区域化工产业环境下高职安全技术管理专业应用型人才培养模式研究与实践

分析珠三角区域化工产业环境,研究化工行业对高职安全技术管理专业应用型人才的素质要求,探讨高职安全技术管理专业应用型人才培养的思路和途径。     

基于苯并噻二唑液晶化合物的研究进展

2,1,3-苯并噻二唑(BTD)类化合物具有优异的光电性能,被广泛应用于有机光电领域。合成具有液晶性的苯并噻二唑类衍生物可以达到改善这类化合物的光电性能的目的。综述了近年来苯并噻二唑类液晶化合物的研究进展,包括含单个苯并噻二唑单元的非对称和对称液晶及含两个苯并噻二唑单元的液晶。介绍了该类化合物的分子结构、液晶自组装行为以及光电性能之间的关系。最后,对苯并噻二唑类液晶化合物研究现状进行了总结,指出当前研究所存在的局限性,并对未来该类液晶化合物的分子设计和发展前景进行了展望。     

Impurities Removal From Metallurgical Grade Silicon Using Gas Blowing Refining Techniques

The removal of impurities from metallurgical grade silicon using the O₂ and H₂O-O₂ gas blowing techniques was firstly studied by thermodynamics. The relationships between the boron content in refined silicon and the equilibrium partial pressures of gaseous boride species were established, which shows a theoretical limitation for boron removal from metallurgical grade silicon using the H₂O-O₂ gas blowing technique. The data also showed that the impurity boron in silicon was mainly volatilized in the form of B₃H₃O₆, BHO₂ and BO and the volatilization of boric hydrate species was much more than that of the oxide species. The impurities removal from metallurgical grade silicon including Fe, Al, Ca, Ti, B, P and C was studied using an O₂ gas blowing in a ladle and in succession a mixed Ar-H₂O-O₂ gas blowing was operated in a DC arc furnace for boron removal. It showed a removal efficiency higher than 90 % for Al, Ca and 50 % for B using the O₂ gas blowing technique in the ladle. Impurity boron was reduced from 35 ppmw to 18 ppmw in the ladle and it was once again reduced to 0.6 ppmw using an Ar-H₂O-O₂ gas blowing technique in the DC arc furnace for a systematic pressure of 5 Pa when the ratio of H₂O to O₂ and the refining times are 2:1 and 12 min, respectively.     

Heat‐sealing properties of soy protein isolate/polyvinyl alcohol film made compatible by glycerol

Heat‐sealing properties are necessary for packaging materials. Soy protein isolate/polyvinyl alcohol (SPI/PVA) blend film is a biodegradable potential packaging material. We analyzed the effects of PVA content (0–20%), glycerol content (1–3%), and sealing temperature (180–230°C) on the heat‐sealing properties of SPI/PVA blend film. Results showed that SPI/PVA film obtained the desired sealing properties when the PVA content exceeded 15%. The sealing strength increased with the PVA content, reaching a maximum upon blending with 20% PVA and 1% glycerol at 220°C. The temperature at sealing strength was approximately twice that at 180°C. However, glycerol migrated to the surface and hindered the entanglement of macromolecular chains in the sealing interface, thereby resulting in reduction of seal strength. Glycerol vaporization at 204°C led to aesthetically unacceptable blistering in the sealing area. Therefore, the optimum sealing temperature of the blended film was ～200°C. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40308.     

Synthesis and characterization of aliphatic polyesteramides mainly composed of alternating diester diamide units from N,N′‐bis(2‐Hydroxyethyl)‐oxamide and diacids

This article provided a convenient method to synthesize aliphatic polyesteramides mainly composed of alternating diester diamide units by polycondensation and chain extension. Two kinds of polyesteramide prepolymers were prepared through melt polycondensation from N,N'‐bis(2‐hydroxyethyl)oxamide and adipic acid or sebacic acid. Chain extension of them was conducted with 2,2′‐(1,4‐phenylene)‐bis(2‐oxazoline) and adipoyl biscaprolactamate as combined chain extenders. The chain extended polyesteramides (ExtPEAs) were characterized by IR, ¹H NMR, differential scanning calorimetry, thermogravimetric analysis, wide‐angle X‐ray scattering, tensile test, and dynamic thermomechanical analysis. The results showed that the ExtPEA(0, m)s were mainly constituted with the diester oxamide alternating units. They had T_m above 140.8°C and the initial decomposition temperature above 298.0°C. They crystallized in similar crystallites to Nylon‐66 and were thermoplastic materials with tensile strength up to 31.47 MPa. POLYM. ENG. SCI., 54:756–765, 2014. © 2013 Society of Plastics Engineers     

Enhancement of flux and solvent stability of Matrimid® thin‐film composite membranes for organic solvent nanofiltration

The development of high flux and solvent‐stable thin‐film composite (TFC) organic solvent nanofiltration (OSN) membranes was reported. A novel cross‐linked polyimide substrate, consisting of a thin skin layer with minimum solvent transport resistance and a sponge‐like sublayer structure that could withstand membrane compaction under high‐pressure was first fabricated. Then the solvent flux was significantly enhanced without compromising the solute rejection by the coupling effects of (1) the addition of triethylamine/camphorsulfonic acid into the monomer solution, and (2) the combined post‐treatments of glycerol/sodium dodecyl sulphate immersion and dimethyl sulfoxide (DMSO) filtration. Finally, the long‐term stability of the TFC membrane in aprotic solvents such as DMSO was improved by post‐crosslink thermal annealing. The novel TFC OSN membrane developed was found to have superior rejection to tetracycline (MW: 444 g/mol) but was very permeable to alcohols such as methanol (5.12 lm^?2h^?1bar^?1) and aprotic solvents such as dimethylformamide (3.92 lm^?2h^?1bar^?1) and DMSO (3.34 lm^?2h^?1bar^?1). © 2014 American Institute of Chemical Engineers AIChE J, 60: 3623–3633, 2014     

高性能醋酸纤维素正渗透膜的研制

本文以醋酸纤维素(CA)为膜材料,N,N-二甲基甲酰胺(DMF)和丙酮作为溶剂体系,聚乙二醇400(PEG400)作为添加剂,聚酯筛网作为支撑层,利用相转化方法制备醋酸纤维素正渗透膜。论文系统研究了CA的含量、DMF与丙酮的比例、添加剂的含量、支撑层的目数以及凝固浴温度对膜性能的影响,结果表明,当CA的质量分数为16%、DMF:丙酮的体积比为1:0.6、PEG400的质量分数为4%、作为支撑层的筛网目数为120mol/L、凝固浴的温度为60℃时,所制备正渗透膜的性能最佳;利用1mol/L NaCl作为驱动液,去离子水作为原料液,在1h的测试时间里,所制备膜的纯水通量可达到15 L/(m2·h)以上,反向盐通量控制在7.5g/(m2·h)以下。     

回火温度对Cr5NiMoVNb支承辊用钢组织与性能的影响

为了研究回火温度对Cr5NiMoVNb支承辊用钢显微组织及力学性能的影响,采用扫描电镜、X射线衍射仪、洛氏硬度计、拉伸试验机和冲击试验机对不同回火温度下Cr5NiMoVNb钢进行了测试。结果表明:Cr5NiMoVNb钢的回火态组织以回火马氏体为主,并含有少量的残留奥氏体。回火过程中伴随有碳化物的析出和马氏体相变。随着回火温度的升高,Cr5NiMoVNb钢的强度(抗拉强度与屈服强度)与硬度逐渐降低,塑性(伸长率与断面收缩率)与韧性(冲击吸收能量)逐渐提高。在试验选定范围内,520 ℃回火的Cr5NiMoVNb钢的硬度、抗拉强度、断面收缩率和冲击吸收能量分别达到53.5 HRC、1735 MPa、25.2%和7.3 J,综合力学性能最优。     

努力水平影响质押物损耗的存货质押融资合约选择

在质押物是一类易损耗物品的情况下,研究存货质押融资业务中银行对物流企业激励的合约选择问题。考虑物流企业努力水平影响质押物损耗,构建斯坦克尔伯格竞争博弈模型。通过比较共同经营、委托监管、统一授信3种业务模式下银行和物流企业的期望利润,探讨质押物存在损耗情况下银行的合约选择,以及物流企业努力成本系数、质押率和物品损耗率对合约选择的影响。研究结果表明,在物流企业努力成本系数较小时,银行应选择共同经营模式和物流企业进行合作;在货物损耗率较小时,银行应选择委托监管模式;在其他情况下,银行应选择统一授信模式,但银行的质押率不应设置过大。