隧道取弃土场的环境生态治理方案

根据张承高速公路沿线的实际情况,对隧道取弃土场进行调查,考虑周围环境、降雨、植被、取弃土方量等条件,对不同位置的取弃土场提出不同的治理方案,具有一定的经济和社会意义。     

Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload

Objective To determine whether reduction In central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-lead or is due to arterial dilation. Methods We compared effects of NTG with these of lower body negative pressure (LBNP). Hemodyunmic measurements were made at rest, during LBNP (10, 20 and 30 mmHg, each for 15 min) and after NTG (10, 30 and 100μg/min, each dose for 15 min) in ten healthy volunteers. Cardiac pre-lead, stroke volume and cardiac output were assessed by echacardiography. Central pressure an mnentation and central systolic pressure were obtained by radial tonometry using a transfer function. Results LBNP (20 mmHg) and NTG (30μg/min) reduced pre-lead (as measured by the peak velocity of the S wave in the superior vena eava) to a similar degree [by (26. 8 ± 3.8) % and (23.9 ± 3. 4) %, respectively]. Compared to LBNP, NTG reduced systemic vascular resistance [by (32. 9 ± 7.5) %, p< 0. 01], decreased peripheral and central pressure augmentation [by (20. 8 ± 3. 4)% units and (12. 9±2. 9)% units, respectively, each P< 0. 01]. Conclusion These results suggest that a reduction in pre-load does not explain reduction in pressure augmentation and central systolic blood pressure by NTG and that these effects are mediated through arterial dilation.     

重庆轻轨工程汇流排预配技术的设计与实现

重庆轻轨是中国西部大开发的10大重点工程之一。该工程在中国第一次采用独轨交通制式，通过跨座在PC梁上运行车辆两侧的集电装置接触梁安装的刚性悬挂系统．解决车辆的取流与回流；有别于传统轮轨形式的轻轨系统：在该系统中主要起载流作用的T型汇流排是通过氩弧焊连接在一起。组成一个个伸缩单元的．由于中国没有成熟的施工经验可以借鉴。只能通过不断地摸索总结出了一套科学的汇流排预配方案，并利用计算机辅助功能得以实现，该方案能取代手工计算，而且提高了计算的准确性，最大限度地减少材料浪费，并使花工工效有较大提高：现针对汇流排预配技术的设计与实现，提出两个方案进行探讨。     

合(肥)裕(溪口)航道裁弯取直工程对长江大堤的影响

文章结合合(肥)裕(溪口)航道人江口裁弯取直工程，综合分析了其对长江大堤的影响。     

关于我国铁路可动心轨道岔的现状与发展

简述了可动心轨道岔和我国现有可动心轨道贫的现状，阐述发展我国可动心轨道岔应从体制上着手，使道贫从产品上升为商品。当前发展可动心轨辙叉，选材应在既有轧制轨件上做文章。     

混匀取料机电控制系统开发

1 引言 QLG1500.40型滚筒式混匀取料机是武钢工业港混匀料场的关键设备.该机自1992年初投入运行以来,由于其电控系统的设计先天不足,调速性能差,致使取料机行走机构多次出现严重故障,不能满足生产需要,大大地影响了混匀料场效益的发挥.为此,我们针对原系统存在的问题进行分析并实施技术改造,使系统调速性能达到或优于设计要求,首次在国内大型混匀取料机中实现了全自动同步运行的作业.     

稳性横交曲线

通常决定船型之静力及动力稳性曲线方法,或包含许金计算表格,使无论计算与校对,都很烦琐,或应用贵重精细仪器,但很多工厂和企业,未必具备。本文之面积仪方法,仅需面积仪及简单计算,且在工作过程中,可随时进行校对。欲计算一船在任一排水量任一倾斜角时之静力及动力稳性,需知下列三者: