柔性桩复合地基承载力计算方法探讨

针对柔性桩复合地基承载力计算的复杂性和不确定性,本文对柔性桩复合地基承载力的计算方法进行探讨,选取指数函数为位移函数,根据弹性理论推导计算了桩体竖向位移、承载力及桩周的侧摩阻力。通过对实际工程的计算比较计算与实测结果,并分析了计算与实测结果存在差异的原因。     

反应—膜分离耦合过程的传质特性

在中空纤维膜系统中用纯水及不同浓度的氢氧化钠溶液和二氧化碳混合气进行反应分离，研究了膜分离与化学反应耦合过程的特性，在低二氧化碳进口摩尔分率、低气速及办高氢氧化钠浓度时，化学反应对分离的增强因子非常大。在反应－膜分离耦合体系中，过程阻力与中空纤维膜自身的阻力及溶液中的反应速度有很大关系。由于增加了中空纤维膜阻力，使得二氧化碳的吸收率比较小，但是增加中空纤维数目可以使膜分离器具有巨大的传质表面积，从     

海水绕流扬矿管边界层分析

介绍不同雷诺数下海水绕流深海扬矿管的流动情况,分析管面形成层流及湍流边界层的分离过程,比较二者分离点的位置及压差阻力情况,分析绕流阻力和举力的形成过程、计算方法、影响因素及相应的减阻措施。     

Mo/Cu爆炸复合棒界面组织特征

本研究用爆炸复合方法制备出钼／铜（Mo／Cu）双金属复合棒，并利用金相显微镜（OM）、扫描电子显微镜（SEM）和能谱（EDS）、显微硬度、压剪分离等实验手段分析了复合界面的组织特征及力学性能。结果表明：在Mo／Cu复合界面附近形成了熔区；结合界面的强度比Cu基体强度高；熔区的硬度高于基体硬度；熔区的成分以Cu为主；并对Mo基体经常出现裂纹的原因进行了分析。     

高铬复合辊中铬偏析对剥落的影响

分析了高铬复合辊中铬偏析形成的原因及对剥落的影响。铬偏析影响共晶碳化物的组成及形态,控制组织对裂纹扩展的阻力,对轧辊的使用性能有直接的影响。     

海水绕流场矿管边界层分析

介绍不同雷诺数下海水绕深海扬矿管的流动情况，分析管面形成层流及湍流边界层的分离过程，比较二者分离点的位置及压差阻力情况，分析绕流阻力和举力的形成过程、计算方法、影响因素及相应的减阻措施。     

分步结晶法分离砷碱的工艺研究

在开展炼锑砷碱渣综合回收利用关键技术研究中,针对砷、碱难以分离的技术难题,研究在高温条件下,利用砷酸钠和碳酸钠在溶解度上的差异,采用分步结晶的方法,优先结晶分离出碳酸钠,实现砷酸钠和碳酸钠高效分离,并探讨了结晶碱通过饱和碳酸钠溶浸继续深度分离砷碱的工艺,分离获得的砷酸钠复合盐能达到市场上用作玻璃澄清剂需要的砷酸钠复合盐要求。     

用于延性断裂韧性测试的载荷分离方法与应用

使用载荷分离理论的延性断裂韧性单试样方法,选取汽轮机转子钢Cr2Ni2MoV对规则化法和S_Pb分离参数法进行了研究.结果表明,在规则化法中,钝化修正时的钝化线方程仅对裂纹扩展较小时的J阻力曲线产生影响.提出了改进S_Pb分离参数法,消除了参考钝裂纹试样的影响;同时采用钝化修正后的初始裂纹长度和试验终止裂纹长度进行标定,可获得合理的裂纹长度预测结果.由改进S_Pb分离参数法得到J阻力曲线在较小裂纹扩展范围内均略高于由规则化法得到的J阻力曲线,而当裂纹产生扩展较大时,两种方法得到的J阻力曲线几乎完全重合;由规则化法得到的条件启裂J积分J_Q值偏于保守.     

复合顶板条件下沿空留巷力学参数研究

以军城煤矿31203复合顶板薄煤层综采工作面为工程背景,在复合顶板综采工作面采用无煤柱护巷技术基础上,建立了沿空留巷围岩力学模型,对巷旁支护阻力、切顶力学参数、顶板下沉量等进行理论计算,并采用FLAC3D数值模拟软件研究了复杂顶板条件下薄煤层大断面沿空留巷力学参数,研究成果可为军城煤矿复合顶板条件下薄煤层大断面沿空留巷提供理论依据。     

双层复合熔剂性球团的开发研究

为了改善高炉炉料的冶金性能,提出了中心为高碱度烧结矿、外层为酸性多孔氧化镁质结构的双层复合熔剂性新型球团.试验研究表明:双层复合熔剂性球团的生球强度可满足高炉原料的质量要求,其熟球具有优良的高温冶金性能.该种球团的内核主要由赤铁矿组成,焙烧时中心不会出现过热,并可避免传统酸性球团"还原停滞"问题.动力学分析表明,双层复合熔剂性球团在还原过程中的总阻力低于普通熔剂性球团.     

Hardening due to pre-existing ϵ-Martensite in an Fe-30Mn-1Si alloy single crystal

Plastic flol of an Fe-30Mn-1Si alloy single crystal has been examined belol and above the M_d temperature. By conducting a tlo step deformation test, it has been found that pre-injected ϵ-plates produce extremely large resistance against motion of either perfect or partial dislocations crossing them, in contrast to the relatively small hardening observed in the identical test of an Fe-18Cr-14Ni alloy. This has been discussed in terms of the dislocation pile-up and the resistance to plastic deformation in the blocking ϵ plates. Collision to and penetration through pre-injected ϵ plates of a groling ϵ plate have been examined under an electron microscope.     

Processing and characterization of plasma-sprayed ceramic coatings on steel substrate: Part II. On coating performance

This investigation envisages the performance evaluation of a series of plasma-sprayed coatings from a few inexpensive powders, namely, alumina, plasma dissociated zircon (PDZ), zircon sand, and zircon-20 wt pct calcia. The hardness and adhesion (bond) strength of the coatings have been evaluated. All coatings offer an attractive thermal fatigue property. An added layer of yttria between the top and bond coats improves the thermal fatigue resistance appreciably. The wear performance of these coatings has also been evaluated using a “pin-on-disc” type wear testing setup. The Indian alumina coating offers a superior wear resistance and thermal fatigue property compared to an imported alumina coating. The coatings based on zirconia-silica offer an attractive thermal fatigue resistance along with an acceptable wear resistance. The latter improves considerably upon annealing of the coatings because of the removal of the residual stresses accumulated during deposition. Among these zirconia-silica-based coatings, the zircon-20 wt pct calcia is the most promising. The finishability of these coatings has been studied using a surface grinding setup equipped with a diamond wheel. The cutting forces and the surface roughness of the ground surface have been measured. The coatings have been found to possess a reasonably good grindability.     

Corrosion-resistant coating for GTE compressor parts made of steels with low tempering temperatures

The corrosion resistance of an Ni–Co–Cr–Al–Si–Y + SPh (SPh is silicophosphate impregnation) alloy coating on 30Kh13, 38Kh2MYuA, VKS5, and VKS7 structural steels with low tempering temperatures has been studied. The steel–coating compositions have been tested to determine the accelerated cyclic corrosion resistance, the corrosion resistance under tropic climate chamber conditions and in salt fog, the stress corrosion resistance, and the corrosion resistance in an industrial atmosphere. The heat stability of coated samples is studied, metallographic studies of the samples before and after the tests are performed, and the influence of the coating on the strength characteristics of the structural steels is studied.     

Resistance.

This article reviews extant literature on how patient resistance has been defined and its effects on psychotherapy. Resistance has been considered as both a patient-in-treatment state and as an enduring trait. In either form, patient resistance seems to interfere with treatment outcome. Resistance also functions as a moderating variable in determining the effectiveness of different levels of therapist directiveness. The evidence that patients who enter treatment with high levels of trait like resistance will benefit most from nondirective interventions is moderately strong. Conversely, those who enter treatment with low levels of trait like resistance benefit most from therapist directed interventions. Therapeutic practices associated with the research evidence are advanced. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The fracture resistance of directionally solidified dual-phase NiAl reinforced with refractory metals

The fracture resistance of two directionally-solidified, NiAl refractory metal systems has been measured and analyzed. One system, NiAl/Mo, has a microstructure consisting of Mo rods. The second system, NiAl/Cr(Mo), has a layered microstructure. Both materials are found to have an appreciably higher initiation toughness than NiAl, followed by a rising resistance, with the layered microstructure giving the superior properties. The results have been rationalized by available models based on the following three mechanisms: crack trapping, crack renucleation and ductile phase bridging.     

Development of quinolone-resistant Campylobacter fetus bacteremia in human immunodeficiency virus-infected patients

Campylobacter fetus subspecies fetus has been recognized as a cause of systemic illness in immunocompromised hosts, including relapsing bacteremia in human immunodeficiency virus (HIV)-infected patients. Acquired resistance to quinolone therapy, while reported for a variety of bacteria, including Campylobacter jejuni, has not been previously documented for C. fetus. Two cases of quinolone-resistant C. fetus bacteremia were detected in HIV-infected patients. Cloning and nucleotide sequencing of the C. fetus gyrA gene in the 2 resistant isolates demonstrated a G-to-T change that led to an Asp-to-Tyr amino acid substitution at a critical residue frequently associated with quinolone resistance. In addition, comparison of the pre- and posttreatment isolates from 1 patient documented outer membrane protein changes temporally linked with the development of resistance. Relapsing C. fetus infections in quinolone-treated HIV-infected patients may be associated with the acquisition of resistance to these agents, and this resistance may be multifactorial.     

A closer look at vancomycin, teicoplanin, and antimicrobial resistance

The worldwide increase in the incidence of resistant Gram-positive infections has renewed interest in the glycopeptide class of antimicrobial agents. Two glycopeptides are available in many parts of the world--vancomycin and teicoplanin. These two agents appear to differ in several respects, including: potential for selecting microbial resistance, dosing convenience, safety, and efficacy in severe infection. Teicoplanin appears to have lower toxicity and greater convenience; however, its widespread acceptance has been plagued by concerns over antimicrobial resistance, efficacy, and appropriate dosing. A review of available studies suggests that teicoplanin, when dosed at 6 mg/kg/day, is better tolerated than vancomycin 15 mg/kg/q12h; however, at these doses, it appears to be somewhat less effective than vancomycin in serious Staphylococcus aureus infection, such as endocarditis. Although higher doses of teicoplanin, 12 mg/kg/day to 30 mg/kg/day, have been associated with efficacy comparable to that of vancomycin in serious S. aureus infections, such doses may eliminate some of the safety advantages conferred by lower teicoplanin doses. Teicoplanin has been associated with resistance among coagulase-negative staphylococci and the selection of resistance in S. aureus. There is some evidence that widespread use of teicoplanin might accelerate the development of S. aureus resistance to both teicoplanin and vancomycin. The selection of an appropriate glycopeptide in an individual patient should be based not only on convenience, but also on a determination of optimal efficacy, safety at an efficacious dose, and the potential for resistance.     

低成本耐候钢的高温热变形行为

 通过在MMS100 SIMULATOR热/力模拟实验机上的热压缩实验,研究了不同热变形条件下耐候钢的变形抗力,考察了变形温度、应变速率及变形程度与变形抗力之间的关系。结果表明：变形温度和应变速率对耐候钢变形抗力的影响最强烈;耐候钢的变形抗力随变形温度的升高而下降,随应变速率的提高而增大。用实测值回归出了耐候钢的新型变形抗力模型,而且该模型具有较高的拟合精度。     

Investigation of the corrosion resistance of nanopowders of refractory borides and carbides in electrolytic solutions

Solubility of nanopowders of vanadium, titanium, chromium, and zirconium borides and carbides and of silicon carbide has been studied in standard electrolytes used for nickel plating. As the objects of the investigation, nanopowders with the contents of the main phase of 92.6–95.3% and an average particle size of 35–62 nm have been used. Their corrosion resistance was estimated depending on the electrolyte acidity, temperature, and duration of the interaction. It has been established that within each group of compounds the nanopowders are close in terms of their corrosion resistance in the electrolytic solutions and are characterized by an unlimited induction period in alkaline media, except for the silicon-carbide nanopowder, which is stable in solutions of any acidity.     

A fundamental study of 99mTc-HMPAO double injection method and clinical application to stress scintigraphy in orthostatic hypotension

Enterococcus faecium, which was highly resistant to vancomycin (MIC 256 mg/liter), but susceptible to teicoplanin (MIC 2 mg/liter), caused two distinct episodes of infection on a renal unit in the United Kingdom. Pulsed field gel electrophoresis (PFGE) indicated that a single strain caused the first episode, while the second episode, which occurred 1 year later, involved multiple strains, all of which were distinct from the original strain. Vancomycin resistance in all but one of these strains was mediated by transferable plasmids that carried the vanB glycopeptide resistance gene. Transfer either of resistance plasmids or the vanB resistance determinant itself to different strains occurred during the second episode. Plasmid-mediated vanB resistance has not been widely documented. A retrospective study of a reference collection revealed two other vanB-encoding plasmids from an E. faecalis and an E. faecium referred from two further UK centers. Although restriction analysis indicated no similarity between the plasmids from the three different centers, all contained a 2.1-kb EcoRV fragment that hybridized with a probe for the vanB gene. This suggests that there has been dissemination of a conserved glycopeptide resistance determinant, of which vanB is a part.