绝对节点坐标列式流体单元建模方法及在液体晃动问题中的研究

计算流体力学的建模方法主要采用欧拉描述,而多体系统动力学的建模方法主要采用拉格朗日描述。与欧拉描述关注于流过空间固定点或固定体积上的流场状态不同,绝对节点坐标列式流体单元采用拉格朗日描述,能够跟踪流体物质点,建立流体与多体系统的统一描述。该文在绝对节点坐标列式流体单元方法基础上,提出和完善单元建模理论,并使用绝对节点坐标列式流体单元实现了对流体系统的建模,并首次将绝对节点坐标列式流体单元应用于液体晃动分析,初步验证了理论的正确性和可行性。仿真结果表明,在单元数量较少情况下,绝对节点坐标列式流体单元可以满足晃动计算需求。     

诱导气流对转载点雾化特性影响规律的数值模拟与试验

为了解决疏水性煤尘难润湿、微米级粉尘降尘率较低等难题,选取1-丁基-3-甲基咪唑氯盐([Bmim][Cl])、1-丁基-3-甲基咪唑四氟硼酸盐([Bmim][BF₄])、1-乙基-3-甲基咪唑四氟硼酸盐([Emim][BF₄])3种咪唑类离子液体,开展不同变质程度的煤尘表面润湿特性试验研究,分析不同阳、阴离子数的复配活性水溶液对煤尘润湿性能的影响规律。结果表明,阳离子[Emim]⁺和[Bmim]⁺能有效屏蔽阴离子[BF₄]^-、Cl^-之间的静电相互作用,促进阴离子在气—液界面之间的吸附和聚集,致使表面张力、接触角均随活性水溶液的离子液体质量分数的增大而逐渐降低;咪唑阳离子侧链上的H原子与煤中的—OH、—COOH等基团形成氢键,破坏了煤中原有氢键,提高了离子液体对煤的溶解能力,长焰煤的润湿效果最好,褐煤次之,焦煤最差;复配后的活性水溶液通过破坏煤中官能团增强了对煤结构的溶解能力,降低了水的表面张力并提高溶液的润湿能力,复配溶液实现了协同增润作用,可为开发新型润湿剂提供新的思路和方向。

     

同位素稀释-超高效液相色谱-串联质谱法测定谷物中隐蔽型伏马菌素

目的 建立谷物中隐蔽型伏马菌素的同位素稀释.超高效液相色谱.串联质谱测定方法.方法 谷物样品溶剂提取后,一部分稀释后用于原型伏马菌素(FBs)检测,另一部分经碱水解后经强阴离子交换(MAX)柱净化用于水解型伏马菌素(HFBs)检测.0.2％甲酸甲醇-0.2％甲酸水作为流动相梯度洗脱,CORTECS C18色谱柱(2.1...     

离子液体在萃取分离中的应用现状与发展趋势

近几年,离子液体作为一种新型理想的“绿色溶剂”已广泛应用于湿法冶金行业。本文主要阐述了离子液体的发展、种类以及性质,并对离子液体作为萃取溶剂萃取分离碱金属、碱土金属、重金属以及过渡金属离子进行了评述。归纳发现：在咪唑类离子液体中加入螯合剂,可以提高萃取率,而且含有醇硫官能团的咪唑类离子液体对许多金属离子的萃取分离都有明显的效果;离子液体萃取与电沉积相结合可以成功分离出碱金属和碱土金属;还有一些功能化离子液体用在工业废水和公共污水中萃取重金属离子的效率颇高;离子液体萃取过渡金属离子的能力比较薄弱需要加入其他萃取剂加以增强。本文对离子液体萃取分离的应用现状指出了问题,展望了其未来的发展方向。     

Amelioration of Cyclosporine A-Induced Acute Nephrotoxicity by Cordyceps cicadae Mycelia via Mg+2 Reabsorption and the Inhibition of GRP78-IRE1-CHOP Pathway: In Vivo and In Vitro

Fruiting bodies of Cordyceps cicadae (CC) have been reported to have a therapeutic effect in chronic kidney disease. Due to the rare and expensive resources from natural habitats, artificially cultivated mycelia using submerged liquid cultivation of CC (CCM) have been recently developed as an alternative to scarce sources of CC. However, little is known regarding potential protective effects of CCM against cyclosporine A (CsA)-induced acute nephrotoxicity in vivo and in vitro. In this study, male Sprague-Dawley rats were divided into six groups: control, CCM (40 mg and 400 mg/kg, orally), CsA (10 mg/kg, oral gavage), and CsA + CCM (40 mg and 400 mg/kg, orally). At the end of the study on day 8, all rats were sacrificed, and the blood and kidneys retrieved. CsA-induced acute nephrotoxicity was evident by increased levels of blood urea nitrogen (BUN). Levels of the endoplasmic reticulum (ER) resident chaperone glucose regulated protein 78 (GRP 78) were increased significantly in rats with acute nephrotoxicity. BUN and GRP 78 were significantly ameliorated in synchronous oral groups of CCM (40 or 400 mg/kg) plus CsA. Examination of hematoxylin and eosin stained kidney tissues revealed that the combined treatment of CCM slightly improved vacuolization in renal tubules upon CsA-induced damage. CsA-induced down-regulation of protein expression of magnesium ion channel proteins and transient receptor potential melastatin 6 and 7 were abolished by the combined treatment of CCM. CCM has the potential to protect the kidney against CsA-induced nephrotoxicity by reducing magnesium ion wasting, tubular cell damage, and ER stress demonstrated further by human renal proximal tubular epithelial cell line HK-2. Our results contribute to the in-depth understanding of the role of polysaccharides and nucleobases as the main secondary metabolites of CCM in the defense system of renal functions in CsA-induced acute nephrotoxicity.     

Theoretical Study of Charge Mobility in Crystal Porphine and a Computer Design of a Porphine-Based Semiconductive Discotic Liquid Mesophase

Organic semiconductors are the focus of numerous studies; they are used in electronic devices. Modern research involves the production of neuromorphic organic materials, including those based on liquid crystal materials. The purpose of this work involves the theoretical modeling of molecules (the “core with branches” type) to construct a discotic mesophase capable of performing the functions of a neuromorphic material. For this purpose, the conductivity of crystal porphine, which can act as the nucleus of a molecule of the “core with branches” type, was investigated. The Marcus theory charge mobility values for the hole and electron were 0.148 and 0.088 cm²/V·s, respectively (the MOO method for calculating transfer integrals), and 0.561 and 0.160 cm²/V·s (DIPRO method). Based on TD-HF (HF-3c level of theory) calculations, possible structures of molecules for the formation of a discotic mesophase are proposed.     

Improvement of a Surfactant Blend for Enhanced Oil Recovery in Carbonate Reservoirs by Means of an Ionic Liquid

The promising experimental performance of surfactant blends encourages their use in recovering the large quantity of crude oil still remaining in carbonate reservoirs. Phase behavior studies were carried out in this work to propose a blend for practical application. To that aim, the surfactants dioctyl sulfosuccinate sodium (AOT) and polyoxyethylene(8) octyl ether carboxylic acid (Akypo LF2) were mixed. A formulation consisting of 1 wt% of AOT_50wt%/LF2_50wt% blend in synthetic sea water (SSW) led to a low value of interfacial tension with crude oil of 1.50·10⁻² mN/m, and 0.42 mg/g_rock of dynamic adsorption. A moderate additional oil recovery (7.3% of the original oil in place) was achieved in a core flooding test. To improve this performance, the surface-active ionic liquid 1-dodecyl-3-methylimidazolium bromide ([C₁₂mim]Br) was added to the system. The electrostatic interactions between the oppositely charged surfactants (AOT and [C₁₂mim]Br) led to a higher surface activity. Thus, a formulation consisting of 0.8 wt% of AOT_20.7wt%/[C₁₂mim]Br_25.3wt%/LF2_54wt% in SSW reduced the interfacial tension and surfactant adsorption achieved with the binary blend to 1.14 × 10⁻² mN/m and 0.21 mg/g_rock, respectively. The additional oil recovery achieved with the blend containing the ionic liquid was 11.5% of the original oil in place, significantly improving the efficiency of the binary blend.     

耦合孪生晶体塑性模型硬化参数的灵敏度分析

基于经典晶体塑性理论,建立了耦合孪生的晶体塑性本构模型并进行了全隐式积分的数值实现.该本构模型采用饱和硬化法则,并采用孪生阻力与滑移硬化之间的正比关系来描述孪生对滑移硬化影响及孪生硬化行为.针对该本构模型的13个参数,结合各参数物理意义提出了参数的分类确定方法.以孪生诱导塑性（TWIP）钢Fe-22Mn-0.6C为例,着重对硬化参数的局部灵敏度进行了分析,研究了各硬化参数对宏观力学响应、孪生激活和演化的影响,根据变形机制的不同宏观变形过程可区分为孪生硬化阶段和孪生硬化失效阶段,进而给出了硬化参数确定的步骤及其建议取值范围.结果表明：初始滑移阻力与屈服极限线性相关,取值范围在80~160 MPa之间;孪生硬化指数增大使得孪生硬化阶段减弱,其取值范围应在0~3之间;孪生阻力与滑移阻力比值增大,则孪生增长率降低,硬化率拐点后移,直至拐点消失,其取值范围在1~1.3之间.     

RP-HPLC测定保加利亚乳杆菌腺苷酸方法的建立与应用

建立适用于测定保加利亚乳杆菌腺苷酸的反相高效液相色谱方法,为评价代谢组学研究中淬灭液的淬灭效果提供方法支持。采用SinoChrom ODS-BPC18色谱柱,甲醇-30mmol/L磷酸钾（V/V=5∶95）缓冲液（pH7.0）作为流动相,流速0.7mL/min,柱温25℃,紫外检测波长254nm。结果表明该方法具有较好的线性和较高的精密度,回收率在94.12%～109.6%之间。利用该方法测定了使用最广泛的60%（v/v）冷甲醇/水溶液淬灭保加利亚乳杆菌的效果,结果发现ATP的泄露率高达70.43%±2.3%,能荷值是0.42±0.015,从而推断该淬灭方案不但会造成胞内代谢物的大量泄漏,而且菌体的代谢反应也没有完全停止,故该淬灭方案不适合保加利亚乳杆菌。      

液相色谱-串联质谱法测定牛奶中万古霉素和去甲万古霉素残留

建立了牛奶中2种多肽类抗生素万古霉素和去甲万古霉素残留量的液相色谱-串联质谱（LC-MS/MS）检测方法。牛奶样品用三氯乙酸水溶液提取、沉淀蛋白,经混合型阳离子固相萃取柱Oasis MCX净化后,利用LC-MS/MS进行定性和定量分析。测定时样品溶液经ZORBAX SB-C18色谱柱分离,0.1%甲酸水溶液和乙腈作为流动相进行梯度洗脱,质谱测定采用正离子模式,多反应监测（MRM）。结果表明,万古霉素和去甲万古霉素的检出限为5μg/kg,回收率为72.5%～87.2%,相对标准偏差小于10%。