对虾白斑杆状病毒基因中的小顺反子及其表达

通过对虾白斑杆状病毒DNA文库和cDNA文库的碱基序列测定和分析,发现对虾白斑杆状病毒的一个开放阅读框的前导序列中含有一个小顺反子,这个小顺反子较多使用对虾基因和白斑杆状病毒基因的稀有密码子.试验表明在该基因的前导序列中存在或不存在小顺反子时,该基因都可在大肠杆菌中诱导表达,但两者的表达量不同.小顺反子可能对基因的表达具有调控作用.     

An Improved Formulation for the Ultimate Static Strength of Tubular Joints subjected to Combined Loads

"The effect of interaction of loads on the ultimate static strength of tubular joints of offshore fixed platforms, is a practical problem. But there is still absence of rigorous theory to explain available experimental data and empirical criteria for the static strength of tubular joints. The idea of yield at hot spot of tubular joints is introduced in this paper. The interaction equations of plastic capacity for the tubular joints under combined loads (two and three different kinds) are derived. Thereafter the Yura's test data and empirical criteria of ultimate static strength for the tubular joints can be explained. The idea of classification of category of loads in accordance with experimental data and the present theory is suggested. Finally, the improved ultimate capacity equations for tubular joints are recommended. The physical significance of the coefficient of plastic reservation Qp is discussed.     

Source rock characteristics and biostratigraphy of the Lower Silurian (Telychian) organic-rich shales at Akyaka, central Taurus region, Turkey

The Akyaka section in the central Taurus region in the southern part of Turkey includes the organic matter and graptolite-rich black shales which were deposited under dysoxic to anoxic marine conditions in the Early Silurian. A biostratigraphical analysis, based on graptolite assemblages, indicates that the sediments studied may well be referable to the querichi Biozone and early Telychian, Llandovery. A total of 15 samples have been subjected to Leco and Rock-Eval pyrolysis and graptolite reflectance measurements for determination of their source rock characteristics and thermal maturity. The total organic carbon content of the graptolite-bearing shales varies from 1.75 to 3.52 wt% with an average value of 2.86 wt%. The present Rock-Eval pyrolytic yields and calculated values of hydrogen and oxygen indexes imply that the recent organic matter type is inert kerogen. The measured maximum graptolite reflectance (G_Rmax %) values are between 5.04% and 6.75% corresponding to thermally over maturity. This high maturity suggests a deep burial of the Lower Silurian sediments resulting from overburden rocks of Upper Paleozoic to Mesozoic Upper Cretaceous and Middle-Upper Eocene thrusts occurred in the region.     

营养盐和微量元素与黄骅赤潮的相关性

本文主要通过１９８９～１９９２年河北省黄骅市沿海一带赤潮水质监测的结果，探讨赤潮发生期间营养盐及微量元素的含量变化与赤潮的关系。结果表明，营养盐的富集导致赤潮藻类的快速增殖，微量元素Ｆｅ和Ｍｎ的过量又是赤潮形成的诱发因子。     

建立白斑综合症病毒在日本对虾体内潜伏性感染的方法研究

在27℃，pH8．0，盐度33条件下，用套式PCR方法和王证点杂交方法对日本对虾(Penaeus japonicus)体内潜伏性感染WSSV的方法进行了研究。对健康日本对虾注射不同稀释倍数的白斑综合症病毒粗提液，死亡率统计显示注射10^4，10^6倍稀释液组的日本对虾死亡率明显低于10，10^2，10^3倍组，结合套式PCR方法和斑点杂交方法进行病毒检测结果发现，仅10，10^2倍稀释液组斑点杂交和一步PCR结果呈阳性；10^3，10^4，10^6倍稀释液组经二步PCR检测为阳性、斑点杂交呈阴性，该结果为建立或界定WSSV在日本对虾体内的潜伏性感染提供了方法学上的依据。     

Parametric Equation of Stress Concentration Factor for Circular X-Joints Under Axial Loads

In engineering practice,tubular X-joints have been widely used in offshore structures.The fatigue failure of tubular X-joints in offshore engineering is mainly caused by axial tensile stress.In this study,the stress concentration factor distribution along the weld toe in the hot spot stress region for tubular X-joints subject to axial loads have been analyzed by use of finite element method.Through numerical analysis,it has been found that the peak stress concentration factor is located at the saddle position.Thereafter,80 models have been analyzed,and the effect of the geometric parameters of a tubular X-joint on the stress concentration factor has been investigated.Based on the experimental values of the numerical stress concentration factor,a parametric equation to calculate the stress concentration factor of tubular X-joints has been proposed.The accuracy of this equation has been verified against the requirement of the Fatigue Guidance Review Panel,and the proposed equation is found capable of producing reasonably accurate stress concentration factor values for tubular X-joints subject to axial loads.     

Dynamic Ice-Induced Responses of Offshore Fixed Platforms

The dynamic responses of offshore fixed platforms under ice loads are analysed in this paper. The responses calculated include the displacement and the hot spot stresses on the basis of a dynamic equation of ice-induced forced vibration for offshore structures. The results obtained can be cited and used for the design and operation of offshore fixed platforms against ice loading.     

东秦岭泥盆纪成矿海盆中一种（准）同生热水蚀变岩研究

赋存层控铅锌矿床的东秦岭泥盆系内发育一类特殊岩石——方柱黑云岩。野外和室内的研究表明,它是与火山及热泉活动有关的异常地热海盆中的一种特殊沉积相。矿物学、岩石学及地球化学特征也为其原凝灰质沉积岩经过热卤水“浸泡效应”(soaking effect)形成方柱黑云岩类的成因提供了可靠信息。据此推测秦岭泥盆纪层控矿床成矿海盆的异常地热背景和热水沉积环境。     

Earthquake-related Changes in Groundwater Levels at the Dogo Hot Spring,Japan

The Dogo hot spring, situated in Matsuyama City, Ehime Prefecture, Japan, is one of the oldest and most famous hot springs in Japan. The groundwater level or discharge at the spring decreased four times during the past eight or nine Nankai earthquakes. These are large interplate earthquakes that have occurred repeatedly in the western part of the Nankai Trough at intervals of 100–200 years since A.D. 684. To clarify the mechanism of these earthquake-related changes in the water level at the spring, we analyzed groundwater-level data recorded at the spring immediately after the 1946 Nankai earthquake and over the period from 1985 to 2006. We detected the other nine postseismic increases in groundwater level and no decreases, except for a large decrease of 11.4 m related to the 1946 Nankai earthquake. The increases were probably caused by ground-shaking, while the decrease was caused by a change in coseismic volumetric strain. These results lead to the following explanation of the recorded earthquake-related changes in the groundwater level at the Dogo hot spring. Both coseismic changes in volumetric strain and ground-shaking can lead to postseismic changes in groundwater pressure. The increase in groundwater pressure arising from ground-shaking is generally greater than the change in pressure associated with changes in coseismic volumetric strain; however, at the time of the Nankai earthquakes, the spring experiences a large increase in coseismic volumetric strain, leading to a considerably larger decrease in the groundwater level than the increase associated with ground-shaking. Therefore, the groundwater level at the Dogo hot spring usually increases at times of relatively large earthquakes, although the groundwater level or discharge decreases in the case of the Nankai earthquakes.     

两种气象绘图软件的对比及应用

介绍了Surfer 8.0和G rads(v1.8L11版本)两个等值线绘制软件的功能,根据不同的业务需要,可采用不同的绘图软件,以提高工作效率。