Features of major greenhouse gases in loess, Shanxi Province, China

According to the investigations of five loess sections in Shanxi Province, China, it was found that the concentrations of the major greenhouse gases CO₂, CH₄ and N₂O in loess-paleosol sequences are generally high, even sometimes may be several times or scores of times higher than their atmospheric concentrations respectively. Although the CO₂ concentration in the same loess section shows poor regularity among different layers, it increases slowly from north to south in space. The CH₄ concentration in the layers under Malan Loess is much higher than that in the atmosphere, although it is not high in Malan Loess. Most of the δ¹³C values of CO₂ in loess are -11.14‰—15.48‰ (relative to PDB standard). Analysis of carbon isotopic compositions of CO₂ indicates that the main source of CO₂ in loess section is decomposition of ‘stable’ organic matters by microbes. The δ¹³C_g of CO₂ is a little heavier than organic source for exchanging carbon isotope with carbonate in loess. The abundant carbonate in loess not only makes the loess a huge carbon reservior but also adjusts     

Antimicrobial activities of isoalantolactone, a major sesquiterpene lactone ofInula racemosa

Isoalantolactone, a major constituent of Inula racemosa (Compositae) was tested for its antimicrobial action against five bacteria, six human and six plant pathogenic fungi. The lactone showed absolute toxicities at 500 m g/mL against 3 soil borne phytopathogenic fungi (Gaeumannomyces graminis var. tritici, Rhizoctonia cerealis and Phytophthora capsici) with the MICs determined to be 100, 100 and 300 m g/mL, respectively. At the MICs, isoalantolactone exhibited its fungistatic nature of toxicity. The lowest fungicidal concentrations of the lactone to G. graminis var. tritici, R. cerealis and >. capsici were shown to be 150, 150 and 350 m g/mL, respectively. Moreover, isoalantolactone displayed weaker antibacterial activities against Bacillus subtilis, Escherichia coli, Pseudomonas fluorecense, Sarcina lentus and Staphylococcus aureus with MICs of 125, 425, 150, 150 and 100 m g/mL, respectively. The investigation disclosed the strong inhibition of isoalantolactone to the phytopathogenic fungi, raising a possibility that the lactone could be considered as a starting point for the project aiming at the development of new fungicide(s).     

光切法三维测量在逆工程中的问题分析

从实际应用的角度出发,对现今光切法三维测量技术应用于逆领域中的测量速度与精度的统一、测量数据的完整性与正确性、测量数据的可视化等关键问题进行了论述,并结合实例给出了各自的改进方案,通过将软、硬件进行有效结合,在不影响精度的前提下有效地提高了速度;通过对称放置对CCD,保证了数据的完整和测量精度,在不影响精度的前提下有效地提高了速度;通过对称放置双CCD,保证了数据的完整和测量精度;采用由粗至精消除误差点的方法,保证了数据的正确性,实验结果表明,研究结果对工程应用具有实际指导意义。     

利用安哥拉山羊改良本地山羊现状及今后的设想

美姑县安哥拉山羊改良本地山羊工作已初见成效,生产的马海毛价格高于绵羊毛3倍,是制作彝族服装擦尔瓦最好的原料。市场需求量大,发展前景可观。如进一步推广人工种草和秸秆综合利用技术,加强养羊科技推广力度,建立安哥拉山羊纯种繁殖场,扩大人工授精配种规模,对发展少数民族地区经济,促进农牧民脱贫致富将起到积极作用。     

海峡两岸部分水产品加工名词比较

摘要 海峡两岸大部分水产品加工名词是一致的,但由于历史原因等许多因素的影响,也有一部分水产品加工名词的定名不一致。本文选取部分名词加以比较,以期起到抛砖引玉的作用,使海峡两岸的水产品加工科技名词能早日取得一致,以利于两岸的科技交流和贸易往来。
由于历史原因和科学概念在传播过程中诸多因素的影响,海峡两岸水产品加工科技名词不一致之处有很多,严重影响了两岸的技术合作与交流,水产科技文献的编纂与检索,以及海峡两岸的贸易往来等。近年来,随着两岸水产贸易和学术交流的不断增多,名词不一致成为亟待解决的问题。最近,国家水产品质量监督检验中心在制定水产行业标准《水产品加工基本术语》,在参与这一工作的过程中,我们查阅了大量国际上关于水产品加工术语的最新资料,并参考了台湾省的有关水产品加工的名词,发现由于海峡两岸长期隔离,两岸的生活方式及语言用法上存在着很大的差异,导致了海峡两岸在水产品加工方面的名词差异较大,以致两岸的学术交流过程中往往需用英文进行名词的统一,这严重阻碍了两岸的学术交流和贸易往来。我们在制定水产行业标准《水产品加工术语》的过程中,根据收集到的海峡两岸出版的有关水产品加工方面的资料^①,将其中水产品加工方面有差异的名词,进行了整理、汇总,并归纳为以下几个部分进行对比,见表1,2,3,4,5,6。我们在查阅台湾有关水产加工文献资料的过程中,发现台湾本地区的水产加工名词也很不统一,如salted product,在台湾就有腌制品、盐藏品、腌酱制品、盐制品等多种叫法。由于长期以来台湾受到日本的影响很大,台湾的水产加工名词中也有很多属于直接引用日文的说法,如鱼介类、佃煮品、盐辛品等;对于那些难以考证的名词,我们原则上应用英文名称进行验证,但对于从日文得来的名词则难以进行考证。由于资料有限,在此仅提供一部分不同的水产名词。我们希望通过本文能引起海峡两岸水产加工及名词术语方面的专家对海峡两岸名词术语不一致现象的重视,能够早日促成海峡两岸的专家学者们聚集一起进行交流、探讨,使两岸水产科技名词早日取得一致,以利于广泛开展海峡两岸的学术交流及贸易往来。 ① 这些资料主要有：《英汉水产学辞汇》(北京：科学出版社,1959)、《水产品冷藏加工》(中国轻工业出版社,1996)、《英汉发酵工业词汇》(中国轻工业出版社,1999)、《水产微生物学》、《水产食品化学》(台北：正中书局,1968)、《冷冻食品学》(台北：复文书局,1973)、《台湾水产加工业实况》(台北：1977)、《水产制造》(台北：徐氏基金会,1979)、《水产品藻源毒素检测操作手册》(<台湾>卫生署,1999)、《水产加工》(台北：复文书局)。     

基于MEM和HMM的中文词性标注方法

为了进一步提高中文语料库中语料的词性标注效率,在分析最大熵模型(MEM)和隐马尔科夫模型(HMM)所涉及理论、算法及其在中文词性标注技术中的应用的基础上,进行了基于MEM和HMM的中文词性标注实验.实验结果显示,基于MEM和HMM的中文词性标注算法都获得了一致性很好且覆盖率较高的标注效果,中文词性标注的准确率、召回率和F1这3个指标均达到92%以上;MEM的标注效果总体上比HMM的稍佳.     

苏轼的幽默和生存艺术

本文选取苏轼流传千古的遗闻轶事 ,从幽默的角度重新观照苏轼的人生形象和内在精神。文章着重归纳分析了苏轼幽默的类型、特征及其抗争厄运和苦难的生存艺术 ,从而展现了苏轼幽默的智慧光彩和乐观精神     

光交联UHMWPE纤维的凝胶质量分数及热性能

通过对UHMWPE纤维凝胶质量分数的测定,热机械分析、红外光谱(FTIR)及扫描电镜(SEM)分析,对影响纤维凝胶质量分数的因素进行了讨论,并对原纤维和经紫外光照交联的UHMWPE纤维的结构、性能等进行了比较。试验结果表明,经光交联的纤维,其原有的一些不良性能得到了改善。     

Cloning, sequencing and function ofsanB, a gene related to nikkomycin biosynthesis ofStreptomyces ansochromogenes

A 6.0 kb DNA fragment related to nikkomycin biosynthesis was cloned from nikkomycin-producingStreptomyces ansochromogenes 7100. Sequence analysis showed that the 1.9 kbTth111 I fragment, a part of the 6.0 kb DNA fragment, contains one complete ORF designatedsanB (GenBank accession No. AF224501), which is composed of 1740 bp encoding a protein consisting of 580 amino acid residues. Its start codon is GTG at 100 bp position and stop codon is TGA at 1840-bp position. Database searching indicated that the deduced protein ofsanB is homologous to the histidinol-phosphate aminotransferase inStreptomyces coelicolor with 31% identities and 47% positives. Gene disruption was performed to study the function ofsanB. It was found that disruptants ofsanB lost the ability to synthesize nikkomycin, which reveals thatsanB is a novel gene essential for nikkomycin biosynthesis.     

Testing relative evolutionary rates and estimating divergence times among six genera of Rhizophoraceae using cpDNA and nrDNA sequences

The molecular phylogenetic trees of 10 species representing 6 genera of the family Rhizophoraceae have been constructed using the sequences of chloroplast genesmatK andrbcL as well as the ITS regions of nuclear ribosomal DNA. Relative-rate tests between lineages in these phylogenetic trees have been performed. On the basis of the results of the relative-rate tests and related molecular evolutionary rate data, the divergence times between the lineages are estimated as follows: (i) the first divergence time in these genera is 132.25 million years ago (mya); (ii) the average divergence time between two tribes, i.e. inland Legnotideae (exceptCarallia brachiata) and mangrove Rhizophoreae, is 64.13 mya; and (iii) the average divergence time between two inland species,C. garciniaefolia andC. pectinifolia, is 19.92 mya.