Electrochemical development of hydrogen silsesquioxane by applying an electrical potential

We present a new method for developing hydrogen silsesquioxane (HSQ) by using electrical potentials and deionized water. Nested-L test structures with a pitch as small as 9 nm were developed using this electrochemical technique in saline solution without adding hydroxyl ions. Furthermore, we showed that high-resolution structures can be electrochemically developed in deionized water alone. Electrochemical development is controlled by the applied voltage and may overcome several of the limitations discussed for alkaline developers, such as poor hydroxyl anion diffusion and charge repulsion effects in small trenches.     

A pi-shaped ultrasonic tweezers concept for manipulation of small particles

A pi-shaped ultrasonic actuator is proposed for the noncontact trapping, extraction, and transportation of small particles. In this actuator, two metal plates clamp a multilayer piezoelectric vibrator by a small bolt, and the metal plates are tapered in their lower parts so that a vibration gradient can be obtained. The flexural vibration of the metal plates is used to generate a sound field in the gap between the two tapered metal plates. At a driving frequency of about 152.8 kHz, shrimp eggs, grass seeds, thyme seeds, rice powder, fine salt, and fine sugar, which have an average diameter from several tens of micrometers to several hundreds of micrometers, can be trapped stably without contact with the actuator, and the particles insoluble in water can be extracted from water and transported in water by the actuator. In the noncontact trapping of small particles, the positions of trapped particles as well as the relationship among the number of trapped particles, vibration velocity, and input power are investigated. The number of trapped particles increases as the vibration velocity or input power increases. However, when the vibration velocity or input power is too large, the particles may be ejected out of the actuator and, therefore, cannot be stably trapped. The minimum vibration velocity to trap small particles increases as particle density increases for the particles that have the shape near to a sphere and a proper density. In the extraction of small particles from water, the relationship between the number of extracted thyme seeds and the input power is investigated. Increasing the input power can increase the extracted thyme seeds. However, there is a maximum particle number that can be extracted from water. In the transportation of thyme seeds in water, the dependence of the particle loss during the transportation on the speed and distance of transportation and the input power is experimentally estimated. As the distance and speed of transportation increase, the particle loss during the transportation increases. Increasing the input power increases the trapping effect and, therefore, decreases the particle loss.     

The effects of sea water and concentrated salt solutions on the fatigue of nylon 6,6 fibres

Cyclic fatigue and creep rupture tests have been run on high-tenacity nylon 6,6 single fibres, yarns and small ropes in air and sea water environments. Fatigue failure in each case is by a creep rupture mechanism; yarns and small ropes show the same fatigue sensitivity as do single fibres. Sea water reduces the strength by approximately 10% under most conditions. Concentrated metallic salt solutions which cause environmental stress cracking in bulk nylon do not degrade the fibres beyond the effect of plain water. Tests on oriented nylon specimens show that environmental stress crack sensitivity is greatly reduced by orientation.     

射流电子水表原理及流量测量特性研究

介绍了基于恒磁励磁电磁检测方法的射流电子水表,研究了其结构原理、主要技术特征、流量测量特性、以及传感与信号处理技术。针对射流电子水表小流量测量特性,提出了降低射流计量腔的起振阈值,改进了电磁传感原理检测射流振荡信号的方法。经射流电子水表批量生产验证,证明了改进小流量特性思路和方法的有效性。     

Light scattering and absorption caused by bacterial activity in water

There is a growing class of elementary particle detectors, large-water ?erenkov detectors, that have a body of water (thousands of tons) as a sensitive medium. Particles are detected when they interact with the water and produce ?erenkov light, so detection efficiency relies on the transparency of the water. These detectors are active typically for many years, so biological activity (primarily bacterial growth) is one of the means by which the transparency of the water may be reduced. We present the results of a measurement of light scattering and absorption from a population of Escherichia coli in water, which is used as a model for bacteria in general. One can separate the scattering and absorption by varying the refractive index of the medium by using a solute of high molecular weight. We show that the results can be understood simply in terms of light scattering from small spheres (radius ≈ wavelength) with an effective refractive index, n(b), plus a small amount of absorption in the ultraviolet. We compare his scattering with Rayleigh scattering in pure water.     

基于机器视觉的水表小流量检定方法研究

针对目前水表小流量检定时间长,人工读数不准确等原因,提出了一种基于机器视觉的水表小流量检定方法.通过工业相机以自适应的采样频率采集水表梅花转子图像,利用图像叠加原理,以检定开始时转子图像为背景,相机后续获取每一帧图像在此背景上作叠加处理.根据转子转动过程中图像叠加后的明暗占比大小的变化规律对其转动齿数进行计数,用双计时...     

Preparation of sodium trisilicate glasses of varying water content

Various properties of glasses are affected by small amounts of structural water. This water is known to be present in essentially all silicate glasses. Much of the differing values reported for various properties, such as electrical resistivity and diffusivity, probably is caused by using glass samples with varying water content. We have developed a technique for making glasses with nearly any desired level of water content.     

DISPLACEMENT OF PARTICLES DEPOSITED ON SOLID SURFACES BY A MOVING GAS-LIQUID-SOLID INTERFACE

Deposited small particles change their position and can build aggregates on surfaces when wetted/dewetted. The size and form of these aggregates depend on the amount of water condensed, the form of the particles and the contact angles. Experiments with glass spheres and quartz particles on three different surfaces with water as wetting liquid were carried out. Results of the wetting/dewetting experiments are shown and discussed. A model is presented to estimate the magnitude of involved forces and the displacement of the particles taking into account contact angles, amount of condensed water, and size of particles. The model explains, why particles, as observed, tend to gather near the edge of a droplet at small surface contact angles and near the droplet center at high surface contact angles.     

对Cu~(2+)兼具检测及分离功能的聚氨酯泡沫的制备与性能

制备了对Cu~(2+)具有高灵敏检测及分离回收功能的聚氨酯泡沫。首先采用荧光前驱体4-溴-1,8-萘二甲酸酐、乙醇胺和2-氨基-4-噻唑乙酸作为原料合成含有羟基和噻唑乙酸基团的小分子传感器N-乙醇-4-(4-噻唑乙酸)-1,8-萘二甲酰亚胺(ETN);再通过其上的羟基与甲苯-2,4-二异氰酸酯(TDI)的-NCO基团反应将小分子感应器化学链接到多孔的聚氨酯泡沫上。荧光分析表明接有小分子感应器ETN的聚氨酯泡沫吸附Cu~(2+)离子后会发出荧光,荧光强度随Cu~(2+)离子浓度增加而变强。当Cu~(2+)离子的浓度低到10-7 mol/L数量级时也可检测到荧光。而且,多孔聚氨酯泡沫(当含1%的ETN)便具有37.66mg/g回收Cu~(2+)离子的能力,这使其具有在诸如废水和污水检测和分离Cu~(2+)的潜能和价值。     

Dynamic 193-nm optical properties of water

Previous assumptions that water is not a 193-nm chromophore during ArF excimer laser tissue ablation are based on room-temperature data and ignore spectroscopic literature that suggests a strong temperature dependence of far-ultraviolet water absorption. By the use of a Q-switched Er:YAG laser as a pump source and an ArF excimer laser as a probe source, thermal generation and relaxation of 193-nm water absorption were characterized under nonequilibrium high-temperature and high-pressure conditions. At volumetric energy densities as small as 2 kJ/cm(3) relative to room temperature, the 193-nm absorption coefficient of water was measured to increase by more than 5 orders of magnitude. These results are consistent with the hypothesis that the absorption of 193-nm radiation by water may play a role in ArF excimer laser ablation of tissue.     

DISPLACEMENT OF PARTICLES DEPOSITED ON SOLID SURFACES BY A MOVING GAS-LIQUID-SOLID INTERFACE

ABSTRACT

Deposited small particles change their position and can build aggregates on surfaces when wetted/dewetted. The size and form of these aggregates depend on the amount of water condensed, the form of the particles and the contact angles. Experiments with glass spheres and quartz particles on three different surfaces with water as wetting liquid were carried out. Results of the wetting/dewetting experiments are shown and discussed. A model is presented to estimate the magnitude of involved forces and the displacement of the particles taking into account contact angles, amount of condensed water, and size of particles. The model explains, why particles, as observed, tend to gather near the edge of a droplet at small surface contact angles and near the droplet center at high surface contact angles.     

Solvent assisted inlet ionization: an ultrasensitive new liquid introduction ionization method for mass spectrometry

A new inlet ionization method requiring no voltage or laser, and using water, methanol, or water/organic solvent mixtures, is shown to produce mass spectra similar to those obtained with electrospray ionization (ESI) for small molecules, peptides, and proteins, at least as large as carbonic anhydrase, with sensitivity that surpasses ESI. With the use of wide mass range acquisitions at 100,000 mass resolution on an Orbitrap Exactive, detection limits below parts per trillion are obtained for small molecules such as arginine, ciprofloxacin, and acetaminophen. Low attomoles of bovine insulin consumed produced a multiply charged mass spectrum. Ions are generated, even using pure water as solvent, within the heated inlet tube linking atmospheric pressure with the first vacuum stage of the Orbitrap Exactive. The extremely high sensitivity observed at this early stage of solvent assisted inlet ionization (SAII) development suggests that inlet ionization may surpass nanoelectrospray in sensitivity but without the need for extremely low solvent flows.     

水冷式半导体冰箱制冷性能的研究

研究了水冷式散热方法对半导体冰箱制冷性能的提高.以常用的半导体小冰箱为实例,分别测试了在风冷、循环水和恒温水条件下小冰箱的制冷性能.结果表明,水冷制冷效果明显优于传统风冷式,且其制冷性能与冷却水的温度有关.水温越低,半导体制冷器的制冷效率越高,制冷温度越低.当冷却水温度为171 ℃时,水冷半导体小冰箱很快达到冷冻.建立了水冷式半导体冰箱的制冷模型,计算分析了在不同恒定冷却水温度下半导体制冷器冷端温度随时间的变化关系,并将理论结果与实验测量结果进行了拟合分析,发现理论模型与实验测量结果一致.研究结果为水冷式半导体冰箱制冷性能的提高提供了实验和理论依据.     

Relationship between water distribution and shear properties of wet granules

Wet granules are utilized in various fields due to their high workability and cost performance. However, it is difficult to observe the water distribution of wet granules directly because such granules only contain extremely small amounts of water. In this study, the water distribution of wet granules was investigated using a confocal laser microscope and quantitatively analyzed using an autocorrelation function. Furthermore, the correlation length of wet granules estimated from the autocorrelation function was compared with the shear properties of the granules. Consequently, it was found that the internal friction angle of wet granules decreased as the water volume between particles increased. These results indicated that the water in wet granules works as a drag reduction agent under shear conditions.     

混合多元醇对无溶剂聚氨酯覆膜胶性能的影响

以聚己二酸-1,4-丁二醇酯(PBA)、植物油多元醇、异弗尔酮二异氰酸酯(IPDI)和小分子多元醇为主要原料,制备了一种双组分无溶剂型聚氨酯胶粘剂。研究了双组分的配比R′和混合多元醇组分对聚氨酯胶粘剂固化速率、固化后胶膜的热稳定性和吸水率的影响,并测试了覆膜样品的T剥离强度。结果表明:当双组分配比R′=1.3时,胶粘剂综合性能最佳;添加小分子多元醇并不能提高胶粘剂的固化速率和耐热性,但能显著改善胶粘剂的粘结性能,并且选择性添加适量的小分子二醇,还能增强其耐水性。     

690合金在去离子水和干态下的微幅冲击磨损行为研究

在小载荷冲击实验台上,通过改造夹具,实现了管/平面接触方式,以模拟蒸汽发生器中传热管与抗震条发生的微幅冲击磨损。以690合金传热管和405不锈钢为试验材料,在不同的冲击载荷和润滑条件(干态与去离子水中)下进行了微幅冲击磨损试验,通过分析磨痕面积、微观形貌、断口形貌和磨损区硬度等,探讨了690合金受微幅冲击磨损和失效机理。研究结果表明:在干态环境下,小载荷时690合金的磨损机制主要为氧化和剥落。随着载荷的增大,其损伤机制为氧化磨损和疲劳磨损;在去离子水环境条件下,小载荷时,损伤轻微;随着载荷的增大,其损伤机制为疲劳磨损。水介质显著的延缓了材料的开裂时间。     

Hydrophobic Hydrogels with Fruit‐Like Structure and Functions

Normally, a polymer network swells in a good solvent to form a gel but the gel shrinks in a poor solvent. Here, an abnormal phenomenon is reported: some hydrophobic gels significantly swell in water, reaching water content as high as 99.6 wt%. Such abnormal swelling behaviors in the nonsolvent water are observed universally for various hydrophobic organogels containing omniphilic organic solvents that have a higher affinity to water than to the hydrophobic polymers. The formation of a semipermeable skin layer due to rapid phase separation, and the asymmetric diffusion of water molecules into the gel driven by the high osmotic pressure of the organic solvent–water mixing, are found to be the reasons. As a result, the hydrophobic hydrogels have a fruit‐like structure, consisting of hydrophobic skin and water‐trapped micropores, to display various unique properties, such as significantly enhanced strength, surface hydrophobicity, and antidrying, despite their extremely high water content. Furthermore, the hydrophobic hydrogels exhibit selective water absorption from concentrated saline solutions and rapid water release at a small pressure like squeezing juices from fruits. These novel functions of hydrophobic hydrogels will find promising applications, e.g., as materials that can automatically take the fresh water from seawater.     

Structural characterizations of diglycerol monomyristate reverse micelles in aromatic solvent ethylbenzene

Using small-angle X-ray scattering (SAXS) we have investigated the shape and size of diglycerol monomyristate (designated as C14G2) nonionic surfactant reverse micelles in aromatic solvent ethylbenzene as a function of surfactant concentration, temperature, and water. When C14G2 is added into ethylbenzene globular type reverse micelles with maximum core diameter ca. 4.5 nm are formed under ambient conditions. The micellar structure (shape and size) did not change with the surfactant concentration. However, an increase in temperature decreased the micellar size due to an increase in the critical packing parameter (cpp). Surfactant becomes more lipophilic upon heating and the micellar curvature tends to become more negative at higher temperature. Addition of a small amount of water caused a significant micellar growth. For instance, incorporation of 0.3% water in the 5% C14G2/ethylbenzene system resulted in the formation of 2.1 time bigger micelles with a small water pool in the micellar core. Besides the micellar shape is modified into an ellipsoidal prolate, whose scenario can be understood in terms of hydration of the surfactant's headgroup. Hydration decreases the cpp and favors micellar growth. An increase of temperature of a water incorporated system decreased the micellar size due to dehydration, which is equivalent to rod-to-sphere type transition.     

炼油厂污油超声破乳脱水

以含水量（体积分数）20%~30%的中石化扬子炼油厂提供的污油为研究对象,在实验室条件下,采用超声波破乳技术进行脱水研究。在超声频率为20 kHz的条件下,考察了超声的其他参数对污油脱水的影响。结果表明：超声辐照时间为5min、超声激励电压为100V、超声辐照后热沉降温度为60℃、沉降时间为2h时,污油破乳脱水效果比较好,作用后,污油含水率可以降低到3.2%。按照小试得到的最佳工艺参数进行中试实验,其污油破乳脱水效果跟预计的结果相当,含水率可以降低到7.2%。