肿瘤多细胞球:一种近似实体瘤的体外肿瘤模型

本文介绍了一种简便易行的方法,用以在体外建立近似体内实体瘤的肿瘤模型—肿瘤多细胞球模型(multicellular tumor spheroids,MCTSs).采用液滴重叠法(liquid overlay method)来构建HeLa肿瘤多细胞球模型,并在光镜下对肿瘤多细胞球的生长状况进行观察描述,再应用场发射扫描电...     

A novel colour image encryption algorithm based on chaos

In this paper, a novel colour image encryption algorithm based on chaos has been proposed. We use chaotic system to encrypt the R, G, B components of a colour image at the same time and make these three components affect each other. So the correlations between R, G, B components can be reduced and the security of algorithm is increased. Simulation results show that the proposed algorithm can encrypt colour image effectively and resist various typical attacks.     

丙烯酰胺与丙烯酸十四酯共聚物的合成及性能研究

利用过氧化苯甲酰为引发剂探讨了丙烯酰胺（ＡＭ）和丙烯酸十四酯（ＴＡ）的自由基共聚合。重点讨论了合成条件如引发剂用量，单体配比、溶剂、温度等对共聚反应及共聚物对苯丙乳胶增稠性能的影响。并用ＩＲ和凯达定氮法表征了共聚物的组成，实验结果表明，ＡＭｔ ＴＡ进行沉淀聚合所得到的共物分子量足够大，可以作为疏水缔合型稠剂使用。     

A novel emitter-sharpened double-gate race-track-shaped fieldemitter structure

In this paper, a new emitter-sharpened double-gate race-track-shaped field emitter structure is reported. The race-track-shaped edge emission with double-gate control is used to provide high uniformity FEAs over a large area without the need of expensive submicron technology. In order to minimize the gate current, which is detrimental to the field emitter performance, an emitter-sharpened structure is used. Experimental results show that the turn-on voltage of the emitter-sharpened double-gate structure is 45 V, which is 60% smaller than that of the single-gate structure (110 V). Furthermore, the gate current of the emitter-sharpened double-gate structure is 7 times and 15 times smaller than that of the nonemitter-sharpened double-gate structure and the single-gate structure, respectively     

Stereoselective Synthesis of 2-(4-Hydroxyphenyl)-3-hydroxymethyl-1,4-benzodioxane-6-aldehyde—The Key Intermediate of Sinaiticin

SlflsltlC！fi10，dn8VOflOI！gflsfl．W3SISOhtCdnOffiSlhQltICtiffiIC3VCSsfldhdIflhibltOYy卜388cellactlvltyl．巨histypeofnaturalproductshaveshownvariousbloactlvltyandreceivedconsiderableattentionfromsyntheticchemlstsy．Wewishtoreportastereoselectlvetotalsynthesisofslnaltlclnfromreadilyavailablestartingmaterials（land4）．OursyntheticdesignIsbaseduponconstructionofthesubstitutedbenzouioxanering，to！lowedbyformationof＊theX＊＊flavanonolmoietyFromSchemel，wecansee！natInnilssynthesisofs…     

Heat-transfer characteristics of climbing film evaporation in a vertical tube

Heat-transfer characteristics of climbing film evaporation were experimentally investigated on a vertical climbing film evaporator heated by tube-outside hot water. The experimental setup was designed for determining the effect of the height of feed water inside a vertical tube and the range of temperature difference on local heat transfer coefficient inside a vertical tube (h_i). In this setup, the height of feed water was successfully controlled and the polypropylene shell effectively impedes the heat loss to the ground. The results indicated that a reduction in the height of feed water contributed to a significant increase in h_i if no dry patches around the wall of the heated tube appeared inside the tube. The height ratio of feed water R_h = 0.3 was proposed as the optimal one as dry patches destroyed the continuous climbing film when R_h is under 0.3. It was found that the minimum temperature difference driving climbing film evaporation is suggested as 5 °C due to a sharp reduction in h_i for temperature difference below 5 °C. The experiment also showed that h_i increased with an increase in temperature difference, which proved the superiority of climbing film evaporation in utilizing low-grade surplus heating source due to its wide range of driving temperature difference. The experimental results were compared with the previous literature and demonstrated a satisfactory agreement.     

A New Capillary Electrophoresis Apparatus with Piezoelectric Ceramics High Voltage Source and Amperometric Detector

IntroductionHighperformancecapiliar}'electrophoresis(HPCE)isanewanalyticaltechnology'rapidly'developedinrecentyears.Withtheadvantagesofsmallsample.highsensitivity,highresolution.rapidanalysisandverycheaprunning,ithasbeenappliedinchemistry'.lifescienc...     

Studies on Chem icalCom position ofIron-m olybdenum Cofactor fromNitrogenase by Fluorescence Analysis

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