神经内镜治疗颅内病变的临床应用

目的探讨神经内镜的临床适应证、操作要点及其优缺点。方法采用神经内镜治疗颅内各种病变69例,其中垂体腺瘤6例,蛛网膜囊肿21例,脑积水18例,透明隔囊肿6例,颅内表皮样囊肿8例,血管网织细胞瘤9例,颅内多发性转移瘤1例。结果69例患者术后临床症状和体征均有不同程度的恢复或好转,头颅CT、MRI复查颅内病灶明显改善。结论神经内镜对于颅内多种病变的治疗具有手术创伤小、术后反应轻和患者恢复快的特点,是目前微创神经外科治疗的首选方法。     

3D Nonlinear Numerical Simulation of Intact and Debonded Reinforced Concrete Beams

To study the behaviour of reinforced concrete (RC) structures with sections of concrete removed and the reinforcement exposed, 3D nonlinear numerical analysis was performed upon both intact and debonded RC beams by using finite element techniques. The deformational characteristics and the ultimate loads were obtained through numerical models, as well as crack and stress distributions. The failure modes can also be deduced from computational results. Compared with intact beams, the normal assumptions of plane section behaviour is not hold true and the patterns of stress and strain are different in debonded RC beams. The numerical results show good consistency with experimental data. This kind of numerical simulation is a supplement to existing codes.     

郑州市客运交通结构发展研究

城市客运交通结构发展模式的研究是城市战略规划的核心问题之一，不同的客运交通结构的运行效率、能源消耗、道路资源的占有以及对环境的影响程度等都是截然不同的，同时它还影响着城市的布局形态与城市的活力。     

不同时间脾切除联用环孢素对协调性异种心脏移植物存活的影响

目的探讨脾切除联用环孢素对协调性异种移植心脏存活时间的影响及其机制。方法建立协调性异种心脏移植模型。分别采用不同时间脾切除联用环孢素,观察异种移植物的生存时间。用CH50法检测各组动物血清中总补体活性。应用流式细胞技术检测动物血清中异种反应性抗体IgG、IgM的滴度变化。移植物标本HE染色观察病理学改变。免疫组化染色观察各实验组不同时间移植物组织中IgG、IgM抗体的沉积。结果脾切除联用环孢素能够显著延长移植物的生存时间(P<0.05),降低受者体内异种反应性抗体的滴度。结论脾切除联用环孢素可以减少移植术后早期受者体内异种反应性抗体的产生,延长异种移植物的生存时间。     

船舶过弯道所需航宽建模

船舶通过弯曲航道所需航宽的计算对于安全生产具有十分重要的意义．根据叠加原理，分别计算出在无风流情况下过弯道所需航宽、流致漂移量、风致漂移量、偏航量。然后相互叠加得到有风流情况下船舶通过弯道所需航宽．     

K190пк钢轨焊机新型程控调压系统的研究

针对Ｋ１９０пк钢轨焊机电源系统所存在的问题，采用大功率晶闸管和可编程序控制器配置Ａ／Ｄ模块和触发控制电路，研制了一种新型实用、性能可靠的程控调压系统，实现了焊接电压无触点控制和无级调节。该系统具有调压范围宽、精度高、抗干扰性强、网压自动补偿及成本低廉等特点。经现场试用，效果良好。     

轴瓦套张开位移的有限元计算

汽轮机在运行过程中,轴推压轴瓦套,使轴瓦套中产生应力和应变,在上下轴瓦套之间产生的一定的张开量.采用ABAQUS软件,建立有限元物理模型,对实际工况进行仿真,计算出上下轴瓦套之间的张开量,并进行应力分析,确定该工况下所产生的张开量是符合要求的.在建立有限元模型过程中,充分考虑轴瓦与轴、轴瓦与螺栓以及上下轴瓦套之间的接触效应,螺栓的联接和螺栓预紧力的作用.     

新旧列车运行图交替期客车车底运用方案的编制

以旧列车运行图中1列列车最多与新列车运行图中1列列车存在接续关系、新列车运行图中1列列车最多与旧列车运行图中1列列车存在接续关系、新列车运行图中所有列车必须有客车车底担当为约束条件,以新旧列车运行图交替期列车接续代价最小为目标函数,建立新旧列车运行图交替期客车车底运用方案优化模型,并设计基于蚁群算法的模型求解算法.以成都站执行新运行图时的数据(成都站为客车车底配属站)为例,采用本方法编制新旧列车运行图交替期客车车底运用方案,并与人工基于车底固定运用模式编制的方案对比,结果表明本方法编制的车底运用方案更优,验证了模型和算法的可行性和实用性.     

The effectiveness of differential pricing on route choice

The use of differential pricing as a means of traffic management has been advocated by specialists in the field of transport for quite some time. Because of technical and political reasons, a full-scale pricing scheme for the use of road space has yet to be introduced. Applying the principle to a highly automatic rail system, however, is technologically much more feasible. The Mass Transit Railway Corporation of Hong Kong has implemented a so-called revenue neutral peal pricing policy after the completion of a second cross-harbour route- the East Harbour Crossing — in May, 1990. Passengers travelling from Kowloon to the central business district (including Jordon and Tsim Sha Tsui on the Kowloon side and stations from Sheung Wan to Causeway Bay on the Island side) during the morning peak hour are confronted with the following choice: either (i) make use of the Nathan Road Corridor and pay 80 cents on top of normal face; or (ii) take the less congested but in general longer route via the East Harbour Crossing and get a 80 cents discount. The present paper attempts to analyse the effectiveness of this differential pricing policy in diverting passengers from the overcrowded section to the less heavily utilized route. A personal interview survey comprising a total of 1094 successful cases was conducted for this purpose. The logit regression model was employed to analyse the route choice. It is found that income, habit and journey time are the most important variables determining the route choice. The effect of cost or fare difference, although large in terms of magnitude, is only marginally significant in the statistical sense. It is suggested that efforts to change the passengers' habit and measures to shorten the train transfer time at the Quarry Bay Station for the East harbour Crossing users would be more effective in achieving this end. This is especially the case given the current political development in Hong King which renders further enlargement of the price difference a highly difficult proposition.     

一种新型二乘二取二冗余列控车载设备硬件同步模块研究

针对二乘二取二冗余列控车载设备同步需求,提出一种新型硬件同步方案.该方案可使二乘二取二冗余列控车载设备可靠性、安全性、可用性和可维护性得到提高.