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胶体滴定技术中应用的化学试剂及其发展 总被引:7,自引:0,他引:7
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 相似文献
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聚电解质的测定方法--胶体滴定法 总被引:4,自引:0,他引:4
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。 相似文献
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Origin 6.0软件在分析化学数据处理中的应用 总被引:2,自引:0,他引:2
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. 相似文献
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利用胶体滴定对纸浆悬浮液进行电荷分析 总被引:6,自引:1,他引:6
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。 相似文献
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Town SC Putman CT Turchinsky NJ Dixon WT Foxcroft GR 《Reproduction (Cambridge, England)》2004,128(4):443-454
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. 相似文献
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A. Toma M.B. Omary L.F. Marquart E.A. Arndt K.A. Rosentrater B. Burns-Whitmore L. Kessler K. Hwan A. Sandoval A. Sung 《Journal of food science》2009,74(5):H139-H146
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). 相似文献
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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. 相似文献
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V. Lopreiato A. Minuti F. Trimboli D. Britti V.M. Morittu F. Piccioli Cappelli J.J. Loor E. Trevisi 《Journal of dairy science》2019,102(10):9312-9327
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. 相似文献
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助留剂及电荷平衡对新闻纸留着率的影响 总被引:3,自引:1,他引:2
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。 相似文献