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春节前后,吉安市遭遇到罕见的冰冻雨雪灾害天气,连续出现了低温、阴雨和雨夹雪,成为全省灾情最严重地区之一.特别是1月25日以后,出现了持续大范围的雨雪冰冻天气.冰冻损坏了市区的电网,压垮了树枝,封锁了道路和桥梁. 相似文献
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收集了2010年7月~2011年6月世界塑料工业的相关资料,介绍了2010~2011年世界塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚氯乙烯、聚苯乙烯、ABS树脂),工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚),特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮),通用热固性树脂(酚醛、不饱和聚酯树脂、环氧树脂、聚氨酯)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍。 相似文献
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2003~2004年国外塑料工业进展 总被引:5,自引:0,他引:5
收集了2003年7月~2004年6月国外塑料工业的相关资料,介绍了2003年~2004年国外塑料工业的发展情况,提供了世界几大区域塑料的产量、增长率及所占份额,美国、德国、日本、韩国、法国、比利时、中国台湾、加拿大、巴西、西班牙等国家和地区的不同树脂的产量及消费量,各国、各地区塑料原料的产量、进出口量、国内消费量和人均消费量,日本塑料原料的生产情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。 相似文献
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萜类化合物具有可观的经济价值,但是目前的生产过程复杂、产量低。酿酒酵母甲羟戊酸途径为萜类化合物的合成提供直接前体,因此酿酒酵母细胞具有合成异源萜类化合物的天然优势。对酿酒酵母甲羟戊酸途径的清晰认识是对其进行有效利用的基础,本文从代谢途径、关键酶的特点和全局调控机制3个方面对该途径进行了介绍。从代谢途径的构建和优化、模块与底盘细胞的适配、模块构建及组装方式的角度概述了酿酒酵母细胞异源合成单萜、倍半烯萜、二萜、三萜类化合物的研究进展。指出实现酿酒酵母高效合成萜类化合物所需要解决的基础问题是对酿酒酵母甲羟戊酸途径进行更为全面了解和对萜类化合物的天然代谢途径进行明确解析;另外,合成生物学的进一步发展也将为此提供应用基础。 相似文献
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我公司回转窑规格为Φ4.0m×60m.窑内使用的耐火砖为镁铬砖、隔热尖晶石、蓝晶石和黏土砖以及硅莫砖.镁铬砖规格为(81×90×150×200)mm,其它耐火砖规格皆为(81×90×200×200)mm.尽管每个品种的砖品质相同,但由于在镶砌和使用过程中方法不同,寿命有长有短.通过多年实践,现总结如下. 相似文献
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Distribution of cholesterol sulfate and its anabolic and catabolic enzymes in various rabbit tissues
Cholesterol sulfate (CS) recently has been shown to be involved in signal transduction pathway. To evaluate its functional
significance, we determined the concentration of CS, and the specific activities of cholesterol sulfotransferase and CS sulfatase
in various tissues of rabbit, and compared them with the concentration of sulfoglycolipids in rabbit tissues. CS was present
in the epithelia and mucosa, but not in the tunica muscularis, of the digestive tract, trachea, uterine endometrium and uterine
cervix. It was also present in lung, spleen, kidney, prostate, skin, hair, and nail at relatively high concentrations. Its
concentration in the uterine endometrium was nine times higher in pseudopregnant rabbits than in nonpregnant rabbits because
of activation of cholesterol sulfotransferase and inhibition of CS sulfatase in the pseudopregnant rabbits. Sulfoglycolipids
were not detected in the uterine endometria of either nonpregnant-or pseudopregnant rabbits. However, sulfoglycolipids were
detected at relatively high concentrations in the cerebrum, cerebellum, stomach, duodenum, jejunum, testis, and kidney of
rabbits and thus the tissues in which both sulfolipids were detected were the gastrointestinal tract and kidney. In the digestive
tract, the concentration of CS decreased in the order esophagus, stomach, duodenum, and jejunum, but that of sulfatide increased
in the same order, indicating distribution of CS in the squamous epithelium. In addition, both CS and sulfatide were detected
in the serum. On the other hand, CS sulfatase activity was detected in all tissues examined, even in hair, from which the
enzyme was liberated by brief sonication, and its highest specific activity was deteted in the liver. The specific activity
of cholesterol sulfotransferase varied among the tissues examined and was found to be significantly high in the esophageal
epithelium and the uterine endometrium of pseudopregnant rabbit, indicating involvement of cholesterol sulfation in the formation
of epithelium. 相似文献
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Mean intakes of dietary fiber (DF) were estimated in the population of Central America and Panama, using the results of dietary surveys conducted in 1969 and 1986 both in rural and urban areas, as well as data on the DF content of foods as consumed in the region. Data on preschool children were also estimated. The results indicated that DF intake in urban areas is lower than that of rural areas, particularly in Costa Rica and Panama. In 1969, intake varied from 32g in El Salvador to 15g in Panama in urban areas, while in rural areas intake was from 45g in El Salvador to 13g in Panama. The foods which contributed most to the total intake in Guatemala, El Salvador and Honduras were tortillas and beans, while in Costa Rica and Panama, beans provided the largest intake. In preeschool children, intake was 12.5g in El Salvador and 5.4g in Costa Rica in 1969, which is the same tendency as that found for adults. From more recent data on food intake, it was found that DF intake had decreased in the rural areas of El Salvador, Honduras and Costa Rica, being between 4 and 9% in the first two countries and 12% in Costa Rica. In the urban area of the latter, from 1969 to 1986 a decrease in DF intake of around 20% has taken place. 相似文献
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复合材料在飞机和汽车上的应用动向(二) 总被引:2,自引:0,他引:2
黄汉生 《高科技纤维与应用》2004,29(6):28-34
复合材料大量用于航空航天工业和汽车工业,特别是先进碳纤维复合材料用于飞机尤为值得注意,不久前,碳纤维复合材料只能在军用飞机用作主结构,但是,由于技术发展的进步,先进复合材料已开始在民航客机上也应用作主结构,如机身、机翼等,在民航客机上使用复合材料的决定,只有波音公司和空车公司这样的拥有雄厚的人力、财力和胆识的大飞机制造公司才可能作出,至于汽车上,主要使用玻纤增强塑料(热固性和热塑性塑料)用作车身、发动机室内零部件、车顶和进气路管;碳纤维复合材料近年来也日益增多的用于汽车上,主要用作车身外板、车门、进气路管和活门盖等。 相似文献
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Xandra Pereiro Noelia Ruzafa J. Haritz Urcola Sansar C. Sharma Elena Vecino 《International journal of molecular sciences》2020,21(23)
RNA binding protein with multiple splicing (RBPMS) is expressed exclusively in retinal ganglion cells (RGCs) in the retina and can label all RGCs in normal retinas of mice, rats, guinea pigs, rabbits, cats, and monkeys, but its function in these cells is not known. As a result of the limited knowledge regarding RBPMS, we analyzed the expression of RBPMS in the retina of different mammalian species (humans, pigs, and rats), in various stages of development (neonatal and adult) and with different levels of injury (control, hypoxia, and organotypic culture or explants). In control conditions, RBPMS was localized in the RGCs somas in the ganglion cell layer, whereas in hypoxic conditions, it was localized in the RGCs dendrites in the inner plexiform layer. Such differential distributions of RBPMS occurred in all analyzed species, and in adult and neonatal retinas. Furthermore, we demonstrate RBPMS localization in the degenerating RGCs axons in the nerve fiber layer of retinal explants. This is the first evidence regarding the possible transport of RBPMS in response to physiological damage in a mammalian retina. Therefore, RBPMS should be further investigated in relation to its role in axonal and dendritic degeneration. 相似文献
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Cárdenas Quintana H Gómez Bravo C Pretell EA 《Archivos latinoamericanos de nutrición》2003,53(4):408-412
With the objective to establish the cause-effect relationship between a geological area and the iodine content in cattle milk, and to estimate the contribution of milk consumption to the dietary iodine intake, the iodine content in cattle milk from the sierra and the coastal regions of Perú was determined. Milk samples were collected of cows from the three main productive zones of Perú, 62 in Cajamarca, 42 in Arequipa, both in the sierra, and 27 in Lima at the coast. The measurement of iodine was made by the method of Zak, based on the Sandell- Kolthoff reaction. The median values obtained were 24 microg/L in Cajamarca, 34 microg/L in Arequipa, and 170 microg/L in Lima. The median value in the sierra, 26 microg/L, was significantly lower than the one found in the coast. Moreover, while in the former 81% of individual values were below 50 microg/L, in the latter, on the contrary, 77% were above 80 microg/L. These results confirm that the iodine content in cattle milk is related to ecological factors. At the same time, they demonstrate that the iodine content in milk from the sierra is six times lower than in milk from the coast, and also that its consumption does not contribute significantly to satisfy the human physiological requirements of iodine in that zone. 相似文献
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Lipid composition of liver and thymus in controls, early stage lymphoma, and advanced stage lymphoma-bearing AKR mice was
studied. There was a significant decrease in the liver total lipid content in mice with advanced lymphoma, whereas in the
early stages, no quantitative change was seen. In livers of mice with advanced stage lymphoma, there was a significant decrease
in the nonpolar fraction. The decrease was in triglyceride, whereas the cholesterol fractions were relatively increased though
highly variable. There was an increase in the polar lipid/nonpolar lipid ratio in the advanced lymphoma livers and a very
large increase in the polar lipid/triglyceride ratio, indicating that the decrease in total lipid in these livers was largely
in the triglyceride fraction. Similar changes were seen in the thymus, in which the lipid composition reflected the transformation
from normal to malignant cells. 相似文献
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Matea
uul Mirela Lozi Natalija Filipovi Samir anovi Ana Didovi Pavi
i Joko Petri
evi Nenad Kunac Violeta olji Mirna Saraga-Babi Suzana Konjevoda Katarina Vukojevic 《International journal of molecular sciences》2022,23(11)
The expression pattern of Connexins (Cx) 37, 40, 43, 45 and Pannexin 1 (Pnx1) was analyzed immunohistochemically, as well as semi-quantitatively and quantitatively in histological sections of developing 8th- to 12th-week human eyes and postnatal healthy eye, in retinoblastoma and different uveal melanomas. Expressions of both Cx37 and Cx43 increased during development but diminished in the postnatal period, being higher in the retina than in the choroid. Cx37 was highly expressed in the choroid of retinoblastoma, and Cx43 in epitheloid melanoma, while they were both increasingly expressed in mixoid melanoma. In contrast, mild retinal Cx40 expression during development increased to strong in postnatal period, while it was significantly higher in the choroid of mixoid melanoma. Cx45 showed significantly higher expression in the developing retina compared to other samples, while it became low postnatally and in all types of melanoma. Pnx1 was increasingly expressed in developing choroid but became lower in the postnatal eye. It was strongly expressed in epithelial and spindle melanoma, and particularly in retinoblastoma. Our results indicate importance of Cx37 and Cx40 expression in normal and pathological vascularization, and Cx43 expression in inflammatory response. Whereas Cx45 is involved in early stages of eye development, Pnx1might influence cell metabolism. Additionally, Cx43 might be a potential biomarker of tumor prognosis. 相似文献
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表面活性剂在油田中的应用 总被引:9,自引:0,他引:9
综述了表面活性剂在油田中的应用。在钻井中 ,表面活性剂用作起泡剂、乳化剂、页岩抑制剂、润滑剂等 ;在采油中 ,表面活性剂用作驱油剂、培水剂、酸化添加剂、压裂添加剂、防蜡剂、乳化降粘剂、解堵剂等 ;在原油集输中 ,表面活性剂用作破乳剂、消泡剂、除油剂、防垢剂、缓蚀剂、杀菌剂等。同时介绍了油田用表面活性剂的发展趋势。 相似文献