机动车防冻冷却液的回收利用

直接排放废弃的防冻冷却液会对环境产生严重影响,本文介绍了2种防冻冷却液回收利用技术:物理蒸馏法和直接再生法,使再生液具有防腐、防锈、防垢、防沸的功能,符合防冻冷却液国家标准。     

浅谈科研院所无形资产的流失与防范

资产的保值增值是企事业单位财务管理的重要环节,但重有形资产管理、轻无形资产管理是普遍存在的现象.科研院所采取有效措施加强无形资产管理、防范无形资产流失,已成为确保自身健康发展必须尽快解决的重要问题.     

编者的话

<正>北汽福田与戴姆勒,双方采用了以对等出资筹建新中重卡合资公司的模式,成立的合资公司只采用福田欧曼单一品牌。注入奔驰技术的新产品上将被烙上"FOTON"的LOGO,而提供戴姆勒核心动力的产品,则在驾驶室上打上"戴姆勒动力"的字样。     

交流信号测量装置的设计

本文论述了以DSP为核心的对交流信号的一种测试方法.在测量技术的基础上,讲解了电气参数测量的设计原理,并给出了实现该系统的基本框图和软件设计方法.     

石板山隧道衬砌施工技术

石太客运专线石板山隧道前长7505m，位于R=12000m曲线上，线间距由4.96m渐变至4.6m，断面变化处采用顺接过渡，设计为单洞双线隧道，是全线贯通的控制工程之一。通过对石板山隧道进口段衬砌施工实践，着重阐述衬砌各分项工程施工工艺和控制措施。     

浅谈道路建设管理中协调与控制要素

道路作为城市重要的市政基础项目,从立项到最后交付使用,需要多部门配合才能完成。该文从道路建设管理工作中的前期协调和施工过程管理两方面进行阐述,指出建设单位作为项目责任主体必须做好的工作。     

京津城际铁路桩板结构地基加固技术的应用

无砟轨道具有高平顺性、少维修养护的特点,在我国高速铁路和客运专线建设中将得到越来越广泛的应用.无砟轨道结构对路基沉降变形控制要求较高.地基沉降变形是影响路基沉降变形的关键.结合京津城际桩板结构地基加固技术设计方案,介绍桩板结构形式和桩型的选用,分析钢筋混凝土结构有效调节地基的差异沉降和低路堤结构动力影响,桩板结构在深厚压缩层地区地基处理效果和应用范围,在高速铁路地基加固处理中提供一种新的设计思路,希望为今后此类结构的应用提供参考.     

摩托车用铆钉的热处理

铆钉是典型紧固件之一,主要用于车辆的不可卸连接,种类有盲铆钉、沉头铆钉、空心铆钉、平头铆钉等,铆钉在摩托车上的用途还是不少的,即要求铆合部分不开裂,还必须抵抗较高应力状态的周期性弯曲负荷.     

Transforaminal lumbar interbody fusion for traumatic lumbar spondylolisthesis

To evaluate the clinical outcome, effectiveness and safety of the surgical management of traumatic lumbar spondylolisthesis with transforaminal lumbar interbody fusion (TLIF) with short segmental instrumentation fixation. A retrospective review of a consecutive series of 24 patients with traumatic lumbar spondylolisthesis treated with TLIF procedure was carried out. Intraoperative spinal cord monitoring was used to confirm the peripheral neural function intact during the reduction of the spondylolisthesis. Preoperative clinical and radiographic evaluation of all cases were originally collected prospectively. Data regarding blood loss, operative time, duration of hospital stay, radiographic fusion, instrumentation failure and clinical result were collected and observed at regular follow-up periods. All patients were engaged in high-energy accidents in the lower back and 16 patients had concomitant injuries. The mean operative time was 124 min, mean blood loss was 350 mL, and mean hospital stay was 6.5 days. There were no complications such as incision infection, cerebrospinal fluide (CSF) leakage and nerve root injury and so on. All patients demonstrated a solid lumbar interbody fusion within 4 months, and no evidence of spondylolisthesis correction loss, instrumentation failure and loosing. They all were completely asymptomatic, with normal neurologic findings, and had resumed their previous level of physical activities on the final follow-up. Meticulous clinical examination and careful imaging assessment could assist an early diagonosis in cases of traumatic lumbar spondylolisthesis. Performing open reduction and the TLIF procedure as soon as possible could restore segmental stability and painless function. The TLIF procedure was a safe, effective technique to treat traumatic lumbar spondylolisthesis.     

Access control policies without inside queues: Their properties and public policy implications

An access control policy that eliminates all queues beyond the entry points to a network has obvious benefits, which include smooth travel and predictable travel times inside the network. Yet it has never been proven, to the best of our knowledge, whether excluding inside queues yields sub-optimal network performance or, in other words, allowing inside queues can actually further reduce the system travel cost. Moreover, it is not clear whether an optimal control policy derived from efficiency considerations can also be a fair policy to all road users. This paper provide answers to these questions in the context of a monocentric network. By analyzing the structure of the access control problem considering all feasible policies (with/without inside queues), we show that the minimal system cost realizable by access control can be obtained without directly solving a non-convex optimization program, and can indeed always be achieved by a control policy excluding all of the inside queues. These optimal policies are defined by a polyhedral set and a Finite Generation Algorithm can be applied to derive the analytical form of this set. The optimal policies are not unique in general, thus making it possible to achieve both minimal system cost and fairness simultaneously.