固体超强酸S_2O_8~(2-)/SnO_2-SiO_2催化合成环己酮1,2-丙二醇缩酮

采用沉淀-浸渍法制备了固体超强酸S2O28-/SnO2-SiO2,以它为催化剂催化环己酮和1,2-丙二醇合成了环己酮1,2-丙二醇缩酮;考察了带水剂种类及用量、酮醇摩尔比、催化剂用量、反应时间对产品收率的影响,并用正交实验对反应条件进行了优化。实验结果表明,适宜的反应条件为:n(环己酮)∶n(1,2-丙二醇)=1∶1.6、催化剂用量为反应物料总质量的2.0%、带水剂环己烷用量5.0mL、反应时间50min。在此条件下,环己酮1,2-丙二醇缩酮收率达到91.47%;催化剂的稳定性良好,在重复使用5次后环己酮1,2-丙二醇缩酮收率为82.20%,活性下降的主要原因为催化剂表面积碳和吸附了有机物;经傅里叶变换红外光谱和气相色谱质谱分析表明,产物为环己酮1,2-丙二醇缩酮,纯度为100%。     

聚合物分解法制备微波介质陶瓷粉体的研究

对采用聚合物分解（Ｐｅｃｈｉｎｉ）法制备ＭｇＴｉＯ＿３粉体进行了研究。通过对聚合中间产物进行红外光谱分析，研究了聚合物分解法制备ＭｇＴｉＯ＿３陶瓷粉体的聚合反应过程及产物。并与用传统固相反应法制备粉体工艺进行对比．从而证明用聚合物分解法可获得单一ＭｇＴｉＯ＿３相材料．并可降低粉体的煅烧温度。     

Palatability of prerigor cooked boar meat

Cooking reduces odor intensity in boar meat but also may induce lipid oxidation unless the meat pH is above approximately 6.0. This research was designed to determine the feasibility of cooking boar meat in the prerigor state to overcome boar odor and lipid oxidation problems. Prerigor and postrigor triceps brachii muscle samples from 40 boars (20 Duroc and 20 Yorkshire) were cooked to 60 degrees C, frozen and stored at -20 degrees C, reheated in a 60 degrees C water bath for 1 h, and then subjected to pH, thiobarbituric acid (TBA), and sensory analyses. Boar odor intensity and skatole concentration in backfat samples were determined by olfactory test and HPLC, respectively. Cooked (initial cooking) prerigor meat was found to have higher (P < .05) pH and lower (P < .05) TBA values than comparable postrigor meat (6.44 vs 6.09 and 2.15 vs 3.23, respectively). Regression analysis indicated an inverse relationship between pH and TBA values (r = -.52; P < .01). No appreciable changes in TBA values were noted after frozen storage for 14 to 98 d, but reheating increased TBA values (P < .05) in both prerigor and postrigor samples (3.45 vs 4.32, respectively). Sensory evaluation scores indicated that prerigor cooked meat was less tender with more pronounced rancid flavor than postrigor cooked meat (P < .05), but panelists may have allowed the toughness of the prerigor samples to adversely affect their flavor scores. No difference in boar odor was detected between rigor states or breeds. Mean skatole concentration in backfat was .12 micrograms/g and no difference was detected between breeds.(ABSTRACT TRUNCATED AT 250 WORDS)     

Metabolism of 6-chloro n-butyl phthalide in rat

6-Chloro n-butyl phthalide (CBP) was orally administered to healthy, male Wistar rats pretreated with or without 3-methylcholanthrene (3-MC) by a single dose of 150 mg/kg, and urine samples were collected for 0-24 h. The urine sample was hydrolyzed with beta-glucuronidase, extracted and concentrated for TMS derivatization, and analysed on a GC-MS system for identification of CBP metabolities. Mass spectral analysis suggests that 7 CBP metabolites were present in the urine sample, and similar metabolism patterns were viewed in rats with or without pretreatment with 3-MC. Four main metabolites of CBP in rat urine were identified as alpha-beta oxolate, beta-gamma oxolate, beta-hydroxylate and gamma-hydroxylate, based on their chromatographic and mass spectral properties. Two hydroxylates have been previously identified in CBP metabolism by rat liver microsomes. The other two metabolites with higher polarity were tentatively identified as dihydroxylation products on the n-butyl side chain by the mass spectra of their TMS derivatives. One minor metabolite was found by the isotopic effect of chlorine, but its specific structure was undetermined. The difference between in vivo and in vitro metabolic profiles of CBP is also discussed.     

Electron microscopic observations and DNA chain fragmentation studies on apoptosis in bone tumor cells induced by ~(153)Sm-EDTMP

ＥｌｅｃｔｒｏｎｍｉｃｒｏｓｃｏｐｉｃｏｂｓｅｒｖａｔｉｏｎｓａｎｄＤＮＡｃｈａｉｎｆｒａｇｍｅｎｔａｔｉｏｎｓｔｕｄｉｅｓｏｎａｐｏｐｔｏｓｉｓｉｎｂｏｎｅｔｕｍｏｒｃｅｌｓｉｎｄｕｃｅｄｂｙ１５３ＳｍＥＤＴＭＰＺｈｕＳｈｏｕＰｅｎｇ，Ｘｉａ...     

军械调运方案优化算法的设计与仿真

军械调运问题的数学模型和手工算法过去已有研究,但是当问题较为复杂时,手工算法就要花费大量时间而且准确性也难以保证。针对这一缺陷,本文在已有的数学模型和手工算法的基础上,设计了一种可以用计算机实现的基于递归的算法来寻求军械紧急调运问题的最优方案,并使用面向对象的java语言将算法实现。     

Study on phase behavior–impact strength relationship of unsaturated polyester/polyurethane hybrid polymer network

The phase behavior of a hybrid polymer network (HPN) composed of poly[(propylene glycol maleate)-co-(propylene glycol phthalate)] crosslinked with styrene and polyester–urethane crosslinked with methylene-bis-ortho-chloroaniline was examined. The correlation between phase separation and impact strength of the HPNs is discussed. The composition of HPNs has an effect on their properties.     

Lubricating behavior of iron rhenate and its relation to matching pairs

The iron rhenate was compounded by chemical method, which may be generated during wear process of Fe-Re alloys at elevated temperature. The friction coefficient of iron rhenate has been determined by a pin-on-disc device. The results show that iron rhenate plays role of lubricating at RT-600 °C. The lubricating behavior is related to the matching pairs. The hardness of the materials of matching pairs, compatibility of iron rhenate with materials of matching pairs and surface roughness of disc affect the lubricating behavior of iron rhenate mostly. The principle of matching pairs is proposed. Project supported by the National Natural Science Foundation of China Synopsis of the first author Xiong Dangsheng. associated professor, born in 1960. Current research fields include high-temperature self-lubricating alloys and tribological properties of material.