Study on phase behavior–impact strength relationship of unsaturated polyester/polyurethane hybrid polymer network

The phase behavior of a hybrid polymer network (HPN) composed of poly[(propylene glycol maleate)-co-(propylene glycol phthalate)] crosslinked with styrene and polyester–urethane crosslinked with methylene-bis-ortho-chloroaniline was examined. The correlation between phase separation and impact strength of the HPNs is discussed. The composition of HPNs has an effect on their properties.     

利用热管纺丝技术一步法生产FCY

利用平板型热管纺丝装置对普通高速纺丝机进行技术改造，并一步法生产出充分结晶的ＰＥＴ纤维（ＦＣＹ）。该纤维可直接用于织造，调节热管温度、热管安装位置可获得满足后道工序不同需要的ＦＣＹ。     

Effects of nitric oxide annealing of thermally grown silicondioxide characteristics

The effects of nitric oxide (NO) annealing on conventional thermal oxides are reported in this letter. The oxide thickness increase, resulting from NO annealing, is found to be only a few angstroms (<0.5 nm) and independent on the initial oxide thickness. Furthermore, both the electrical and physical characteristics are improved. This technique is expected to achieve sub-5 nm high quality ultrathin dielectric films for the applications in EEPROM's and ULSI     

钨酸镁催化超声降解金橙Ⅱ研究

采用水热法合成了钨酸镁(MgWO4)半导体催化剂,并使用金橙II为有机污染物模型研究了其声催化降解性能.结果表明:MgWO4具有良好的声催化活性,可显著提升超声对有机污染物的降解效果,而且MgWO4具有优秀的可重复利用性能.同时,MgWO4催化超声降解金橙Ⅱ的机理研究表明,产生的活性物质如羟自由基(·OH)、超氧阴离子自由基(·O2-)和空穴(h+)是声催化降解金橙II的主要原因.以上研究结果表明MgWO4作为声催化剂用于处理有机染料废水具有良好的应用前景.     

LD7铝合金时效工艺的研究

通过试验系统地研究了ＬＤ７铝合金的单级和两级时效工艺。结果表明，与传统的单级时效相比，两级时效在不降低室温强度，硬度的前提下，可显著提高合金的电导率及高温性能。     

透明香皂的研制

介绍了生产透明香皂的新配方和新工艺 ,提出了透明香皂的企业标准。新工艺用丙二醇取代传统工艺所用的乙醇做溶剂 ,生产周期大为缩短。采用速冻隧道设备 ,可方便地实现不同品种的切换 ,操作方便 ,设备投资少 ,产品综合成本低 ,具有较大的工业应用价值     

A two‐station embossing process for rapid fabrication of surface microstructures on thermoplastic polymers

An embossing strategy involving a hot station and a cold station for sequentially heating and cooling the embossing tool was investigated to reduce cycle times in hot embossing polymer microstructures. Experimental studies showed that aluminum stamps with a thickness of 1.4 mm can be rapidly heated from room temperature to 200°C in 3 s using contact heating against a hot station at 250°C. Microchannels and microlenses were successfully embossed onto high‐density polyethylene and acrylonitrile–butadiene–styrene substrates using a heating time less than 3 s and a total cycle time around 10 s. The two‐station embossing process for the microlens was also numerically studied. The simulated filling behavior agreed with the experimental observation and the predicted thermal and deformation history of the polymer offered a good explanation on the experimentally observed process characteristics. POLYM. ENG. SCI., 47:530–539, 2007. © 2007 Society of Plastics Engineers.     

Photoinitiated crosslinking of ethylene‐vinyl acetate copolymers and characterization of related properties

Photoinitiated crosslinking of EVA in the presence of benzophenone (BP) as photoinitiator and triallyl isocyanurate (TAIC) as crosslinker and characterization of the related properties have been studied by gel determination, heat extension, DSC, DMTA, TGA, and mechanical measurements. The photoinitiated crosslinking efficiency of the EVA‐BP‐TAIC system and various factors affecting the crosslinking process, such as photoinitiator and crosslinker and their concentrations, irradiation temperature, and irradiation atmosphere were studied in detail and optimized by comparison of gel contents. The results show that the EVA samples with a thickness of 1 mm are readily crosslinked to a gel content of above 80% with 5 s UV‐irradiation under optimum conditions. The data from the heat extension and DSC show that the crosslinking density of photocrosslinked EVA increase and their crystallinities decrease with increasing the UV‐irradiation time. At the same time, photocrosslinking of EVA leads to a lowering of the melt temperature and a decrease of heat of fusion. The DMTA results show that photocrosslinking increases the amorphous phase and storage modulus of the crosslinked EVA, but does not change the glass transition temperature. The data from TGA and mechanical tests give evidence that the thermal stability and mechanical properties of photocrosslinked EVA samples are much better than those of the uncrosslinked EVA. POLYM. ENG. SCI., 47:1761–1767, 2007. © 2007 Society of Plastics Engineers     

A model for studying LCAT reaction: In vitro cholesterol esterification in pig ovarian follicular fluid

Phosphatidylcholine acyltransferase (lecithin:cholesterol acyltransferase or LCAT; EC 2.3.1.43) activity was found to be present in pig ovarian follicular fluid (POFF), in addition to pig serum (PS). The cholesterol esterification rate in both POFF and PS is linear with incubation time up to 2 hr. The mean absolute rate of POFF-cholesterol esterification was 8.1±0.4 nmoles per ml per hr approximately one-fourth of that in PS. However, the fractional rate (percent of labeled cholesterol esterified per hr) of POFF-cholesterol esterification was similar to that observed in PS. There was little variation of absolute rate of cholesterol esterification in the fluid obtained from different sizes of follicles. Fatty acid or triacylglycerol did not participate in the reaction of cholesterol esterification in POFF. No appreciable change in enzymatic activity was found from storing POFF at 4 C for periods of time up to 24 hr or at −70 C up to 2 months, but activity was lost thereafter. On the other hand, PS showed a much longer period of stability (5 days at 4 C and 9 months at −70 C). A discrepancy between the fatty acid composition of cholesteryl esters formed by the LCAT reaction and the fatty acid composition at the C-2 position of phosphatidylcholine led us to propose a two-step mechanism for the LCAT reaction. It is concluded that the LCAT of POFF, as well as that of plasma, is specific for individual fatty acids rather than for the fatty acid composition of phosphatidylcholine. The fatty acid concentration of lysophosphatidylcholine decreased during prolonged incubation times (6 to 21 hr) suggesting that the increased lysophosphatidylcholine formed as a product of the LCAT reaction may be reused as substrate for the LCAT reaction or for hydrolysis by lysophosphatidylcholine hydrolase. Presented at the AOCS Meeting, New York, May 1977.     

Coupled oscillations of H2/O2/CO on silica supported rhodium catalyst

Self-sustained oscillations obtained during the catalytic oxidation of CO and H₂ were studied over Rh/SiO₂ by an FTIR-mass spectrometric technique. An average oscillatory period of 7.1±0.5 minutes was obtained for the CO/O₂ reaction at 348 K. For the H₂/O₂ oscillatory reaction the period was observed to be 1.3±0.8 minutes. When the oscillations were coupled at the same temperature, the period for both the CO/O₂ and the H₂/O₂ reactions was observed to be 7.9±0.8 minutes. The kinetic coupling of the reaction rates is explained by considering the periodic fluctuations in surface temperature which occur as a result of the more exothermic CO/O₂ reaction.