北海盆地形成演化对大油气田的控制作用

分析了北海盆地的形成演化对大油气田形成的控制作用。研究认为,北海盆地经历了8个构造演化期,加里东运动期形成了主要变质岩基底;海西运动导致古特提斯洋关闭,形成联合古陆,同时沉积了盆地南部重要的煤系烃源岩;陆内克拉通期盆地南、北部持续沉降,前期干旱,后期大范围海侵,形成了盆地南部有利的储、盖配置;裂谷期区域拉张环境,产生了以维京、中央和默里湾为典型的地堑系与海槽;热隆起期中部区域隆起,伴随大量火山活动,为盆地北部储集层的发育提供大量物源;主要裂谷期中部穹窿沉降并被海水淹没,盆地北部发育优质烃源岩;晚裂谷期沉积环境相对稳定,盆地中部发育大量白垩,北部沉积泥灰岩,形成了盆地北部区域性的盖层;后裂谷期挪威—格林兰海陆壳分离,在之前的构造格架下持续稳定地接受沉积,为油气保存提供有利环境。最终形成南部为大气田、北部以大油田为主的分布格局,同时在维京和中央地堑内分别形成了"上生下储"与"下生上储"2种不同的成藏特征。     

Some Remarks on the Endogeneous Pulsed Source Technique in Reactor Noise Analysis

It was established that the dynamics of an evaporator show markedly asymmetric responses. These phenomena are closely related to the response of the liquid level which directly affects the heat capacity.

What is more, the time constants of an evaporator are so large that the transfer functions expressing uranium product evaporator are better approximated by a form representing no self-regulation. Examination of the controllability aspects of three different control algorithms, i.e. control by boiling point raising, cascade control and multivariable control, resulted in the conclusion that the last-mentioned algorithm is superior to the two others for controlling the uranium concentration which is the most important element in uranium product evaporation.     

Preparation and functional characterisation of fish skin gelatin and comparison with commercial gelatin

Gelatin was extracted from the skin of farmed giant catfish (GC) and tilapia (TP) at a yield of 19.50% and 23.34% (wet wt). It was high in protein (84–88%) but low in fat (0.09–1.24%) and ash content (0.15–0.17%). The GC exhibited lower emulsifying activity (24–35%), but greater foam ability (98–110%), water holding capacity (477–844%) and fat binding capacity (2541–3314%) than commercial beef skin gelatin (BF) (P < 0.05). GC and TP showed comparable functional properties to BF. SDS‐PAGE patterns of TP gelatin showed high band intensity for the α‐ and β‐components, while the lowest band intensity of the major component was found in the BF. From the study, it can be concluded that the farmed freshwater fish skin GC and TP is a prospective source for producing a significant gelatin yield with desirable functionalities. Because of these, fish skin gelatin could be more effectively and widely used in food industries as a good food ingredient.     

Deformation micromechanisms of collagen fibrils under uniaxial tension

Collagen, an essential building block of connective tissues, possesses useful mechanical properties due to its hierarchical structure. However, little is known about the mechanical properties of collagen fibril, an intermediate structure between the collagen molecule and connective tissue. Here, we report the results of systematic molecular dynamics simulations to probe the mechanical response of initially unflawed finite size collagen fibrils subjected to uniaxial tension. The observed deformation mechanisms, associated with rupture and sliding of tropocollagen molecules, are strongly influenced by fibril length, width and cross-linking density. Fibrils containing more than approximately 10 molecules along their length and across their width behave as representative volume elements and exhibit brittle fracture. Shorter fibrils experience a more graceful ductile-like failure. An analytical model is constructed and the results of the molecular modelling are used to find curve-fitted expressions for yield stress, yield strain and fracture strain as functions of fibril structural parameters. Our results for the first time elucidate the size dependence of mechanical failure properties of collagen fibrils. The associated molecular deformation mechanisms allow the full power of traditional material and structural engineering theory to be applied to our understanding of the normal and pathological mechanical behaviours of collagenous tissues under load.     

大悬挑钢屋面的结构设计

通过对某大楼大悬挑钢屋面结构设计的介绍,结合工程实践提出了设计中值得注意的关键问题及技术措施     

Nanostructured giant magneto-impedance multilayers deposited onto flexible substrates for low pressure sensing

Nanostructured FeNi-based multilayers are very suitable for use as magnetic sensors using the giant magneto-impedance effect. New fields of application can be opened with these materials deposited onto flexible substrates. In this work, we compare the performance of samples prepared onto a rigid glass substrate and onto a cyclo olefin copolymer flexible one. Although a significant reduction of the field sensitivity is found due to the increased effect of the stresses generated during preparation, the results are still satisfactory for use as magnetic field sensors in special applications. Moreover, we take advantage of the flexible nature of the substrate to evaluate the pressure dependence of the giant magneto-impedance effect. Sensitivities up to 1 Ω/Pa are found for pressures in the range of 0 to 1 Pa, demostrating the suitability of these nanostructured materials deposited onto flexible substrates to build sensitive pressure sensors.     

Lightweight Design and Verification of Gantry Machining Center Crossbeam Based on Structural Bionics

The lightweight and high efficiency of natural structures are the inexhaustible sources for engineering improvements. The goal of the study is to find innovative solutions for mechanical lightweight design through the application of structural bionic approaches. Giant waterlily leaf ribs and cactus stem are investigated for their optimal framework and superior performance.Their structural characteristics are extracted and used in the bio-inspired design of Lin MC6000 gantry machining center crossbeam. By mimicking analogous network structure, the bionic model is established, which has better load-carrying capacity than conventional distribution. Finite Element Method (FEM) is used for numerical simulation. Results show better specific stiffness of the bionic model, which is increased by 17.36%. Finally the scaled models are fabricated by precision casting for static and dynamic tests. The physical experiments are compared to numerical simulation. The results show that the maximum static deformation of the bionic model is reduced by about 16.22%, with 3.31% weight reduction. In addition, the first four natural frequencies are improved obviously. The structural bionic design is a valuable reference for updating conventional mechanical structures with better performance and less material consumption.     

弹性金属塑料推力轴瓦在巨型水电机组应用的可靠性

分析弹性金属塑料推力瓦的特性和在大型水电机组上安全运行实践,提出弹性金属塑料推力轴瓦在巨型水电机组上应用的可行性。     

A New Technique: Fishbone Well Injection

Abstract

As a new developing method, fishbone well injection has been used in buried hill reservoirs. Based on numerical simulation, optimization research on the new reservoir developing method, which means fishbone wells injecting water at the bottom and horizontal wells producing oil at the top, is present. Compared with horizontal well injection, the results show that the fishbone well can increase the control area, form planar flooding, and hold the injection water upward slowly and evenly. The reasonable fishbone well parameters, such as branching angle, branch number, and branch length, are obtained. The fishbone well injection provides a new technical method for developing buried hill reservoirs efficiently.     

玻璃包覆层对钴基非晶丝巨磁阻抗效应的影响

分别用机械法和HF酸化学腐蚀方法去除金属芯丝直径为13μm、总直径为47μm的钴基Co68.15Fe4.35Nb1Si11.5B15.0非晶态玻璃包覆丝的玻璃包覆层,发现HF酸腐蚀去除玻璃层比机械法处理过的非晶丝的巨磁阻抗磁场灵敏度要高,HF酸剥离的非晶裸丝的巨磁阻抗最大磁场灵敏度可达ξ=105.02%/(79.6A/m)。HF酸去除玻璃包覆层的微细丝的阻抗效应要比有玻璃包覆层的丝在更低的外部磁场作用下达到巨磁阻抗比的最大值,在频率为f=4.07MHz、磁场强度为Hdc=176A/m处,非晶裸丝的磁阻抗效应达到最大值113.6%,其巨磁阻抗效应的磁场灵敏度ξ=42.9%/(79.6A/m)。