对"自我"-男性世界的否定——以女权主义解读戴维·洛奇的《换位》

戴维洛奇是当代英国杰出的小说家兼评论家,因其特殊身份,其作品中涉及到了形形色色的文学理论.近十几年来,国内学术界对他的小说创作多有评论,但从女性主义角度解读的尚不多见.本文将从女权主义中"自我"和"他者"的观点评析戴维洛奇的<换位>.     

A dynamical approach to precision entry in multi-body regimes: Dispersion manifolds

The identification of trajectories that target a precise location and approach vector during planetary entry is sensitive to the quality of the startup arc supplied to iterative path planning and guidance algorithms. These sensitivities are especially evident when multi-body effects are significant; low-energy spacecraft trajectories that dwell near the gravitational boundary of two bodies, for instance, are more susceptible to third-body effects. Dynamical sensitivities are also significant when maneuvers are scheduled within a region of space susceptible to multi-body effects. The present study considers precision entry targeting from the perspective of the multi-body problem.     

Vertical motions in Thailand after the 2004 Sumatra–Andaman Earthquake from GPS observations and its geophysical modelling

Following previous findings from ongoing GPS research in Thailand since 2004 we continue to exploit the GPS technique to monitor and model land motions induced by the Sumatra–Andaman Earthquake. Our latest results show that up to the end of 2010, Thailand has been co-seismically displaced and is subsequently undergoing a post-seismic horizontal deformation with total displacements (co-seismic plus post-seismic) ranging from 10.5 to 74.7 cm. We observed the largest horizontal displacements in the southern part of Thailand and moderate and small displacements in the central and northern parts. In addition to horizontal displacements throughout Thailand, continuous GPS measurements show that large parts of Thailand are subsiding at rates up to 1 cm/yr. It is the first time that such vertical post-seismic deformations at large distances (650–1500 km away from the Earthquake’s epicentre) have been recorded. We have investigated the physical processes leading to the observed subsidence. While after-slip on the subduction interface induces negligible or even slightly positive vertical motions, relaxation in the asthenosphere is associated with a sizable subsidence. Predictions from a 3D finite element model feature an asthenosphere with an effective viscosity of the order of 3 * 10¹⁸ Pas, fit the horizontal post-seismic data and the observed subsidence well. This model is then used to predict the subsidence over the whole seismic cycle. The subsidence should go on with a diminishing rate through the next two decades and its final magnitude should not exceed 10 cm in the Bangkok area.     

廊坊市体育健身娱乐市场现状调查与对策分析

本文采用问卷调查、文献资料、观察、数理统计、逻辑分析等研究方法,对廊坊市体育健身娱乐经营单位的基本情况、经营状况和居民体育健身娱乐消费情况进行了调查研究,揭示了市场供求的现状特征及存在的问题,并据此提出了拓展廊坊市体育健身娱乐市场的若干对策.     

基于LabVIEW的通信系统的构建

本设计基于LabVIEW仿真软件完成了基本通信系统和通信综合系统的构建。该系统涵盖了模拟调制,数字调制,模拟信号数字传输,信道编码,最佳接收系统几部分内容。通过系统仿真,实现了系统输入输出波形的直观显示,解决了教学中实验效果不理想,理论内容不好理解的问题。同时通过内置的Web Server进行网页发布后,用户可以在客户端通过web浏览器远程调用并运行本系统,提高效率,节约成本。     

模态测试设备系统校准方法研究

为了解决模态测试设备面向模态参数的校准问题,研究了模态分析与模态叠加理论,根据该理论得到一个闭环模态信号控制算法,由该闭环控制算法构建一个由5台激振器构成的闭环系统,该组激振器模拟模态测试过程中的一组信号,此组信号包含了标准模态参数的信号,最后用该组信号来校准模态测试设备。根据该方法进行了数值模拟和试验测试,结果显示该校准方法是可行的,并且可以脱离具体的模态结构,不同模态信号的模拟也可灵活实现。     

高超声速飞行器二元进气道试验和计算

设计了一种吸气式面对称高超声速飞行器,针对进气道性能,分别在两座风洞开展通流试验研究。针对第1次风洞试验大攻角状态(α=8°)测量值偏离线性的问题,辅助采用数值模拟手段分析原因,并对试验方案进行改进设计,解决了首次试验出现的问题。结果显示,在典型状态(Ma=5~6)下,进气道起动正常,性能良好,具有一定的抗侧滑能力;随来流马赫数增加,进气道流量系数增大,总压恢复系数减小,计算结果和试验结果一致;试验结果和数值计算的差异主要表现为基本测压方案α>4°后,流量系数和总压恢复系数出现严重的非线性。数值模拟结果表明,主要原因为模型支撑方式及测压方式所引起的偏差,通过改进试验方案,解决了大攻角状态下测量值偏离正常趋势的问题。     

Trajectory correction maneuver design using an improved B-plane targeting method

A spacecraft for interplanetary mission is usually perturbed by some disturbance sources. The trajectory correction maneuver (TCM) is required to adjust this trajectory error, and the B-plane targeting method is widely used in this field. However, this B-plane targeting method is based on the differential correction algorithm, and a numerical Jacobian matrix is usually used for this algorithm. Therefore, our main goal in this paper is to suggest the improved B-plane targeting method to overcome the disadvantages of the conventional B-plane method which requires a numerical Jacobian matrix for the initial perturbation selection and iterations. For this improvement, an analytical Jacobian matrix is introduced instead of the numerical Jacobian matrix. Then, another B-plane approach that offers an analytical solution is suggested using the target eccentricity instead of the target time of closest approach (TCA). Using a modified Kepler's equation, the previous B-plane targeting approach can be replaced with the new method through the analytical solution.     

Influences of the turbulence model and the slot width on the transverse slot injection flow field in supersonic flows

Transverse slot injection scheme is very important for the mixing process between the air and the fuel in supersonic flows. The effect of the turbulence model and slot width on the transverse slot injection flow field has been investigated numerically based on the grid independency analysis, and the predicted results have been compared with the experimental data available in the open literature. The obtained results show that the grid scale makes only a slight difference to the wall pressure profiles for all jet-to-crossflow pressure ratios employed in this study, and the wall pressure profile with low jet-to-crossflow pressure ratio is predicted accurately by the RNG k–ε turbulence model, the SST k–ω turbulence model for the flow field with high jet-to-crossflow pressure ratio. High jet-to-crossflow pressure ratio can increase the jet penetration depth in supersonic flows, and the gradient of the length of the upstream separation region is larger than that of the height of the Mach surface. At the same time, when the jet-to-crossflow pressure ratio is maintained constant, the jet penetration depth increases with the increase of the slot width.     

Newton–Euler equations of multibody systems with changing structures for space applications

Multibody systems with changing structure are considered. These systems have stages in their motion that distinct from each other by degree of freedom (DOF), joint connection structure and joint types. These mechanical systems are common in space application e.g. separation subsystems. Single coordinate set is used to formulate Newton–Euler equations of motion at each stage. Proposed equation form simplifies equations building process for certain stages and whole motion. Numerical experiment was carried out using proposed method.