海藻酸钙海绵的结构与性能

以海藻酸钠为原料,氯化钙/甘油/酒精溶液为凝固浴,采用冷冻干燥方法制备了海藻酸钙海绵,通过红外光谱和扫描电镜对其结构进行了表征,并对其物理和力学性能、孔隙率、透气率、吸液量和保液量进行评价和测定。结果表明,海藻酸钙海绵的弹性和柔韧性好,具有均匀、连通的孔隙结构,孔径大小为100μm～500μm,孔隙率为84.37%,透气率为44.75%,拉伸强度为0.21 MPa,初始模量为7.72 N/mm,对伤口渗出液的吸液量和保液量为30.48 g/g和5.13 g/g,各项性能均优于或接近海藻酸钙无纺布医用敷料。     

魔芋葡甘聚糖海绵状创面敷料的制备与表征

以质量分数为1.0%的魔芋葡甘聚糖水溶液为原料,质量分数为3.0%的氢氧化钠乙醇溶液为凝固浴,采用冷冻诱导相分离的方法制备了能够大量吸收水分而不溶解的海绵材料。研究结果表明,该海绵的表面和内部具有均匀、连通的孔隙结构,孔径大小为400μm左右,孔隙率为93.87%,透气率为45.30%,对人造血浆的吸液量和保液量分别为25.98g/g和3.36 g/g,海绵的厚度为3 mm,表观密度为25.15 mg/cm3,拉伸强度为0.43 MPa。各项性能均优于或接近市售的海藻酸钙和粘胶非织造布创面敷料的水平,可用于治疗手术伤口、烧烫伤创面等各种类型的皮肤创伤。     

耐盐耐洗涤剂海藻纤维的制备及性能

不耐盐和不耐洗涤剂一直是困扰海藻纤维制备的难题。针对这一问题文中采用四硼酸钠对海藻纤维进行改性,通过红外光谱、X射线衍射对改性海藻纤维进行了结构表征,并利用吸液量、纤维钙离子含量、纤维断裂强度、纤维和纺丝液微观形貌测试,研究了改性海藻纤维的耐盐、耐洗涤剂性能。结果表明,利用四硼酸钠对海藻纤维进行改性可以提高海藻纤维的交联程度和结晶度,从而降低生理盐水和洗涤剂中的钙钠离子交换对海藻纤维结构的破坏,有利于保持纤维形貌。经生理盐水和洗涤剂浸泡后,海藻纤维的吸液量仅为10.2%和10.1%,断裂强度损失仅为5.1%和9.0%,显著提升了海藻纤维的耐盐、耐洗涤剂性能。     

耐盐性海藻酸钙纤维的制备及性能研究

针对海藻酸钙在盐溶液中易溶问题,利用戊二醛交联反应制备了耐盐海藻酸钙纤维,红外光谱及溶胀度的测试证明发生了缩合交联反应;讨论了不同工艺条件下,改性纤维的溶胀度和力学性能。结果表明,最佳合成条件为温度30℃、交联剂含量8%、反应时间3.0h、pH=5;改性海藻酸钙纤维的溶胀度只有98%,为纯海藻酸钙纤维的27%,改性纤维断裂强度为2.23cN/dtex。     

壳聚糖接枝物与琼脂复合膜的制备及性能研究

目的 以琼脂(Agar)和壳聚糖-氧化微晶纤维素接枝物(CS-g-MCC(O))为原料制备海绵状薄膜,探究薄膜在医用敷料领域的应用.方法 采用共混法将琼脂和壳聚糖-氧化微晶纤维素接枝物按不同体积比混合,然后使用冷冻干燥法制得薄膜,利用扫描电子显微镜对其多孔结构进行表征;对薄膜的溶胀率、溶失率、水蒸气透过率以及力学性能进行检测.结果 制备出的海绵敷料形貌结构规整,有明显的孔洞,利于伤口排出代谢产物;随着琼脂含量的增加,海绵敷料的溶失率先减小后增加,溶胀率、孔隙率、透湿量、拉伸强度和断裂伸长率先增加后减小.结论 海绵敷料各项性能都较为优异,有利于伤口渗出液的吸收和细胞生长,对伤口的愈合起到了重要作用,促进了其在医用敷料领域的应用.     

氧化石墨烯/海藻酸钙复合膜的制备与性能

以海洋生物多糖海藻酸钠为基质,氧化石墨烯(GO)为改性添加剂,乙二醇双(2-氨基乙醚)四乙酸钙(EGTA-Ca)为交联剂,制备了网络结构均匀的氧化石墨烯/海藻酸钙复合膜。分别利用红外光谱、扫描电子显微镜、电子拉力机考察了复合膜的结构、表面形貌、力学性能和溶胀性能。结果表明,GO均匀分散在海藻酸盐基体中,GO的加入对于海藻酸钙膜的力学性能具有显著影响,当GO添加量为海藻钠原料质量的1%时,复合膜的断裂强度和断裂伸长率均达到最大,比未添加氧化石墨烯膜分别增加了~82%和~265%,适量乙二醇的加入对于复合膜具有很好的增塑作用。GO的加入对复合膜的溶胀性能影响不大。     

鸡毛角蛋白海绵垫的制备及对丙酮的吸附性能

利用还原C法提取鸡毛中可溶性角蛋白后产生的残渣,通过简单的物理方法处理后制得致密多孔的角蛋白海绵材料.针对增塑剂对角蛋白海绵结构的影响进行了实验研究,结果发现,甘油质量分数4%时,其机械性能最佳,拉伸强度为5.04 MPa,断裂伸长率为8.60%,完整性和柔韧性最好.利用红外光谱仪对组成残渣的分子基团等进行了表征,以有机挥发性气体丙酮作为实验对象,考察孔隙率和吸附温度等因素对鸡毛角蛋白海绵垫吸附性能的影响.实验结果显示:当角蛋白海绵垫的孔隙率为82.59%、环境温度为25℃时,对丙酮挥发性气体24 h的吸附量为205.4 mg/g;吸附1个月后达到饱和状态,饱和吸附量达374.8 mg/g.充分利用废弃鸡毛这一资源,对于去除环境中气体污染物具有一定的应用潜力.     

海藻酸盐医用敷料的研究与应用进展

现代"湿性伤口愈合"理论表明,伤口处在湿润的环境下,愈合速度会加快。海藻酸盐作为一种从褐藻中提取的天然高分子材料,具有高吸湿性、凝胶特性以及良好的生物相容性。以其为原料开发伤口愈合敷料一直是国内外的研究热点。目前海藻酸盐伤口敷料的主要形式有纤维、海绵、水胶体、水凝胶等。其中,海藻酸盐纤维敷料在临床上应用最为广泛。海藻酸盐海绵、水胶体、水凝胶作为新型的敷料形式更有利于伤口愈合,因此在基础理论及临床应用研究方面均受到广泛重视。国内外少数相关海藻酸盐新型敷料产品已经成熟并上市。基于目前国内外研发现状,对以上4种海藻酸盐敷料的研究与应用进展进行综述,并对其开发前景做出展望。     

两种海藻酸钙膜的制备及吸水性能

分别采用冷冻干燥法和自然晾干法制备海藻酸钙膜材料,考察比较了两种海藻酸钙膜材料的形貌及吸水性能。海藻酸钙自然晾干膜为无色透明膜,冻干膜为白色海绵膜,且冻干膜与晾干膜相比具有开放、贯通的多孔结构,其孔径介于100μm～200μm之间。海藻酸钠质量百分比含量为2%时,晾干膜和冻干膜对蒸馏水的吸水率分别为78.7%和985.0%,经3500r/min离心3min后保水率分别为42.5%和81.8%,两膜材料均具有较好的重复使用性能,其中反复吸水-放水4次后冻干膜的吸水率仍高达869.4%。     

猪跟腱胶原蛋白海绵的制备

目的为了更好利用猪跟腱资源,提高其附加值及拓宽胶原在包装方面的应用,探讨猪跟腱胶原蛋白海绵的制备及该海绵对乙醇的吸附作用。方法采用单因素实验考察猪跟腱胶原蛋白浓度、甘油含量、浇注厚度对力学性能的影响,并考察海绵孔隙率和时间对乙醇吸附性能的影响。结果当胶原的质量分数为1%,甘油的质量分数为0.6%,浇注厚度为5 mm时,制备的海绵抗张强度为210.91 k Pa,断裂伸长率为6.98%,此工艺条件下制备的海绵孔隙率为91.19%,30 d乙醇吸附量为416.32 mg/g,吸附量与海绵的孔隙率成正相关。结论猪跟腱胶原蛋白在此工艺下制备的海绵比其他动物胶原蛋白海绵的抗张强度高,且对乙醇具有吸附作用。     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

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.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

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.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.