金属雕塑的历史沿革

人类进入文明社会之际 ,硬度远远高于陶器的青铜器 ,有力地促进了人类的文明进程。铁器的出现和广泛使用 ,极大地促进了社会生产力的发展 ,导致封建社会的建立和奴隶制社会的崩溃。大工业革命的历史巨轮隆隆行驶在用新的金属材质“钢”制成的轨迹上 ,崭新的历史纪元伴随日新月异的现代科学技术的急速发展 ,不断为人类拓展着新的生活空间 ,金属在人类历史上所起的重要作用 ,超越了艺术的领域 ,甚至成为人类社会文明进步的一种标识。     

生熟三七总皂甙对蛋白质合成的影响

按序贯法给小鼠静注TSPN和PTSPN求得LD_(50)分别为110.67±14mg/kg和105.33±58.6mg/kg。当给小鼠TSPN和PTSPN灌胃或皮下注射,在适当剂量时,都能使~3H-亮氨酸参与肝、肾和血清蛋白质合成的放射性强度明显增高。但超过适当剂量时,则无作用或呈现放射性强度降低。不同脏器对这两种总皂甙的敏感性也不完全相同。     

Research on Dynamic Strength and Inertia Effect of Concrete Materials Based on Large-Diameter Split Hopkinson Pressure Bar Test

The Split Hopkinson Pressure Bar (SHPB) test device is an important tool to study the dynamic characteristics of concrete materials. Inertial effect is one of the main factors that cause inaccurate results in SHPB tests of concrete materials. To solve this problem, Large-diameter SHPB tests on concrete and mortar were performed. A dynamic increase factor (DIF) model considering strain rate effect and inertia effect was established. This model provides a scientific reference for studying the dynamic mechanical properties of concrete materials. The experimental results indicate that the strain rate effect of concrete is more sensitive than that of mortar, but the inertia effect of mortar is more sensitive than that of concrete. Under the same strain rate, the energy utilization rate, average fragment size, and impact potentiality of mortar are higher than concrete.     

Smart Bone Graft Composite for Cancer Therapy Using Magnetic Hyperthermia

Magnetic hyperthermia (MHT) is a therapy that uses the heat generated by a magnetic material for cancer treatment. Magnetite nanoparticles are the most used materials in MHT. However, magnetite has a high Curie temperature (Tc~580 °C), and its use may generate local superheating. To overcome this problem, strontium-doped lanthanum manganite could replace magnetite because it shows a Tc near the ideal range (42–45 °C). In this study, we developed a smart composite formed by an F18 bioactive glass matrix with different amounts of Lanthanum-Strontium Manganite (LSM) powder (5, 10, 20, and 30 wt.% LSM). The effect of LSM addition was analyzed in terms of sinterability, magnetic properties, heating ability under a magnetic field, and in vitro bioactivity. The saturation magnetization (M_s) and remanent magnetization (M_r) increased by the LSM content, the confinement of LSM particles within the bioactive glass matrix also caused an increase in Tc. Calorimetry evaluation revealed a temperature increase from 5 °C (composition LSM5) to 15 °C (LSM30). The specific absorption rates were also calculated. Bioactivity measurements demonstrated HCA formation on the surface of all the composites in up to 15 days. The best material reached 40 °C, demonstrating the proof of concept sought in this research. Therefore, these composites have great potential for bone cancer therapy and should be further explored.     

Test and Microstructural Analysis of a Steel Slag Cement-Based Material Using the Response Surface Method

In this study, the silica fume replacement rate, fly ash replacement rate, and curing temperature were regarded as the independent variables, and the compressive and flexural strengths were regarded as the response values. The response surface method was used to construct the response surface polynomial regression model and obtain the optimal preparation parameters of a steel slag cement-based gel slurry (SCGS). The univariate and multivariate effects on the SCGS’s strength were investigated via analysis of variance and a three-dimensional surface model, and the hydration products and strength development law were characterized via scanning electron microscopy and X-ray diffraction. The actual compressive strengths at 3 and 28 d of age were 31.78 and 53.94 MPa, respectively, which were close to the predicted values (32.59 and 55.81 MPa, respectively), demonstrating that the optimized strengths were accurate and reliable. Further, the hydration reaction rate of SiO₂ in the silica fume and the physical filling effect of the inert components of fly ash and steel slag under the optimal parameters were the key factors for the early strength of the material. Moreover, continuous C₃S hydration in steel slag and the continuous excitation of the volcanic ash properties of fly ash were important factors for the later strength.     

Material Extrusion of Structural Polymer–Aluminum Joints—Examining Shear Strength,Wetting, Polymer Melt Rheology and Aging

Generating polymer–metal structures by means of additive manufacturing offers huge potential for customized, sustainable and lightweight solutions. However, challenges exist, primarily with regard to reliability and reproducibility of the additively generated joints. In this study, the polymers ABS, PETG and PLA, which are common in material extrusion, were joined to grit-blasted aluminum substrates. Temperature dependence of polymer melt rheology, wetting and tensile single-lap-shear strength were examined in order to obtain appropriate thermal processing conditions. Joints with high adhesive strength in the fresh state were aged for up to 100 days in two different moderate environments. For the given conditions, PETG was most suitable for generating structural joints. Contrary to PETG, ABS–aluminum joints in the fresh state as well as PLA–aluminum joints in the aged state did not meet the demands of a structural joint. For the considered polymers and processing conditions, this study implies that the suitability of a polymer and a thermal processing condition to form a polymer–aluminum joint by material extrusion can be evaluated based on the polymer’s rheological properties. Moreover, wetting experiments improved estimation of the resulting tensile single-lap-shear strength.     

介孔碳-二氧化钛纳米复合材料的制备及其电化学应用

通过多巴胺的原位聚合,将聚多巴胺（PDA）均匀包裹在钛纳米管（TNTs）表面,再在氮气保护下经过高温灼烧,制备得到介孔碳-二氧化钛(MC-TiO2)纳米复合材料,进一步采用氢氟酸（HF）对该复合材料进行处理可调控其中二氧化钛的含量。将HF处理前后的复合材料分别制成锂离子电池的负电极。采用透射电镜（TEM）、扫描电镜（SEM）、氮气吸附测试、X射线衍射（XRD）、热重分析（TG）等多种测试手段对复合材料进行了表征。研究结果表明：由这两种电极构成的锂电池均有较好的充-放电效率和循环稳定性;未经HF处理的复合材料（MC-TiO2）作负极的电池的电容量较低（约130 mA·h/g）,而经HF处理的复合材料(MC-TiO2)a作负电极的电池的电容量有显著提升,首次放电容量达到1 100 mA·h/g,之后的59次循环中放电容量稳定在360 mA·h/g。     

硅橡胶印模材料在口腔修复中的应用

目的:探讨硅橡胶印模材料在烤瓷冠修复中的应用效果.方法:将我院2010 年6月至2011 年2月收治的60 例60 颗进行烤瓷冠修复的牙齿分别采用硅橡胶印模和藻酸盐印模,比较两组患者的印模的精确性和烤瓷冠的边缘适合性.结果:硅橡胶组的印模评价的优秀率为80.0% 显著高于藻酸盐组的60.0%,P<0.05.且硅橡胶组的烤瓷冠的边缘的密合率为96.7% 显著高于藻酸盐组的80.0%,P<0.05.结论:硅橡胶印模材料在烤瓷冠修复中的应用可提高印模的精确性和烤瓷冠边缘的密合度.     

Comparative Analysis of Domestic and International Test Guidelines for Various Concrete Repair Materials

The number of aged bridges among concrete structures is increasing. Therefore, to increase their lifespans, repair and reinforcement schemes ought to be implemented. This study selected various repair materials according to crack-surface treatment, crack-filling, and crack-injection methods. These repair materials were evaluated using various test methods proposed by the Korean Standards and the American Society for Testing and Materials for structure protection, structure restoration, and crack repair; the results were analyzed and compared. Consequently, the structure restoration material exhibited a similar freezing–thawing trend as that of chloride, while also exhibiting similar flexural, compressive, bond, and splitting-tensile strengths. However, chloride yielded performance differences (up to two-fold) depending on the type of material used for comparison. The crack-repair material yielded similar trends only for bond strength but yielded differences (up to 2–4-fold) in tensile, compressive, and flexural strengths depending on the material used for comparison. These results confirmed that crack-repair materials exhibit significant differences in performance depending on the manufacturer compared with structure protection and structure restoration materials. Therefore, it is expected that repair materials appropriate for usability, durability, and structure safety, while also being environmentally friendly, could be used in future bridge repairs based on these test evaluations.     

牛去细胞骨基质的生物相容性研究

目的 研究新型骨修复材料牛去细胞基质骨的生物相容性,为其在骨缺损修复领域中的临床应用提供实验依据.方法 对牛去细胞骨基质进行急性毒性实验、热源实验、溶血实验、兔肌肉内种植实验和兔桡骨骨缺损修复实验研究.结果 牛去细胞骨基质无毒性、无热源性、不引起溶血反应,植入兔肌肉后逐渐发生生物降解并被纤维组织取代,兔骨缺损区植入后可被骨组织取代.结论 牛去细胞骨基质具有良好的生物相容性,是理想的骨支架材料.