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陈克强 《武汉科技学院学报》1998,(3)
Textilemanufacturingplantsarerequiredtoremovecolorfromeffluents.Traditionaltreatmentmethodssuchasextendedaerationremoveonlypartofthecolorfromdyehousewastewater.Additionaltreatmentsthatmaybeusedtoremovecoloraftertraditionalbiologicaltreatmentin-.eludechemi… 相似文献
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机械活化粉末制备W-Cu合金的微观组织 总被引:5,自引:2,他引:5
为了改善制备工艺和提高W-Cu合金的密度与性能,对原料粉末进行了机械活化处理,通过成形和烧结制备了W-Cu合金,考察了活化后粉末的变化,观察了合金的烧结组织并测量了密度.结果表明,机械活化能增大钨铜粉末的表面能和晶格畸变能,有效地促进烧结,改善烧结组织;烧结体中存在大量团絮状组织,团粒内部钨颗粒主要以固相方式烧结在一起,而团粒之间则以液相烧结为主.烧结组织细密、均匀,相对密度达98%以上;烧结组织中钨铜两相在微米尺度下仍然结合良好,部分界面出现了互溶. 相似文献
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Functional significance of the Kunitz-type inhibitory domains of lipoprotein-associated coagulation inhibitor 总被引:20,自引:0,他引:20
T J Girard L A Warren W F Novotny K M Likert S G Brown J P Miletich G J Broze 《Nature》1989,338(6215):518-520
Blood coagulation can be initiated when factor VII or VIIa, a plasma protease, binds to its essential cofactor, tissue factor (TF), and proteolytically activates factors IX and X, triggering a cascade of events which eventually leads to the formation of thrombin and a fibrin clot. Plasma contains a lipoprotein-associated coagulation inhibitor (LACI) which inhibits activated factor X (Xa) directly and, in a Xa-dependent way, inhibits VII(a)/TF activity, presumably by forming a quaternary Xa/LACI/VII(a)/TF complex. Sequence analysis of complementary DNA clones has shown that LACI contains three tandemly repeated Kunitz-type serine protease inhibitory domains. To investigate the relationship between these Kunitz structures and LACI function, we have used site-directed mutagenesis to produce altered forms of LACI in which the residue at the active-site cleft of each Kunitz domain has been individually changed. The second Kunitz domain is required for efficient binding and inhibition of Xa, and both Kunitz domains 1 and 2 are required for the inhibition of VIIa/TF activity; but alteration of the active-site residue of the third Kunitz domain has no significant effect on either function. We propose that in the putative inhibitory complex, Kunitz domain 1 is bound to the active site of VII(a)/TF and that Kunitz domain 2 is bound to Xa's active site. 相似文献
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Cruz FW Burns SJ Karmann I Sharp WD Vuille M Cardoso AO Ferrari JA Dias PL Viana O 《Nature》2005,434(7029):63-66
During the last glacial period, large millennial-scale temperature oscillations--the 'Dansgaard/Oeschger' cycles--were the primary climate signal in Northern Hemisphere climate archives from the high latitudes to the tropics. But whether the influence of these abrupt climate changes extended to the tropical and subtropical Southern Hemisphere, where changes in insolation are thought to be the main direct forcing of climate, has remained unclear. Here we present a high-resolution oxygen isotope record of a U/Th-dated stalagmite from subtropical southern Brazil, covering the past 116,200 years. The oxygen isotope signature varies with shifts in the source region and amount of rainfall in the area, and hence records changes in atmospheric circulation and convective intensity over South America. We find that these variations in rainfall source and amount are primarily driven by summer solar radiation, which is controlled by the Earth's precessional cycle. The Dansgaard/Oeschger cycles can be detected in our record and therefore we confirm that they also affect the tropical hydrological cycle, but that in southern subtropical Brazil, millennial-scale climate changes are not as dominant as they are in the Northern Hemisphere. 相似文献
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Identification of the familial cylindromatosis tumour-suppressor gene 总被引:25,自引:0,他引:25
Bignell GR Warren W Seal S Takahashi M Rapley E Barfoot R Green H Brown C Biggs PJ Lakhani SR Jones C Hansen J Blair E Hofmann B Siebert R Turner G Evans DG Schrander-Stumpel C Beemer FA van Den Ouweland A Halley D Delpech B Cleveland MG Leigh I Leisti J Rasmussen S 《Nature genetics》2000,25(2):160-165
Familial cylindromatosis is an autosomal dominant genetic predisposition to multiple tumours of the skin appendages. The susceptibility gene (CYLD) has previously been localized to chromosome 16q and has the genetic attributes of a tumour-suppressor gene (recessive oncogene). Here we have identified CYLD by detecting germline mutations in 21 cylindromatosis families and somatic mutations in 1 sporadic and 5 familial cylindromas. All mutations predict truncation or absence of the encoded protein. CYLD encodes three cytoskeletal-associated-protein-glycine-conserved (CAP-GLY) domains, which are found in proteins that coordinate the attachment of organelles to microtubules. CYLD also has sequence homology to the catalytic domain of ubiquitin carboxy-terminal hydrolases (UCH). 相似文献
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