无临设工程施工的沉桩方法及工法设计

传统的打桩(振动、冲击)技术,不仅需要打桩机,还需要施工车辆、大型附带设备及暂设工程,施工效率低、占地面积大,对生态环境影响大。以黄河堤岸刚性加固为需求导向,设计了无临设工程施工的沉桩方法,并开发出整套设备,该设备主要包含静压植桩机、动力单元、桩用起吊装置及桩材自走装置。该工法实现了无暂设工程施工,提高了作业效率,减小了对生态的影响。从工法特点、施工周期、施工成本、硬质地层适应性、成桩质量、占地面积和环境影响(CO_(2)排放)等方面对比分析了此方法与传统施工的优缺点。结果表明,该方法可广泛应用于坝决口封堵、堤防加固、植入式斜桩护岸、挡土墙、止水墙、基础和地基工程加固等方面。

施工现场临设间距不满足消防要求的处理方案之探讨

房地产开发商设计时大都将土地最大化利用,施工现场留给用来布置临设的场地有限,施工单位在进行临设布置时,往往因临设间距不满足防火要求需减少临设的布置,为生产及生活带来极大的不便。文中针对防火间距不满足要求的现象提出处理方案。

预制混凝土板在施工现场临设中的应用

混凝土构件大体分为两大类——现浇式和预制装配式。预制混凝土构件施工方便,易于搭建和拆卸,适用于跨度小、楼层少的建筑,大部分临时建筑都会使用这种构件。使用预制装配式混凝土构件是建筑施工行业的发展方向。

基于三维可视化BIM技术项目临设标准化策划及快速建造

院文章以某工程为例,阐述了BIM技术项目临设标准化策划的特点、建造工艺流程、初期临设平面策划、临设三维BIM技术仿真、临建设施快速安装。

风冷模块机组空调系统在临设中的应用

目前,工程施工现场临设生活区、办公区区域大多如较传统的采暖及制冷设备分体空调等.一般生活区、办公区房间众多,全部使用的话不仅在美观上大打折扣,还会由于生活区使用强电这一情况造成诸多安全隐患.针对上述情况,通过实际案例,介绍了一种风冷模块机组中央空调系统,并通过其与分体空调在经济上、安全上进行对比,论证其推广应用的可行性.

Effects of the profile of a supercavitating vehicle's front-end on supercavity generation

The authors designed three different front profiles for supercavitating vehicles based on cavity theory and the Granville streamlined equation are designed. Experiments were done using these front profiles in the Northwestern Polytechnical University high-speed water tunnel. The experiments indicated that the critical volume of gas required for supercavitation is affected by the axial distribution of the front-end＇s slope. The experimental data showed critical gas flow rates required for the three designs were less than rood-l, with the greatest decrease 24%. The experimental results also showed the supercavitation generation speeds of the models were faster than mod-1 by up to 32.4%. This verifies that the front profile of a supercaviting vehicle effects supercavity generation speed and critical gas flow rates. The smaller the changes in axial distribution of pressure, the higher the supercavity generation speed. The smaller the changes in curvature distribution of axial, the smaller the critical gas flow rates.

福建省建筑工程安全文明施工费测算工作心得

本文主要阐述安全文明临时设施费率的测算过程,介绍其测算的原因,依据、测算内容及测算方法等。

Adaptive designs for sequential experiments

Various adaptive designs have been proposed and applied to clinical trials, bio assay, psychophysics, etc.Adaptive designs are also useful in high cost engineering trials.More and more people have been paying attention to these design methods. This paper introduces several broad families of designs, such as the play-the-winner rule, randomized play-the-winner rule and its generalization to the multi-arm case, doubly biased coin adaptive design, Markov chain model.

Critical safe distance design to improve driving safety based on vehicle-to-vehicle communications

A critical safe distance(CSD)model in V2V(vehicle-to-vehicle)communication systems was proposed to primarily enhance driving safety by disseminating warning notifications to vehicles when they approach calculated CSD.By elaborately analyzing the vehicular movement features especially when braking,our CSD definition was introduced and its configuration method was given through dividing radio range into different communication zones.Based on our definition,the needed message propagation delay was also derived which could be used to control the beacon frequency or duration.Next,the detailed CSD expressions were proposed in different mobility scenarios by fully considering the relative movement status between the front and rear vehicles.Numerical results show that our proposed model could provide reasonable CSD under different movement scenarios which eliminates the unnecessary reserved inter-vehicle distance and guarantee the safety at the same time.The compared time-headway model always shows a smaller CSD due to focusing on traffic efficiency whereas the traditional braking model generally outputs a larger CSD because it assumes that the following car drives with a constant speed and did not discuss the scenario when the leading car suddenly stops.Different from these two models,our proposed model could well balances the requirements between driving safety and traffic throughput efficiency by generating a CSD in between the values of the two models in most cases.

Open pit waste removal optimization through equipment fleet scheduling

A neighborhood search algorithm was proposed to simultaneously schedule the waste removal quantity and the equipment fleet profile over the mine life for open pit mines.An initial search domain was first defined and a good schedule was obtained as the current best schedule by searching in this domain.Then,progressively narrower neighborhood search domains were constructed around the current best schedule to search for better schedules.The objective is to minimize the present value of waste removal costs over the mine life.The resulting schedule from this algorithm provides a complete fleet profile for each year over the mine life:the selected equipment models,the number of equipment units of each model,the age of each unit,as well as the quantity of waste removed.A numerical example of application was provided to demonstrate the feasibility and merits of the algorithm.

Progress of Animal Research on Electro-acupuncture Treatment for Depression

This paper summarized the Chinese literatures in the previous 5 years about the pre-clinical animal researches on the application of electro-acupuncture(EA) treatment for depression,searched in China National Knowledge Infrastructure(CNKI).The efficiency of EA treatment for depression and the mechanism of it were discussed,to shed light on new ideas and new fronts for the further research on depression in clinical or pre-clinical fields.

Measurement of Walnut Properties and Analysis on the Compressive Stiffness of the Critical Value of Shell-cracking

Based on the measurement of walnut properties, a computational analysis was conducted on the compressive stiffness of the critical val-ue of shell-cracking. As indicated by the results, to crack the walnuts shell from its longitudinal or edge directions could save lots of efforts. The study provided theoretical basis for the design and improvement of walnut shell-cracking machine as well as theoretical references for the design, mak ng and use of some spec a crack ng-a d ng too s such as nutcracker.

Strategic Scientific and Technological Capacity-Building in Clinical Medicine in China:Taking the Innovative Development of Reproductive Medicine at Peking University Third Hospital as an Example

Based on the macroanalysis of the unbalanced development of the"demand side"and the"supply side"of clinical medicine in China,this paper elucidates the stakeholders,resources,and ecosystem of the strategic scientific and technological capacity-building and calls for a larger coverage,smoother supply chain,and more sustainable ecosystem to ensure the development of clinical medicine.Furthermore,focusing on the establishment and development of clinical reproductive health in China,the authors introduce the strategic scientific and technological capacity-building of reproductive medicine in Peking University Third Hospital,with an attempt to inform similar efforts in other fields and even the whole clinical medicine in China.

Clinical trial:Lactobacillus plantarum 299v(DSM 9843)improves symptoms of irritable bowel syndrome

AIM:To assess the symptomatic efficacy of Lactobacillus plantarum 299v(L.plantarum 299v)(DSM 9843) for the relief of abdominal symptoms in a large subset of irritable bowel syndrome(IBS) patients fulfilling the Rome Ⅲ criteria.METHODS:In this double blind,placebo-controlled,parallel-designed study,subjects were randomized to daily receive either one capsule of L.plantarum 299v(DSM 9843) or placebo for 4 wk.Frequency and intensity of abdominal pain,bloating and feeling of incomplete rectal emptying were assessed weekly on a visual analogue scale while stool frequency was calculated.RESULTS:Two hundred and fourteen IBS patients were recruited.After 4 wk,both pain severity(0.68 + 0.53 vs 0.92 + 0.57,P < 0.05) and daily frequency(1.01 + 0.77 vs 1.71 + 0.93,P < 0.05) were lower with L.plantarum 299v(DSM 9843) than with placebo.Similar results were obtained for bloating.At week 4,78.1 % of the patients scored the L.plantarum 299v(DSM 9843) symptomatic effect as excellent or good vs only 8.1 % for placebo(P < 0.01).CONCLUSION:A 4-wk treatment with L.plantarum 299v(DSM 9843) provided effective symptom relief,particularly of abdominal pain and bloating,in IBS patients fulfilling the Rome Ⅲ criteria.

Optimal design of heat exchanger header for coal gasification in supercritical water through CFD simulations

Heat exchangers play an important role in supercritical water coal gasification systems for heating feed and cooling products. However, serious deposition and plugging problems always exist in heat exchangers. CFD modeling was used to simulate the transport characteristics of solid particles in supercdtical water through the shell and tube of heat exchangers to alleviate the problems. In this paper, we discuss seven types of exchangers CA, B, C D, E, F and G）, which vary in inlet nozzle configuration, header height, inlet pipe diameter and tube pass distribution. In the modeling, the possibility of deposition in the header was evaluated by accumulated mass of particles; we used the velocity contour of supercritical water （SCW） to evaluate the uniformity of the velocity dis- tribution among the tube passes. Simulation results indicated that the optimum heat exchanger had structure F, which had a rectangular configuration of tube pass distractions, a bottom inlet, a 200-mm header height and a 10-ram inlet pipe diameter.

Orthogonal array design for the optimization of stripping Sr(Ⅱ) from ionic liquids using supercritical CO2

The strontium ions extracted from the aqueous phase into 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(C_2mimNTf2) with dicyclohexyl-18-crown-6(DCH18C6) was stripped effectively by supercritical CO_2(sc-CO_2).Hexafluoroacetylacetone(HFAA)-acetonitrile was found to be an excellent modifier of sc-CO_2 to enhance the stripping efficiency.In the orthogonal array design(OAD),OA_(25)(5~5)matrix was employed to optimize the stripping of Sr(Ⅱ) from the DCH 18C6-C_2mimNTf_2 system.Effects of five experimental factors:temperature,pressure,concentration of HFAA,static and dynamic extraction times as well as each factor at five-levels on the stripping of Sr(Ⅱ) were optimized.The effects of these parameters were treated by the analysis of variance(ANOVA).The results showed that Sr(II) could be nearly 100%extracted from the IL phase at 308 K,30 MPa,40 min of dynamic extraction and 60 mmol·L^(-1) HFAA in acetonitrile,respectively.Finally,the stripping mechanism was studied by ESI-MS.

Chinese Herbal Medicine in Treatment of Polyhydramnios:a Meta-analysis and Systematic Review

Objective To compare the efficacy of Chinese herbal medicine （therapy A） or Chinese herbal medicine plus indomethacin （therapy B） with that of indomethacin alone （therapy C） in treating polyhydramnios. Methods Literatures published up to April 2012 were retrieved from PubMed, Embase and Cochrane library, Chinese National Knowledge Infrastructure （CNKI）, Chinese Scientific and Technological Periodical Database （VIP）, Wangfang, and Traditional Chinese Medicine online. Two researchers collected data independently. The assessment of methodological quality was based on Cochrane handbook and the materials were analyzed with software RevMan 5.1.2. The outcome measure index was relative risk or difference of mean value （95% confidence interval）. The following outcomes were evaluated： （1） general clinical improvement rate; （2） maximum vertical pocket depth; （3） amniotic fluid index （AH） value; （4） rate of fetal ductus arteriosus constriction; （5） incidence of adverse events. Results Based on the search strategy, 5 trails involving 1017 patients were finally included. Compared with therapy C, therapy A decreased the rate of fetal ductus arteriosus constriction （P〈0.01）. Therapy B was more effective than therapy C in general clinical improvement and decrease of AH for polyhydramnios （P〈 0.01 ）. No serious adverse events were reported in therapy A and therapy B. Conclusions Compared with therapy C, therapy A and therapy B may appear to be more effective for polyhydramnios. However, the exact effect needs to be confirmed with well-designed large-scale clinical trials.

Transcatheter aortic valve implantation： a revolution in the therapy of elderly and high-risk patients with severe aortic stenosis

Transcatheter aortic valve implantation （TAV1） represents a real revolution in the field of interventional cardiology for the treatment of elderly or high-risk surgical patients with severe symptomatic aortic valve stenosis. Today, TAVI seems to play a key and a reliable role in the treatment of intermediate and maybe low-risk patients with severe aortic stenosis. TAVI has also evolved from a complex and hazardous procedure into an effective and safe therapy by the development of new generation devices. This article aims to review the background and future of TAVI, elinieal trials and registries with old and new generation TAVI devices and to focus on some open issues related to post-procedural outcomes.

Theoretical Analysis of Cold Storage Devices in a CO2 Transcritical/Subcritical Supermarket Refrigeration Plant

This paper proposes a theoretical study of a cold storage system in a CO2 （carbon dioxide） MT （medium temperature） plant for supermarkets application. The aim of this plant strategy is that in the daily hours the storage can export heat form the refrigerant outcoming the gas cooler/condenser whereas during the nightly hours it can be maintained cooled by this latter before its incoming into the evaporator. Besides, the storage can be used for reducing the energy peak consumption, permitting to size the plant on a lower energy target, and it can influence the choice of the optimisation logic of the plant controller, in this work a model for a MT CO2 transcritical/subcritical cycle, able to manage the transient due to the changes of loads and external conditions, is proposed to take into account the evolution with time in a fixed time step. A parametrical analysis has been conduced for understanding the optimal design of the plant. A seasonal analysis is considered too, for understanding the cold storage benefits in different periods of year.

The dam design of Three Gorges Project

The dam of Three Gorges Project is a concrete gravity dam with the crest elevation of 185 m,the maximum height of 181 m and dam axis length of 2 309.5 m.The dam consists of spillway,powerhouse,non-over flow,ship-lift,temporary ship-lock,left diversion wall and longitudinal cofferdam blocks.Some key techniques relating to dam structure design are presented,including hydraulics of flood discharge structure,dam joint design,layout and structural type of penstock,deep anti-sliding stability of dam foundation,reconstruction of temporary ship-lock and closed drainage and pumping of dam foundation.