挤压膨化后微体化预处理水酶法提取大豆油脂工艺研究

在单因素实验的基础上,选取挤压温度、螺杆转速、物料含水量、模孔孔径和膨化后物料粉碎粒度5个因素为自变量,以总油提取率为响应值,进行响应面实验设计,确定了最佳提油率下的挤压-微体化参数。结果表明,挤压最佳条件为温度96℃、螺杆转速96r/min、物料含水率14.6%、模孔孔径15mm、膨化后物料粉碎粒度120目,此时提油率为94.34%±0.74%。并且采用红外光谱分析了大豆挤压膨化前后提取的大豆分离蛋白二级结构变化,进而讨论蛋白结构变化对水酶法提取油脂过程中油脂释放的影响,结果表明,挤压膨化后蛋白质二级结构中β-折叠含量降低,无规卷曲含量升高,蛋白质由有序向无序结构的转化,可以使得酶解过程中油脂释放量增加。

挤压膨化后微体化预处理水酶法提取大豆油脂工艺研究

在单因素实验的基础上,选取挤压温度、螺杆转速、物料含水量、模孔孔径和膨化后物料粉碎粒度5个因素为自变量,以总油提取率为响应值,进行响应面实验设计,确定了最佳提油率下的挤压-微体化参数。结果表明,挤压最佳条件为温度96℃、螺杆转速96 r/min、物料含水率14.6%、模孔孔径15 mm、膨化后物料粉碎粒度120目,此时提油率为94.34%±0.74%。并且采用红外光谱分析了大豆挤压膨化前后提取的大豆分离蛋白二级结构变化,进而讨论蛋白结构变化对水酶法提取油脂过程中油脂释放的影响,结果表明,挤压膨化后蛋白质二级结构中β-折叠含量降低,无规卷曲含量升高,蛋白质由有序向无序结构的转化,可以使得酶解过程中油脂释放量增加。

贵州瓮安新元古代陡山沱组磷酸盐化管柱状微体化石新材料

在用醋酸浸泡处理采自贵州瓮安新元古代陡山沱组磷酸质岩石样品时 ,获得大量微体动物骨骼化石。文中重点报道部分管柱状微体化石 ,即 :Sinoquadraticusporatusgen .etsp .nov .和Sinoquadraticuswenganensisgen .etsp .nov .。并对Sinocyclocylicus的部分特征进行补充。

塑性成形表面微凸体平坦化行为研究

在金属塑性成形中,工件表面微凸体的平坦化对产品表面质量、工件-模具接触界面的摩擦和润滑有重要影响。为了研究拉延成形过程中工件表面微凸体的平坦化行为,建立模具与工件粗糙表面接触的有限元模型,分析了接触压力、基体塑性应变、界面摩擦和微凸体角度等因素对微凸体平坦化的影响。结果表明,界面滑动摩擦有利于微凸体平坦化,但其促进效应无法与基体塑性应变和接触压力相比;微凸体平坦化阻力随着其角度的增加而增加,但增加趋势逐渐减缓,特别是微凸体角度大于10°时。

静态接触中表面纹理对塑性变形界面微凸体平坦化的影响

试验研究了静态接触中表面纹理对塑性变形界面微凸体平坦化的影响。运用抛光技术制备了两种试件表面:单向纹理表面和各向同性表面。采用HDM-20端面摩擦试验机,分别在有、无润滑油条件下对试件进行了压缩试验。用JM-6200型光学显微镜观测试件表面形貌结构的变化;用Talysurf CCI Lite测量三维表面参数,并选取S_a、S_(al)、S_(tr)、S_(dr)和S_(dq)等参数来定量描述试件表面形貌结构的变化。结果表明,试件表面纹理对微凸体平坦化行为具有明显的影响,无润滑油时各向同性表面微凸体平坦化程度大于单向纹理表面,但有润滑油时刚好相反;表面纹理对微凸体平坦化的影响使得三维表面参数发生了规律性变化。基于机械流变模型的分析表明,封闭润滑油坑的出现导致了有润滑油时表面纹理影响微凸体平坦化行为。通过封闭润滑油坑特征的提取,验证了分析的正确性。

《我和我的祖国》:献礼电影的角色塑造方法

国庆献礼电影《我和我的祖国》打破传统以宏观叙事展现共和国成立的伟大历史进程,并以伟人为人物角色塑造的献礼电影单一闭环叙事模式,通过沉浸式生活化的人物角色塑造,以"我"的视角讲述我和祖国的故事。影片建构起激昂又温情的人物角色,不仅疏通了献礼电影与时代距离感的壁垒,更贴近当代观众的审美取向和情感架构,这一成功的人物角色塑造方法有效地改进了献礼主旋律电影的剧本创作模式及丰富了故事的表达方式,为其他献礼主旋律电影在人物角色塑造上提供一定范式。

Elemental Composition of the Shell of the Testate Amoeba Difflugia tuberspinifera (Sarcodina:Rhizopoda)

X-ray microanalysis was used to study the elemental composition of the shell of the freshwater testate amoeba Difflugia tuberspinifera Hu et al.,1997 collected from Mulan Lake,Hubei province,China in July 2003.The results show that the shell is composed of ten elements:Si in greater quantity;then Ca and Al;and traces of K,Na,Cl,Fe,Mg,S and P.The analysis of results suggests that D.tuberspinifera in elemental composition appears to occupy a middle position between marine and soil testate amoebae.

Preparation and characterization of ZrO_2/TiO_2 composite photocatalytic film by micro-arc oxidation

ZrO2/TiO2 composite photocatalytic film was produced on the pure titanium substrate using in-situ Zr（OH）4 colloidal particle by the micro-arc oxidation technique and characterized by scanning electron microscope （SEM）, energy dispersive X-ray （EDX）, X-ray diffraction （XRD） and ultraviolet-visible （UV-Vis） spectrophotometer. The composite film shows a lamellar and porous structure which consists of anatase, futile and ZrO2 phases. The optical absorption edge of film is shifted to longer wavelength when ZrO2 is introduced to TiO2. Furthermore, the photocatalytic reaction rate constants of degradation of rhodamine B solution with ZrO2/TiO2 composite film and pure TiO2 film under ultraviolet irradiation are measured as 0.0442 and 0.0186 h 1, respectively.

Structure and corrosion resistance of modified micro-arc oxidation coating on AZ31B magnesium alloy

A hydrophobic surface was fabricated on a micro-arc oxidation (MAO) treated AZ31 Mg alloys via surface modification with myristic acid. The effects of modification time on the wettability of the coatings were investigated using the contact angle measuring device. The surface morphologies and structure of the coatings were evaluated using SEM, XRD and FT-IR. The corrosion resistance was investigated by potentiodynamic polarization curves and long-term immersion test. The results showed that the water contact angle (CA) increases gradually with modification time from 0 to 5 h, the highest CA reaches 138° after being modified for 5 h, and the number and size of the micro pores are decreased. The modification method hardly alters crystalline structure of the MAO coating, but improves the corrosion resistance based on the much positive potential and low current density. Moreover, the corrosion resistance and hydrophobicity can be enhanced with increasing the alkyl chain. The wetting and spreading for the alkylcarboxylate with low surface energy become easier on the micro-porous surface, and alkylcarboxylate monolayer will be formed through bidentate bonding, which changes the surface micropores to a sealing or semi-sealing structure and makes the MAO coating dense and hydrophobic. All the results demonstrate that the modification process improves the corrosion protection ability of the MAO coating on AZ31B Mg alloy.

AFM Observation of GaN Grown on Different Substrates at Low Temperatures

Aim To study the relationship between the substrate temperature and the morphology and properties of GaN. Methods\ Applying the hydride chemical vapor deposition method, GaN films were deposited on different kinds of substrates, including sapphire, Si(111),Si(100),GaAs and GaP(111) both on the P face and the Ga face. The growth was performed at low temperatures of below 700℃. XRD, Hall measurement, cathodoluminescence (CL) and atomic force microscopy (AFM) were used to characterise the film properties. Results\ It was found that the temperature and the nature of substrate materials influence the layer morphology. Conclusion\ The analysis shows that no apparent relationship exists between the optical properties and layer morphology.

A system for evaluation of ultrasound contrast agent's enhancement effect

A system for in vitro investigation of ultrasound contrast agent＇s enhancement effect is presented and evaluated. It includes the digital B-mode ultrasound scanner Belson3000A, the tissue-mimicking ultrasound phantoms and the software which is used for image quantitative analysis. The linear range, optimal settings and repeatability of the system are assessed and explored by scanning the ultrasound phantoms with different reflective intensities. The measurements are performed under an acoustic power from 4.8 to 12.3 mW, the scanner centre frequency is 3.5 MH and the gain setting is 50 dB. Both a self-made surfactant encapsulated microbubble and a commercial ultrasound contrast agent are scanned. The results show that the pixel intensity of ultrasonic images increases with the increase in the sound power, and for the stronger reflective phantoms of more particles, the increasing trend is much more evident. The system is optimal for evaluating the microbubble contrast agents＇ enhancement effects. It presents a simple, effective and real-time means for characterizing the enhancement ability of microbubbles.

Influence of Atomic Hydrogen on Transparent Conducting Oxide During Hydrogenated Microcrystalline Si Preparation by PECVD

The hydrogen plasma degradation of transparent conduction oxides （TCO） is studied for hydrogenated microcrystalline Si（μc-Si：H）prepared by plasma enhanced chemical vapor deposition （PECVD）. TCO films such as SnO2 and SnO2/ZnO bi-layer films were exposed to atomic H at various substrate temperatures and for various treatment times. A decrease in the transmittance due to reduction by atomic H was scarcely observed for SnO2 / ZnO bi-layer,while a decrease for SnO2 was found to depend strongly on the substrate temperature. The resistivity of SnO2 films decreases significantly when substrate temperature exceeds 150℃in H-plasma. However, H-plasma treatment has little impact on the resistivity of SnO2/ZnO bi-layer film. The reason for the decrease in the transmittance is the appearance of metallic Sn on the surface, and under this condition no μc-Si： H film is deposited. SnO2/ZnO bi-layer is very effective for the suppression of the reduction of TCO during μc-Si：H deposition. The performance of microcrystalline silicon solar cells fabricated on ZnO/SnO2/glass is also investigated.

Modification on epoxy-based adhesive

This research adopted four methods to toughen epoxy adhesives. They were liquid hydroxyl group terminated polybutadiene (HTPB) rubber modification, silicon rubber modification, polyacrylate multiplicity elastomer particulates emulsion modification and chemical grafting modification. After modification, the shearing strength and the rupture elongation were tested. The interface and the chemical reaction between the modifiers and the epoxy were analyzed by scanning electron microscope (SEM) and infrared optical spectrum. The results show that the elastomer particulates modification and the chemical grafting modification can reach the better toughening effects.

Directional solidification and characterization of NiAl-9Mo eutectic alloy

Ni-45.5Al-9Mo （mole fraction,%） alloy was directionally solidified with a constant temperature gradient （GL=334 K/cm） and growth rates ranging from 2 to 300 μm/s using a Bridgman type crystal growing facility with liquid metal cooling （LMC） technique. The effect of growth rate （v） on the solidified microstructures such as rod spacing （λ）, rod size （d） and rod volume fraction was experimentally investigated. Two types of the solidified interfaces, planar and cellular, were identified. On the condition of both planar and cellular eutectic microstructures, the relationships between λ, d and v were given as： λv1/2=5.90 μm·μm1/2·s1/2 and dv1/2=2.18μm·μm1/2·s1/2, respectively. It was observed that the volume fraction of Mo phase could be adjusted in a certain range. The variation of phase volume fraction was attributed to undercooling increase and the growth characteristics of the individual constituent phases during the eutectic growth.

An accelerated method to evaluate thymopentin release from microspheres in vitro

To design an accelerated method to evaluate thymopentin release from PLGA microspheres in vitro. Microspheres were prepared by double emulsion technique, using poly（lactide-co-glycolide） （PLGA） as carrier. At higher medium temperature （45℃, 50℃ and 55℃）, an accelerated release testing in short time was studied and correlated with the conventional release （37℃） in vitro. The release in vitro of thymopentin from PLGA microspheres at 45 ℃, 50℃ and 55℃ was significantly accelerated （P 〈 0.05）. In particular, at 50℃, an accelerated release （30 h） of the hydrophilic peptide from the PLGA matrix was achieved and correlated well with the conventional release （30 d）. An accelerated release testing in vitro at higher temperature could be used to monitor thymopentin release from PLGA microspheres.

Quasi-classical Trajectory Study of C＋CD--C2＋D at Different Collision Energy

Quasi-classical trajectory calculations have been employed to investigate the influence of collision energy on the stereodynamics of the title reaction C＋CD--~C2＋D on the poten- tial energy surface of the 12AI state developed by Boggio-Pasqua et al. [Mol. Phys. 98, 1925 （2000）]. The product angular distributions which reflect the vector correlation have been calculated. In addition, two polarization-dependent different cross-sections are also presented in the center-of-mass frame respectively. The results indicate that the product C2 is sensitively affected by collision energy.

Low Voltage Class C SiGe Microwave Power HBTs

The structure and microwave characteristics of low-voltage SiGe power HBTs are given.With this structure,the device can operate in a low-voltage and high-current state.By using an interdigital emitter strip layout and the operating voltage ranging from 3 to 4V,the output power in Class C operation can reach 1 65W at 1GHz,with the gain of 8dB.The highest collector efficiency is 67 8% under 3V.

Characteristics of Inconel Powders for Powder-Bed Additive Manufacturing

In this study, the flow characteristics and behaviors of virgin and recycled Inconel powder for powder-bed additive manufacturing （AM） were studied using different powder characterization techniques. The results revealed that the particle size distribution （PSD） for the selective laser melting （SLM） process is typically in the range from 15 μm to 63 μm. The flow rate of virgin Inconel powder is around 28 s·（50 g）^-1. In addition, the packing density was found to be 60%. The rheological test results indicate that the virgin powder has reasonably good flowability compared with the recycled powder. The inter-relation between the powder characteristics is discussed herein. A propeller was successfully printed using the powder. The results suggest that Inconel powder is suitable for AM and can be a good reference for researchers who attempt to pro- duce AM powders.

Determination of trace multi-elements in coal fly ash by inductively coupled plasma mass spectrometry

The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with HNO3, HClO4 and FIE The optimum conditions for the determination were obtained. The applicability of the proposed method was validated by the analysis of coal fly ash reference material （NIST SRM 1633a）. The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode （maximum mass resolution R=9 000）. The detection limit is from 0.05 to 0.21 μg/g, and the precision is fine with relative standard deviation less than 4.3%.

Coating of Fe, Ni on α-alumina microspheres by heterogeneous precipitation

The precursors with NiCO3·2Ni（OH）2·2H2O, Fe2O3·nH2O coated alumina microspheres were prepared by the aqueous heterogeneous precipitation using metal salts, ammonium bicarbonate and α-Al2O3 micropowders as the starting materials. Magnetic metal Ni, α-Fe coated alumina, core-shell structural microspheres were successfully obtained by thermal reduction of the precursors at 700℃ for 2h, respectively. Powders of the precursors and the resultant metal （Ni, α-Fe） coated alumina micropowders were characterized by scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. The results show that optimized precipitation parameters are concentration of alumina micropowders of 15g/L, rate of adding reactants of 5mL/min and pH value of 7.5. And under the optimized conditions, the spherical precursors without aggregations or agglomerations are obtained, then transferred into Ni, α-Fe coated alumina microspheres by thermal reduction. It is possible to adjust metal coating thicknesses and fabricate a multilayer structured metal/ceramics, core-shell microspherical powder materials.