对虾养殖生态系中有机碳的初步研究本研究由

对于围隔养殖对虾生态系中有机碳的变动进行了研究 ,结果表明 :溶解有机碳 (DOC)含量波动在 5 .2 99～ 13.39mg/ L之间 ,平均为 8.5 3mg/ L± 2 .2 5 mg/ L;颗粒有机碳 (POC)含量波动在0 .6 5～ 6 .6 3mg/ L之间 ,平均为 3.2 5 mg/ L± 1.76 mg/ L;总有机碳 (TOC)含量波动在 6 .92～ 2 0 .0 2mg/ L之间 ,平均为 11.78mg/ L± 3.82 mg/ L ;其中 DOC∶ POC∶ TOC为 0 .72∶ 0 .2 8∶ 1。各种有机碳组分的含量明显高于自然海水中各种有机碳的含量 ;各种有机碳组分的含量在养殖期间总体上呈上升的趋势 ;其变化与 DCOD的变化呈显著线性正相关的关系。     

Seven-frequency VLBI Observations of the GHz-Peaked-Spectrum Source OQ 208

We present quasi-simultaneous VLBI images of the GHz-Peaked-Spectrum radio source OQ 208 obtained with the Very Long Baseline Array at 1.4,1.7,2.3,5.0,8.4,15.4GHz and the European VLBI Network at 6.7 GHz.The low frequency(1.4,1.7 and 2.3GHz)ob- servations reveal a weak and extended steep-spectrum component at about 30mas away at position angle-110°,which may be a remnant emission.The radio structure of OQ 208 con- sists of two mini-lobes at 5.0,6.7,8.4 and 15.4 GHz.Our spectral analysis further confirms that the southwest lobe undergoes free-free absorption and finds that the free-free absorption is stronger in the inner region.By fitting the 8.4 GHz images from 1994 to 2005,we obtain a separation speed of 0.031±0.006 mas yr~(-1)between the two mini-lobes.This indicates a jet proper motion of 0.105±0.020 c and a kinematic age of 219±42 yr for the radio source.     

Scattered emission from a relativistic outflow and its application to gamma-ray bursts

We investigate a scenario of photon scattering by electrons within a relativistic outflow. The outflow is composed of discrete shells with different speeds. One shell emits radiation for a short duration. Some of this radiation is scattered by the shell(s) behind. We calculate in a simple two-shell model the observed scattered flux density as a function of the observed primary flux density, the normalized arrival time delay between the two emission components, the Lorentz factor ratio of the two shells and the scattering shell's optical depth. Thomson scattering in a cold shell and inverse Compton scattering in a hot shell are both considered. The results of our calculations are applied to the gamma-ray bursts and the afterglows. We find that the scattered flux from a cold slower shell is small and likely to be detected only for those bursts with very weak afterglows. A hot scattering shell could give rise to a scattered emission as bright as the X-ray shallow decay component detected in many bursts, on a condition that the isotropically equivalent total energy carried by the hot electrons is large, ∼10⁵²–10⁵⁶ erg. The scattered emission from a faster shell could appear as a late short γ-ray/MeV flash or become part of the prompt emission depending on the delay of the ejection of the shell.     

Eruption of an Active-Region Filament Driven by an Emerging Bipole

1 INTRODUCTION Filaments are cool, dense material suspended in the hot, tenuous corona. It is widely accepted that the global magnetic field surrounding the filaments plays a key role in their formation, structure and stability (Tandberg-Hanssen1995). Fil…     

在舆情热点中开展防震减灾科普的思考

防震减灾科普工作应与时俱进,在舆论引导中体现更大作用,在舆情治理中承担更多责任。本文认为防震减灾科普具有重要的舆论引导作用。一是舆情热点为防震减灾科普提供了契机。二是舆情热点为防震减灾科普提供了内容。本文从3个方面提出了防震减灾科普的舆论引导策略。一是合理设置科普议程,掌握舆论引导主动权 ;二是借力新媒体传播技术,有意识地引导舆论;三是打好 “组合拳” ,形成舆论引导最大合力。本文认为应在舆情热点中积极主动做好防震减灾科普宣传,创新传播形式、方法,巧妙设置议程,全时空覆盖,全社会参与,构建政府、媒体和公众信息互通的良性舆论场,增强社会公众的风险意识和防灾减灾能力,真正筑牢风险防控的人民防线。     

鄂尔多斯盆地正宁地区三叠系延长组长9油层组成岩作用*

综合利用岩心、铸体薄片、扫描电镜等多种资料,对鄂尔多斯盆地正宁地区三叠系延长组长9油层组储集层的岩石类型、成岩作用类型、成岩相分布特征及主控因素进行了系统研究。延长组长9油层组储集层的岩石类型为细—中粒岩屑质长石砂岩和长石质岩屑砂岩,成岩作用类型主要为压实作用,同时还有绿泥石、方解石、铁方解石及硅质胶结作用,方解石交代作用和少量的溶蚀作用,储集层目前处于中成岩A期。根据层理频率和塑性颗粒含量将岩石划分为高频层理富片状塑性颗粒粉—细砂岩岩石相和低频层理富刚性矿物细—中砂岩岩石相,前者分布于水下分流河道边部,发育压实致密成岩相;后者形成于水下分流河道主河道和河口坝。根据砂体结构可划分为厚层单砂体和厚层多砂体。厚层单砂体为单期形成的河道或河口坝砂体,上部以方解石充填胶结成岩相为特征,下部以绿泥石衬边胶结成岩相为特征;厚层多砂体为多期砂体冲刷叠置形成,发育方解石绿泥石充填胶结成岩相。塑性颗粒含量对压实作用强度影响最大,叠加碳酸盐胶结致使储集层质量变差,而早期绿泥石环边胶结抑制压实作用,是有利储集层发育的重要条件。综合评价表明,延长组长9油层组有利储集层发育于绿泥石衬边胶结相,其次为绿泥石和方解石充填胶结相,最差储集层为方解石充填胶结相和压实致密相。     

塔里木盆地哈拉哈塘地区走滑断裂带油气分布与油藏模式

塔里木盆地哈拉哈塘地区石油勘探开发进入深度高达8 000 m的坳陷区,油气主要沿走滑断裂带分布,研究超深层断控油气藏分布规律对油气勘探开发具有重要意义。通过大量勘探开发资料分析与油藏解剖表明,哈拉哈塘地区奥陶系碳酸盐岩油气沿主断裂带1.8 km范围内条带状分布,高效井主要分布在距主断裂带600 m范围内。油气沿断裂带分布具有分段性,断裂的类型、规模与性质影响油气运聚成藏,油气富集主要受控于主断裂带的规模。高效井一般距主断裂近、储层规模大、侧向封闭好,为断控缝洞型碳酸盐岩油藏。走滑断裂断控油气藏不同于礁滩体与风化壳“相控”油气藏,对复杂碳酸盐岩油气藏评价开发具有重要意义。     

Caledonian Low-Temperature Granulite-Facies Metamorphism in the West Kunlun Orogenic Belt—SHRIMP Chronological Evidence from Zircon

The West Kunlun orogenic belt is located at the conjunction of the paleo-Asian tectonic system and the Tethys tectonic system. Petrological and mineralogical studies of the Early Cambrian metamorphic surface crust in this region have shown that in case the metamorphism reached low-temperature granulate facies, the typical mineral assemblage is biotite-garnet-silimanite-K feldspar-plagioclase-quartz. The peak metamorphic temperatures are within the range of 720–740°C and the pressure is 0.6 GPa ±. Three types of metamorphic zircon have been detected in the metamorphic rocks: the complex inclusion-bearing type ; the early relic zircon inclusion-bearing type; and the inclusion-free type. SHRIMP age determination of these three types of metamorphic zircon have revealed that these zircons were formed principally during 400–460 Ma, indicating that pre-Cambrian metamorphic surface crust rocks underwent low-temperature granulite facies metamorphism during the Caledonian. In combination with the geological characteristics of this region, it is considered that when the oceanic basin was closed, there occurred intense intracontinental subduction (type A), bringing part of the Early Cambrian metamorphic basement in this region downwards to the lower crust. Meanwhile, there were accompanied with tectonic deformation at deep levels and medium- to high-grade metamorphism. This study provided important chronological and mineralogical evidence for the exploration of the evolutionary mechanism and process of the West Kunlun Early Paleozoic. Part of the results from the research project “ Research on the West Kunlun pre-Cambrian tectonic events” under the program “ Research on the important geological problems of China’ s pre-Cambrian” (No. 200113900070) sponsored by the China National Geological Surveying Bureau.     

Improving performances of ITO/GaP contact on AlGaInP light-emitting diodes

In this paper AlGaInP light emitting diodes with different types of electrodes: Au/Zn/Au-ITO Au/Ti-ITO Au/Ge/Ni-ITO and Au-ITO are fabricated. The photoelectricity properties of those LEDs are studied. The results show that the Au/Zn/Au electrode greatly improves the performance of LEDs compared with the other electrodes. Because the Au/Zn/Au electrode not only forms a good Ohmic contact with indium tin oxide (ITO), but also reduces the specific contact resistances between ITO and GaP, which are 1.273×10^-6 Ω · cm² and 1.743×10^-3 Ω ·cm² between Au/Zn/Au-ITO and ITO-GaP respectively. Furthermore, the textured Zn/Au-ITO/Zn electrode is designed to improve the performances of LEDs, reduce the forward-voltage of the LED from 1.93 to 1.88 V, and increase the luminous intensity of the LEDs from 126 to 134 mcd when driven at 20 mA.     

Analysis of Transient Flow to an Extended Fully Penetrating Well at Constant-Head Pumping

Vertical wells with radial extension at the well bottom can improve the rate of water production. No study has yet investigated the effects of the transient state and anisotropy in directional hydraulic conductivities on the wellbore flux rate for this type of well. This study derives a semianalytical transient drawdown solution for constant-head pumping at a fully penetrating well radially extended at the bottom of a confined, anisotropic aquifer by applying Laplace transform and separation of variables as well as conducting a Fourier analysis. The results of this new solution indicate that transient and steady-state wellbore flux rates can be increased by a factor of two for greater radial extension of the well. Compared with an isotropic aquifer (a ratio of vertical and horizontal hydraulic conductivities equal to one), an anisotropic aquifer with the ratio less than one may produce a higher transient wellbore flux rate and lower steady-state wellbore flux rate. Moreover, the time required to achieve the steady-state wellbore flux rate can be substantially affected by anisotropy of the aquifer.