高产壳聚糖酶菌株的筛选和发酵产酶条件研究

为探讨专一性地降解甲壳质或壳聚糖的甲壳质酶或壳聚糖酶 ,从采集的土样中分离到 4株产壳聚糖酶能力较强的菌株 ,经摇瓶复筛 ,菌株YJ0 2产酶能力最强。对其发酵产酶条件的研究结果表明其产酶最适培养基组分为 (% ,w/v) :粉末壳聚糖 2 .0 ,葡萄糖 0 .1,NH4NO3 1.0 ,酵母提取物 0 .5 ,K2 HPO40 .0 7,KH2 PO40 .0 3 ,NaCl0 .5 ,MgSO4·7H2 O 0 .0 5 ,起始 pH 6.0。最适产酶培养条件是 :5 0 0mL三角烧瓶装瓶量为 15 0mL ,2 .0 % (v/v)接种量 ,3 0℃ ,15 0r/min培养 72h。在最适产酶培养条件下 ,72h时菌株YJ0 2发酵液中壳聚糖酶活力可达到 17.0 4U/mL。     

虾夷扇贝天然苗种筛选装置的研究与应用

随着贝类底播增养殖产业的迅猛发展,为保证底播贝苗的成活率,养殖企业对天然苗种更加重视。天然苗种采用中间育成方法,需要对苗种进行筛选作业,但目前筛选作业仍以人工作业为主,存在作业效率低、劳动强度大等问题。作者通过对大连地区虾夷扇贝(Patinopecten yessoensis)天然苗种筛选作业调研的基础上,设计了满足生产实际需求的扇贝苗种筛选装置,可实现3种规格贝苗的筛选作业。试验分2阶段进行,第1阶段对影响筛选准确性的因素进行正交分析于验证,确定了最佳工艺参数;第2阶段在大连旅顺进行的生产性对比试验得出,机械筛选的平均准确率为91.33%,误差率低于10%,且5组筛选结果无显著性差异(P0.05);同时机械筛选的平均作业效率为80g/(人/min),约为人工筛选作业效率的8倍。由此说明扇贝苗种筛选装置具有较高的准确性、稳定性和高效性,具有推广应用价值。     

Effect of superstrong magnetic field on electron screening at the crusts of neutron stars

The influences of electron screening (ES) and electron energy correction (EEC) are investigated by superstrong magnetic field (SMF). We also discuss in detail the discrepant factor between our results and those of Fushiki, Gudmundsson and Pethick (FGP) in SMF. The results show that SMF has only a slight effect on ES when B < 10⁹ T on the surfaces of most neutron stars. Whereas for some magnetars, SMF influence ES greatly when B > 10⁹ T . For instance, due to SMF the ES potential may be increased about 23.6% and the EEC may be increased about 4 orders of magnitude at ρ/μ_e = 1.0×10⁶ mol/cm³ and T₉ = 1. On the other hand, the discrepant factor shows that our results are in good agreement with FGP's when B < 10⁹ T . But the difference will be increased with increasing SMF.     

A factor analytic approach to the identification of geomorphic processes from soil particle size characteristics

Q-mode factor analysis of soil particle size data is used to identify the three dominant geomorphic processes responsible for the spatial variability of particle size in a catchment on the basaltic Darling Downs landsurface. Three factors are shown to account for 95 per cent of the textural variability of a suite of transported and sedentary materials. The spatial characteristics of groups of samples associated with the three factors suggests that the three factors are associated with suspended sediment transport and deposition, weathering, and bedload transport and deposition respectively. These interpretations are supported by the detailed graphical analysis of the cumulative particle size curves. The spatially variable influence of the three factors and related processes is given by their respective factor loadings which are mappable for the surface layer materials.     

均质土坡的安全系数

本文用变分法的基本理论的方法，推导出了均质土坡稳定性在平面应变情况下的基本方程，将简单边坡无粘性土（Ｃ＝０）与纯粘性土ψ＝０）的情况作为特例导出了相应的计算方法与计算公式，并对传统的条分法与土坡临界高度计算方法进行了讨论。     

上扬子台区下寒武统黑色岩系中的钒矿床

我国南部早寒武世黑色岩系中，蕴藏丰富的金属和非金属矿产。而位于扬子地台东南缘的钒矿床尤其令人瞩目。本文以湘西为例，剖析该类钒矿地质特征和成矿规律。矿床产于下寒武统黑色岩系底产的碳系页岩、硅岩及黑色页岩组合。矿层呈层状、似层状，产权稳定，埋藏浅，储量大。矿石主要由水云母（伊利石）和石英组成，含有机质及藻类化石。成矿受地层、岩性、古构造和古地理条件控制。矿床具有微生物成矿与海底热水沉积双重特征，成因应属生物地球化学积积矿床范畴。     

随州-信阳ML4.2地震前定点形变异常特征

分析了2000年1月28日随州和信阳交界处发生的ML4．2地震前，信阳地震台（△＝35km)定点形变中短期及临震异常特征。分析研究表明：该次地震前信阳台目视水管倾斜仪EW向测值从1999年6开始出现反向变化，NS向测值从1999年3月开始出现加速变化；水平摆倾余仪EW向和NS向测值分别从1999年2月和1999年6月开始出现反向变化。这些异常于2000年下半年结束。震前3天水管倾斜仪EW向测值出现加速变化；震前5－8天NS向测值除了出现加速变化外，还出现突跳。城前约20天，水平摆倾斜仪2个方向测值构出现了准周期性波动变化。另外，形变固体潮潮汐因子也有明显异常。     

金沙江流域（云南段）砂金成因类型及其找矿前景

根据成矿作用、成矿环境及矿床特征，金沙江流域（云南段）砂金矿床，可划分为：残坡积、洪积、冲洪积、冲积和冰碛等五种类型。成矿主要受碰撞带、深大断裂、大断裂及其派生断裂、基底岩石、地貌、水质和水化学环境等综合控制。以巨甸－大具及中江街－金江街两片区最具有找矿前景。     

缅北中部脉金矿带控矿因素及成矿作用浅析

缅北中部，印缅岛弧及弧后盆地东侧、新生代造山带的前缘推覆构造带中，分布有许多脉金矿床及矿点，构成金矿带。矿带、矿田、矿床及矿体的形成、分布及其规模，受不同级别的近南北向逆冲断裂，及其间派生的北东向张性扩容断裂组成的剪切断裂带控制。可渗透的下麦尔组下部中一粗粒砂岩，起着很好的容矿作用。下麦尔组上部泥岩、细砂岩、粉砂岩和页岩互层单元，在携金热液的迁移、氧化硅的沉淀和矿质沉积定位等方面，可能起到圈闭作用。     

WINDOW FACTOR ANALYSIS:THEORETICAL DERIVATION AND APPLICATION TO FLOW INJECTION ANALYSIS DATA

Window factor analysis(WFA)is a self-modeling method for extracting the concentration profiles ofindividual components from evolutionary processes such as flow injection,chromatography,titrationsand reaction kinetics.The method takes advantage of the fact that each component lies in a specificregion along the evolutionary axis,called the‘window’.Theoretical equations are derived.The methodis used to extract the concentration profiles and spectra of seven bismuth species from data obtained byGemperline and Hamilton,who injected bismuth perchlorate into a flowing stream of hydrochloric acid.