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11.
分析了目前泥石流临界雨量确定常用方法存在的问题 ,以及泥石流临界雨量实验研究中实验降雨量确定的随意性和盲目性 ,提出以兰利 ( Langlie)法为指导进行实验 ,使实验降雨量的确定有了理论依据 ,减少了取得可靠实验结果所需实验次数 ,从而使泥石流临界雨量实验研究更趋完善和可行 相似文献
12.
Expression of the Phycoerythrin Gene of Gracilaria lemaneiformis (Rhodophyta) in E. coli and Evaluation of the Bioactivity of Recombinant PE 总被引:1,自引:0,他引:1
WEN Ruobing) SUI Zhenghong) * ZHANG Xuecheng) ZHANG Shuang) and QIN Song) ) Laboratory of Marine Genetics Breeding College of Marine Life Sciences Ocean University of China Qingdao P. R. China ) Institute of Oceanology Chinese Academy of Sciences Qingdao P.R. China 《中国海洋大学学报(英文版)》2007,6(4):373-377
Phycoerythrin (PE) is one of the most important proteins involved in light capturing during photosynthesis in red algae. Its potential biological activities had gained wide concerns. In the present study, tumor cytotoxic and hydroxyl radical assay were preformed to detect the bioactivity of recombinant PE. Recombinant plasmids pGEX-PE and pBGL were transformed into E.coli BL21 to make two recombinant strains BEX (pGEX-PE) and BGL (pBGL). PE expressing in BEX (pGEX-PE) was validated by SDS-PAGE and Western blotting analysis. SDS-PAGE analysis indicated that the PE-GST fusion protein was mostly inclusion bod- ies. Specific expression of PE was confirmed by Western blotting analysis. The recombinant E. coli BEX (pGEX-PE) cells were col- lected and sonicated. The supernatants were reserved for the tumor cytotoxic experiments. The result of tumor cytotoxic assay indi- cated that the supernatants containing PE had the activity of inhibiting the growth of Hela cells and with the increase of protein con- centration, the inhibiting rate increased from 37.31% to 63.26%, which showed significant difference from the control. Hydroxyl radical scavenging effect was tested with supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates treated with sonication and heating. For the sonication samples, the scavenging rates of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were significantly higher than the negative control BL21(pGEX-4T) (P<0.02), and the scavenging rates increased slowly following the increase of the protein content. For the heating samples, except for the 0.2 mg mL-1 BGL (pBGL) products, the scavenging effects of the supernatants of BEX (pGEX-PE) and BGL (pBGL) cell lysates were stronger than that of negative control BL21(pGEX-4T). However, the effect intensity was not positively correlated with the increase of the protein concentration. Though a partially de- creased hydroxyl radical scavenging activity was led by heating, the biological activity was still retained and conspicuous. This re- search showed that phycoerythrin protein expressing in E. coli has the potential medical and sanitarian value. 相似文献
13.
无实测资料河流逐月水量估算是最严格水资源管理制度考核的重要支撑。基于流域水文相似性原理和水量平衡原理,选用径流模数法、径流系数法、区域水量平衡法,研究提出其逐月水量估算适用范围和估算成果合理性分析标准。以现有水文站为假设断面,采用参证水文站资料进行假设断面水量估算,对三种方法的适用范围和估算成果合理性分析标准进行验证。结果表明,径流模数法适用于集水面积相差不超过20%情形和考虑区间蓄泄水变量情况的集水面积相差在20%至1倍之间情形;径流系数法适用于集水面积相差在20%至1.5倍之间且估算时段有洪水过程情形;区间水量平衡法适用于上下游参证水文站面积比在3倍以内情形;“两种方法相对偏差小于18%”的估算成果合理性分析标准可行。 相似文献
15.
黔西南水银洞金矿床流体包裹体研究 总被引:5,自引:0,他引:5
水银洞金矿床是黔西南典型的特大型卡林型金矿床之一。但其成矿流体来源尚有争议。通过对水银洞金矿床脉石英和方解石中流体包裹体的温度与压力、盐度与密度、包裹体成分和包裹体H和O同位素等方面的研究,指出水银洞卡林型金矿床成矿流体属中低温(96.7~220℃)、低盐度(NaCl)0.635%~9.861%,平均值为4.282%±2.260%、中等密度(0.725~0.977 g/cm3,平均值为0.910±0.061 g/cm3);脉石英阶段流体水化学类型属Cl--Na+型或SO42--Cl-Na+型,方解石阶段属SO42--Cl--Ca2+型。成矿流体压力可能为高-超高压(160±40 MPa);成矿流体主要是大气降水形成的地下热水,可能有部分岩浆热液的掺入。 相似文献
16.
The Constitute of Thick Tight Sandstone Belt and the Main Controlling Factors of Effective Reservoir
FAN Guangjuan WANG Yongchao Ma Shizhong YAN Baiquan WEN Huijian and ZHAO Yuejun 《《地质学报》英文版》2015,89(Z1):184-187
<正>1 Introduction The western 3D region of the Sulige gas field is located in the Yi-shan slope north of northern Su47 and south of Su48 medium sand belt of the Ordos Basin,the area of it is about 431 km2.The average thickness of He8 is 69.1m,the thickness of it is 83.9m;The effective sand thickness is14.4 m,the thickness of it is 21.5m. 相似文献
17.
以添加不同掺量填料的氯氧镁水泥(MOC)试件为基体,在空气和碳化箱中分别养护至规定龄期,研究碳化对掺加填料MOC力学性能的影响,并与空气环境进行对比,运用XRD和SEM分析碳化后水化产物和微观结构的变化规律。结果表明,28 d龄期内,随着填料掺量的增加MOC试件碳化后的抗折强度均有所增加,碳化后的抗压强度均有提升,碳化过程反应生成了MgCO_3,不同碳化龄期的主要物相均为5Mg(OH)_2·MgCl_2·8H_2O(5相),而掺加填料不影响MOC的水化产物的组成。 相似文献
18.
19.
150kaBP以来巴丹吉林沙漠东南区域地层序列的新研究 总被引:1,自引:7,他引:1
巴丹吉林沙漠东南部边缘查格勒布鲁剖面中更新统/上更新统下部、上更新统下部/上更新统上部和上更新统上部/全新统的地质界线依次发生在59AGS/60L、39FD/40G和9L/10FD之沉积界面上。其时限依次大致为150kaBP、75kaBP和10kaBP,该剖面记录了150kaBP以来25个旋回的沙漠与湖相等沉积交替变更的历史过程。通过该剖面粒度和SiO2、Al2O3、Fe2O3、FeO在地层中的分布特征、软体动物化石指示的古生态等综合研究表明,所述这些沉积旋回是自那时以来,在北半球冰期间冰期气候波动影响下,冬夏古季风往复更迭所导致的非季风沙区沙漠期与间沙漠期多次正逆交替演变的结果。 相似文献
20.
A Closure Study of Aerosol Hygroscopic Growth Factor during the 2006 Pearl River Delta Campaign 总被引:3,自引:0,他引:3
LIU Xingang ZHANG Yuanhang WEN Mengting WANG Jingli Jinsang JUNG CHANG Shih-yu HU Min ZENG Limin Young Joon KIM 《大气科学进展》2010,27(4):947-956
Measurements of aerosol physical, chemical and optical parameters
were carried out in Guangzhou, China from 1 July to 31 July 2006 during the
Pearl River Delta Campaign. The dry aerosol scattering coefficient was measured
using an integrating nephelometer and the aerosol scattering coefficient for
wet conditions was determined by subtracting the sum of the aerosol absorption
coefficient, gas scattering coefficient and gas absorption coefficient from the
atmospheric extinction coefficient. Following this, the aerosol hygroscopic
growth factor, f(RH), was calculated as the ratio of wet and dry aerosol
scattering coefficients. Measurements of size-resolved chemical composition,
relative humidity (RH), and published functional relationships between particle
chemical composition and water uptake were likewise used to find the aerosol
scattering coefficients in wet and dry conditions using Mie theory for
internally- or externally-mixed particle species [(NH4)2SO4, NH4NO3, NaCl, POM, EC and residue]. Closure was obtained by comparing
the measured f(RH) values from the nephelometer and other in situ optical
instruments with those computed from chemical composition and thermodynamics.
Results show that the model can represent the observed f(RH) and is
appropriate for use as a component in other higher-order models. 相似文献