临湘市铁山咀泵站工程泵基处理方案分析比较

临湘市铁山咀该泵站工程主泵房基础为淤泥质粉质壤土,该土层呈软塑状、压缩性较高、承载力较低。为此,对比分析了目前常用的几种处理方法,结合工程实际情况,提出适合该类淤泥质粉质壤土基础的处理方案,并对施工技术条件、基础工程质量控制、工程投资等方面进行了技术经济综合比选,优选出适宜本工程的泵基基础处理的最佳方案。

GaSb基光泵浦半导体碟片激光器的研究进展(特邀)

GaSb基光泵浦半导体碟片激光器(OP-SDLs)可以获得高光束质量和高功率的红外激光输出,是近年来新型中红外激光器件研究领域的热点。文中介绍了GaSb基光泵浦半导体碟片激光器增益芯片的外延结构和工作原理,综述了2μm波段GaSb基泵浦半导体碟片激光器的研究进展,讨论了该类激光器的波长扩展、功率提升、实现窄线宽短脉冲发射和有效热管理关键问题,评述了性能发展的主要技术方向和应用前景。

浅析如何避免乳胶基质泵压力超高联锁停机现象

分析了冬季生产乳化炸药时,乳胶基质泵压力超高的多方面原因,阐述了冬季作业环境变化而引起的乳胶基质黏度增大,而导致基质泵管路压力上升的原因,并提出了行之有效的防控措施。

Design of a CMOS Current-Adjustable Charge-Pump Circuit Insensitive to Power Supply and Temperature

A CMOS charge-pump circuit with adjustable current is presented.A bandgap voltage reference,a low drop-out regulator,and a capacitive DC-DC voltage-booster are used to generate supply voltage for the current reference.This generated voltage is insensitive to the changes of external power supply voltage and temperature,while the current reference itself is insensitive to temperature.The circuit is designed in 0.18μm 1.8V standard digital CMOS process.The simulated results show that the performance of the circuit is satisfied.

DCS控制系统在低温静态乳化炸药中的应用

为探讨DCS控制系统在低温静态乳化炸药中的应用,以马鞍山江南化工有限责任公司乳化炸药生产线改造为背景,分别从工艺流程、关键控制参数、DCS控制实现原理等多方面介绍了低温静态乳化工艺条件下的DCS控制系统。低温静态乳化炸药生产工艺实现了生产的本质安全,是响应国家政策同时行业积极推广的一种乳化炸药生产工艺,DCS控制系统的稳定运行对本工艺的推广起到了很好的作用。

粗乳器对乳化质量影响的研究

本文主要针对民爆炸药生产线试生产过程中常发生的设备故障,制乳中产品质量不稳定引起的一系列问题,本文结合乳化炸药粗乳器的使用过程中出现的影响乳胶质量问题,通过改进粗乳器的进料方式和安装方式后的达到良好效果,使乳胶基质的性能稳定,乳胶泵输送压力稳定在安全范围内,解决乳化炸药储存期质量稳定问题。

Effect of antisense transfecting of monocarboxylate transporter gene on biological characteristics of lung adenocarcinoma A549 cells

Objective: To study the influence of transfecting antisense expression vector of the first subtype of the monocarboxylate transporter (MCT1) gene into lung cancer cells on pHi regulation, lactate transportation and cell growth. Methods: MCT1 antisense gene recombinant vector was introduced into human lung cancer cell line A549 by electroporation. The transfected A549 cells resistant to G418 were selected. Positive clones were examined by using PCR. The changes of intracellular pH and lactate were examined with spec-trophotometric method. Cell growth was studied with cell growth curve. Results: Intracellular pH and lactate were remarkably decreased in the cells transfected pLXSN-MCT1 in comparison with A549 cells without transfection (P<0. 001). The growth of A549 cells transfected pLXSN-MCTl was also inhibited remarkably. Conclusion: MCT1 gene may play an important role in pHi regulation, lactate transportation and cell growth in tumor cells.

Factors associated with irritable bowel syndrome symptoms in hemodialysis patients

AIM: To investigate clinical characteristics associated with the presence of irritable bowel syndrome (IBS) symptoms in hemodialysis (HD) patients.METHODS: This was a cross-sectional study. A questionnaire based on the Bowel Disease Questionnaire that records gastrointestinal symptoms was given to 294 patients in 4 dialysis centers. A total of 196 (67%) subjects returned the survey. A multivariable logistic regression model was used to identify factors significantly associated with IBS symptoms. RESULTS: Symptoms compatible with IBS were present in 27 (13.8%) subjects and independently associated with low post-dialysis serum potassium [OR = 0.258, 95% CI (0.075-0.891), P = 0.032], paracetamol use [OR = 3.159, 95% CI (1.214-8.220), P = 0.018], and Kidney Disease Quality of Life (KDQOL) cognitive function score [OR = 0.977, 95% CI (0.956-0.999), P = 0.042]. Univariate regressions were also performed and the reported significance is for multivariate analysis. No association was detected for age, gender, depressed mood, smoking (present or past), body mass index, albumin level, Kt/V, sodium preor post-dialysis level, change in potassium level during HD, proton pump inhibitor or H2 blocker use, aspirin use, residual diuresis, hepatitis B or C infection, diabetes mellitus, marital status and education level. CONCLUSION: This study examined potential risk factors for symptoms compatible with IBS in HD patients and identified an association with paracetamol use, post-dialysis potassium level and KDQOL-cognitive function score.

Electromagnetic Pump Made in a Hybrid Polymer-Ceramic Technology--Preliminary Results

This paper describes technology of the electromagnetic pump made in a hybrid polymer-ceramic technology. The pumping mechanism is realized with a mutual excitation between an electromagnetic coil and a neodymium magnet bonded to a flexible membrane. A PDMS （poly（dimethylsiloxane）） material was used to manufacture a membrane sufficient for the presented micropump. A fish trap construction is adapted to the ceramic technology. The bonding process of ceramics and polymer, using plasma oxidation method, is described as well. Moreover, a membrane deflection depending on magnet dimensions and applied voltage was measured.

Introduction of the Archimedean Screw Pump to East Asia during the Seventeenth and Eighteenth Centuries

The Jesuits played an important role in the transmission of Western science and technology to China during the seventeenth and eighteenth centuries,though their impact on water technology has received scant attention thus far.As a case in point,Sabatino de Ursis,Society of Jesus熊三拔,in collaboration with the Chinese official Xu Guangqi徐光啟,published in 1612 Hydraulic Methods of the Far West(Taixi shuifa泰西水法),the earliest book in China on Western water-lifting devices,which contained a detailed description of the Archimedean screw pump.While the impact of the Archimedean screw pump in China and Korea remained rather limited,the screw pump was used to drain water from gold mines in the Japanese Sado Island from as early as 1637.This fact became known in the West only in the very late 1800s when hand-colored picture scrolls about the Japanese gold mining process became available.These scrolls show various applications of Archimedean screw,which apparently were made according to the manufacturing instructions in Hydraulic Methods of the Far West.

Clopidogrel and proton pump inhibitors-where do we stand in 2012?

Clopidogrel in association with aspirine is considered state of the art of medical treatment for acute coronary syndrome by reducing the risk of new ischemic events.Concomitant treatment with proton pump inhibitors in order to prevent gastrointestinal side effects is recommended by clinical guidelines.Clopidogrel needs metabolic activation predominantly by the hepatic cytochrome P450 isoenzyme Cytochrome 2C19(CYP2C19) and proton pump inhibitors(PPIs) are extensively metabolized by the CYP2C19 isoenzyme as well.Several pharmacodynamic studies investigating a potential clopidogrel-PPI interaction found a significant decrease of the clopidogrel platelet antiaggregation effect for omeprazole,but not for pantoprazole.Initial clinical cohort studies in 2009 reported an increased risk for adverse cardiovascular events,when under clopidogrel and PPI treatment at the same time.These observations led the United States Food and Drug Administration and the European Medecines Agency to discourage the combination of clopidogrel and PPI(especially omeprazole) in the same year.In contrast,more recent retrospective cohort studies including propensity score matching and the only existing randomized trial have not shown any difference concerning adverse cardiovascular events when concomitantly on clopidogrel and PPI or only on clopidogrel.Three meta-analyses report an inverse correlation between clopidogrel-PPI interaction and study quality,with high and moderate quality studies not reporting any association,rising concern about unmeasured confounders biasing the low quality studies.Thus,no definite evidence exists for an effect on mortality.Because PPI induced risk reduction clearly overweighs the possible adverse cardiovascular risk in patients with high risk of gastrointestinal bleeding,combination of clopidogrel with the less CYP2C19 inhibiting pantoprazole should be recommended.

The Human PsB-ATPase ATP13A2 Is Not a Ca2＊ Transporting Pump

The human gene ATP 13A2 has been proposed to code for an ATP powered ion transporter of the PsB subfamily. Mutations of the human gene ATP1 3A2 were found to underlie an autosomal recessive form of early-onset parkinsonism （PD） with pyramidal degeneration and dementia. The ion transported by the ATP13A2 pump is not known, but several studies have shown that the Ps-ATPases influence the homeostasis of intracellular Ca2＋, and thus it has been suggested that they transport Ca2＋. In order to evaluate this possibility Chinese hamster ovary （CHO） cells stably expressing the human ATP13A2 protein have been obtained and the Ca2＋ transport activity of ATP 13A2 was assessed by measuring the ATP-dependent uptake of Ca2＋ into microsomal vesicles. As a positive control vesicles containing the human plasma membrane Ca2＋ pump （PMCA） were used. No significant differences were found between vesicles containing the ATP 13A2 protein and the control. Moreover, Ca2＋ was unable to induce the formation of the P-ATPase acylphosphate intermediate in vesicles containing the expressed ATPl3A2. These results favor the idea that the ATPI3A2 does not transport Ca2＋.

Multi-objective optimization of a mixed-flow pump impeller using modified NSGA-II algorithm

In order to maintain a uniform distribution of pareto-front solutions, a modified NSGA-II algorithm coupled with a dynamic crowding distance(DCD) method is proposed for the multi-objective optimization of a mixed-flow pump impeller. With the pump meridional section fixed, ten variables along the shroud and hub are selected to control the blade load by using a three-dimensional inverse design method. Hydraulic efficiency, along with impeller head, is applied as an optimization objective; and a radial basis neural network(RBNN) is adopted to approximate the objective function with 82 training samples. Local sensitivity analysis shows that decision variables have different impacts on the optimization objectives. Instead of randomly selecting one solution to implement, a technique for ordering preferences by similarity to ideal solution(TOPSIS) is introduced to select the best compromise solution(BCS) from pareto-front sets. The proposed method is applied to optimize the baseline model, i.e. a mixed- flow waterjet pump whose specific speed is 508 min?1?m3s?1?m. The performance of the waterjet pump was experimentally tested. Compared with the baseline model, the optimized impeller has a better hydraulic efficiency of 92% as well as a higher impeller head at the design operation point. Furthermore, the off-design performance is improved with a wider highefficiency operation range. After optimization, velocity gradients on the suction surface are smoother and flow separations are eliminated at the blade inlet part. Thus, the authors believe the proposed method is helpful for optimizing the mixed-flow pumps.

On-chip fast mixing by a rotary peristaltic micropump with a single structural layer

In this work,a rotary pump based micromixer for on-chip rapid mixing and liquid transportation is demonstrated and characterized.Both pumping and mixing are realized using a microfluidic chip with a single structural polydimethylsiloxane layer and a portable electric control system.The rotary pump consists of an annular channel and is driven by a motor and magnets.The flow field caused by the peristaltic movement of the channel membrane of the rotary pump is simulated and analyzed.By statistically calculating and comparing the normalized standard deviations of the flow velocity components in a microchannel,it is revealed that up-and-down mixing is the fastest,followed by segment mixing and parallel mixing.Two mixing styles,segment mixing and parallel mixing,were experimentally demonstrated using the chip.The pump achieved 90% of the mixing index in 1 s for the segment mixing type.As for the parallel mixing type,the mixing index was up to 90% after 5 s,which is more than 100-fold improvement compared to conventional mixing by interfacial diffusion.The mixing speeds in both directions were improved prominently by increasing the rotational speed of the pump.

Performance of DRA with different pumping schemes based on coupling equation

After the coupling equations of co-pumping,counter-pumping and bidirectional-pumping distributed Raman amplifiers(DRAs) are theoretically analyzed,the power distributions of these three DRAs are acquired with numerical analysis.The performance factors,such as net gain(NG),amplified spontaneous emissions(ASE) noise,double Rayleigh backscattering(DRB) noise,noise figure(NF) and optical signal noise ratio(OSNR),are discussed in depth.It can be found that the NGs of the three DRAs are almost equal.The counter-pumping scheme will induce higher ASE.And the co-pumping DRA has greater DRB noise,but its NF and OSNR are both better than the others'.Furthermore,the relations between signal power and NG,NF,OSNR are also investigated.It is shown that the NF and OSNR of the co-pumping scheme are superior to those of the other two schemes at small input signal power.The above conclusions can play a very important role in guiding the optimum design of DRA.