济南张夏组灰岩岩溶地下水供水潜力探讨

济南南部广布巨厚张夏组灰岩,其中赋存优质丰富的岩溶地下水。出露众多泉水,其流量为800～8000m3/d。该文通过简述济南地区张夏组灰岩岩溶地下水的赋存条件与水文地质特征,概略计算与评价其资源量,论证开发利用这一新水源的可行性,以期为济南供水与保泉开辟新途径。     

文蛤抗癌多肽对N-乙酰-β-D氨基葡萄糖苷酶活力的影响

从文蛤体中分离纯化得到了抗癌多肽,研究该多肽对N-乙酰-β-D-氨基葡萄糖苷酶(NAGase)活力的影响,结果显示文蛤抗癌多肽对该酶有明显的抑制作用.在本文中,我们将深入地研究其抑制作用机理和抑制效应类型,结果表明:随着文蛤多肽加入量的增大,该酶活力呈指数下降,测得导致酶活力下降50%的抑制剂浓度(IC50)为112.9 μg/cm3,该多肽对酶的抑制作用是一种可逆过程,抑制机理表现为混合型抑制类型,对游离酶(E)的抑制常数(KI)和酶-底物络合物的抑制常数(KIS)分别为77.03和697.44μg/cm3,说明文蛤抗癌多肽与游离酶的结合导致酶活力的丧失,明显的强于对酶-底物络合物的抑制效应,底物的存在对该酶被文蛤抗癌多肽抑制作用起了保护作用.     

一种针对规则冲突的规则集语义比较算法

应用DFD(Diverse Firewall Design)方法进行防火墙规则集设计时,需使用规则集语义比较算法,判断多个规则集是否语义一致。规则冲突是导致规则集语义不一致的主要原因。因此,需要研究针对规则冲突的规则集语义比较算法。而现有算法时空复杂度较高,性能低下。文中提出了1种基于关键数据包选取映射的规则集语义比较算法(KPCM)。KPCM算法针对规则冲突选取关键数据包,并通过比较这些数据包在不同规则集中的处理动作,判断这些规则集是否语义一致。理论分析和测试表明,KPCM算法时空性能均优于现有算法。     

Sensitivity of penman-monteith reference crop evapotranspiration in Tao’er River Basin of northeastern China

A non-dimensional relative sensitivity coefficient was employed to predict the responses of reference crop evapotranspiration （ET0） to perturbation of four climate variables in Tao＇er River Basin of the northeastern China. Mean monthly ET0 and yearly ET0 from 1961 to 2005 were estimated with the FAO-56 Penman-Monteith Equation. A 45-year historical dataset of average monthly maximum/minimum air temperature, mean air temperature, wind speed, sunshine hours and relative humidity from 15 meteorological stations was used in the analysis. Results show that： 1） Sensitivity coefficients of wind speed, air temperature and sunshine hours were positive except for those of air temperature of Arxan Meteorological Station, while those of relative humidity were all negative. Relative humidity was the most sensitive variable in general for the Tao＇er River Basin, followed by sunshine hours, wind speed and air temperature. 2） Similar to climate variable, monthly sensitivity coefficients exhibit large annual fluctuations. 3） Sensitivity coefficients for four climate variables all showed significant trends in seasonal/yearly series. Also, sensitivity coefficients of air temperature, sunshine hours and wind speed all showed significant trends in spring. 4） Among all sensitivity coefficients, the average yearly sensitivity coefficient of relative humidity was highest throughout the basin and showed largest spatial variability. Longitudinal distribution of sensitivity coefficients for air temperature, relative humidity and sunshine hours was also found, which was similar to the distribution of the three climate variables.     

城镇地籍测量实施方案探讨

以地籍测量为研究对象,阐述了现代地籍调查的特征,结合湖北省安陆市城镇地籍调查项目的实际工作和成功经验,对地籍调查工作进行了各个方位的理性分析,提出了现代地籍测量完善可行的工作实施方案,较好地解决了地籍调查工作中的一些实际矛盾。并对实施方案中如何提高工作效率进行了有益的探讨。     

基于GIS技术的耕地坡度分级方法

分析传统耕地坡度分级方法的缺陷,提出利用GIS技术的耕地坡度分级新方法。以枝江市董市镇为例实证,研究制定定量融合指标和工作流程,不仅有效地控制了耕地图斑的数量,而且确保利用耕地坡度分级数据统计汇总的各耕地坡度级面积数据与真实值基本一致,提高了汇总面积数据的精度。     

Total lipid and fatty acid composition of eight strains of marine diatoms

Fatty acid composition and total lipid content of 8 strains of marine diatoms (Nitzschia frustrula, Nitzschia closterium, Nitzschia incerta, Navicula pelliculosa, Phaeodactylum tricornutum, Synedra fragilaroides) were examined. The microalgae were grown under defined conditions and harvested at the late exponential phase. The major fatty acids in most strains were 14∶0 (1.0%–6.3%), 16∶0 (13.5–26.4%), 16∶1n−7 (21.1%–46.3%) and 20∶5n−3 (6.5%–19.5%). The polyunsaturated fatty acids 16∶2n−4, 16∶3n−4, 16∶4n−1 and 20∶4n−6 also comprised a significant proportion of the total fatty acids in some strains. The characteristic fatty acid composition of diatoms is readily distinguishable from those of other microalgal groups. Significant concentration of the polyunsaturated fatty acid 20∶5n−3 (eicosapentaenoic acid) was present in each strain, with the highest proportion in B222 (19.5%). Project supported by the Hi-Tech “863” Programs of the China Ministry of Science and Technology (863-819-02-01).     

Time-Domain Full Waveform Inversion Using the Gradient Preconditioning Based on Transmitted Wave Energy

The gradient preconditioning approach based on seismic wave energy can effectively avoid the huge memory consumption of the gradient preconditioning algorithms based on the Hessian matrix. However, the accuracy of this approach is prone to be influenced by the energy of reflected waves. To tackle this problem, the paper proposes a new gradient preconditioning method based on the energy of transmitted waves. The approach scales the gradient through a precondition factor, which is calculated by the ‘approximate transmission wavefield' simulation based on the nonreflecting acoustic wave equation. The method requires no computing nor storing of the Hessian matrix and its inverse matrix. Furthermore, the proposed method can effectively eliminate the effects of geometric spreading and disproportionality in the gradient illumination. The results of model experiments show that the time-domain full waveform inversion(FWI) using the gradient preconditioning based on transmitted wave energy can achieve higher inversion accuracy for deep high-velocity bodies and their underlying strata in comparison with the one using the gradient preconditioning based on seismic wave energy. The field marine seismic data test shows that our proposed method is also highly applicable to the FWI of field marine seismic data.     

Simulation Study of Potential Impacts of Tidal Farm in the Eastern Waters of Chengshan Cape,China

The sea area east of Chenshan Cape has peak tidal current flows that exceed 2.3 m s-1, which make it a promising site for the development of tidal current energy. Before these resources can be exploited, a comprehensive assessment is needed of the potential environmental impacts of the extraction of this energy. In this paper, we describe our construction of a three-dimensional hydrodynamic model of the waters near Chengshan Cape, and verify the performance of the model using continuous data measured in situ. We modeled the potential impacts of the exploitation of these resources on the flow field by adding a momentum loss term in the governing equation of the model. Simulation results show that an assumed tidal farm with an estimated power output of 20.34 MW would have a significant impact on the surrounding water level, especially next to the farm, where fluctuation could reach 6 cm. The maximum drop in the flow velocity in the wake of the farm was predicted to be more than 0.8 m s-1, and this influence would extend 10 km downstream.     

Characteristics of Sulfide Removal by Hydrogenovibrio thermophilus Strain TT in Mariculture System

To biologically inhibit the production of highly toxic sulfide in the aquaculture area, one bacterium, designated as Hydrogenovibrio thermophilus strain TT, was isolated from sediment in Jiaozhou Bay, China. The strain was found to be microaerobic mixtrophic, employing both carbon dioxide and organic carbons, e.g. citrate, lactate, glucose, and peptone as carbon sources. When it oxidized the sulfide and thiosulfate, oxygen was the optimal electron acceptor, followed by nitrite and nitrate, which benefited to removal of sulfide under low-oxygen mariculture environment. In addition, the strain TT exhibited remarkable tolerance of sulfide and thiosulfate in seawater, and it was able to oxidize 18.52 mmol L~(-1) S~(2-) in 12 h or 45 mmol L~(-1) S_2O_3~(2-) in 24 h at initial pH 7.0-9.0, 30-40℃. Therefore, this strain showed a quite promising application for biological remediation of sulfide-contaminated mariculture system.