Preparation of nanosize Pt clusters using ion exchange of Pt(NH3) 4 2+ inside mesoporous channel of MCM-41

Mesoporous molecular sieve MCM-41 with a Si/Al ratio of 35 was obtained by hydrothermal synthesis using a gel mixture with a molar composition of 6 SiO₂0.1 Al₂O₃1 hexadecyltrimethylammonium chloride 0.25 dodecyltrimethylammonium bromide 0.25 tetrapropylammonium bromide0.15 (NH₄)₂O1.5 Na₂O300 H₂O. The MCM-41 sample was calcined in O₂ flow at 813 K and subsequently ion exchanged with Ca²⁺. A small Pt cluster has been supported on the MCM-41 sample following a procedure using ion exchange of Pt(NH₃) ₄ ²⁺ . The Pt(NH₃) ₄ ²⁺ ion supported on MCM-41 has been activated in O₂ flow at 593 K and subsequently reduced with Fh flow at 573 K, in the same way used for the preparation of a Pt cluster entrapped inside the supercage of zeolite NaY. The resulting Pt cluster supported on the MCM-41 shows hydrogen chemisorption oftotal two H atoms per Pt at 296 K (based on the total amount of Pt) and high catalytic activity for hydrogenolysis of ethane. The chemical shift in¹²⁹Xe NMR spectroscopy of adsorbed xenon indicates that the Pt cluster is located inside the mesoporous molecular sieve.     

利用电阻探针对石油设备及管道的腐蚀进行监测

从1998年起，国内石油炼制行业开始大量炼制进口高硫原油，油气管道的腐蚀问题受到了重视。介绍了电阻探针腐蚀监测系统的原理及组成。并针对油气管道，实施了在线监测，安装了6组腐蚀电阻探针，分析了测量结果，为今后防腐工作提供了依据。     

New phenothiazine-containing monomers and polymers

Summary Three new phenothiazine-containing electrono-donor monomers: methacryloyl-2-hydroxyethyl-2-(N-phenothiazinyl)propionate (i) acryloyl-2-hydroxyethyl-2-(N-phenothiazinyl) propionate (ii) and 2-(N-phenothiazinyl) propionic acid vinyl ester (iii) were synthesized and radically polymerized. The ionization potentials of poly(i), poly(iii) and of the model for the structural unit of the acrylic polymers: acetyl-2-hydroxyethyl-2-(N-phenothiazinyl) propionate determined with two small acceptors were discussed in terms of sterical hindrances.     

基于云端协同计算架构的边缘端I/O密集型虚拟机资源分配方案

大型制造业生产车间业务流程复杂,传统固定资源配置方式将产生负载不均衡的问题。针对此问题,设计并实现了一种基于云端协同架构的边缘端I/O密集型虚拟机资源的分配算法,通过定义计算节点中每个I/O密集型虚拟机三个维度的信息计算得出I/O密集型虚拟机的优先级,并按最大优先级队列实时统一分配硬件资源。实验结果表明,该算法在应对工业机械设备高响应和高通量的要求上有较为明显的提升,为实际生产起到了优化资源配置的作用。     

A visual study on flame behavior in tone-excited non-premixed jet flames

A visualization study on the effect of forcing amplitude in tone-excited jet diffusion flames has been conducted. Visualization techniques are employed using optical schemes, which are a light scattering photography. Flame stability curve is attained according to Reynolds number and forcing amplitude at a fuel tube resonant frequency. Flame behavior is globally grouped into two from attached flame to blown-out flame according to forcing amplitude; one sticks the tradition flame behavior which has been observed in general jet diffusion flames and the other shows a variety of flame modes such as the flame of a feeble forcing amplitude where traditionally well-organized vortex motion evolves, a fat flame, an elongated flame, and an in-burning flame. Particular attention is focused on an elongation flame, which is associated with a turnabout phenomenon of vortex motion, and on a reversal of the direction of vortex roll-up. It is found that the flame length with forcing amplitude is the direct outcome of the evolution process of the formed inner flow structure. Especially the negative part of the acoustic cycle under the influence of a strong positive pressure gradient causes the shapes of the fuel stem and fuel branch part and even the direction of vortex roll-up to dramatically change.     

Hydrogen bonding,miscibility, crystallization,and thermal stability in blends of biodegradable polyhydroxyalkanoates and polar small molecules of 4‐tert‐butylphenol

The hydrogen bonding, miscibility, crystallization, and thermal stability of poly(3‐hydroxybutyrate) (PHB)/4‐tert‐butylphenol (BOH) blends and poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) [P(3HB‐3HHx)]/BOH blends were investigated by Fourier transform infrared (FTIR) spectroscopy, solid‐state¹³C‐NMR, differential scanning calorimetry, wide‐angle X‐ray diffraction (WAXD), and thermogravimetric analysis. The results of FTIR spectroscopy and solid‐state¹³C‐NMR show that intermolecular hydrogen bonds existed between the two components in the blends and that the interaction was caused by the carbonyl groups in the amorphous phase of both polyesters and the hydroxyl groups of BOH. With increasing BOH content, the chain mobility of both the PHB and P(3HB‐3HHx) components was improved. After the samples were quenched, the detected single glass‐transition temperatures decreased with composition, indicating that both PHB/BOH and P(3HB‐3HHx)/BOH were miscible blends in the melt. Moreover, as BOH content increased, the melting temperatures of PHB and P(3HB‐3HHx) clearly decreased, which implied that their crystallization was suppressed by the addition of BOH. Although the crystallinity of PHB and P(3HB‐3HHx) components decreased with increasing BOH content in the blends, their crystal structures were hardly affected after they were blended with BOH, which was further proven by WAXD results. In addition, the thermal stability of PHB was improved by a smaller amount of BOH.     

金属铝诱导法低温制备多晶硅薄膜

以氢气稀释的硅烷（SiH4）和硼烷（B2H6）为气源,利用等离子体增强化学气相沉积法（PECVD）制备出p型a-Si薄膜.采用铝诱导晶化技术对不同厚度的铝膜对a-Si薄膜晶化的影响进行了研究.实验中发现,铝膜溅射为10 s的非晶硅薄膜样品在450℃下退火10 min后,p型a-Si结构仍为非晶态,铝膜溅射为20 s的非晶硅薄膜在450℃下退火20 min后,p型a-Si薄膜开始晶化为polySi薄膜,并且铝膜厚度越厚,则a-Si薄膜晶化程度越强.     

Viscoelastic Behavior, Thermodynamic Compatibility, and Phase Equilibria in Block Copolymer-Based Pressure-Sensitive Adhesives

The viscoelastic behavior, thermodynamic compatibility, and phase equilibria in block copolymer-based pressure-sensitive adhesives were investigated. The block copolymers investigated were: (1) polystyrene-block-polybutadiene-block-polystyrene (SBS) copolymer (KRATON® D-1102, Shell Development Company) and (2) polystyrene-block-polyisoprene-block-polystyrene (SIS) copolymer (KRATON® D-1107, Shell Development Company). The tackifying resins investigated were: (1) WINGTACK® 86 (Goodyear Tire & Rubber Company) and (2) PICCOTAC® 95BHT (Hercules Inc.). Samples of various compositions were prepared by a solution-casting method with toluene as solvent. Measurements of dynamic storage modulus (G'), dynamic loss modulus (G'), and loss tangent (tan δ) were taken, using a Rheometrics Mechanical Spectrometer. It was found that: (1) both WINGTACK 86 and PICCOTAC 95BHT were equally effective in decreasing the plateau modulus (G^O_N), and increasing the glass transition temperature (T_g) of the polyisoprene midblock of KRATON 1107; and (2) WINGTACK 86 was very effective in decreasing the G^O_N and increasing the T_g of the polybutadiene midblock of KRATON 1102, whereas PICCOTAC 95BHT was not. The observed difference between WINGTACK 86 and PICCOTAC 95BHT in decreasing the G^O_N and increasing the T_g of the polybutadiene midblock of KRATON 1102, whereas PICCOTAC 95BHT was not. The observed difference between WINGTACK 86 and PICCOTAC 95BHT in decreasing the G^O_N and increasing the T_g of the polybutadiene midblock of KRATON 1102 (perhaps to SBS block copolymers in general) is explained by the values of the interaction parameter for WINGTACK 86 and KRATON 1102, and for PICCOTAC 95BHT and KRATON 1102. The interaction parameter was determined, using the piezoelectric quartz sorption method. Phase diagrams were constructed for the four block copolymer/tackifying resin systems investigated, using information obtained from both dynamic viscoelastic measurements and optical microscopy. It was found that when mixed with KRATON 1102, PICCOTAC 95BHT formed separate domains whereas WINGTACK 86 did not over the range of concentrations and temperatures investigated. This confirms the evidence obtained from two other independent experimental techniques, namely, dynamic viscoelastic measurements and the piezo-electric sorption method. We have concluded from the present study that PICCOTAC 95BHT is not as an effective tackifying resin as WINGTACK 86, when each is mixed with KRATON 1102. It is pointed out further that information on the order-disorder transition temperature T_r, which was determined from a rheological technique proposed by us, is valuable in determining optimal processing conditions for block copolymer-based pressure-sensitive adhesives.     

Effects of soaking soybeans in dilute acids on biologically active components

Soaking soybeans in dilute acids affected activities of lipoxygenase, trypsin inhibitor and urease. Effects of soaking time, acid concentration and soaking temperature were investigated. Lipoxygenase activity was completely eliminated by soaking in 0.3 M HC1 at either 23°C or 40°C for 8 hr. Less than 50% trypsin inhibitor remained and urease was inactivated to an acceptable level (0.04 ΔpH).     

Conceptual and basic designs of the Mobile Harbor crane based on topology and shape optimization

The Mobile Harbor (MH) has been recently proposed as a novel maritime cargo transfer system that can move to a container ship anchored in the deep sea and handle containers directly at sea with the aid of a stabilized MH crane. Because this system operates under at-sea conditions, the MH crane must be designed to support an inertia load and wind force, as well as its self-weight. The wave-induced motions of the MH, e.g. rolling, pitching, and heaving, generate a significant amount of inertia load, which has not been considered in the design of conventional quayside cranes installed on stable ground. Wind force is also a critical design factor due to the higher wind velocity in the open sea. In addition to the aforementioned structural rigidity, mass minimization is also important in the structural design of MH cranes because it reduces the overturning moment and therefore enhances ship stability. In this paper, the sensitivities of the design-dependent loads (i.e. self-weight, inertia load, and wind force) are derived with respect to the design variables, and then a topology optimization is conducted with the derived sensitivities in order to obtain a conceptual design. Then, the conceptual design is elaborated into a three-dimensional basic design through shape optimization with design regulations for offshore cranes. Through the integrated design process with the topology and shape optimizations, a conceptual and basic design is successfully obtained for the MH crane.