LLDPE及VLDPE对LDPE／HDPE共混物拉伸性能的影响

研究了线性低密度聚乙烯（ＬＬＤＰＥ）和极低密度聚乙烯（ＶＬＤＰＥ）对高密度聚乙烯（ＨＤＰＥ）／低密度聚乙烯（ＬＤＰＥ）共混物拉伸性能的影响。由于ＬＬＤＰＥ或ＶＬＤＰＥ的加入，改善了ＨＤＰＥ与ＬＤＰＥ间的相互作用，提高了ＨＤＰＥ／ＬＤＰＥ共混物的拉伸性能。     

DVD的分量视频输出端子

ＤＶＤ即ＤｉｇｉｔａｌＶｉｄｅｏＤｉｓｋ，其视频标准依据ＭＰＥＧ２（ＩＳＯ／ＩＥＣ１３８１８２），音频标准依据ＤｏｌｂｙＤｉｇｉｔａｌ（ＤｏｌｂｙＡＣ３）。图像水平清晰度大于５００线，远胜ＶＨＳ（２４０线）、ＶＣＤ（２６０线）和ＬＤ（４２０线）...     

Cu2O＼MoO3体系对PVC阻燃和抑烟的协同作用

用锥形量热仪（ＣＯＮＥ）研究Ｃｕ２Ｏ／ＭｏＯ３体系对ＰＶＣ的阻燃和抑烟协同效应可以同时获得气相和凝聚相的综合信息。实验结果表明：Ｃｕ２Ｏ／ＭｏＯ３对ＰＶＣ有良好的协同抑烟作用;尽管它们协同提高了平均有效燃烧热（ａｖ－ＥＨＣ）,但动协同降低了ＰＶＣ总热释放量（ＴＨＲ）,表现出了一定的协同阻燃作用。其原因是Ｃｕ２Ｏ／ＭｏＯ３改变了ＰＶＣ的热解途径,协同降低了ＰＶＣ炭骨架的热裂解速度,增加了残余炭的生成     

PVC／CEVA共混体系相容性研究

采用ＤＳＣ对ＰＶＣ／ＣＥＶＡ溶液共混物的玻璃化转变进行了研究。结果表明，对ＣＥＶＡ／ＰＶＣ质量比分别为１：９、２：８、４：６、８：２的共混体系，各共混物均分别出现一个明显的玻璃化转变温度，表明ＶＡｃ质量含量为５．９％，但氯含量为５８％的ＣＥＶＡ与ＰＶＣ具有较好的相容性，这是ＣＲ－ＭＭＡ－ＣＥＶＡ接枝共聚物对增塑ＰＶＣ人造革显示出较高粘合性能的主要根源。     

增效膨胀阻燃聚乙烯的制备与性能研究

将ＺＥＯ（分子利）作为膨胀阻燃增效剂,分别引入ＡＰＰ／ＰＥＲ（聚磷酸铵／季戊四醇）和ＡＰＰ／ＤＰＥＲ（聚磷酸胺／双季戊四醇）两个ＩＦＲ（膨胀型阻燃剂）中,用于阻燃ＰＥ。结果表明：这一方法显著提高了ＩＦＲ的阻燃效率,ＩＦＲ－ＰＥ的ＬＯＩ（极限氧指数）又分别提高了２．４和６．５,达到２８．９和３０．９。研究了ＺＥＯ型号及用量对增效作用的影响。进一步利用ＴＧ（热重分析）和ＤＴＡ（差热分析）研究ＩＦＲ－ＰＥ的热降解行为,探讨了ＺＥＯ的增效作用原理。     

HDPE／EVA共混体系的研究

采用ＤＳＣ，ＷＡＸＤ和力学性能测试，研究了ＨＤＰＥ／ＥＶＡ共混体系。结果表明，ＨＤＰＥ／ＥＶＡ共混体系是不相容的，但在共混组成中含有少量（＜１０％）的ＥＶＡ，力学性能下降很少，而加工性能得到改善，具有一定实用价值。     

聚丙烯膨胀阻燃剂PPN的研究

合成了一系列聚丙烯（ＰＰ）的膨胀阻燃剂ＰＰＮ，红外光谱显示ＰＰＮ为蜜胺（ＭＥＬ）交联聚磷酸胺结构。ＰＰＮ／尼龙６６（ＰＡ６６）复合组分对ＰＰ有良好的阻燃作用，阻燃体系氧指数最高可达３４．２。实验认为，ＭＥＬ对该阻燃ＰＰ体系的磷氮协同效应有较大的影响。     

EVA增容PVC／PE共混体系的研究

采用乙烯－醋酸乙烯酯共聚物（ＥＶＡ）作为聚氯乙烯（ＰＶＣ）／高密度聚乙烯（ＨＤＰＥ）共混物的增容剂，通过冲击实验、拉伸实验、动态力学分析和扫描电镜（ＳＥＭ），系统地研究了共混体系的性能与其形态结构之间的关系。结果表明，ＥＶＡ是ＰＶＣ／ＨＤＰＥ良好的增容剂，在一定范围内，ＥＶＡ与ＰＥ对ＰＶＣ有协同增韧效应     

HMW—HDPE与LMW—HDPE的共混改性

选用一种高分子量高密度聚乙烯（ＨＭＷ－ＨＤＰＥ）和一种低分子量高密度聚乙烯（ＬＭＷ－ＨＤＰＥ），对它们的共混行为和共混物的热性能、流动性能和力学性能进行了研究。结果表明，在研究的共混比范围内，由ＤＳＣ发现双组分体系可能存在共晶相。ＨＭＷ－ＨＤＰＥ／ＬＭＷ－＝ＨＤＰＥ共混体系的熔体指数基本符合Ａｒｒｈｅｎｉｕｓ粘度加和方程：ＭＩ＝ＭＩ．ＭＩ２。在ＬＭＷ－ＨＤＰＥ质量百分含量为２０％时，共混体系的拉伸     

电子束辐照对HDPE及其与Mg(OH)_2共混体系力学性能影响的研究

研究了高密度聚乙烯（ＨＤＰＥ）经电子束辐照后性能的变化，与Ｍｇ（ＯＨ）２的相容性，以及ＨＤＰＥ／Ｍｇ（ＯＨ）２共混体系的力学性能。实验结果表明，经电子束辐照后，ＨＤＰＥ分子被引入了极性基团（羰基），增加了ＨＤＰＥ与Ｍｇ（ＯＨ）２的相容性，使ＨＤＰＥ／Ｍｇ（ＯＨ）２体系的拉伸强度得到提高。     

Nanodots of multiferroic oxide material BiFeO3 from the first Principles

Multiferroic nanodots can be harnessed to aid the development of the next generation of nonvolatile data storage and multi-functional devices. In this paper, we review the computational aspects of multiferroic nanodot materials and designs that hold promise for the future memory technology. Conception, methodology, and systematical studies are discussed, followed by some up-to-date experimental progress towards the ultimate limits. At the end of this paper, we outline some challenges remaining in multiferroic research, and how the first principles based approach can be employed as an important tool providing critical information to understand the emergent phenomena in multiferroics.     

z向流动RTM工艺树脂的流动浸润行为

研究了层间“离位”附载多孔薄膜结构形式增韧层的大厚度纤维预成型体中等代流体（树脂）沿预成型体厚度方向（z向）的流动行为,通过压力传感器监测z向流动RTM（z-RTM）工艺注射过程中进、出胶口压力的变化规律,进一步反推树脂在层间“离位”增韧与非增韧预成型体中的宏观流动及微观浸润模式。结果表明,在 z-RTM工艺注射过程中,树脂在沿纤维束间z向快速流动的同时完成对纤维丝束内部的浸润。层间“离位”附载的增韧层虽延缓了树脂的宏观流动,但使流动前锋曲面更加平滑。层间“离位”增韧预成型体z向渗透率为3.5×10^-15m²,与非增韧预成型体的z向渗透率2.9×10^-14m²相比,降低约一个数量级。     

氯苯标准气体的研制

介绍了氮气中氯苯标准气体的研制方法。氯苯标准气体所采用制备方法为称量法,分析方法为GC-FID法。实验结果显示,氯苯标准气体具有良好的线性、瓶内均匀性和稳定性,有效期为12个月。研究制备的氯苯标准气体标准值为1~5μmol/mol,相对扩展不确定度为5%（置信度为95%）,与美国Scott Specialty Gases的同类标准气体具有可比性。     

Effect of Dosage on the Conduction of Electron Beam Cross-Linked Thermoplastic Elastomeric Films from Blend of LDPE and EVA Copolymer

The effect of electron beam irradiation at different radiation doses (50, 100, 150, 200, and 300 kGy) on Low-density polyethylene/ethylene-vinyl acetate copolymer (LDPE/EVA) blend was investigated. Measurements of I-V characteristics have been carried out at room temperature. It was found that the β parameter increases with the doses. This feature was attributed to the differences in electrical conductivity of the materials. The conduction mechanism is discussed qualitatively on the basis of Poole-Frenkel conduction mechanisms (enhanced conductivity at high electric fields due to the lowering of the potential barrier), also, at low-voltage region conduction was discussed in terms of the Schottky conduction mechanism namely β_s (Schottky field-lowering coefficient). The value of the Poole-Frenkel high field-lowering coefficient β_PF increases with increasing voltage range. Both mechanisms are related and display a highly consistent response to electron beam exposure.     

Impact of β-Sheet Conformations on the Mechanical Response of Protein in Biocomposites

Proteins in biological nanocomposites play an important role in their mechanical response. Proteins in nacre, the inner layer of seashells, have been shown to have exceptional mechanical properties. One of the important nacre proteins, Lustrin-A, has abundance of polypeptides in zig-zag conformation called β-sheets. β-sheets of protein when present close to each other in multiple numbers could take the shape of a planar β-sheath like structure or a β-barrel to form a domain. In natural proteins both these types of structures are commonly found. However, the conformation of β-sheets in Lustrin-A is not known at this time. Effort has been made through this work to study the mechanical response of these β-planar sheath and β-barrel structures when subjected to external loads. Comparative study of the stress-deformation characteristics of these two types of structures has been made. Both these structures with almost similar number of amino acids have been extracted from one single spinach protein: Ferredoxin Reductase (1FNR). Steered molecular dynamics has been used to conduct these studies. The article deals with the separation of the two domains from the main protein, simulation details, and results comparing the responses.     

Evaluation of the Heat Treatment Response of a Multiphase Hot-Rolled Steel Processed by Controlled Rolling and Accelerated Cooling

The tensile properties of hot-rolled multiphase steel after heat treatment were analyzed on a laboratory scale. Subcritical treatments applied to the hot-rolled strip revealed an increase in the yield stress and elongation with increasing temperature. Normalizing of the strip at 920°C notably improved the ductile response, while both the yield stress and the anisotropy of every property evaluated at 0°, 45°, and 90° to the rolling direction in the rolling plane were significantly reduced.     

Evaluation of critical formulation factors in the development of a rapidly dispersing captopril oral dosage form

New methods of manufacture have enabled the creation of novel dosage forms with unique rapid-dispersion properties. This study combines one such technique with a statistical experimental design to develop dosage forms from captopril, an angiotensin-converting enzyme inhibitor used to treat cases of hypertensive emergency. The TheriForm™ process, a novel microfabrication technique, was used to build the dosage forms in a layer-by-layer fashion. Three key formulation factors were chosen for the design of experiments. A modified central composite design (Box-Behnken design) was used to maximize the efficiency of the experiments. A total of 13 distinct formulations were fabricated and tested, using mannitol as the bulk excipient. In addition, three replicates of the center point were tested to assess variability and experimental error. These formulations were tested for speed of dispersion (flash time), active content, hardness, friability, and moisture absorption. Regression analysis was performed to fit data responses to quadratic equations. Excellent dose accuracy (95% to 102% of target) and content uniformity (between 1.03% to 2.84%) were observed from all experimental formulation batches. As expected, the choice of powder additive (maltitol, maltodextrin, polyvinyl pyrrolidone), level of additive (2.5% to 7.5%), and saturation level of the binder liquid (45% to 65%) were all found to be significant factors for the TheriForm process. The regression analysis suggested that a rapidly dispersing dosage form of optimal physical properties would be obtained when a powder mixture of mannitol (97.5%) and maltitol (2.5%) is used at a saturation level of 45%. In conclusion, rapidly dispersing captopril oral dosage forms were successfully fabricated and tested. A wide range of physical properties, flash time, and hardness, were determined experimentally, and the effects of key formulation factors were identified.     

Mg-α-SiAlON/MgO复合材料中Mg-α-SiAlON的原位合成

为改善低品位Mg基材料高温性能,采用烧结Mg砂、金属Al粉、单质Si粉和Al₂O₃粉为主要原料,制备了Mg-α-SiAlON/MgO复合材料。通过XRD、SEM及EDS等检测手段,研究了不同原料质量分数及氮化温度条件下Mg-α-SiAlON/MgO复合材料中Mg-α-SiAlON的原位合成,结合热力学分析确定了合成Mg-α-SiAlON的气氛条件并分析了合成Mg-α-SiAlON的反应机制。结果表明：1 550℃时的氮、氧分压满足合成Mg-α-SiAlON的热力学条件。当烧结Mg砂粉、Al粉、Si粉和Al₂O₃粉的质量分数之和为40wt%时,1 550℃保温3 h氮化后的Mg-α-SiAlON/MgO复合材料中板片状Mg-α-SiAlON相生成量最高可达32.1%,且相互交错构成骨架,将低熔点物相包裹其中。利用烧结Mg砂原位氮化制备Mg-α-SiAlON/MgO复合材料,有利于提高Mg基材料的抗热震性能。     

超声辅助制备β-磷酸三钙/Mg-Zn-Ca生物复合材料及性能

在生物Mg合金基体中添加β-磷酸三钙（β-TCP）颗粒可以调控其力学性能及腐蚀降解性能,满足人体不同植入部位的服役需求。本研究在机械搅拌铸造的基础上,采用超声方法对Mg基复合材料的熔体进行辅助处理,制备了β-TCP添加量为1%（质量比）、Zn含量为3%（质量比）、Ca含量为0.2%（质量比）的β-TCP/Mg-Zn-Ca可降解生物复合材料,对超声处理制备的β-TCP/Mg-Zn-Ca复合材料的显微组织、力学性能和腐蚀行为与未超声处理制备的β-TCP/Mg-Zn-Ca复合材料进行了对比研究。结果表明：超声处理可以细化β-TCP/Mg-Zn-Ca复合材料的显微组织,有利于β-TCP复合颗粒的均匀分散;β-TCP/Mg-Zn-Ca复合材料在模拟体液环境下的耐蚀性得到提高;其屈服强度、抗拉强度和伸长率分别为211.54 MPa、334.32 MPa和7.28%,与未超声处理的β-TCP/Mg-Zn-Ca复合材料相比,分别提高了8.44%、4.67%和17.99%。