青城子小佟家堡子、林家金矿成矿流体特征及成矿机制

小佟家堡子、林家金矿是青城子铅锌、金、银矿集区的中-大型金矿床,金矿床与沉积-变质期硅化岩关系密切。通过与矿区尖山岩体、新岭岩体中流体包裹体对比研究表明,金矿床与尖山岩体中主要发育水溶液包裹体,极少量的CO2包裹体、含CO2三相包裹体,而新岭岩体除发育以上包裹体外,还发育含子矿物多相包裹体。测温结果显示金矿床成矿流体温度为110～335℃,盐度3．9％～16．2％NaClrq拉曼光谱分析表明金矿床流体成分以H2O为主,少量的CO2、CH4等气体,表明成矿流体属NaCl-H2O体系。金矿床与尖山岩体中流体包裹体温度、盐度及成分相近,推断成矿流体主要来自沉积-变质期。     

Mesozoic Bimodal Volcanic Suite in Zhalantun of the Da Hinggan Range and Its Geological Significance： Zircon U-Pb Age and Hf Isotopic Constraints

1 Introduction Mesozoic volcano-intrusive rocks are widely distributed in the Da Hinggan Range of northeastern China, and are considered as one of the most spectacular geological sights in eastern Asia. Recently, studies on granites with high εNd(t) values and Phanerozoic crustal growth in the Centra Asian Orogenic Belt have greatly promoted fundamental research into the geology of this area (Jahn et al., 2000, 2001, 2004; Wu et al., 2000, 2002, 2003). However, work on the eruption time,…     

A Modified Form of Mild-Slope Equation with Weakly Nonlinear Effect

Nonlinear effect is of importance to waves propagating from deep water to shallow water.Thenon-linearity of waves is widely discussed due to its high precision in application.But there are still someproblems in dealing with the nonlinear waves in practice.In this paper,a modified form of mild-slope equa-tion with weakly nonlinear effect is derived by use of the nonlinear dispersion relation and the steady mild-slope equation containing energy dissipation.The modified form of mild-slope equation is convenient to solvenonlinear effect of waves.The model is tested against the laboratory measurement for the case of a submergedelliptical shoal on a slope beach given by Berkhoff et al,The present numerical results are also comparedwith those obtained through linear wave theory.Better agreement is obtained as the modified mild-slope e-quation is employed.And the modified mild-slope equation can reasonably simulate the weakly nonlinear ef-fect of wave propagation from deep water to coast.     

Application of Line Boundary Technique to 2D Tidal Current Simulation

To deal with the problems concerning the shore boundary,moving boundary and engineeringboundary which are encountered frequently in 2D tidal current simulation by the finite difference method,theconcept of line boundary is introduced and studied here,and then the line boundary technique in common useis proposed in this paper.Analysis of some calculation cases shows that this technique is practical,effective,and simple in 2D tidal current simulation involving different boundaries.     

湛江流沙湾马氏珠母贝的养殖容量

2008年3月—2009年1月调查分析流沙湾浮游动植物的生物量、叶绿素a含量、初级生产力、马氏珠母贝Pinctada martensii含壳重与鲜组织重的比值、养殖贝类和野生滤食性动物的滤水率、潮间带和潮下带底栖贝类及吊养区附着滤食性动物现存量等,应用营养动态模型和贝类养殖容量估算模型估算滤食性动物的总容量,扣除野生滤食性动物现存量,最终确定马氏珠母贝的养殖容量。结果显示,2种模型估算马氏珠母贝的养殖容量分别为19637.5t和20126.4t,平均养殖容量19881.95t。依据流沙湾马氏珠母贝的通常养殖密度(1.05×105个.hm-2)和平均商品规格(41g.个-1)计算,流沙湾马氏珠母贝的适养面积为461.83hm2。     

Inheritance Pattern of Microsatellite Loci and Their Use for Kinship Analysis in the Japanese Scallop Patinopecten yessoensis

The inheritance mode of seven microsatellite markers was investigated in Patinopecten yessoensis larvae from four con-trolled crosses,and the feasibility of using these markers for kinship estimation was also examined. All the seven microsatellite loci were compatible with Mendelian inheritance. Neither sex-linked barriers to transmission nor major barriers to fertilization between gametes from the parents were evident. Two of the seven loci showed the presence of null alleles in two families,suggesting the...     

Isolation and Characterization of Collagen from Squid(Ommastrephes bartrami) Skin

Collagen of squid(Ommastrephes bartrami) skin was examined in the present study. Histology showed that collagen fiber in the skin was partially cross-linked with muscle fiber. Acid-solubilized collagen(ASC) and pepsin-solubilized collagen(PSC) were extracted from the skin and characterized. The results of amino acid composition and electrophoretic patterns revealed that ASC and PSC were both type Ⅰ collagen,containing α1 and α2 chains. FTIR(fourier transform infrared spectroscopy) investigations confirmed t...     

Distribution and characteristics of volcanic reservoirs in China

About forty productive oil/gas fields hosted in volcanic reservoirs have been found since 1957 in fourteen basins of China. They can be simply subdivided into two groups, the east and the west. Reservoir volcanic rocks of the east group are predominantly composed of Late Jurassic to Early Cretaceous rhyolite and Tertiary basalt, preferred being considered as rift type volcanics developed in the circum-Pacific tectonic regime. Those of the west are Permo-Carboniferous intermediate/basic volcanic rocks, being island-arc type ones developed in paleo-Asian Ocean tectonic regime.     

Study on drilling mechanism and optimization of percussion-extruding DTH hammer bit

The authors tested the percussion-extruding Down-the-hole （DTH）hammer bit with five different structures and mainly analyzed the drilling mechanism between conical bit and stepped bit. In addition, aiming at ＂the pile effect＂ in combination with the advantage＇ of stepped bit, we design a new cam spinning bit and test it outdoors. The result shows that using cam spinning bit can solve the problem of ＂the pile effect＂, which can also obtain higher drilling efficiency than using conical bit in high confining pressure strata. It is characterized by novel structure and high drilling speed as well as good guiding, and it is significant for improving efficiency in percussion-extruding drilling technique.     

Causes of rockfalls in Al-Huwayshah area,Yemen

According to topography of Yemen,most areas and villages are located at obligated crest,toe of mountain and under cliffs.Therefore Al-Huwayshah consisting of Tawilah sandstone group is characterized by steep slope reach to 90° in some areas.This area is affected by strong tectonic movements and faults that occurred during the geological epochs.This effect enhances to find out fractures and joints as well as the rocks become brittle and ready to slide depending on the position of area.And there are some frac...