直接金属粉末激光成型异型水路在模具冷却系统中的应用

介绍了利用直接金属粉末激光烧结技术制作具有快速控温功能的异型水路的方法,该异型水路用在型腔模上不受传统加工工艺的限制,更能贴近成型制品轮廓,对制件的死角或不易散热区域,异型水路均能达到良好的散热效果。将异型水路设计应用于注射模冷却系统中,可使模具温度控制达到最佳的效果,塑件的质量也得以提高。     

斑蝥素及其衍生物的作用机制及临床应用

斑蝥为芫菁科昆虫,南方大斑蝥Mylabrisphalerala Pallas或黄黑小斑蝥Mylabris cichoriiLinnaeus的干燥全虫,味辛、热,有大毒,在我国已经应用两千多年,是一种重要的昆虫类药物。现代药学研究表明其主要药用成分是斑蝥素,主要用于治疗肝癌、食管癌及胃癌。去甲斑蝥素(norcantharidin,NCTD)为斑蝥素的衍生物,是我国首先合成的具有较强抗肿瘤活性和独特升高白细胞作用的新型杭肿瘤药物。明显增强了抗癌效果,并显著降低了斑蝥素对人体的毒副作用。文章对国内外有关斑蝥素及其衍生物的作用机制和临床应用现状进行了综述。     

ANTIRADICAL EFFICIENCY OF TEA COMPONENTS

Tea contains antioxidant compounds, such as (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG), gallic acid and caffeine. The antioxidant activity of these compounds as well as 1,3,7-trimethyluric acid (the major metabolite of caffeine) was evaluated using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH). The antiradical ability according to the EC₅₀ was EGCG > ECG > EGC > gallic acid > EC > BHT > 1,3,7-trimethyluric acid > caffeine. The time for these compounds to reach the steady state was considered, and the concept of antioxidant efficiency (AE₅₀) involving the EC₅₀ and the time to reach the steady state was used to evaluate the antiradical efficacy. The order of antiradical efficiency according to AE₅₀ was ECG gallic acid > EGCG > EC > EGC > BHT > 1,3,7-trimethyluric acid > caffeine.     

卷烟纸中助燃剂的分离与鉴定

为了解卷烟纸中助燃剂的种类,采用不含二氧化碳的二次去离水浸提,浸提液加热蒸干,残留物与KBr一起研磨压片进行红外光谱(IR)扫描,再与酒石酸钠、酒石酸钾钠、酒石酸钾和乙酸钾标准样品的IR谱图比对的方法,对3种卷烟纸中的助燃剂进行了分离鉴定。结果显示,所分析的3 种卷烟纸样中的助燃剂均为酒石酸钠。     

凉潭岛海域海洋环境现状调查研究

2010年8月作者对凉潭岛附近海域的水质、沉积物质量和生态环境质量(浮游植物、浮游动物、底栖生物和潮间带生物)进行调查,结果表明水质、沉积物监测项目中的无机氮和磷酸盐部分站位超标,水质富营养化严重。浮游植物、浮游动物、底栖生物和潮间带生物的生物多样性指数较高,种类较丰富。     

基于SOAP网关的Web Services访问控制

本文探讨了Web Services通信中对SOAP网关的需求,提出了基于SOAP网关的Web Services访问控制架构,分析了架构中的参与者及其职责,并给出了两种SOAP网关的实现方法和基于XACML的授权服务的实现机制。     

静电纺丝纳米纤维的新进展和未来动向

综述了日本和欧美静电纺丝纳米纤维技术和制品的新进展、已产业化的品种和正在研发的多样新品种和新用途,指出未来的研发方向和动向.     

THE DEVELOPMENT OF A MACHINE VISION SYSTEM FOR SHIITAKE GRADING

A grading system was developed to classify shiitake automatically into various grades of quality in terms of size, shape and color. A shiitake is scanned with a color charge‐coupled‐device camera and then various geometrical and color characteristics are determined by image processing. The online grading procedure includes the following sequences in processing dried shiitake: (a) color abnormality is eliminated by image analysis; (b) broken caps are detected by calculation of the area‐to‐perimeter ratio; and (c) size is determined by pixel counting from the bottom view. Image processing and algorithmic manipulations are done on a personal computer (PC) while grading is carried out by a programmable logic controller (PLC). The PLC accepts grading instructions from the PC, hence controls the grading mechanisms. Pilot system validation was done on 250 dried shiitake samples and resulted in a 97.6% accuracy rate. This result is better than that by visual inspection. A complete grading cycle takes 4.8 s, of which the PC unit participates 0.3–0.7 s depending on the physical complexity of the shiitake being processed.     

Pulsed Ultra High Pressure Treatments for Pasteurization of Pineapple Juice

Sinusoidal and step-pressure pulses were compared with static pressure treatments for the inactivation of Saccharomyces cerevisiae 2407-1a in pineapple juice. No inactivation was observed after 40–4,000 fast sinusoidal pulses (10 cycles/s) at 4–400 sec in the 235–270 MPa range. Static 270 MPa treatments at 40 and 400 sec resulted in 0.7 and 5.1 decimal reductions, respectively. Slower 0–270 MPa step pulses at 0.1 (10 pulses), 1 (100 pulses), and 2 (200 pulses) cycles/s with 100 sec total on-pressure time resulted in 3.3, 3.5, and 3.3 decimal reductions, respectively. A comparable static pressure treatment resulted in 2.5 decimal reductions. Changing the on-pressure/off-pressure time ratio (3:1, 3:3 and 1:3) showed that treatments with longer on-pressure time, e.g., 0.6 sec on-pressure and 0.2 sec off-pressure were significantly more effective showing nearly a 4 decimal reduction in 100 sec.