制备低硫可膨胀石墨的研究

研究了以过二硫酸铵作氧化剂低硫可膨胀石墨的制备，找到了在较低温度下，制备低硫可膨胀石墨的最佳条件。即过二硫酸铵和石墨的重量比为１５％；反应温度为５５℃；反应时间为４０ｍｉｎ；硫酸浓度为９８％；硫酸与石墨的重量比为４∶１，草酸和硝酸（浓度为６５％）的重量比为７．５％时，所制得的可膨胀石墨含硫量为０．６５％，膨胀容积为２００ｍＬ／ｇ可膨胀石墨。并且，其终端产品柔性石墨具有优良的力学性能和抗氧化性能。     

混酸法制备低硫可膨胀石墨

用硫酸（９８％）、硝酸（６５％）和草酸的混合液与天然鳞片石墨反 制备低硫可膨石墨，最佳反应条件是：石墨、硫酸（８％）、硝酸（６５％）、草的重量比为１：２．３：１．７：０．０５，反庆时间为４５ｍｉｎ，反应温度为２５℃，可膨胀石墨的含硫量为１．６３％时，膨胀容积为２５０ｍＬ／ｇ。其终端产品柔性石墨的含硫量为７８０ｐｐｍ。     

以乙酸酐为反应介质制备低硫可膨胀石墨

本文报道了一种制造低硫可膨胀石墨的新方法，即于２５℃，在含有少量硫酸的乙酐溶液中制备低硫可膨胀石墨。其最佳参数是：乙酐与石墨的重量比为１：１；高锰酸钾与石墨的重量比为６％；硫酸和石墨的重量比为１３％；反应时间２ｈ；反应温度２５℃，所制得的可膨胀石墨含硫量为０．９１％，膨胀容积为每克可膨胀石墨２４０ｍＬ，比传统方法制得可膨胀石墨含硫量降低了三倍左右。迄今为止，未见文献做过类似报道。     

用柔性石墨制备低密度膨胀石墨块

通过在浓硫酸或浓硝酸中浸泡柔性石墨纸（板），然后在200℃～750℃膨化制备了低密度膨胀石墨块。研究了插层剂、插层时间和膨化温度对膨胀石墨块体积密度和外形完整程度的影响。结果表明：膨化温度越高，制得的膨胀石墨块密度越低，越难获得完整的外形。以浓硫酸或浓硝酸插层时，适宜的膨化温度分别约为550℃和650℃，插层时间应为3h以上。发现膨胀石墨块主要存在两种外观，一种为均匀膨胀，另一种为非均匀膨胀。     

制备无硫可膨胀石墨的研究

用硝酸（65％）和乙酸酐混合液、高锰酸钾和天然鳞片石墨反应制备无硫可膨胀石墨,最佳反应条件是：石墨、乙酸酐、硝酸、高锰酸钾的重量比为1：0．8：0．5：0．07,反应时间为40min,反应温度为30℃,可膨胀石墨的膨胀容积为280mL／g;不含硫,含氮量为1．27％,其终端产品柔性石墨不含氮．迄今为止,未见文献报道．     

HClO4-GIC的制备及其柔性石墨的性能

以天然鳞片石墨、高氯酸、硝酸为原料，采用化学法经插层、水洗、干燥、膨化等工艺过程制备膨胀石墨；以石墨蠕虫的膨胀体积为判据，采用正交实验方法确定工艺参数对石墨蠕虫膨胀体积的影响大小：探讨了反应温度、时间、膨化温度，GIC的挥发分对膨胀体积的影响；利用XRD表征了天然鳞片石墨、酸化石墨、柔性石墨的微观结构；利用EDS确定了插入物为HClO4；并对制备的柔性石墨的力学、电／热性能进行了测试。结果表明：工艺参数影响大小依次为反应温度、高氯酸／硝酸间的配比及反应时间、鳞片石墨／高氯酸间的配比。在较宽的温度范围内（室温～100℃），可容易地制备出GIC，且能在低温200℃下膨化。以最佳工艺条件：鳞片石墨：高氯酸：硝酸=1：4：0．15（质量比）制备的GIC，在200℃下膨化，可以制备出膨胀体积达360mL/g的膨胀石墨；在高温900℃下膨化，可以制备出膨胀体积达540mL/g的高倍膨胀石墨。石墨蠕虫经压制成型制备的柔性石墨的抗拉强度、电阻率同其表观体积密度存在密切的相关性，密度增加，抗拉强度增加，电阻率下降；其电阻率与导热率间也存在密切的相关性，电阻率下降，导热率提高，且其导热率高于同电阻率的人造炭／石墨材料的导热率。     

膨胀石墨对水面浮油的吸附性能

以硫酸为插层剂、过氧化氢为氧化剂,用化学法制备了膨胀石墨,分析了膨胀石墨对水面原油的吸附过程,测试了膨胀石墨对水面原油和齿轮油的最大吸附量。结果表明:膨胀石墨对水面原油和齿轮油的最大吸附量均与油的黏度和温度有关,最大吸附量随温度的升高而升高,随黏度的升高而降低。     

膨胀石墨对纯油的吸附性能

以硫酸为插层剂、过氧化氢为氧化荆,用化学法制备了膨胀石墨。用扫描电子显微镜（SEM）分析了膨胀石墨的孔状结构,测试了膨胀石墨对纯油的吸附量。结果表明：膨胀石墨具有明显的三级孔状结构,膨胀石墨对原油、齿轮油、液压油和汽油的最大吸附量分别为80、85、60和50g／g,这种结果与油品的粘度有关。     

不同粒径膨胀石墨的制备及其微观结构

对化学法制备膨胀石墨的工艺条件的选择进行了分析,以硝酸与磷酸的混酸为插层剂、高锰酸钾为氧化剂制备出了不同粒径的膨胀石墨,利用正交实验和平行实验确定了最佳工艺条件;研究了石墨粒度效应对氧化剂用量的影响;并对不同粒径膨胀石墨的微观结构进行了研究。研究结果表明,制备大鳞片膨胀石墨的最佳工艺为：石墨与混酸的质量体积比为1：4,...     

TiO2负载工艺对膨胀石墨吸附原油性能的影响

将异丙醇钛盐与水洗后的可膨胀石墨，或者与水洗并干燥后的可膨胀石墨混合并加热，分别制备了负载TiO2的两种膨胀石墨吸附材料-膨胀石墨／TiO2-1（记为EG／TiO2-1）和膨胀石墨／TiO2-2（记为EG／TiO2-2）。结果表明：异丙醇钛盐与水洗后的可膨胀石墨混合后，部分TiO2溶胶存在于石墨层间；而与水洗并干燥后的可膨胀石墨混合后，绝大部分TiO2溶胶分布在石墨层表面及边缘。EG／TiO2-1和EG／TiO2-2对原油的最大吸附量分别为57g／g和55g／g。     

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.     

Effect of Permeable Crystalline Material on Steel Reinforcement Corrosion of Concrete

Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.     

The Research and Application About "Dry Peeling Off" Technology for Airplane Surface Paint Layer

In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.     

Quality Study of Honeycomb Core Shaping Without Wax Stabilization

Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.     

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.     

In-process thermal treatment of polylactic acid in fused deposition modelling

Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.     

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.