438 resultados para 7140-237


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科技论文的题名具有高度浓缩文章内容、文献编制、信息导读和类型识别等功能。科技编辑应精雕细琢地编辑科技论文题名,使其准确恰当、言简意赅和清楚明朗;但在审编科技论文题名时应当遵循“严谨慎重”“宁不改,不误改”和“最终听从作者”等几条原则。通过案例实证分析科技论文中的不当题名及其编辑方法。

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科技学术期刊编辑部对论文的初审是决定期刊学术水平的基础环节和决定期刊工作效率的主要环节,其效果直接影响到外审、决审、编辑、出版等一系列后续工作,也是影响论文出版周期的重要因素。系统论述了科技学术期刊论文初审的意义、内容、结论、原则以及初审人的条件等。

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科技学术期刊的稿件录用率是当前影响期刊出版时滞的关键因素之一.稿件录用与否和录用率的高低当由编辑部根据论文质量和期刊特点来全面衡量和确定.提出调控录用率和出版时滞的指导原则和具体方法.认为对论文进行全程质量控制,降低录用率而增加单位空间的有效信息量,可使科技期刊取得稿源充分而出版时滞又短的双赢.

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文章从德国的商业实验室的建立、业务范围、质量管理、工作程序几个方面作了介绍,并将商业实验室与国内的监测站进行了比较。

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会计作为一个提供财务信息为核心的信息系统,在企业经营管理中发挥着重要的作用。随着经济和科技的不断发展,以及新的会计思想和理论逐渐确立,在推动会计自身发展和变革的同时,也进一步完善和发展了电算化会计。本文就电算化会计与传统会计的差别以及会计对电算化对传统会计的影响进行了简要的分析和总结。

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本文以X-线衍射、裂解色谱、GPC以及XPS等手段,着重研究了用预辐照法合成的氧化镁、二氧化硅、Y型分子筛等无机化合物与甲基丙烯酸甲酯、苯乙烯、丙烯腈等烯类单体的辐射接枝共聚物。

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本文采用接枝共聚方法合成功能高分子型钆化合物活性材料,研究了它们的结构和某些性能,结果表明这些活性材料的结构和性能对钆离子选择电极性能有较大的影响。

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本文合成了系列稀土三氟醋酸盐晶体[Re(CF_3COO)_3·3H_2O](Re=Eu,Gd,Tb,Dy)和[Tb_xY_(1-x)(CF_3COO)_3·3H_2O]_2(x=0.05,0.10,0.15,0.20,0.25mol),测定其晶体结构属单斜晶系,空间群为P_(21/c);较详细地讨论了Eu~(3+),Gd~(3+),Tb~(3+),Dy~(3+)在这些化学计量化合物中的光谱特性,以及在[Tb_xY_(1-x)(CF_5COO)_3·3H_2O]中Tb~(3+)的发光强度随其浓度的变化规律。

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Heterotrophic culture of microalgae to develop methods of increasing biomass productivity and storage lipids has brought new insight to commercial biodiesel production. To understand the relationship between heterotrophy and lipid production, the effects of carbon sources on the growth and lipid accumulation of Chlorella sorokiniana GXNN01 was studied. The alga exhibited an increased growth rate in response to the addition of carbon sources, which reached the stationary phase after 48 h at 30A degrees C. In addition, glucose and NaAc had a significant effect on the lipid accumulation during the early-stationary phase. Specifically, the lipid content was 0.237 +/- 0.026 g g(-1) cell dry weight and 0.272 +/- 0.041 g L-1 when glucose was used as the carbon source, whereas the lipid content reached 0.287 +/- 0.018 g g(-1) cell dry weight and 0.288 +/- 0.008 g L-1 when NaAc was used as the carbon source. The neutral lipid content was found to first decrease and then increase over time during the growth phase. A glucose concentration of 20 mmol L-1 gave the maximal lipid yield and the optimum harvest time was the early-stationary phase.

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Environmental microbiology investigation was carried out in Jiaozhou Bay to determine the source and distribution of tetracycline-resistant bacteria and their resistance mechanisms. At least 25 species or the equivalent molecular phylogenetic taxa in 16 genera of resistant bacteria could be identified based on 16S ribosomal deoxyribonucleic acid sequence analysis. Enterobacteriaceae, Pseudomonadaceae, and Vibrionaceae constituted the majority of the typical resistant isolates. Indigenous estuarine and marine Halomonadaceae, Pseudoalteromonadaceae, Rhodobacteraceae, and Shewanellaceae bacteria also harbored tetracycline resistance. All the six resistance determinants screened, tet(A)-(E) and tet(G), could be detected, and the predominant genes were tet(A), tet(B), and tet(G). Both anthropogenic activity-related and indigenous estuarine or coastal bacteria might contribute to the tet gene reservoir, and resistant bacteria and their molecular determinants may serve as bioindicators of coastal environmental quality. Our work probably is the first identification of tet(E) in Proteus, tet(G) in Acinetobacter, tet(C) and tet(D) in Halomonas, tet(D) and tet(G) in Shewanella, and tet(B), tet(C), tet(E), and tet(G) in Roseobacter.

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A crustin-like protein (CruFc) from Fenneropenaeus chinensis was expressed in Pichia pastoris and then purified to electrophoretic homogeneity on a Sephacryl S-100 column with a band corresponding to the expected one (13 kDa) shown by 15% SDS-PAGE. Western blot indicated that the rCruFc specifically reacted with polyclonal rabbit anti-Fenneropenaeus chinensis CruFc. Production in a 5 l bioreactor gave 237 mg rCruFc/l. Antimicrobial assay revealed that 4 mu M rCruFc inhibited growth of Staphylococcus aureus.

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To reconstruct the formation and evolution process of the warm current system within the East China Sea (ECS) and the Yellow Sea (YS) since the last deglaciation, the paleoceangraphic records in core DGKS9603, core CSH1 and core YSDP102, which were retrieved from the mainstream of the Kuroshio Current (KC), the edge of the modern Tsushima Warm Current (TWC) and muddy region under cold waters accreted with the Yellow Sea Warm Current (YSWC) respectively, were synthetically analyzed. The results indicate that the formation and evolution of the modern warm current system in the ECS and the YS has been accompanied by the development of the KC and impulse rising of the sea level since the last deglaciation. The influence of the KC on the Okinawa Trough had enhanced since 16 cal kyr BP, and synchronously the modern TWC began to develop with the rising of sea level and finally formed at about 8.5 cal kyr BP. The KC had experienced two weakening process during the Heinrich event 1 and the Younger Drays event from 16 to 8.5 cal kyr BP. The period of 7-6 cal kyr BP was the strongest stage of the KC and the TWC since the last deglaciation. The YSWC has appeared at about 6.4 cal kyr BP. Thus, the warm current system of the ECS and the YS has ultimately formed. The weakness of the KC, indicated by the occurrence of Pulleniatina minimum event (PME) during the period from 5.3 to 2.8 cal kyr BP, caused the main stream of the TWC to shift eastward to the Pacific Ocean around about 3 cal kyr BP. The process resulted in the intruding of continent shelf cold water mass with rich nutrients. Synchronously, the strength of the YSWC was relatively weak and the related cold water body was active at the early-mid stage of its appearance against the PME background, which resulted in the quick formation of muddy deposit system in the southeastern YS. The strength of the warm current system in the ECS and the YS has enhanced evidently, and approached to the modern condition gradually since 3 cal kyr BP.

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The Late Pliocene is thought to be characterized by the simultaneous intensification of both the East Asian winter monsoon (EAWM) and East Asian summer monsoon (EASM). However, the evolution of the EASM during the Pliocene remains still controversial and only little is known about the dynamics of the EASM during the Pliocene on orbital time scales. Here we use clay mineral assemblages in sediments from Ocean Drilling Program (ODP) Site 1143 in the southern South China Sea (SCS) to obtain proxy records of past changes in the EASM climate during the Pliocene. Provenance analysis suggests that illite, chlorite and kaolinite originated mainly from the Mekong River drainage area. Smectite was derived mainly from the Indonesian islands. The kaolinite/illite ratio and the chemical index of alteration (CIA) of siliciclastic sediments allowed us to reconstruct the history of chemical weathering and physical erosion of the Mekong River drainage area and thus, the evolution of,the EASM during the Pliocene. Our clay minerals proxy data suggests a stronger EASM during the Early Pliocene than during the Late Pliocene. We propose that the long-term evolution of the EASM has been driven by global cooling rather than the uplift of the Tibetan Plateau. Spectral analysis of kaolinite/ illite ratio displays a set of strong periodicities at 100 ka, 30 ka, 28 ka, 25 ka, and 22 ka. with no clear obliquityrelated signal. Our study suggests that the Pliocene EASM intensity on orbital time scales is not only controlled by the Northern Hemisphere summer insolation, but also strongly influenced by equatorial Pacific ENSO-like ocean atmosphere dynamics. (C) 2010 Elsevier B.V. All rights reserved.