氧化处理方法与多壁碳纳米管表面羧基含量的关系

从羧基定量化出发，采用红外光谱法、热重分析法和X-射线光电子能谱法详尽研究了氧化处理方法与多壁碳纳米管（MWCNTs）上引入羧基量的关系。结果表明，硝酸氧化法、混酸氧化法和混酸与过氧化氢共同氧化法均可以使MWCNTs表面产生羧基。热重分析法和XPS分析法可以定量分析MWCNTs表面羧基的含量，并且分析结果相近。XPS分析表明，2．5mol／L硝酸氧化48h可以使MWCNTs表面产生摩尔分数为4．80％的-COOH，而混酸（浓HNO3与浓H2SO4体积比为1：3）氧化4h可产生摩尔分数为5．35％的～COOH，如果进一步由质量分数20％的过氧化氢氧化2h，MWCNTs表面产生的-COOH摩尔分数提高到7．55％。     

T6热处理对1.0%CNTs@TiO2/2024复合材料腐蚀性能研究

目的 研究T6热处理对1.0％CNTs@TiO2/2024(CNTs质量分数为1.0％)微观组织和腐蚀性能的影响,以期提高2024复合材料的耐腐蚀性能.方法 通过熔铸法制备CNTs质量分数为1.0％的CNTs@TiO2/2024复合材料,并研究了T6热处理(495℃,2 h+180℃,4～16 h)对CNTs质量分数为1.0％的CNTs@TiO2/2024复合材料微观组织和腐蚀性能的影响.结果 经固溶处理(495℃,2 h),S相(Al2CuMg)和θ相(Al2Cu)基本融入基体中;在时效处理(180℃,12 h)后,S相和θ相均匀析出.当加入CNTs质量分数为1.0％的CNTs后,与2024合金相比,复合材料的腐蚀电流密度大幅度增加了77.4％.与2024合金相比,T6态复合材料的腐蚀电位增加了4.4％,腐蚀电流密度下降了80.9％.结论 CNTs的加入会降低2024合金耐腐蚀性能,但是合适的T6处理工艺能够很好地提升其耐腐蚀性能,有效拓宽该系复合材料的应用领域.     

肉桂精油-海藻酸钠可食性抗菌膜的研制

以海藻酸钠为成膜材料,并添加不同质量浓度的肉桂精油来制备可食性抗菌膜。根据膜的力学性能和抑菌性能,确定了可食性膜中添加海藻酸钠、甘油和肉桂精油的最佳质量分数,以及可食性抗菌膜的最佳干燥温度和干燥时间。实验结果表明：在海藻酸钠的质量浓度为20mg／mL,甘油的添加质量分数为1．0％,肉桂精油的添加质量分数为2．0％,干燥温度为50℃和干燥时间为4．5h的条件下,所制备的膜具有最佳的力学性能和抑菌性能。     

废纸纤维素/壳聚糖膜的制备及性能

为增强壳聚糖膜的力学性能,制备了废纸纤维素/壳聚糖膜.以包装废弃瓦楞纸为原料,通过碱处理和漂白处理得到再生纤维素,再以不同组分与壳聚糖制备成膜,并对不同原料膜进行形态观察和力学性能检测.研究结果表明:废纸纤维素呈丝状,纤维直径约为15～20μm,结晶度较原始瓦楞纸有大幅提高;当在质量分数为2％的壳聚糖溶液中添加相对质量分数为5％的废纸纤维素时,废纸纤维素/壳聚糖膜力学性能最好,最大拉伸强度达52.3 MPa,断裂伸长率超过20％,纤维素分布均匀.     

海藻酸钙水凝胶过滤膜的制备及其对硫酸钙的截留

以尿素为致孔剂制备了海藻酸钙(CA)水凝胶过滤膜,测试了其通量、截留率和力学性能;通过扫描电子显微镜(SEM)观测其过滤硫酸钙前后的表面形貌。结果表明,增加尿素含量,均导致膜应力和应变的下降;而膜的纯水通量则迅速增大,尿素含量为3.0%(质量分数)时达到28.7 L/(m2·h),为最大;0.2 MPa下,过滤1.7 g/L硫酸钙时对Ca2+和SO2-4的截留率分别为83%和92%,稳定通量达到21.7 L/(m2·h)。     

辐射防护用特种橡胶制品的制备与性能研究

一种新型γ射线防护用橡胶制品填充料由PbWO4和WO3复合制成，其组成为：WO3：PbWO4=40-60：60～40（质量分数）；制备方法：在分散剂、助剂存在下，由Na2WO4溶液与Pb（Ac）2溶液在快速搅拌下沉淀反应得到PbW04沉淀，然后将此PbW04沉淀加入到磨细的WO3浆体中，再研磨1～2h即成。该填充料与硫化橡胶乳液形成的分散系稳定性很好，制成的橡胶制品（手套）对59．5KeV的了射线的屏蔽率可迭15％～18％，抗拉强度达7．8～9．1MPa，断裂伸长率迭700～1000％；对产品中的Pb作迁移性检测，证明是符合安全卫生要求的。     

液体丁腈橡胶的化学改性及应用

用新型Rh-Ru双金属加氢催化剂研究液体丁腈橡胶(LNBR)加氢成液体氢化丁腈橡胶(LHNBR)的工艺。主要讨论LNBR胶液浓度、催化剂浓度、三苯膦用量、温度、压力和反应时间等因素对液体丁腈橡胶加氢的影响。得到较佳加氢工艺参数：NBR的质量分数为30％、催化剂质量分数为0．35％、三苯麟用量为催化荆用量的6～8倍、加氢温度140C、压力1．4MPa、反应时间6h,加氢度可达87％以上。获得的LHNBR用做氢化丁腈(HNBR)的增塑剂,可使HNBR具有好的耐油性和更高的耐热性能。因而LHNBR是一种新型、特种的耐热、耐油增塑剂。     

乳液基碳化硅纳米工作液的沉降稳定性、流变性与介电性

目前混粉电火花加工液添加的粉末粒径主要局限于微米级,与工作基液不能形成均匀、稳定的悬浮液.本研究以乳化液为基液,纳米碳化硅粉体(SiC)为分散相,十二烷基苯磺酸钠(SDBS)、羧甲基纤维素钠(CMC)等作分散剂,采用两步法制备了乳液基SiC纳米工作液,研究不同分散条件下SiC粉体在乳化液中的分散行为,分析了乳液基SiC纳米工作液的沉降稳定性、流变性和介电性.结果表明:质量分数为0.3％～0.6％的CMC对SiC纳米粒子的润湿、分散作用显著,而SDBS作用不明显;CMC分别与SDBS、SDS协同作用时,工作液均具有很好的沉降稳定性;当SDBS质量分数为0.3％,CMC为0.3％～0.6％时,工作液黏度呈非线性增加;当CMC质量分数为0.3％,SDBS为0.3％～1.4％时,工作液黏度先增大后快速降低;工作液电导率随CMC、SDBS分散剂质量分数的增加、液体温度的升高而增大.因此,当SiC质量分数为0.3％、添加0.3％～0.5％(质量分数)的CMC和0.3％～0.7％(质量分数)的SDBS,乳液基SiC纳米工作液有较好的沉降稳定性、流变性和介电性.     

镍锌铁氧体的制备及其吸波性能的研究

利用溶胶直接自蔓延反应制备了镍锌铁氧体纳米粉末，采用XRD分析了其结构。以聚乙烯醇为基体（PVA）制备了炭黑，镍锌铁氧体复合材料吸波平板；采用矢量网络分析仪测量了其在2～18GHz频带上的吸波性能。结果表明：具有双层结构的炭黑，镍锌铁氧体复合材料具有较好的吸波效果，试样厚度为3mm；当面层镍锌铁氧体的质量分数为40％，底层炭粉的质量分数为20％时，在8～18GHz的测试频段范围内，复合材料最大吸收峰值为-15．7GHz，优于-6dB的有效带宽为6．4GHz；当底层炭粉的质量分数为15％时，复合材料最大吸收峰值为-13．6GHz，优于-6dB的有效带宽为8．2GHz。     

铝粉对化学敏化水胶炸药性能影响的实验研究

为研究不同形状和含量的铝粉对化学敏化水胶炸药性能的影响,在水胶炸药中分别添加质量分数为1％、2％、3％、4％片状和粒状铝粉.对比分析添加不同的质量分数及不同形状铝粉水胶炸药的爆热、爆速和猛度变化情况.结果表明:随着铝粉质量分数从0％增加到4％,炸药的爆热增加,爆速和猛度下降.当炸药中分别添加质量分数为4％的片状铝粉和粒状铝粉的水胶炸药比不含铝粉的水胶炸药,其爆热分别提高了17.99％、16.54％,爆速分别降低了15.12％、13.27％,猛度分别下降了18.18％、16.78％.     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.