴定溶液及所用制剂的制备。     

白酒生产检验(十七):标准滴定溶液及所用制剂的制备(续)

紧接上期,本期介绍"试验方法中标准滴定溶液及所用制剂的制备"的部分内容。     

白酒生产检验(十八):标准滴定溶液及所用制剂的制备(续二)

紧接上期,本期介绍"试验方法中标准滴定溶液及所用制剂的制备"的部分内容。     

造纸湿部中施胶铝盐的电荷分析

运用胶体滴定方法对几种施胶铝盐在施胶时的造纸湿部浆料电荷变化进行了研究.结果表明,随着聚合氯化铝-有机高分子复合物(PACP)用量的逐渐增加,麦草浆的胶体滴定比率(CTR值)明显增大;加入相同用量的PAC或PACP时,纸浆的CTR值随pH值的增大而增大;在相同pH值及相同用量的条件下,CTR值由高到低的顺序为PACPc＞PAC＞PACPa.对于PACPa,CTR值随有机高分子/铝比值(O/A)的增加而降低;而PACPc的CTR值随该比值的增加而增加.     

纸浆悬浮液胶体滴定比率的初步研究

采用胶体滴定方法,研究了纸浆悬浮液的胶体滴定比率（ＣｏｌｏｉｄＴｉｔｒａｔｉｏｎＲａｔｉｏ,简称ＣＴＲ）特性及其影响因素;还用动态滤水试验仪验证了ＣＴＲ值对湿部留着和滤水的相关性。初步研究表明,通过控制纸浆悬浮液的ＣＴＲ值,可优化造纸化学助剂的添加工艺     

电荷测量技术用于阳离子淀粉对脱墨浆助留的研究

应用Zeta电位和CTR(胶体滴定比率)分析脱墨(旧报纸)浆料体系的电荷分布情况。研究了不同阳离子淀粉用量、pH值、电导率对浆料Zeta电位、CTR和单程留着率的影响。研究表明,浆料的Zeta电位和CTR可以说明实际电荷分布情况且与阳离子淀粉对浆料的助留作用密切相关。     

季铵型CPAM助留助滤作用的电荷分析

通过胶体滴定法测定了CPAM电荷密度,研究了加填及加入CPAM后浆料悬浮液的电荷变化。结果表明,浆料中加入CaCO3后,浆料的胶体滴定比率(CTR)大幅度降低;随CPAM用量增加浆料的CTR值显著增大,且Zeta电位与logCTR之间存在一定的相关性。     

Number of conceptuses in utero affects porcine fetal muscle development

Unmodified, third parity, control sows (CTR; n = 30) or sows subjected to unilateral oviduct ligation before breeding (LIG; n = 30), were slaughtered at either day 30 or day 90 of gestation and used to determine the effects of numbers of conceptuses in utero on prenatal, and particularly muscle fibre, development. Ovulation rate, number of conceptuses in utero, placental and fetal size, and (day 90 sows) fetal organ and semitendinosus muscle development were recorded. Tubal ligation reduced (P < 0.05) the number of viable embryos at day 30 and fetuses at day 90. Placental weight at day 30 and day 90, and fetal weight at day 90, were lower (P < 0.05) in CTR sows. All body organs except the brain were lighter, and the brain:liver weight ratio was higher in CTR fetuses (P < 0.05), indicative of brain sparing and intrauterine growth restriction in fetuses from CTR sows. Muscle weight, muscle cross-sectional area and the total number of secondary fibres were also lower (P < 0.05) in CTR fetuses. The number of primary fibres, the secondary:primary muscle fibre ratio, and the distribution of myosin heavy chain-Ibeta, -IIa, fetal and embryonic isoforms did not differ between groups. Thus, even the relatively modest uterine crowding occurring naturally in CTR sows negatively affected placental and fetal development and the number of secondary muscle fibres. Consequences of more extreme crowding in utero on fetal and postnatal development, resulting from changing patterns of early embryonic survival, merit further investigation.     

Children's Acceptance, Nutritional, and Instrumental Evaluations of Whole Grain and Soluble Fiber Enriched Foods

ABSTRACT:  The Dietary Guidelines for Americans 2005 report recommends 3 or more daily ounce-equivalents of whole grains (WG), and the FDA suggests consumption of 25 g of total dietary fiber (TDF) and 6 g of soluble fiber (SF) for a 2000-calorie diet. Efforts to increase the consumption of WG and SF among elementary school-aged children are needed. The objectives of this study were to examine the consumption of WG- and SF-enriched burritos and cookies among elementary school-aged children and to perform a quality evaluation of all products. Children in grades K to 6 from a local elementary school consumed control (CTR) products made with refined flour along with the test products (TRT) over a 13-wk period. TRT burritos and cookies contained 51% and 100% WG, respectively. CTR and TRT products were served on 3 and 4 different Fridays, respectively. Children's consumption was determined via plate waste. Quality parameters such as texture, color, water activity, weight, and product dimensions were also measured. No significant differences in consumption between CTR and TRT burritos and cookies were found (36% and 90%, respectively). Texture (area) was higher for CTR burritos compared with TRT burritos (1.31 and 0.66 kg-s, respectively). CTR burritos were lighter than TRT burritos with L * values of 80.04 and 64.61, respectively. CTR cookies required a higher breaking force (3.14 compared with 0.58 kg), were lighter than TRT cookies (63.18 compared with 50.27), and had lower water activity (0.5 compared with 0.71).     

Burdizzo pre-pubertal castration effects on performance, behaviour, carcass characteristics, and meat quality of Holstein bulls fed high-concentrate diets

The effects of Burdizzo pre-pubertal castration on performance, behaviour, carcass, and meat quality of Holstein bulls fed high-concentrate diets were evaluated. Two hundred bulls (8.0 ± 0.42 months old) were randomly assigned to control (CTR) or Burdizzo castration (BURD). After 121 d, ADG, BW, and HCW were greater in CTR animals than in BURD animals, as well as, the agonistic and sexual behaviour. However, carcass fatness and intramuscular LT (longissimus thoracis) fat percentage were greater in BURD animals than in CTR animals. Additionally, CTR animals showed lower L^∗, a^∗, and b^∗ than BURD. The WBSF was smaller (P < 0.01) in BURD than in CTR bulls at all ageing days, and in both treatments decreased (P < 0.01) from 0 to 7 d of ageing. Additionally, at day 0 of ageing, meat from BURD animals showed similar WBSF to meat from CTR bulls after 7 d of ageing. However, 23% of BURD animals did not have a complete testicular atrophy, suggesting that the method of castration was not completely effective.     

Immunometabolic status and productive performance differences between periparturient Simmental and Holstein dairy cows in response to pegbovigrastim

In the present study, we aimed to investigate the side effects of pegbovigrastim, injected approximately 7 d before parturition and on the day of calving, on a panel of plasma biomarkers to evaluate energy, inflammatory, oxidative, and liver function status. We also addressed treatment responses in different breeds during the transition period. Holstein and Simmental cows were randomly assigned into 2 groups based on expected calving date and according to parity: the treated group (PEG; 14 Holstein and 12 Simmental cows) received pegylated recombinant bovine granulocyte colony stimulating factor (pegbovigrastim, Imrestor; Elanco Animal Health, Greenfield, IN), and the control group (CTR; 14 Holstein and 14 Simmental cows) received saline solution. The PEG or CTR treatments were administered via subcutaneous injection in the scapular region at approximately 7 d (mean 7.80 ± 5.50 d) before expected parturition and within 24 h after calving. Blood samples were collected at ?21, ?7 (before injection), 1, 3, and 28 d relative to calving. Milk production was recorded at 7, 15, 21, 30, and 42 d. A mixed model with repeated measures was fitted to the normalized data using Proc MIXED of SAS (SAS Institute Inc., Cary, NC). Simmental PEG cows showed higher plasma protein concentrations at 1 and 3 d after calving compared with Simmental CTR and Holstein PEG cows, whereas no differences were detected between Holstein PEG and CTR cows. Albumin was greater at 1 d in Simmental PEG compared with Simmental CTR cows. In contrast, γ-glutamyl transferase was higher overall (across breed) in PEG than in CTR. The PEG group had higher values throughout the postcalving period compared with CTR. Cows treated with pegbovigrastim had also higher alkaline phosphatase (ALP) activity at 1 and 3 d after calving. The Holstein PEG group had higher ALP activity at 3 d compared with the Holstein CTR and Simmental PEG groups, and higher ALP at 1 d compared with the Simmental CTR group. The PEG group had higher levels of IL-6 at 3 and 28 d but higher IL-1β only at 28 d after calving compared with the CTR group. Overall, Holstein cows were characterized by a greater response in the production of inflammation biomarkers (cytokines, haptoglobin, and ceruloplasmin). In addition, PEG cows had higher values of zinc at 1 and 3 d after calving compared with CTR cows. The response observed in plasma biomarkers for energy metabolism and liver functionality after pegbovigrastim treatment in Simmental and Holstein cows was not different from that in control cows. However, our data shed light on the different metabolic adaptations during the transition period between Simmental and Holstein cows, characterized by different energy, inflammatory, and oxidative pattern responses. For the first time, we have highlighted the effect of pegbovigrastim in maintaining stable cytokine levels during the first month after parturition, reflecting greater regulation of neutrophil recruitment, trafficking, and maturation during the inflammatory response. These results provide evidence of the immunomodulatory action of pegbovigrastim around parturition, when dairy cows are highly immunosuppressed. At the same time, these data demonstrate that increasing release of cytokines after parturition is not linked to exacerbation of a systemic inflammation evaluated based on haptoglobin and ceruloplasmin levels.     

助留剂及电荷平衡对新闻纸留着率的影响

介绍了助留剂在新闻纸中的应用,观察了使用助留剂前后留着率及成纸质量的变化。测定了胶体滴定比值（CTR值）,并分析了CTR对留着率的影响。