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71.
Mohammad Hossein Keshavarz 《含能材料》2006,14(6):449-452
A new method for prediction of Gurney velocity of explosives is introduced in which energy output is correlated with the heat of detonation, the number of moles of gaseous products of detonation per gram of explosive and the average molecular weight of gaseous products. It is assumed that the CHNO explosive reacts to form products composed of N2 , CO, H2O, CO2, H2,O2 and C(s) as determined by the oxygen balance of the unreacted compound. Good agreement is obtained between measured and calculated values of Gurney velocity as compared to previous correlations which assumed the reaction products to consist of N2 , H2O, CO2 and either C(s) or O2. 相似文献
72.
实验考察了8种市售水溶性破乳荆对长庆油田陕北区有代表性的宝塔区、安塞和子长原油(均为低硫中间基-石蜡基原油)的脱水效果(加量100mg/L,脱水温度55℃,时间3h)。目前长庆采油一厂使用的YT-100和延炼集团使用的GT-940对这3种原油的脱水效果均较好,但对子长原油的脱水率不高,分别为69.7%和58.9%。在由所选性能较好的破乳刺组成的4种二元复配物中,GT-940 HQ96-1对3种原油的脱水效果均高于单剂,最佳配比分别为4:1,4:1,3:2;其余3种复配物则对原油有选择性,其中GT-940 YT-100相近(97.5%);YT-100 HQ96-1仅能改善子长原油的脱水效果,配比为4:1时脱水率最高(76.4%);SP-169 HQ96-1仅能改善宝塔区原油的脱水效果.配比3:2和2:3时脱水率最高(92.9%)。表5参6。 相似文献
73.
普通热轧钢材的合理洁净度及生产工艺探讨 总被引:7,自引:0,他引:7
钢凝固前、后生成的非金属夹杂物形貌和在钢中的分布特点不同,凝固前生成的夹杂物尺寸较大,在钢中随机分布,主要影响钢材的疲劳强度和延性等性能。凝固后生成的夹杂物尺寸小,主要在晶界富集析出。硅锰脱氧钢脱氧后钢液仍含有20×10-6以上溶解氧,这部分溶解氧在钢凝固后绝大多数会转变为微细的氧化物或氧硫化物夹杂。钢凝固后生成的夹杂物主要影响钢材的冲击韧性、韧-脆转换温度等性能。 对热轧长型材用普碳钢和低合金钢不必采用铁水脱硫预处理,对热轧钢板用普碳钢可采用铁水轻度脱硫预处理,对热轧钢板用低合金高强度钢可采用铁水脱硫预处理、炼钢过程抑制回硫和出钢过程脱硫的工艺。对超低硫低合金钢,在钢水炉外精炼脱硫处理过程钢-渣间须维持非常低的氧势,炉渣成分应控制在CaO:SiO2:Al2O3=60%~65%:4%-8%:30%~35%范围。 普通热轧长型材用钢脱氧后溶解氧含量可放宽至(30-50)×10-6,对中、厚板钢溶解氧含量必须较严格控制,最好采用铝脱氧将溶解氧控制在较低的水平,并将T[O]含量控制在50×10-6以下。采用降低炼钢终点钢水氧含量、出钢挡渣、CAS和CAB等较简易炉外精炼方法和防止铸坯夹渣等措施,能够生产满足普通热轧钢洁净度要求的高品质钢材。 相似文献
74.
传统块状炭材料的发展概况 总被引:2,自引:0,他引:2
传统块状炭材料,如石墨电极、炼铝用阳极和阴极炭块、电炭制品、特种炭和石墨、炭砖等,在国民经济中占据不可替代的举足轻重的地位。本文简要概述了传统块状炭材料的国内外发展现状,在此基础上论述了我国相关领域中存在的问题,以期引起对传统但却十分重要的块状炭材料的进一步重视。 相似文献
75.
Forest and bioenergy strategies offer the prospect of reduced CO2 emissions to the atmosphere. Such strategies can affect the net flux of carbon to the atmosphere through 4 mechanisms: storage of C in the biosphere; storage of C in forest products; use of biofuels to displace fossil-fuel use; use of wood products which often displaces other products that require more fossil fuel for their production. We use the mathematical model GORCAM (Graz/Oak Ridge Carbon Accounting Model) to examine these mechanisms for 16 land-use scenarios. Over long time intervals the amount of C stored in the biosphere and in forest products reaches a steady state and continuing mitigation of C emissions depends on the extent to which fossil fuel use is displaced by the use of bioenergy and wood products. The relative effectiveness of alternative forest and bioenergy strategies and their impact on net C emissions strongly depend, for example, on the productivity of the site, its current usage, and the efficiency with which the harvest is used. When growth rates are high and harvest is used efficiently, the dominant opportunity for net reduction in C emissions is seen to be fossil-fuel displacement. At the growth rates and efficiencies of harvest utilization adopted in many of our base scenarios, the net C balance at the end of 100 years is very similar whether trees are harvested and used for energy and traditional forest products, or reforestation and forest protection strategies are implemented. The C balance on a plantation system that provides a constant output of biomass products can look different than the balance of a single parcel of land. 相似文献
76.
Savitree Jungsakulrujirek & Athapol Noomhorm 《International Journal of Food Science & Technology》1998,33(4):367-374
The effect of fruit size and harvesting of Thai tangerine fruit ( Citrus reticulata , Blanco) at different growth stages, 8–12 months after fruit set, on the distribution of limonin in whole fruit as well as in the individual fruit parts and extracted juice was investigated. The highest limonin concentration was observed in seed, followed by albedo, flavedo, segment membrane and juice sacs in decreasing order. The limonin concentration in juice as well as in whole fruit was decreased when fruit was harvested 8–12 months of fruit set. Increasing harvesting time from 8 to 12 months showed corresponding decreases in the amount of limonin in flavedo, albedo and seed. There was a decrease in titrable acidity and increase in total soluble solid and total soluble solid/titrable acidity ratio of juice with a later than normal harvesting time. However, fruit size showed no effect on limonin content and other properties of juice extracted from tangerine. 相似文献
77.
Poly(N‐vinylformamide) (PNVF) was synthesized and hydrolyzed to poly(vinylamine) (PVAm) in both HCl and NaOH solutions. The hydrolysis kinetics and the equilibrium hydrolysis were examined experimentally at different temperatures, polymer concentrations, and acid‐ or base‐to‐amide molar ratios. The hydrolysis kinetics strongly depended on temperature, polymer, and HCl or NaOH concentrations, but showed little dependence on PNVF molecular weight. The acid hydrolysis of PNVF exhibited limited conversions because of the electrostatic repulsion among the cationic amine groups generated during hydrolysis and proton hydrates. In the basic hydrolysis, complete amide conversions were observed when the NaOH/amide molar ratios were greater than unity. The effects of temperature and PNVF concentration on the equilibrium amide conversion appeared to be negligible in both acidic and basic hydrolysis. The equilibrium conversions of base hydrolysis were higher than those of acidic hydrolysis under the same reaction conditions. At NaOH/amide ratios of less than unity, the equilibrium hydrolysis experiments revealed that one base molecule could induce the hydrolysis of more than one amide group. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3412–3419, 2002 相似文献
78.
An algorithmic approach was used to select recoveries for non-sharp sequence designs. Simple distillation columns were employed. The non-key component distribution was modeled using the Fenske equation. The combination of producing impure products and allowing non-key component distribution, results in a large search space. With this large search space size and software limitations, five problems were solved (see summary table in the Design Examples sub-section). The optimal non-key component distribution was found to be significant but not necessarily maximal. Parallel processing was selected as optimal in contrast to the more traditional sequential processing. 相似文献
79.
莱钢1500mm热轧生产线于2005年6月投产。通过对轧钢生产过程中各环节的有效控制,使成材率显著提高,居于全国同行业领先水平,取得了良好的经济效益。 相似文献
80.
The soil microbial biomass quotient (expressed as a percentage of the total soil organic carbon) and the specific rate of carbon-dioxide production by soil microbes (respiration quotient) are often used as indicators of stress on soil microbial populations. A low biomass quotient or a high respiration quotient is considered to be an indication of stress from, for example, toxicity from metals in sewage sludge applied to soils. These metabolic quotients are affected by a wide variety of other factors such as the biodegradability of soil organic-carbon amendments, plant inputs of organic carbon into soils, natural variations in microbial population sizes with depth, and in the rhizosphere of plants. These variations could be sufficiently large to make interpretation of changes in biomass quotient and respiration quotient, as a response to stress, problematical. 相似文献