丁基胶塞使用过程中的临床问题

探讨丁基胶塞自使用以来出现的一系列临床现象:胶塞因硬度过低增加了翻塞难度;盖塞后因瓶壁和胶塞的密合性差增加了药液的外漏和污染的可能性;瓶塞长度不规范易引起跳塞现象的发生;开瓶时启盖器与瓶口的直接接触使瓶口破损导致玻璃碎屑的产生;胶塞强度过低使穿刺所致微粒增多;胶塞弹性过低引起换针时药液外流;挂壁现象的产生使患者和家属怀疑药物的质量;胶塞与瓶口不匹配引起胶塞松动和药液侧漏等.,期望生产厂家能从人民生命安全的角度出发,逐渐完善生产工艺、优化橡胶的配方.     

琥珀酰壳聚糖的制备及其与HL-60细胞亲和性的研究

以粘均相对分子质量700000和17500的高脱乙酰度壳聚糖为原料,通过吡啶催化制备N-琥珀酰壳聚糖(N-SUCC-CCTS),通过甲磺酸保护氨基制备O-琥珀酰壳聚糖(O-SUCC-CTS).应用异硫氰酸荧光素黄(FTTC)对合成的2种琥珀酰壳聚糖进行标记,荧光标记率分别为0.97%(O-SUCC-CTS)、0.66%(N-SUCC-CTS1.75)和0.34%(N-SUCC-CTS70).用流式细胞仪测定琥珀酰壳聚糖与人白血病HL-60细胞的结合能力,亲和性能力顺序为O-SUCC-CTS1.75＞N-SUCC-CTS1.75＞N-SUCC-CTS70.O-SUCC-CTS是一种很有潜力的抗肿瘤靶向载体.     

后续烧结对爆炸压实CuCr合金性能的影响

采用机械合金化工艺由Cu,Cr元素粉按重量比各半合成CuCr预合金粉,尔后爆炸压实工艺制坯,再加后续烧结制备了电触点材料CuCr合金,着重研究了后续烧结对爆炸实CuCr合金性能的影响,结果表明,真空烧结略微提高爆炸压实的CuCr合金的密度,而氢气烧结处理反而使其密度降低,真空烧结和氢气烧结都能显著降低CuCr合金硬度,而且氢气烧结降低得更明显,真空烧结和氢气烧结都显著提高CuCr合金的电导率,而且真空烧结提高更显著。     

Methodical factors in coulometric determination of the sum of uranium and plutonium weight fractions in MOX fuel

The influence exerted on the accuracy of coulometric titration by the composition of the supporting electrolyte solution in the titration step, by the way of stirring of the supporting electrolyte solution, by the weight of the aliquot of the solution being titrated, by the weight of the substance being titrated in the aliquot, by the kind of reductant, and by the solution compositions in the steps of oxidation and reduction of U-Pu mixtures was studied by spectrophotometry and coulometry. The optimum conditions for performing the analysis were found.     

Nanostructure fabrication by ultra-high-resolution environmental scanning electron microscopy

Electron beam induced deposition (EBID) is a maskless nanofabrication technique capable of surpassing the resolution limits of resist-based lithography. However, EBID fabrication of functional nanostructures is limited by beam spread in bulk substrates, substrate charging, and delocalized film growth around deposits. Here, we overcome these problems by using environmental scanning electron microscopy (ESEM) to perform EBID and etching while eliminating charging artifacts at the nanoscale. Nanostructure morphology is tailored by slimming of deposits by ESEM imaging in the presence of a gaseous etch precursor and by pre-etching small features into a deposit (using a stationary or a scanned electron beam) prior to a final imaging process. The utility of this process is demonstrated by slimming of nanowires deposited by EBID, by the fabrication of gaps (between 4 and 7 nm wide) in the wires, and by the removal of thin films surrounding such nanowires. ESEM imaging provides a direct view of the slimming process, yielding process resolution that is limited by ESEM image resolution ( approximately 1 nm) and surface roughening occurring during etching.     

Modification of dispersibility of nanodiamond by grafting of polyoxyethylene and by the introduction of ionic groups onto the surface via radical trapping

To improve the dispersibility of polycrystalline nanodiamond (ND) in solvents, the grafting of polymers and introduction of ionic groups onto ND surface via radical trapping by ND surface were investigated. The grafting of polyoxyethylene (POE) onto ND surface by trapping of POE radicals formed by the thermal decomposition of POE macro azo-initiator (Azo-POE) was examined. The polymer radicals formed by the thermal decomposition of Azo-POE were successfully trapped by ND surface to give POE-grafted ND. The effect of temperature on the grafting of POE onto ND was discussed. In addition, the introduction of cationic protonated amidine groups onto ND was achieved by the trapping of radicals bearing protonated amidine groups formed by thermal decomposition of 2,2′-azobis(2-methylpropionamidine)dihydrochloride (AMPA). The anionic carboxylate groups was introduced onto ND surface by the trapping of the radicals bearing carboxyl groups formed by thermal decomposition of 4,4′-azobis(4-cyonovaleric acid) (ACVA) followed by the treatment with NaOH aqueous solution. The dispersibility of ND in water was remarkably improved by the grafting of POE, based on the steric hindrance of polymer chains and by the introduction of ionic groups, based on the ionic repulsion, onto ND surface.     

Comparison of structural and photoluminescence properties of ZnO thin films grown by pulsed laser deposition and ultrasonic spray pyrolysis

ZnO thin films have been deposited by pulsed laser deposition (PLD) and ultrasonic spray pyrolysis (USP) method, respectively. X-ray diffraction and transmission electron microscopy characterizations indicate that ZnO film grown by PLD exhibits better crystallinity than that grown by USP. Photoluminescence spectra show that the near-band edge ultraviolet emission of film grown by PLD is narrower and shifts to higher energy, compared with that of film grown by USP. In the visible range, ZnO film grown by PLD exhibits four local level emission centered at 470 nm, 486 nm, 544 nm, and 613 nm, respectively, while the film grown by USP only presents a weak broad band emission centered at 502 nm. Hall measurement shows higher carrier density and lower hall mobility in ZnO film grown by PLD than that in film grown by USP. The higher density of intrinsic defects as well as higher crystallintiy is considered to account for the difference of photoluminescence in ZnO film grown by PLD with that in film grown by USP.     

Fracture of shear bands in atactic polystyrene

Thick shear bands in polystyrene formed by compression could cause fracture or the formation of cracks by intersecting with themselves, by relaxing after the removal of the load, by propagating all the way to the side surfaces and by subsequent tensile deformation. The microstructural mechanisms involved in all these fracture processes are discussed.     

微热量热计法研究几种盐对硝酸铵晶变的影响

硝酸铵(AN)中添加质量分数5%的无机盐并碾磨混合,通过微热量热计研究4种常用无机盐对AN晶型Ⅳ~Ⅰ型转变的影响。结果表明:两种氯盐使AN晶型Ⅱ~Ⅰ型开始转变的温度明显提前;4种无机盐使AN晶型Ⅳ~Ⅲ型转化温度降低;硝酸钾使AN晶型Ⅲ~Ⅱ型转变温度提高约7℃,氯化钾提高约3℃;氯化钾可以使AN晶型的Ⅳ~Ⅲ型、Ⅲ~Ⅱ型相转变焓降低,使晶型转变难度增大;氯化钠使AN晶型转变焓明显增大,促进AN晶型转变。     

快速烧结制备纳米Y-TZP材料

研究了快速热压烧结和放电等离子快速烧结（ＳＰＳ）制备纳米Ｙ－ＴＺＰ材料．利用快速热压烧结和 ＳＰＳ快速烧结,可在烧结温度为 １２００℃、保温９～１０ｍｉｎ条件下,制得相对密度超过９９％的 Ｙ－ＴＺＰ材料．研究发现：虽然快速热压烧结和 ＳＰＳ烧结都可使Ｙ－ＴＺＰ在相同温度下的密度高于普通热压烧结,但两种快速烧结所得Ｙ－ＴＺＰ的晶粒都大于无压烧结所得;另外,快速热压烧结所得样品的结构不够均匀,而ＳＰＳ烧结的样品的均匀性较好．文章对产生这些现象的原因进行了理论探讨．     

基于心电信号采集与处理的刺绣型织物电极研究

为实现对心电信号的长期穿戴式监测和生理状态的反馈,选用140D的镀银尼龙纱线,采用刺绣法制备织物电极,从织物电极的形状、尺寸以及使用过程中偏置电压的变化情况进行静态分析,得出电极本身因素和穿戴时间对电极使用效果的影响。然后,将小波变换除杂后织物电极采集的心电信号与标准电极采集的心电信号经过Matlab处理,分析织物电极采集心电信号的可行性。利用R波检测算法和QRS波群提取原理提取出两种特征波以及程序语言得到特征波形的规律,并反馈出受试者的生理状态。借助SPSS软件对两者采集的心电信号进行了相关性检验和回归分析,结果表明,刺绣型织物电极采集的心电信号与标准电极采集的心电信号具有强相关性。     

室外换热器分液装置的实验研究

制冷剂分配不均现象是室外换热器研究的重点内容.本文设计了两种隔板形式,共制作7种样件放置于换热器集管中进行实验研究.通过实验分析了换热器用作蒸发器的6种工况与用作冷凝器的4种工况下的制冷剂分配情况及换热性能.结果表明:本文利用挡流板实现了良好的制冷剂分配效果,两种挡流隔板(A和B)的加入均有助于改善换热器制冷剂分配不均...     

An improved correlation for the viscosity of simple fluids at high densities

The Batschinski-Hildebrand relation is improved by plotting the fluidity versus the molar volume minus the hard-core volume of the molecules, the latter given by equation of state calculations. The relation can be cast in a corresponding states form by reducing the fluidity by the molar mass, the critical temperature, and the critical volume and by reducing the volume by the zero temperature hard-core volume. The random close-packed volume, where the fluidity is zero, is in reasonable agreement with theoretical considerations of hard spheres. The small deviations from corresponding states for liquids are interpreted either by polarity or by nonconvexity of the molecules.Dedicated to Professor Klaus Gersten on the Occasion of His 60th Birthday     

酸酐固化环氧树脂-有机蒙脱土纳米复合材料的制备及性能研究

以甲基四氢酸酐为固化剂,对含羟基长链烷基季铵盐改性蒙脱土-环氧树脂纳米复合材料的制备进行了研究。通过TEM、SEM、TGA和DMA等对其微观结构、热性能和动态力学性能等进行表征和分析。TEM结果表明:有机蒙脱土以纳米片层分散在环氧树脂基体中,形成了纳米复合材料;有机蒙脱土含量3wt％时,环氧树脂被同时增韧增强:冲击强度提高87.8%,拉伸强度提高20.9%。纳米片层蒙脱土的加入同时也改善了环氧树脂的热稳定性和动态力学性能;有机蒙脱土含量5wt%时,热分解温度提高24.7℃,热变形温度提高了8.7℃;在T<T_g时,环氧树脂的储能模量提高42.86%,在T>T_g时,提高229.8%;相应玻璃化转变温度T_g提高14.7℃。      

化学共沉淀粉体制备ZnO压敏电阻

本文采用化学共沉淀法制备了颗粒细、活性好的ZnO压敏电阻粉体,表征了粉体的性能．利用共沉淀粉体制备了α＝50、压敏电压高、通流能力大的压敏电阻．与传统氧化物机械混合粉体制得的压敏电阻比较,共沉淀粉体获得的压敏电阻微观结构均匀．     

8090Al-Li 合金亚晶倾转的动态再结晶机制

通过对8090Al-Li 合金热变形的研究,发现了一类亚晶倾转形核的动态再结晶。从应力及能量的角度分析了亚晶倾转形核过程及应变对形核的作用。亚晶倾转形核再结晶是在外界应力的作用下,位错克服亚晶界的短程应力场所造成的能垒,进入亚晶界,增大亚晶界角度,同时发生亚晶倾转的过程。     

Alumina–mullite–zirconia composites: Part II Microstructural development and toughening

Densification characteristics and fracture toughness of the alumina–mullite–zirconia (AMZ) composites fabricated by the colloidal mixing route were examined. The densification of boehmite–silica–zirconia precursor compacts was characterized by three distinct stages. Stage I was represented by a rapid shrinkage between 1100 and 1300°C and was caused by the viscous flow sintering of the SiO2 component. Stage II was characterized by a temporary cessation of the shrinkage caused by the mullitization. Stage III was represented by a restoration of the shrinkage for temperatures above 1450 °C. The α-Al2O3 seeding facilitated the formation of elongated grains in the AMZ composites, and these elongated grains correspond to α-Al2O3. The toughening caused by the microcrack nucleation was comparable to that by the t → m martensitic transformation and increased with increasing total content of zirconia.     

Preliminary study on theory and experiment of photo-mechanics manufacturing and detecting technologies based on laser thermal stress

Mechanical effects of laser thermal stress is a new manufacturing technology, which is made use of thermal stress by high power laser acted on the surface of metal material to generate stress field. The technologies such as formation by laser thermal stress, measurement by laser scratch, measurement by XRD and so on are formed based on mechanics effects of laser thermal stress. The mechanisms of formation by laser thermal stress, measurement by laser scratch and measurement by XRD are analyzed. The theory of photo-mechanics manufacturing based on laser thermal stress is originally put forward whose experiment is primitively researched, and the manufacturing theory by mechanics effects of laser thermal stress is established.     

铅锌尾矿用于中热水泥的制备

本文采用铅锌尾矿为原料烧制中热硅酸盐水泥,并与用粘土配料烧制的中热水泥进行对比。用差热分析测定熟料的易烧性;用X射线衍射分析研究了熟料的矿物组成;依据国标GB2022-80测量了中热水泥的水化热;通过砂浆和净浆实验测定了中热水泥水化后的强度;并用X射线衍射和扫描电镜对水化产物进行了分析。实验结果表明,使用铅锌尾矿来配料,可以提高熟料的易烧性,矿物形成良好。熟料掺入4%的石膏制得水泥,其性能符合GB200-2003规定的强度等级42.5中热硅酸盐水泥的各项标准,并且其后期强度高于用粘土配料的试样。     

Real‐Time Activity Bioassay of Single Osteoclasts Using a Silicon Nanocrystal‐Impregnated Artificial Matrix

The lack of an in vitro real‐time osteoclast (OC) activity assay has hampered mechanistic studies of bone resorption. Such an assay is developed, employing a hydroxyapatite matrix impregnated with alkyl‐capped silicon nanocrystals, which is capable of monitoring the time‐course of resorption by single osteoclasts. Resorption of the matrix by OC releases the nanocrystals, which are internalized by the cell and detected as an increase in OC luminescence. This particular choice of nanocrystals is motivated by their bright pH‐independent luminescence, proportional to concentration, and by their rapid uptake without cytotoxicity. In this in vitro assay, OCs are inhibited by calcitonin (CT) and methyl‐β‐cyclodextrin (MCD), and stimulated by receptor activator of nuclear factor kappa‐B ligand (RANKL) in the expected manner. The kinetics of the assay exhibit a lag phase representing cell attachment and commencement of resorption processes, followed by a growth of cell luminescence intensity, and the whole time‐course is satisfactorily described by the logistic equation.