降膜蒸发过程熵产分析

从热力学第二定律出发,将普适体系的熵产表达推广于降膜蒸发过程熵产分析并得到熵产计算式.引入单位熵产数并得到Reynolds数大于1450(c_pμ/λ)^-1.06(0.5-0.25ω)^-1情况下和Reynolds数之间的定量关系,据此揭示了降膜蒸发过程熵产随降膜管内液膜厚度减小先降低再增大的规律,对应存在最小熵产数.与φ30×2×6000传热管内磷酸降膜蒸发实验数据对比结果吻合良好,表明本文熵产计算式可以根据过程的热力参数表达降膜蒸发过程的熵产规律,对过程强化和提高热力学效率具有实际指导意义.     

Thin film graphite electrodes with low stress generation during Li-intercalation

We report here the development of thin film ‘graphite’ electrodes for Li-ion batteries, with near theoretical Li-intercalation/de-intercalation capacity (∼372 mAh/g). These films, synthesized by chemical vapor deposition at a relatively low temperature of 1000 °C, exhibit strong graphitic order with the basal planes oriented parallel to the Ni current collector. During galvanostatic cycling, in-situ stress measurements show that full lithiation corresponds to the development of only modest in-plane compressive stresses of ∼ −250 MPa. These stresses are more than an order of magnitude lower than expected, which should promote long cycle life.     

Carrier generation within the surface region of hydrogenated thin film polycrystalline diamond

Low temperature Hall effect measurements made on diamond films subjected to a hydrogenation process, such that the near surface region becomes p-type without the addition of conventional dopant atoms, are reported. The carrier concentration within the temperature range 10–300 K does not change as expected for most films, actually increasing as the temperature falls. However, polished films display more conventional behaviour in that the carrier concentration falls with falling temperature. A model involving carrier transport within both valance and impurity bands can be considered to explain these observations, leading to the suggestion that the hydrogenation process is capable of creating acceptor states with an activation energy within the range of 10–40 meV.     

共挤膜机组中新一代内冷控制技术

介绍新一代内冷控制技术的结构和原理。在共挤吹膜机组中的应用中,冷却效果好,机组产量大幅提高,膜泡控制稳定,制膜质量可靠。     

翻板式半自动轮胎修毛机的改进

介绍翻板式半自动轮胎修毛机的工作流程、存在问题以及改进措施和效果。通过采取改进进出通道辊筒、修毛工位设置防静电软毛刷装置、改进翻板机构以及对主动辊筒驱动电机实施变频控制措施,使轮胎平均修毛时间由12 s缩短为8 s,同时延长了设备使用寿命,减轻了工人劳动强度。     

Characterisation of buried glass/cyclo-olefin polymer film interfaces by sum-frequency generation vibrational spectroscopy

Plasma gas-modified cyclo-olefin polymer (COP) surfaces and the interfaces between borosilicate glass and COP films were investigated by sum-frequency generation (SFG) vibrational spectroscopy. Upon exposure to oxygen gas plasma, the SFG signal intensities increased, indicating an improvement in the orientational order at the surface functional groups. In addition, thermal annealing following lamination improved the COP interphase molecular ordering and increased the number density of functional molecules at the interfaces.     

Effects of free volume in thin‐film composite membranes on osmotic power generation

For the first time, the effects of free volume in thin‐film composite (TFC) membranes on membrane performance for forward osmosis and pressure retarded osmosis (PRO) processes were studied in this work. To manipulate the free volume in the TFC layer, a bulky monomer (i.e., p‐xylylenediamine) was blended into the interfacial polymerization and methanol immersion was conducted to swell up the TFC layer. Results from positron annihilation lifetime spectroscopy (PALS) show that p‐xylylenediamine blending and methanol induced swelling enlarge and broaden the free volume cavity. In addition, the performance of TFC membranes consisting of different free volumes were examined in terms of water flux, reverse salt flux, and power density under high pressure PRO operations. The TFC‐B‐5 membrane (i.e., a TFC membrane made of blending monomers) with a moderate free volume shows the highest power density of 6.0 W/m² at 9 bar in comparison of TFC membranes with other free volumes. After PRO operations, it is found that the free volume of TFC layers decreases due to high pressure compression, but membrane transport properties in terms of water and salt permeability increase. Interestingly, the membrane performance in terms of resistance against high pressures and power density stay the same. A slow positron beam was used to investigate the microstructure changes of the TFC layer after PRO operations. Compaction in free volume occurs and the TFC layer becomes thinner under PRO tests but no visible defects can be observed by both scanning electronic microscopy and PALS. © 2013 American Institute of Chemical Engineers AIChE J, 59: 4749–4761, 2013     

天然气调节球阀阀体半自动气压试验装置设计

为保证球阀的质量,必须进行三个方面的试验。一是阀体水压试验,二是阀体气压试验,三是球阀密闭性试验。其中,阀体气压试验主要是在一定压力下检测其密闭性,以使其能够安全有效地运行,正常地实现其调节功能。气压试验装置可为球阀的性能测试提供高效高质量的测试平台,提高球阀阀体气压试验的效率。     

无功补偿的意义及补偿方式

从理论上阐述了无功功率对系统的影响和无功补偿的方法。随着电力工业的发展,冲击性负荷和非线性负荷的大量增加,造成电网的电压波动、闪变,功率因数低下日趋严重,因此,迫切需要对电网电能质量问题进行治理。     

使用半自动定氮仪测定天然橡胶氮含量方法的优化

对使用半自动定氮仪测定天然橡胶氮含量的方法进行优化,试验方法1为0. 5 g胶料+3. 25 g混合催化剂+70mL氢氧化钠溶液+50mL硼酸溶液吸收;试验方法2为0. 1～0. 2g胶料+0. 65g混合催化剂+20mL氢氧化钠溶液+20mL硼酸溶液吸收。结果表明:试验方法1和2测得的胶料氮含量基本一致,均可行;但与试验方法1相比,试验方法2具有用时短、效率高、成本低和安全可靠的优点。     

全自动酶免仪与半自动酶标仪比对研究

目的评价LABAT2+FAME24/20全自动酶免仪与BIO-RAD680酶标仪临床检测结果的一致性。方法使用LABAT2+FAME24/20全自动酶免仪与BIO-RAD680酶标仪对40例临床标本进行HBsag,HBsab,HBeag,HBeab,HBcab,HBc-IgM,HBV-pres1,anti-HCV,anti-HIV,anti-TP10个项目检测,比对检测结果。结果 LABAT2+FAME24/20全自动酶免仪与BIO-RAD680酶标仪对此10个项目指标检测结果的符合率均为100%。结论这2台仪器检测结果具有一致性,可以同时应用于临床免疫项目的检测。     

Effect of current density and sulfuric acid concentration on persulfuric acid generation by boron-doped diamond film anodes

This research investigated the effects of current density and sulfuric acid concentration on the rates of persulfate generation by boron-doped diamond film anodes. Also investigated was the maximum conversion of sulfate to persulfate that could be achieved from electrolysis of sulfuric acid. Experiments were performed in batch systems using a rotating disk electrode (RDE) and a flow-through reactor with parallel plate electrodes. Both the RDE and flow-through experiments showed that there was a linear relationship between persulfate generation rates and current density. Persulfate generation rates became current limited at sulfuric acid concentrations of 2.25 M and above; however, Faradaic efficiencies under current-limited conditions were only ~60 %, and were only weakly dependent on the current density. Persulfate generation rates in the flow-through reactor showed similar dependencies on current density and sulfuric acid concentration as those in the RDE reactor, but were 20–50 % lower. Acid catalyzed and thermal decomposition of persulfate limited the maximum conversion of sulfate to persulfate. A maximum fractional conversion of 78 % was achieved using an initial sulfuric acid concentration of 0.77 M. Surprisingly, this value was independent of the current density over the range of 100–300 mA cm^?2.     

医用真空冷冻干燥机半自动及全自动进出料系统的研发

以上海远东制药机械有限公司为例,简述了国产医用真空冷冻干燥机的现状,并介绍了最新研发的符合医药新版GMP要求的半自动及全自动进出料系统。     

Understanding the change in electrical resistance of TiO2 thin film irradiated with YVO4 third-harmonic generation pulse laser

To selectively control the electrical resistance, thin films of TiO₂ were irradiated with a YVO₄ third-harmonic generation pulse laser in various power conditions. It was observed that when the laser power was less than 0.26 W, the electrical resistance of thin films decreased with the increase in laser power, whereas when the laser power was more than 0.26 W, the electrical resistance increased as the laser power increases. The minimum electrical resistance of the irradiated thin film was found to be four orders of magnitude lower than that of the unirradiated thin film. X-ray absorption fine structure analysis revealed that the valence of Ti ions in the thin films was reduced after laser irradiation, indicating the formation of oxygen vacancies with electron doping. The cross-sectional observation by a scanning electron microscope revealed that high laser power irradiation caused the thin films to become porous, and the percolation theory explains the origin of the increase in electrical resistance with developing porous structure. We propose a phase diagram to completely explain the relationship between electrical resistance and laser power, which supply a guideline on laser modification in TiO₂ electrical resistance.     

小粉料半自动精确称量及数据溯源控制系统

在轮胎胶料生产中,用量很小的小粉料的手工称量受人为因素影响容易出现取错料、称量不准、物料混杂、生产过程缺乏记录和管控等问题,易导致后期轮胎出现质量问题而无法溯源。本工作设计一种小粉料半自动精确称量及数据溯源控制系统,其操作过程如下:通过MES(制造执行系统)获取工单、生产配方、物料信息等生产数据,按工单要求准备好物料,将物料投入料仓工位内;通过打码机将条码信息打到小粉料袋子上,根据配方进行小粉料称量。在轮胎厂的实际使用表明,该系统可以对小粉料称量过程进行有效管控和追溯。     

Ultrathin carbon film from carbonization of spin-cast polyacrylonitrile film

Here we present ultrathin carbon films derived from polyacrylonitrile precursor film. Subsequent carbonization was investigated to examine the optical and electrical properties of resulting carbon films. The precursor PAN solution was carefully prepared and heated in order to have thin and uniform PAN film, and X-ray reflectivity of the precursor film and the carbon film shows uniformity. X-ray diffraction pattern of the carbon film indicated that the obtained carbon films possess low crystallinity. It was also found that the thickness for ultrathin carbon film from PAN layer showed counterbalanced optical and electrical performance in the range of experiment.     

干膜用聚酯薄膜产生疵点的原因

详细介绍并分析了干膜用聚酯薄膜疵点的分类和产生原因。大疵点形成的原因为煳料造成的内部杂质和外来杂质造成的表面杂质,小疵点形成的原因为添加剂粒子团聚造成的内部原因和辊筒烙印造成的表面原因。