极地产适冷脂肪酶菌株的酶学性质研究

从南北极环境样品中分离到7株产脂肪酶的细菌,经16SrDNA序列分析表明,这些细菌分别属于假交替单胞菌属（Pseudoalteromonas）和嗜冷杆菌属（Psychrobacter）．采用p-NPP法对这7株细菌所产的脂肪酶进行酶学性质研究,结果显示这些酶的最适作用温度在30～40cC、最适作用pH值在7—8之间,在低温下能保持较高的剩余活力,对热敏感,属于适冷脂肪酶．其中假交替单胞菌（Psychrobacter sp．7342）所产脂肪酶具有低温下酶的剩余活力高、有效作用温度和pH范围广、热稳定性较好及对多种金属离子抗性强等特点．该菌株能利用多种单一氮源和碳源产酶,最适产酶温度为25℃．在此基础上进行正交实验分析得到了该菌株的最佳发酵条件为：蛋白胨和淀粉含量各为1．33％,酵母膏含量为0．3％,温度为25℃．     

辽宁省积雪对自动气象站观测地气温差的影响

利用1971—2016年辽宁省61个气象站气温、地表温度、积雪日数和积雪深度资料,分析了积雪的保温作用及其对地气温差的影响。结果表明：更换自动站前后地表温度观测方式的差异导致地气温差显著增大,地气温差的增大程度受所在区域积雪日数、积雪深度的影响显著。在积雪期较长、积雪较厚的地区,积雪引起反照率增大,使得雪面温度降低,导致雪气温差减小,而雪的保温作用使得地气温差显著增大。因此,更换自动站前地（雪）气温差与积雪日数呈显著负相关,而更换自动站后地气温差与积雪日数呈显著正相关。各台站之间地气温差随积雪深度的变化系数差异较大,为0.045~0.858 ℃?cm^-1,在年平均积雪日数＜40 d、年平均极端积雪深度＜10 cm的区域,积雪的保温作用随积雪深度增大而显著增大;在年平均积雪日数＞40 d、年平均极端积雪深度＞10 cm的区域,10 cm以下的积雪对土壤保温作用随积雪深度增大显著,当积雪深度＞10 cm后,其保温作用随积雪深度增大的幅度明显减小。     

中国中央造山带资源环境态势与可持续发展对策

资源与环境是谋求发展的物质基础和重要前提,其合理开发利用是实现可持续发展的重要内容。中国中央造山带富能、富矿、少植被、土地瘠薄,这对该区的经济发展既显示了无穷的诱惑,却又制约着对其的开发利用。对此,从保护利用水土资源、利用资源优势促进经济发展以及发展科技教育与提高人口素质三方面提出建议以促进该区走上可持续发展之路。     

建筑基坑土钉支护时机探讨

本文采用FLAC软件，通过建筑物基坑随开挖深度增加而变形的模拟，得出基坑每一阶段开挖及土钉支护条件下的位移发展演变规律，跟踪最大不平衡力变量的变化提出了最佳土钉支护时机。     

近50年气候变化对滦河上游径流的影响

为了解近50年滦河上游气温和降水气候的变化特征、趋势及其对该流域径流量的影响,利用1956-2009年滦河上游的实测气温、降水量和径流深资料,分析了该流域气温、降水和径流深的年均和季度变化的时间序列,并建立了该流域气候变化对径流影响的复相关回归模型。结果表明,年径流深随着年降水量的减少而减少,随着年平均气温的升高而减少;春、夏和秋季的径流深随着同期降水量和气温的变化趋势与年际变化趋势基本一致,但冬季径流深则相反,而且其变化幅度非常小。     

Granule ripples in the Kumtagh Desert,China: Morphology,grain size and influencing factors

Granule ripples are found mainly in four regions of the Kumtagh Desert in China; they are characterized by an asymmetrical shape, with gentle lower slopes on both sides and abrupt crests. The ripples tend to be oriented perpendicular to the prevailing winds, except when they form near obstacles such as yardangs. The wavelengths (λ) range between 0·31 m and 26 m and heights (h) range from 0·015 m to 1 m. The relationship between wavelength and height can be described by a simple linear function, and the mean ripple index (λ/h) is about 20·4 for the study sites. The sediments are poorly sorted, with negative to very negative skewness at lee and stoss slopes and between‐ripple troughs, which confirms the ‘poured in’ and ‘shadow’ appearance described by previous researchers. The bimodal or trimodal distributions of grains (with modes of ?1·16φ, ?0·5φ and 3·16φ) and the enrichment of coarse particles at the ripple surface (with coarse granule contents ranging between 5·2% and 62·1%) indicate that the underlying layer is the original sediment source and that the granule ripples resist erosional processes. Although the impact of saltating particles and, consequently, the creep and reptation of coarse grains are responsible for granule ripple initiation at a micro‐scale, however, the characteristics of local sediments, wind regimes and topographical obstacles, as well as the feedbacks among bedform and airflow, more strongly affect the development and alignment of granule ripples at a macro‐scale.     

地心和月心引力常数及月球形心与质心的确定

指出了地心引力常数GMe、月心引力常数GMl及月球形状中心和月球质量中心的意义和重要性;介绍了用空间探测器观测数据测定GMe与GMl及月球形状中心和月球质量中心的原理和方法;综合给出了利用空间探测器测定的数值。     

Dynamical response to supernova-induced gas removal in spiral galaxies with dark matter halo

We investigate the dynamical response, in terms of disc size and rotation velocity, to mass loss by supernovae in the evolution of spiral galaxies. A thin baryonic disc having the Kuzmin density profile embedded in a spherical dark matter halo having a density profile proposed by Navarro, Frenk & White is considered. For the purpose of comparison, we also consider the homogeneous and   r ⁻¹  profiles for dark matter in a truncated spherical halo. Assuming for simplicity that the dark matter distribution is not affected by mass-loss from discs and the change of baryonic disc matter distribution is homologous, we evaluate the effects of dynamical response in the resulting discs. We found that the dynamical response only for an adiabatic approximation of mass-loss can simultaneously account for the rotation velocity and disc size as observed particularly in dwarf spiral galaxies, thus reproducing the Tully–Fisher relation and the size versus magnitude relation over the full range of magnitude. Furthermore, we found that the mean specific angular momentum in discs after the mass-loss becomes larger than that before the mass-loss, suggesting that the mass-loss would most likely occur from the central disc region where the specific angular momentum is low.     

相态研究在化探异常评价中的应用——以马架子水系沉积物异常评价为例

利用相态研究可确定异常元素的赋存状态,马架子水系沉积物综合异常强度高,浓集中心明显,经过几次异常检查及查证,未获得良好的找矿效果,引起异常的成因机制不清。对异常样品中元素在氧化物相、结合相及硫化物相中分配的综合研究证实,Ph、Zn元素主要是以均匀分散形式存在于岩石中,为非矿致异常,从而节省了大量的人力、财力及物力,为异常查证及评价提供了一套新的思路。     

亚洲夏季风区中尺度地形降水结构及分布特征

采用高分辨率TRMM、AIRS卫星实测资料, 从气候态的降水微物理过程角度分析了亚洲夏季风期间中尺度山脉对不同性质降水垂直结构和水平分布的影响。研究表明, 中尺度山脉迎风、背风坡均以层云降水为主, 层云降水强度在迎风坡强于背风坡; 对流降水在迎风坡主要为浅对流, 背风坡主要为深对流, 对流降水强度在背风坡强于迎风坡。沿西南季风推进方向依次经过的中尺度山脉, 其两侧发生降水像素个数、 降水微物理特征等差异逐渐减小, 其中, 对流降水迎风坡向背风坡转变明显, 而层云降水背风坡向迎风坡转变明显。大气稳定度与对流降水在迎风、背风坡的分布相一致。另外, 对中尺度地形降水的研究为区域气候模式模拟高精度地形降水分布提供了实测依据。