二甲醚作为冰箱制冷剂的理论分析

对二甲醚（DME）用作冰箱制冷剂进行理论分析，比较制冷剂DME与冰箱制冷剂HFC134a和HC600a的基础热物理性质。对它们的冰箱标准工况制冷循环性能和变工况制冷循环性能进行理论计算及分析。分析表明：制冷剂DME的制冷性能与HFC134a和HC600a的制冷性能基本相似，性能系数（COP）却优于HFC134a和HC600a。并且，二甲醚具有环保、无毒和与材料兼容的特点。因此，二甲醚适合做新一代的冰箱制冷剂。     

三氟甲醚作为汽车空调制冷剂的性能研究

对三氟甲醚（HFE143a）用作汽车空调制冷剂的性能与现有汽车空调制冷剂R134a进行了对比。首先比较了三氟甲醚和R134a的基础热力性质,然后对三氟甲醚和R134a的汽车空调标准工况和变工况下制冷循环性能进行了详细的理论计算及分析。分析表明：三氟甲醚的制冷性能与R134a基本相似,而性能系数（COP）却优于R134a。因此,更具环保优势的三氟甲醚是一种理想的潜在汽车空调制冷剂。     

回热器对制冷循环性能影响的研究

分析了回热器对理论制冷循环性能的影响,考虑了制冷剂质量流量变化和压力损失时的影响,推导出了回热器对制冷循环性能影响的理论计算方法.并计算出了R22、R134a等常用制冷剂及替代制冷剂在标准工况下回热器对理论制冷循环性能的影响,对工程实践有一定的指导意义.     

二甲醚作为汽车空调制冷剂的性能研究

对二甲醚（DME）在用作汽车空调制冷剂与现有R134a汽车空调制冷剂在基础热力性质、汽车空调标准工况和变工况下制冷循环性能进行了对比分析，并作理论计算。分析表明：二甲醚的制冷性能与R134a基本相似，而性能系数COP却优于R134a。因此，更具环保优势的二甲醚是一种理想的潜在的汽车空调制冷剂。     

二甲醚作为汽车空调制冷剂的性能研究

本文对二甲醚（DME）用作汽车空调制冷剂的性能与现有汽车空调制冷剂R134a进行了对比。首先比较了二甲醚和R134a的基础热力性质，然后对二甲醚和R134a的汽车空调标准工况和变工况下制冷循环性能进行了详细的理论计算及分析。分析表明：二甲醚的制冷性能与R134a基本相似，而性能系数（COP）却优于R134a。因此，更具环保优势的二甲醚是一种理想的潜在的汽车空调制冷剂。     

HFE143m制冷剂热物理性质及其与HFC134a的循环性能对比

HFE143m是一种新型环保制冷剂,目前国内的相关研究十分欠缺。在广泛查阅文献的基础上,列出了HFE143m的热物理性质计算公式,并将其与HFC134a的典型制冷循环特性进行了理论分析、比较和计算。计算结果表明:HFE143m的运行压力低于HFC134a,在等熵压缩工况下,单位质量制冷量和COP分别提高2.9%和3.6%,在固定压缩机出口过热度(25℃)工况下,单位质量制冷量和COP分别提高2.9%和16.6%,是HFC134a的潜在制冷剂替代物。     

一种替代HFC-134a的制冷剂混合物

HFO-1234yf/HFO-1234ze(E)/HFE-143a组成的制冷剂混合物,具有良好的环境性能;通过对该混合物的理论循环研究及制冷性能和燃烧性能的试验研究,发现该制冷剂混合物在干空气中不可燃,在65%左右湿度空气中的燃烧等级为2L,制冷量和能效比均优于HFO-1234yf,是具有应用前景的HFC-134a替代物。     

低温冷库制冷领域使用CO2作为制冷剂的应用概述

对天然制冷工质CO2(R744)应用于低温大容量制冷工况下的循环形式进行了叙述,在给定工况下进行了循环性能计算,并与传统工质进行了比较.指出CO2跨临界循环与传统制冷剂循环相比有明显优势,适合应用于低温冷库工况.     

一种新型汽车空调制冷剂CMR-05

介绍了一种新型的用于汽车空调的混合制冷剂(CMR-05).介绍了CMR-05的物理性质,分析了CMR-05作为汽车空调替代制冷剂的可能性.对CMR-05进行了理论循环计算,并与R12和R134ad的理论循环的计算结果进行了对比.通过汽车空调测试证明了CMR-05具有较好的制冷性能,分析了CMR-05存在的问题,得出CMR-05可以作为R12与R134a的替代制冷剂.     

新型压缩／喷射冰箱混合制冷循环理论及实验研究

针对双门冰箱冷冻室及冷藏室温差较大的特点,提出了一种新型压缩/喷射混合制冷循环,并加工制造了新循环冰箱,降低了冷藏室与蒸发器之间由于温差过大造成的有效能损失。以R12以及它的可能替代物R152a、R134a、R22/R152a等作为制冷剂的模拟计算结果表明:新循环性能系数COP及容积制冷量较原蒸汽压缩循环有明显提高。实验结果表明:新循环冰箱,具有明显的节能效果。     

甲基紫光度法测定红霉素肠溶片中的红霉素

在pH 6.8条件下,用二次石英蒸馏水为溶剂,甲基紫和红霉素在常温下可以反应形成稳定的离子缔合物,导致吸收光谱发生变化,且在一定范围内吸光度变化值与红霉素的浓度成正比,从而建立一种测定红霉素的分光光度法.实验表明:该方法灵敏度较高(ε=1.63×104 L/(mol/cm)),精密度好(对15.00 mL 5.0×10-3 mg/mL红霉素测定6次,RSD=0.9％).红霉素的浓度在0.000 8～0.050 mg/mL范围内服从Beer定律,方法的检出限为0.18 μg/mL.该方法简便可靠,重现性和选择性好,可用于红霉素肠溶片中红霉素含量的测定.     

Fluorescence and structure of methyl red-clay nanocomposites

Two types of clay minerals-montmorillonite and vermiculite have been chosen as a host matrix for the intercalation of methyl red (MR) in order to investigate a possible fluorescence tuning via dye-clay interactions. The effect of silicate layer charge on the structure and fluorescence of dye-clay intercalated hybrid nanostructures was investigated using combination of molecular modeling with experiment. Structure of both intercalates MR-vermiculite (MR-VER) and MR-montmorillonite (MR-MMT) exhibits high degree of structural disorder resulting in broaden emission band. The fluorescence wavelength range of MR intercalated in clays is shifted to lower wavelengths compared with the pristine MR polycrystalline sample (800 nm). Results showed the strong dependence of fluorescence band maximum on the silicate layer charge, lambda(max) = 565 nm for MR-MMT, 645 nm for MR-VER and 800 nm for the methyl red fine crystalline powder, whereas the structural disorder in the arrangement of dye molecules affects the emission band broadening.     

The hematological effects of methyl parathion in rats

The effects of methyl parathion (MP) at sublethal concentration on hematological constituent [red blood corpuscles (RBC), white blood corpuscles (WBC), mean cell volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), platelet (PLT) counts, hemoglobin (Hb) and hematocrite (HCT) levels] and serum damage marker enzymes [aspartate aminotransferase (AST), alanin aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH)] of rats were investigated under laboratory conditions. 5 and 10 ppm dosages of MP were administered orally to six female rats ad libitum during the tests for 4 weeks consecutively. MP treatments caused different effects on the hematological constituents and the serum marker enzymes of the treatment groups as compared to the controls. According to the results, MP treatments increased significantly the levels of serum marker enzyme activities except for ALT with both dosages and LDH with 5 ppm dosage. Also, the hematological constituents were affected by MP. For example, WBC significantly increased in rats treated with both dosages of MP whereas the other hematologic constituents did not change at 5 and 10 ppm of MP treatments. The observations presented led us to conclude that the administration of subacute MP elevates tissue damage serum marker enzymes, and increases the number of WBC in rats. These data, along with the determined changes suggest that MP produce substantial systemic organ toxicity in rats during the period of a 28-day subacute exposure.     

CaSnO3粒子对甲基橙溶液的脱色性能

采用水热合成法制备出完整的正交晶型CaSnO3粉末,通过X射线衍射图谱(XRD)、红外光谱(IR)等分析方法对样品的晶体结构和形态进行了表征。并研究了其对甲基橙溶液的脱色性能。结果表明:CaSnO3对甲基橙溶液有良好的脱色效果。当CaSnO3浓度为60mg/L,光照时间为100min时,其对pH为3-5的甲基橙溶液的脱色率可达89%以上。     

Transport of methyl methacrylate monomer through natural rubber

The diffusion and transport of inhibitor-free methyl methacrylate monomer through crosslinked natural rubber (NR) have been studied at different temperatures. NR has been vulcanised by conventional, efficient and peroxide vulcanisation technique. ESR spin probe spectroscopy was used to study the flexibility of NR network chains at different temperatures. The dependence of diffusion coefficient on the nature of crosslinks and temperature has been studied. The intrinsic diffusion coefficient was found to increase with increase of temperature. The interaction parameter, permeability, sorption coefficient and molecular weight between crosslinks have been evaluated using diffusion data. The morphology of the swollen network and thermodynamic parameters has been determined using diffusion data. The efficient and peroxide system showed the least uptake and the conventional system showed the highest uptake. This study also proved that same extent of crosslinking can be achieved for different vulcanising systems by curing the samples to a common rheometric torque. The theoretical modelling shows Fickian mode of diffusion with a slight deviation.