某重型汽车空气压缩机替用管材料性能分析

重型载货汽车上的空气压缩机用通气管材料,通常使用精密冷拔镀锌无缝钢管进行再加工而成,再加工及运输时管材表面镀层易被划伤,防锈能力下降,同时电镀钝化工艺会产生大量废液,影响环境。铝合金材料自身拥有较好的耐腐蚀能力,通过对铝合金无缝管的折弯性能、耐腐蚀性、密封性、耐热性和经济性等方面的对比分析,铝合金无缝管满足作为空气压缩机用通气管的要求,是一种良好的空气压缩机钢管的替用管材。

一种虚拟现实三维空间图像缓存加速新方法

随着虚拟现实技术的更新,渲染硬件也有了新的进展,但是由于现存渲染技能的局限性,较为复杂大型的虚拟场景还是无法以足够高的帧频进行显示.立足于视点替用特效、场景层次细分等概念,提出一种加速三维空间图像缓存的新方法.经实验验证,该方法对于大规模的几何场景具有明显的加速绘制效果.

电喷汽油机甲醇燃料性能试验研究

通过采用甲醇和汽油双燃料供给装置、利用发动机尾气中的余热对甲醇燃料进行汽化、加大电喷汽油机喷油咀喷孔直径提高甲醇燃料循环供应量等技术方式,研究甲醇燃料对车用电喷汽油机性能的影响。试验结果表明,使用甲醇燃料的经济性要明显优于汽油燃料,同工况下甲醇燃料的排放明显低于汽油燃料。

同名不同剂型中成药的方效异同辨议

目的:探讨同名不同剂型中成药组方、功效的异同。方法:对国家中成药标准中同名不同剂型中成药(简称“同名异型中成药”)作统计。结果:组方与功效均相同的占同名异型中成药的64.40%;组方同功效不全同的有7.53%;组方不同功效相似的有24.46%;组方、功效均不同的有3.62%。结论:同名不同剂型中成药不能完全互换替用。

Peashrub Community May Accelerate the Successional Process in a Meadowland-Peashrub-Birch Sere

Net N mineralization and nitrification were determined using the closed_top PVC tube in situ incubation method in a subalpine meadow (Saussurea iodostegia Hance + Carex capillaris L.)→shagspine peashrub (Caragana jubata (Pall.) Poir) shrubland→ribbed birch (Betula costata Trautv.) successional sere. The ability of the three communities to supply available N was comparatively studied. The results showed that there were apparent seasonal changes in the inorganic N pools (including NH + 4_N and NO - 3_N) and net N mineralization and nitrification rates in the three sites. There were generally no significant differences in the inorganic N pools among sampling events. But the NH + 4_N concentration in both birch (P<0.01) and meadow (P<0.01) sites was significantly higher than that in peashrub site in June 1996, and the NO - 3_N concentration in peashrub site was significantly higher than that of meadow site (P<0.05) in August 1996. The annual net N mineralization and nitrification rates in peashrub site (16.01 kg·hm -2 ) were higher than in birch (12.05 kg·hm -2 ) and meadow sites (1.64 kg·hm -2 ). The annual net nitrification rate in peashrub site (11.37 kg·hm -2 ) was higher than in meadow site (10.90 kg·hm -2 ) and much lower than in birch site (14.36 kg·hm -2 ). We conclude that the ability of peashrub shrubland soil to supply available N for plant uptake and the ability to prevent available N from denitrification and leaching were higher than that of the other two sites. The leguminous peashrub might play a potential role in supplying more N, which in turn facilitate the invasion of birch saplings during the successional processes.

浮筒式铝浮盘的改进措施

目前浮筒式铝浮盘在我厂轻质油储罐中广泛使用,主要从浮筒式铝浮盘的破坏失效机制探讨浮筒式铝浮盘的改进甚至替用方向。

Study on Relative Bioavailability of Famotidine Sustained-release Tablets in Healthy Volunteers

The relative bioavailability of famotidine sustained release (SR) tablets was studied in 16 healthy male volunteers. Famotidine plasma concentration was determined by HPLC method, and the plasma concentration time data were processed with the method provided by USP XXIII. For single dose administration the peak plasma concentration occurring at 8 13±0 34 h was 69 52±3 00 ng/ml and the relative bioavailability was 112 4±8 6%. For multiple dose administration the peak plasma concentration of SR tablet was 86 14±2 95 ng/ml and the degree of fluctuation (DF) was 140 6±13 5% at steady state. Two one sided tests were performed in bioequivalence assessment. The results showed that the sustained release tablets were basically bioequivalent to the immediate release (IR) tablets on sale.

Electrochemical hydrogen storage performance of as-cast and as-spun RE-Mg-Ni-Co-Al-based alloys applied to Ni/MH battery

The La-Mg-Ni-Co-Al-based AB2-type La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1(x=0,0.05,0.1,0.15,0.2)alloys were prepared via melt spinning.The analyses of the X-ray diffraction(XRD)and scanning electron microscopy(SEM)proved that the experimental alloys contain the main phase LaMgNi4 and the second phase LaNi5.Increasing Y content and spinning rate lead to grain refinement and obvious change of the phase abundance without changing phase composition.Y substitution for La and melt spinning make the life-span of the alloys improved remarkably,which is attributed to the improvement of anti-oxidation,anti-pulverization and anti-corrosion abilities.In addition,the discharge capacity visibly decreases with increasing the Y content,while it firstly increases and then decreases with increasing spinning rate.The electrochemical kinetics increases to the optimum performance and then reduces with increasing spinning rate.Moreover,all the alloys achieve to the highest discharge capacities just at the initial cycle without activation.

并联DC/DC系统中高速无线通信接收装置的设计

为了解决并联DC/DC控制系统中信息高频、单次传输量小的问题,就目前基带处理平台功能单一、灵活性差、运算效率低等问题,提出了一种改进型基带处理方案。该方案以FPGA+DSP为处理架构,依托高性能器件和高速接口搭建了基带处理平台。分别从基带处理和射频前端两个方面对无线通信系统接收装置进行硬件设计,重点研究基带处理DSP与FPGA的接口设计和零中频架构射频前端,通过FPGA对本地振荡器、A/D进行动态配置,采用基于BPSK的软件无线电平台,通过编写程序进行测试,结果验证了该方案满足科研要求,且具有一定的通用性和灵活性。

Reduction of Praziquantel Elimination by Cimetidine in Rats

The effect of cimetidine on the elimination of praziquantel(PQT)in rats was studied. The results showed that cimetidine 100 mg/kg,ip 2 reduced the clearances of intravenous and oral PQT by 60 and 69 percent respectively.Cimetidine also markedly reduced liver blood flow of rats(a reduction of 58%)and inhibited PQT metabolism in hepatic microsomes of rats(an inhibition of 55%). The reduction in clearance of intravenous PQT could be attributed to the result of cimetidine lowering liver blood flow,whereas the reduction in clearance of oral PQT might be related mainly to the inhibition of cimetidine on the activity of hepatic drug-metabolizing enzymes.

Effect of Alternative Raw Materials on Resistance of Concrete to Chemical Actions

The results of experimental works aimed on finding the optimal composition of concretes containing alternative materials as mineral additives for assurance their high resistance to chemical aggressive attack are presented in the paper. 4 kinds of additives （blast furnace slag, fly ash, non-treated and treated serpentinite waste） and 4 kinds of aggressive environments （distilled water, HCI, MgSO4 and NaOH） representing the concrete corrosive processes was checked within experimental process. The open laboratory curing was used as a reference environment. Moreover, the amounts of additives were varied, so 16 various recipes were checked on the whole. The resistance of samples was tested in the terms of flexural strength, compressive strength and evaluation of decrease/increase of strengths after long time （28 months） exposition in monitored aggressive media. Based on obtained results, it is possible for each of aggressive environments recommend the most promising recipe from various points of view, in accordance with user＇s priorities. From the percentage increase of 28-day compressive strengths point of view, there are： for HCI action - recipe with 20% of non treated serpentinite waste with plasticizer application, for MgSO4 action - recipe with 20% of blast furnace slag without plasticizer application and for NaOH action - recipe with 10% of non treated serpentinite waste without plasticizer application. Application of alternative materials as partial substitution of cement appears to be beneficial for achievement the resistance to aggressive chemical actions. With the keeping or enhancement of technical parameters it extra represents both the environmental and economic benefit.

Value Generation through Integrated Teams： A Socio-Cognitive Approach

Value generation is defined as meeting client requirements while minimizing waste. Researchers concur on the issues related to sequential design in handling client requirements, and suggest the use of an integrated design approach as an alternative. Little has been said, however, about the impact of adopting integrated design＇s work organization to traditional design practice, processes and tools, nor about the importance of breaking down socio-cognitive barriers related to mental model fragmentation between design professionals, clients and users. This may result in cognitive inertia, a major source of waste. The objective of this research is to develop and test the introduction of boundary objects, such as new technologies, to the context of integrated teams and organizations to break the cognitive inertia that hinders value generation. The research is conclusive about the effectiveness of using boundary objects to transform practices in construction. This research also contributes to a better understanding of the new purposes of construction projects by framing its context and process dimensions within a theoretical framework, as well as to the evolution of practices in construction - and of practices that could be applicable to other fields.

Trichromatic Animation

The process described here is well at the heart of the appearance of pigmentary materials and their interactions with light. It is indeed based on the property of colored materials to reflect, in a selective way, the colored radiations of light. The innovation is here based on a more subtle and more complete process, using the trichromy, i.e., all the possibilities of the white light, which is split in three primary radiations： red^een--blue. One can, indeed, animate a pigmentary surface by the alternate projection of these three colors, and thus reveal three different images on the same support, or create a motion effect. However, in this process, the weakness of bhie, compared to green and red, might constitute an obstacle. But that will be compensated by the use of fluorescent colors, instead of ordinary colors. This process may provide very spectacular applications in the fields of lighting, architecture, design, scenography, booths, display windows, etc.. We shall propose a step-to-step approach.

Key substitution attacks on some verifiably encrypted signature schemes

As a special kind of digital signature, verifiably encrypted signatures are used as a building block to construct optimistic fair exchange. Many verifiably encrypted signature schemes have been proposed so far and most of them were proven secure under certain complexity assumptions. In this paper, however, we find that although some schemes are secure in a single-user setting, they are not secure in a multi-user setting any more. We show that Zhang, et al. ＇ s scheme, Gorantla, et al. ＇ s scheme and Ming, et al. ＇ s scheme are vulnerable to key substitution attacks, where an adversary can generate new keys satisfying legitimate verifiably encrypted signatures created by the legitimate users. We also show that this kind of attacks can breach the fairness when they are used in fair exchange in a multi-user setting.

Drug-Drug Interaction Studies of Levocetirizine with Atenolol

The objective of the study was to evaluate the drug-drug interaction studies of levoceterizine with atenolol. Calibration curve studies of working standard solutions of levocetirizine and atenolol （0.01-0.1 mmol） were scanned. Maxima appeared at 231 nm for levocetirizine and 224 nm for atenolol. The calibration curve obeyed Beer Lambert＇s Law. Lone availabilities of both the drugs were studied in pH 1, pH 4, pH 7.4 and pH 9 at 37℃ on B.P. （British Pharmacopoeia） dissolution apparatus. To study the drug-drug interaction of levocetirizine （5 mg tablet） and atenolol （100 mg tablet）, both the drugs were introduced to the dissolution apparatus in simulated gastric juice （pH 1）, pH 4, pH 7.4 and pH 9 at 37℃ at zero time and measured the absorbance maxima of both the drugs at the corresponding wavelength. Graphs were plotted for availability percentage （%） of drug versus time at each set of experiment. The availability percentage （%） of levocetirizine in the buffers of pH simulated to gastric pH 4, pH 7.4 and pH 9 in the presence of atenolol was 436.78%, 376.90%, 436.78% and 436.78%, respectively, but the availability of atenolol was increased up to 214.80%, 212.96%, 214.93% and 231.51% in simulated to gastric pH and in the buffers ofpH 4, pH 7.4 and pH 9, respectively. On the basis of these studies, it is concluded that levocetirizine forms a charge-complex with atenolol; therefore, co-administration of these drugs should be avoided.

Application of 2D Numerical Model to Unsteady Performance Evaluation of Vertical-Axis Tidal Current Turbine

Abstract Tidal current energy is renewable and sustainable, which is a promising altemative energy resource for the future elec- tricity supply. The straight-bladed vertical-axis turbine is regarded as a useful tool to capture the tidal current energy especially under low-speed conditions. A 2D unsteady numerical model based on Ansys-Fluent 12.0 is established to conduct the numerical simulation, which is validated by the corresponding experimental data. For the unsteady calculations, the SST model, 2x 105 and 0.01 s are se- lected as the proper turbulence model, mesh number, and time step, respectively. Detailed contours of the velocity distributions around the rotor blade foils have been provided for a flow field analysis. The tip speed ratio （TSR） determines the azimuth angle of the appearance of the torque peak, which occurs once for a blade in a single revolution. It is also found that simply increasing the incident flow velocity could not improve the turbine performance accordingly. The peaks of the averaged power and torque coeffi- cients appear at TSRs of 2.1 and 1.8, respectively. Furthermore, several shapes of the duct augmentation are proposed to improve the turbine performance by contracting the flow path gradually from the open mouth of the duct to the rotor. The duct augmentation can significantly enhance the power and torque output. Furthermore, the elliptic shape enables the best performance of the turbine. The numerical results prove the capability of the present 2D model for the unsteady hydrodynamics and an operating performance analy- sis of the vertical tidal stream turbine.

A Rational Reflection on the Application of Computer Assisted Instruction in Teaching

Nowadays, Computer Assisted Instruction is widespread in universities while the teaching effect is far from satisfying. Therefore. it is necessary to explore the current situation of Application of Computer Assisted Instruction, analyze irreplaceable advantages as well as causes of ineffectiveness in teaching, and and bring forward the approach to solving them.

A Critique on the Application of the Principle of Subsidiarity Concerning Human Embryonic Stem Cell Research in South Africa

Researchers from all around the world emphasize on the enormous possible benefits that stem cells may have for the treatment of diseases. However, this technology is considered morally problematic when the source of the stem cell is from a human embryo. Nonetheless, there is a consensus that of all the types of stem cells, hESC （human embryonic stem ceils） are the most promising for particular and important research and therapies. Yet, there are controversial issues regarding the ＂killing＂ of the human embryo for stem cell derivation. There are two general ethical conditions that should govern the instrumental use of embryo. One of them, the principle of subsidiarity, which is defined as ＂a state we have that we have to choose the less contentious means of achieving the intended goal＂. Based on this principle, we ought only to use hESC when there are no other alternatives, which are less morally controversially. Subsidiarity is based on the assumption that there is something ethically unsound about the use ofhESC. However, this principle only makes sense if it is based on consistently upheld views of the moral status of embryo, moreover, the law should also not limit or prohibit hESC research based on this principle. In this paper, I argue---using the South African law for hESC technology--that criterion for deciding which type of stem cells to use should be based on their potential and suitability for advancing scientific knowledge and development of new therapies which will be greatly beneficial in alleviating human suffering.

The Effects of Size-fractionated Fish Hydrolysate in the Diet on Growth, and Feed Utilization of Turbot （Scophthalmus maximus）

Four experimental diets were fed to turbet to examine the effect of fish bydrolyside and ultra filtered fish hydrolysafe on growth performate feed utilization and growth regulation using diets low in dietary fish meal inclusion. Diets A, B contained 3.7%,1.2% fish hydrolysate to replace fish meal respectively and the fish hydrolysate in two diets was ultra filtered to keep low molecular weight compounds. The diets A,