齐家古龙凹陷葡萄花油层顶面构造演化史研究

古构造演化史的研究是目前解决油气运移的难题之一,尤其是油气运聚期的古构造格局的恢复对搞清油气分布具有非常重要的意义.以典型构造-岩性油气藏的齐家-古龙凹陷葡萄花油层为例,阐述了古构造图恢复的重点环节——古厚度恢复,得出断层归位、压实恢复和剥蚀恢复是决定古厚度恢复成败的三个关键技术,详细并解析了其具体实现原理和方法.在此基础上,结合沉积补偿原理完成了目标区葡萄花油层顶面古构造演化史的恢复,研究发现,葡萄花油层经历了三个重要沉积阶段:自沉积起至嫩四段沉积末期为持续沉降阶段,嫩五段沉积末期至今为萎缩抬升阶段;明二段段沉积末期为构造定型阶段,其中,凹陷周边早期发育的鼻状构造及背斜构造为油气运聚有利构造位置,这对该区下一步油气的勘探具有重要的指导意义.     

医疗资源影响下具有潜伏期的一类传染病模型建立及性态分析

建立了医疗资源影响下的考虑疾病具有潜伏期的一类传染病模型,并分析了模型的动力学性态.发现疾病流行与否由基本再生数和医院病床数共同决定,并得到了病床数的阈值条件.当基本再生数R_0大于1时,系统只存在惟一正平衡点,且通过构造Dulac函数证明了正平衡点只要存在一定是全局渐近稳定的;当R_01,我们得到系统存在两个正平衡点及无正平衡点的条件,且只有当医院的病床数小于阈值时,系统会经历后向分支.因此,可根据实际情况使医院病床的投入量不低于阈值条件,不仅有利于疾病的控制而且不会出现医疗资源过剩的现象.     

基于ISM的地震灾后恢复重建影响因素分析

地震灾后恢复重建是地震灾害受灾国的一项艰巨而繁重的工作任务.地震灾害的破坏性使恢复重建具有复杂性、不确定性和开放性的特点,因此地震灾后恢复重建影响因素不但具有复杂性,而且影响范围和程度也各不相同.引入ISM模型解决了地震灾后恢复重建影响因素多而杂的问题,在文献资料统计基础上构建地震灾后恢复重建影响因子解析结构模型.通过分析确定地震灾后恢复重建关键影响区素共16个:重建主体、重建经验、施工条件、物价、资金、工程成本、建材质量、施工工期、标准施工、检验维修、工程利用、公共服务、自然环境、运行经费、社会饵障、居民激励.该结论为政府优化地震灾后恢复重建工作,保证重建效果具有重要意义.     

Supercloseness analysis and polynomial preserving Recovery for a class of weak Galerkin Methods

In this article, we analyze convergence and supercloseness properties of a class of weak Galerkin (WG) finite element methods for solving second‐order elliptic problems. It is shown that the WG solution is superclose to the Lagrange interpolant using Lobatto points. This supercloseness behavior is obtained through some newly designed stabilization terms. A postprocessing technique using polynomial preserving recovery (PPR) is introduced for the WG approximation. Superconvergence analysis is performed for the PPR recovered gradient. Numerical examples are provided to illustrate our theoretical results.     

利用光锁相环路实现40 Gb/s时钟恢复

提出并建立了一种新型的基于光纤四波混频效应和压控光脉冲源的光锁相环路(OPLL),用于光时分复用系统(OTDM)中的时钟恢复过程。从理论上分析了其工作原理,及各模块结构和功能。利用高非线性光纤中的四波混频效应实现全光鉴相器,有效缩短了光纤长度,减小了光纤色散引起的脉冲走离,鉴相器消光比超过30 dB。采用再生锁模光纤激光器实现压控光脉冲源,在保证脉冲质量的前提下,重复频率调节范围达到380 kHz。在40 Gb/s时钟恢复实验中,获得脉宽为7.2 ps、接近变换极限的时钟脉冲,时间抖动(RMS)为152 fs,超模抑制比大于60 dB。实验证明,输入信号幅度波动和码型效应对环路影响很小。     

State-of-the-art on ultrasonic oil production technique for EOR in China

Ultrasonic oil production technique for enhanced oil recovery (EOR) attracts more attention due to its high adaptability, simple operation, low cost and zero pollution to the oil reservoir. In this paper, recent new downhole tools used for enhanced oil recovery developed in China are summarized. Furthermore, research advance on some key problems that affect the widespread application of ultrasonic oil production technique in China are also summarized in view of what are the primary factors that influence crude oil paraffin inhibition and viscosity reduction, whether ultrasonic excitation is better than chemical agent for any plugs removal and whether ultrasound-chemical combination plug removal technology has the best plugs removal effect. The purpose of this paper is to provide reference for the broad application of ultrasonic oil production for enhance oil recovery.     

Development of a novel self-healing dental nanocomposite containing PUF nanocapsules and nanoclay

The aims of this research were to develop the first self-healing dental nanocomposite and to evaluate mechanical properties (compressive and flexural strength), crack-healing, and self-healing longevity after 90 days of water aging. The principal reasons for failure are microcracks formed by polymerization shrinkage, recurrent dynamic mechanical stress, water sorption, and thermal fatigue. N, N-dihydroxyethyl p-toluidine and triethylene glycol dimethacrylate (DEPT-TEGDMA) nanocapsules were synthesized as they have been proven previously to be biocompatible for dental materials. Nanoclay was used as a filler to improve the mechanical properties of self-healing tooth nanocomposites. Nanocapsules were prepared by in situ emulsion polymerization of poly urea-formaldehyde (PUF) shells. The synthesized PUF shells were characterized by FTIR, SEM, and DLS analyses. The results showed that incorporating nanocapsules at a 7.5% mass fraction into the nanocomposite increased the mechanical properties. A good self-healing efficiency ranging from 54.06 to 58% recovery was obtained. The 90 days of water-aging compared to 1 day did not reduce the self-healing efficiency (p > 0.1), showing water-aging did not damage the nanocapsules.     

SF6气体的富集与解吸方法

介绍SF6的低温富集及高温解吸方法.测定了SF6在Porapak Q和PorapakT两种吸附剂上的动态吸附系数(kd).结果显示,Porapak Q对SF6的吸附性能明显优于Porapak T,温度是影响kd值的主要因素之一,温度和kd的关系符合Arrhenius方程,实验范围内的样品气流量对kd的影响较小.SF6解吸前需预抽真空至30 kPa,然后放入热水浴中恒温30 min,用N2洗提,逐段收集洗提气体,洗提流量为2mL/min.当解吸体积为7 mL时,回收率可达到90％以上,富集系数可达到102量级.     

Annealing texture of a cold-rolled Fe–Mn–Al–Si–C alloy

The study of recrystallization texture of a cold deformed Fe–Mn–Al–Si–C alloy, with about 30% Mn, has been discussed in this paper. The alloy is fully austenitic at room temperature, and therefore, principal FCC rolling textures were developed in this material at different stages of cold rolling. The present study was undertaken to observe the transformation of FCC rolling texture during recrystallization of a heavily cold deformed specimen. It was observed that isothermal annealing at 750 °C led to a weak recrystallisation texture, which was quite similar to the deformation texture developed at the early stage of cold rolling. During recovery stage, a strong Bs/Goss-type texture was developed, which was identified as a new observation in this work.     

Simulation of Three-Phase Displacement Mechanisms Using a 2D Lattice-Boltzmann Model

Using a numerical technique, known as the lattice-Boltzmann method, we study immiscible three-phase flow at the pore scale. An important phenomenon at this scale is the spreading of oil onto the gas–water interface. In this paper, we recognize from first principles how injected gas remobilizes initially trapped oil blobs. The two main flow mechanisms which account for this type of remobilization are simulated. These are the double-drainage mechanism and (countercurrent) film flow of oil. The simulations agree qualitatively with experimental findings in the literature. We also simulate steady-state three-phase flow (fixed and equal saturations) in a small segment of a waterwet porous medium under both spreading and nonspreading conditions. The difference between the two conditions with respect to the coefficients in the generalized law of Darcy (which also includes viscous coupling) is investigated.