地面防喷器控制装置远控系统的研制与应用

电控气型地面防喷器控制装置远控系统采用先进的SIEMENS S7-300系列PLC和PROFIBUS总线技术,使得地面防喷器控制装置对防喷器的控制时间大大缩短,提高了整个控制系统的安全、可靠性;通过电气按钮实现对防喷器的控制,通过增加声、光报警系统、控制状态指示灯、压力显示数码管,提高了作业人员的可操作性,使得整个控制系统更加人性化。     

在模拟井下环境中堵剂的结构形成与失效机理

采用XRD，TG和SEM－EDS等研究了在模拟油井深处温度，压力条件下养护的G级油井水泥和YLD型堵漏剂浆体的水化产物和显微结构。在高温高压动态养护条件下，硬化水泥浆体内部存在大量CSH凝胶和Ca(OH2)晶体，而堵漏剂浆体的主要水化产物是CSH凝胶。在钢管－浆体界面，虽然水化程度更高，但CSH凝胶和Ca(OH)2晶体的量却很少；主要的水化产物是钙矾石和水化钙黄长石。界面处的显微结构也比浆体内部疏松。这表明在钢管－浆体界面处存在严重的溶蚀现象，导致水泥浆体很快损失胶凝性，这可能是水泥基堵剂失效的主要原因。堵漏剂浆体的溶蚀速率小于油井水泥浆体，其溶蚀表面可发生再水化过程，新生成的CSH凝胶具有修补受损界面的“自愈”作用，使堵漏剂浆体与钢管的粘结作用得以维持，从而延长堵漏剂的有效使用期。     

Quantitative analysis of the ankle strategy under translational platform disturbance.

The ankle strategy is one of the postural adjustment maneuvers humans utilize when the support platform is disturbed. This paper presents a quantitative analysis of the ankle strategy. A three-link sagittal biped model is considered. The first link represents the two legs locked together. The second link represents the two thighs locked together. The third link represents the hip, the torso, the upper limbs, the neck, and the head. The dynamics, control, and stability of the three-link biped, under platform translation, are considered. The disturbance of the platform is represented as an input and the effect of the muscular system is reduced to a set of torques applied to the joints and across the joints. Two digital computer simulations are presented to demonstrate the behavior of the biped under backward or forward platform disturbance. The simulations are compared with experimental measurements of humans subjected to postural disturbances. It is shown that the effect of a horizontal disturbance at the ankle appears to be about 40 times that of the effect of the disturbance at the knees and at least a few hundred times larger than the effect of a disturbance at the hip. This means that, under translational platform disturbance, the ankle angle is subjected to the largest excursion. The knee and the hip angle excursions are relatively minor. Consequently, the biped, as a whole, appears to move as a single inverted pendulum. Major postural corrections are initiated by the ankle excursion. Further, when the available ankle torque is limited or nonexistent, the stability requires resorting to the knee or hip strategies.     

基于割集分析与回路分析的撕裂方程的直接生成方法

基于割集分析与回路分析的撕裂方程直接生成方法，是一咱能避免撕裂方程生成过程中大量阵运算的一种方法，具有计算简单、便于编制计算程序的特点。     

混凝土结构早龄期开裂的分析与预测

目的预测混凝土结构早龄期开裂的可能性.方法以可靠度理论为基础,建立了混凝土结构早龄期开裂的分析模型,利用开裂概率和临界开裂风险来分析与预测混凝土结构早龄期的开裂情况,并将分析模型在混凝土挡土墙工程中应用.结果混凝土挡土墙分析模型的预测结果与观测结果基本一致.结论应用开裂概率和临界开裂风险来分析与预测混凝土结构早龄期开裂,可以优选混凝土材料的组成,尽量减少混凝土结构早龄期的开裂.     

采用置信度风险测度的鲁棒发电计划模型及算法

针对大规模风电并网所带来的电网运行调度的不确定性及运行风险,提出基于置信度风险测度的鲁棒发电计划模型及求解算法。首先,提出一种新的风险测度—置信度风险测度（Risk_α）,对于既定置信度α及相应的风电功率预测区间,以弃风风险值与切负荷风险值的和构成置信度综合风险测度,以量化风电实际功率超出风电可接纳域的风险。在此基础上,以发电成本和置信度风险之和最小为优化目标,构建计及置信度风险测度的鲁棒发电计划模型及分解求解算法,同时优化机组组合决策和风电可接纳域,使得所制定的发电计划方案实现经济性和运行风险之间的均衡。最后,通过算例证明算法的正确性及有效性。     

优选状态数的MCMC算法在风电功率序列生成中的应用

传统马尔科夫链蒙特卡洛(MCMC)法的状态数选择常依赖于人工经验,应用于风电功率序列建模时难以较好地同时模拟原始风电功率序列的概率分布特性和自相关特性。针对该问题,提出一种优选状态数的MCMC(OSN-MC)算法。首先给出MCMC方法状态数的选取范围,其次在该范围内以生成序列与原始序列的自相关函数的误差平方和最小为原则确定优选状态数,然后利用各状态对应功率范围内的累积分布函数抽样生成随机风电功率,提高优选状态数下生成风电功率序列对于原始序列分布特性的模拟精度。应用OSN-MC法和MCMC法对中国、美国和欧洲的12个风电场生成风电功率序列,并与原始实测序列进行特性比较,结果表明:OSN-MC法生成的风电功率序列对原始序列的分布特性和自相关特性的模拟效果均优于MCMC法所生成的风电功率序列。     

燃气管道非稳态泄漏及扩散的模拟

为了得到准确可靠的燃气泄漏扩散规律及事故的危险范围,基于对燃气管道实际泄漏过程特点的分析,结合湍流扩散微分方程,分别建立了非稳态泄漏及扩散模型,并分析了其求解过程.以实例为基础,讨论并分析了泄漏相对孔径、气源切断时间、风速、扩散距离以及大气稳定度等对泄漏扩散浓度范围的影响.同时,针对泄漏扩散的中毒、火灾爆炸事故可能性危险范围给予了讨论和分析.研究结果将为控制和降低燃气泄漏事故的危害性提供理论参考.     

Modification of exposure conditions by the magnetic field configuration in helicon antenna-excited helium plasma

Modification of exposure conditions downstream in the diffusion chamber has been performed in helicon antenna-excited helium plasma by adjusting the magnetic field(intensity and geometry).In the inductively coupled mode(H mode), a reduction in ion and heat fluxes is found with increasing magnetic field intensity, which is further explained by the more highly magnetized ions off-axis around the last magnetic field lines(LMFL). However, in helicon wave mode(W mode), the increase in magnetic field intensity can dramatically increase the ion and heat fluxes.Moreover, the effect of LMFL geometry on exposure conditions is investigated. In H mode with contracting LMFL, off-axis peaks of both plasma density and electron temperature profiles shift radially inwards, bringing about a beam with better radial uniformity and higher ion and heat fluxes. In W mode, although higher ion and heat fluxes can be achieved with suppressed plasma cross-field diffusion under converging LMFL, the poor radial uniformity and a small beam diameter will limit the size of samples suitable for plasma irradiation experiments.     

Resolution enhanced light field near eye display using e‐shifting method with birefringent plate

Light field near eye displays (LFNED) can produce lightweight devices and address the accommodation–convergence conflict. However, low spatial resolution creates a poor immersive experience in LFNED. In addition, although many e‐shifting devices have been proposed to enhance resolution in projection system, yet those devices are too bulky to be applied in an LFNED to keep it lightweight. In this paper, a compact e‐shifting component is proposed to enhance image resolution in an LFNED by using a birefringent plate and twisted nematic switch cell. The proposed e‐shifting device is a flat and thin component with only 2.6 mm of thickness, which could be placed in the gap of an LFNED without increasing the thickness. The results show that the proposed components could be easily integrated in an LFNED with the result of resolution enhancement.