长江中下游干流河底沉积物环境磁性特征

通过多参数磁性测量,分析探讨了长江中下游干流3种不同粒级(<2mm,<0.28mm和<0.125mm)河底沉积物中磁性矿物的类型、含量、颗粒变化及空间分布特征。3种粒级中,磁性矿物主要富集在<0.125mm的细质沉积物中。对细质沉积物的分析表明,长江中下游干流河底沉积物的磁性矿物含量较长江口高近10倍,类型以亚铁磁性矿物磁铁矿为主,颗粒以假单畴-多畴为主,超顺磁性颗粒含量较低。从中游到下游,磁性矿物含量呈下降趋势,颗粒呈变细趋势。干流磁性矿物含量远高于支流,颗粒远粗于支流,支流泥沙的汇入不断影响干流沉积物的磁性特征。     

汶川地震中唐家山滑坡稳定性研究

根据唐家山边坡滑坡前的基本地形地貌,建立相关模型,采用Mohr-Coulomb准则,利用折减强度法计算其安全系数,并分析在地震波作用下唐家山滑坡的稳定性状况。安全系数计算结果显示,边坡模型在自然状态(即只有重力作用)下的安全系数为1.46,表明边坡在自然状态下是相对稳定的。选取汶川地震最初30秒幅值较大的地震波,对边坡采用自由场边界条件进行分析计算,结果表明边坡在地震作用下将在坡面产生贯通的塑性区,这一塑性区与真实的滑坡坡体一致,由于地震加速度的作用边坡将产生较大的位移和速度,这些大的位移和速度在边坡滑坡后将产生巨大的能量,造成灾难和损失。     

马氏珠母贝壳长生长模型研究

以Cp统计量作为确定马氏珠母贝壳长最优生长模型的准则,通过Levenberg-Marquardt迭代法求出模型中各生长参数,用Brody、von Bertalanffy、Gompertz、Logistic和Richards 5个生长模型对马氏珠母贝壳长的生长进行了拟合。结果表明,在马氏珠母贝生长的第一年中,壳长生长过程遵循Brody生长模型,其壳长生长极限值为56.572 mm(43.807～69.337,95%置信区间)。     

Numerical Study on Density Residual Currents of the Bohai Sea in Summer

M2 tide and density residual currents in the Bohai Sea were examined using the Blumberg and Mellor 3D nonlinear numerical coastal circulation model incorporating,Mellor and Yamada level 2.5 turbulent closure model.The tidal results showed good agreement with previous work.The model results indicated that the density residual currents are robust in summer;and that at the transition zone between well-mixed and stratified water,the horizontal velocity is high and the vertical velocity is positive.     

三维建构筑物地理信息模型制作方法研究

介绍了项目中建构筑物地理信息模型的等级与精度要求,以及三种不同的三维模型制作方法,分析方法的优点和缺点,在实际生产中根据模型等级和重要性分别选择不同方法进行了生产试验,取得了一定的成效.     

基于系统耦合的旅游业与新型城镇化协调发展分析——以云南省为例

以云南省为例,分析了新型城镇化系统与旅游业系统之间的耦合机理,采用熵值赋权法测度了其旅游业和新型城镇化的发展水平;继而在此基础上,利用系统耦合模型和协调发展度模型度量了两个子系统之间的耦合度和耦合协调度。结果表明:1明显地出现了以昆明为中心的新型城镇化水平的3级空间等级扩散,第2圈层呈现"V"字形空间分布;2滇西北、滇中、滇南的旅游业发展水平要高于其他地区;3从各市(州)的耦合协调发展度来看,昆明为优质协调,丽江为中级协调,迪庆、西双版纳为初级协调,昭通为轻度失调,其他市(州)为勉强协调和濒临失调。     

Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

A central composite experimental design and response surface method were used to investigate the combined effects of water temperature(18–34℃) and copper ion concentration(0.1–1.5 mg/L) on the catalase(CAT) activity in the digestive gland of C rassostrea ariakensis. The results showed that the linear effects of temperature were significant(P 0.01), the quadratic effects of temperature were significant( P 0.05), the linear effects of copper ion concentration were not significant(P 0.05), and the quadratic effects of copper ion concentration were significant(P 0.05). Additionally, the synergistic effects of temperature and copper ion concentration were not significant(P 0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.     

Effects of salinity and body mass on oxygen consumption and ammonia excretion of mudskipper Boleophthalmus pectinirostris

We evaluated the effects of salinity andbody mass on the oxygen consumption rate and ammonia excretion rate of mudskipper Boleophthalmus pectinirostris under laboratory conditions.Salinity and body mass had highly significant effects on the oxygen consumption rate(R_O) and ammonia excretion rate(R_N)(P0.01).The interactive effects between salinity and body mass onR_O and R_N were insignificant(P0.05)and highly significant(P0.01),respectively.R_O and R_N of B.pectinirostris decreased significantly as the individual body mass increased.The relationship between R_O and body mass was represented by R_O=aW~b(R~2=0.956,P0.01).The relationship between R_N and the body mass of B.pectinirostris was represented by R_N=cW~d(R~2=0.966,P0.01).The R_O/R_N(O:N) ratios increased significantly as the salinity increased from 12 to 27,but decreased as salinity increased from 27 to 32.The atomic O:N ratios were significantly higher at27 than at other salinity levels.The average O:N ratio was 25.25.Lipid and carbohydrate were the primary energy sources and protein was the secondary energy source within the salinity range 12-32.R_O and R_N were significantly higher at 27 than at other salinity levels.Our results suggest that the optimum salinity level for B.pectinirostris is 27.