FRP补强疲劳损伤钢结构裂纹扩展研究

钢结构在服役过程中,因超载、疲劳等原因会引起损伤累积,极大地影响了结构的安全使用.对纤维增强复合材料(FRP)补强钢结构张开型裂纹疲劳扩展进行了实验研究.比较了不同的钢结构表面处理方式对FRP与钢结构粘接接头剪切强度的影响,根据剪切强度选择最佳表面处理工艺.对FRP补强后钢结构试样进行疲劳实验,与未补强试样的结果加以对比.结果表明,用FRP增强后钢结构FRP增强区疲劳裂纹扩展速率得到抑制、疲劳循环次数得到了提高.     

电沉积Co-Ni-Al2O3复合镀层微观结构及高温性能

在氨基磺酸盐电解液中,利用复合电沉积技术制备得到了Co-Ni合金基中弥散分布Al₂O₃颗粒的金属基复合镀层。通过SEM,AFM以及XRD等分析测试方法,研究了Co-Ni-Al₂O₃复合镀层的表面形貌和微观晶体结构。结果发现:Co-Ni-Al₂O₃的表面形貌和微观晶体结构主要受镀层中钴含量的影响。高钴含量复合镀层具有Hcp结构,其表面形貌比具有Fcc结构的低钴含量镀层的表面更加均匀细致。Al₂O₃颗粒在Co-Ni合金中的共沉积,没有改变合金固溶体的相组成,但却改变了各晶面的优势生长。通过研究复合镀层的硬度、高温耐磨性、高温抗氧化性、热膨胀系数和热导率表明:Co-Ni-Al₂O₃具有较好的高温耐磨性和高温抗氧化能力,并且高钴含量的复合镀层相对于低钴镀层具有较低的热膨胀系数和较高的热导率。      

Generation of Mannitol from Copra Meal

Saccharification of copra meal with hydrochloric acid was found to be suitable method for forming reducing sugars. The presence of protein and lignin in the meal did not have a significant effect on the yield of reducing sugars. Borohydride reduction of the reducing sugars gave sugar alcohols in 44% yield based on the raw material or 81% based on carbohydrate content. The sugar alcohol mixture contained 66% mannitol, 24% sorbitol and 5% galactitol. The recovery of hydrochloric acid which renders the process more economically feasible was done by vacuum distillation.     

High Temperature Storage Effect on Longevity of Rice Seeds

Storage of Indica (Oryza sativa L. cv. Katakutara) and Japonica (Oryza sativa L. cv. Kusabue) rice seeds at 30° and 40°C for 2 months in the dark did not result in the loss of viability in both cultivars. Storage at 60°C, however, resulted in a complete loss of germination after 45 days in the case of Kusabue while the Katakutara rice seeds retained the germination potential well above 95%. Corresponding increases in the linoleic acid content of the free fatty acid fraction and TBA values of the extracted lipid fraction were also observed in Kusabue rice seeds. The investigation indicated that the Indica rice seeds were better protected than the Japonica rice seeds by the enclosing rice hull during the storage period.     

Volatile Flavor Components of Chive (Allium schoenoprasum L.)

Using well-established techniques, a sample was obtained of the steam volatile oil of chive (Allium schoenoprasum L.). A total of 30 components were identified and the neutral oil contained mainly sulfur compounds (16.8%). The most important constituents are dipropyl disulfide, methyl pentyl disulfide, pentyl hydrodisulfide and (cis and trans) 3,5-diethyl-1,2,4-trithiolane. Methyl pentyl disulfide and pentyl hydrodisulfide have not been described previously.     

AN OPTICAL METHOD FOR CONTINUOUSLY MEASURING FLOW VELOCITY AND COMPOSITION OF A MIXTURE OF POWDERS

ABSTRACT

A new method for continuously measuring flow velocity and composition of a mixture of powders in solid mixing equipment is proposed in this paper. This method uses an optical technique combining the image sensor anemometer of reflected light system and an image fiber inserted directly into the flowing powders' bed. From experiments for demonstration of this method, it is found that the flow velocity and the composition of the powder mixture in the mixer can be measured accurately and with high precision by applying this method.     

Parts loading scheduling in a flexible forging machine using an advanced genetic algorithm

A flexible forging machine (FFM) is one of the most important machines in a general flexible manufacturing system. The scheduling problem of parts loading in FFM is to reduce or preferably eliminate the changeover cost, and is an NP (Nondeterministic Polynomial solvable)-hard combinatorial optimization problem. The genetic algorithm (GA) is known to be a modern heuristic search algorithm, and is suitable for solving such a problem. When applying GA to the scheduling problem, we frequently obtain a local optimal solution rather than a best approximate solution. The goal of this paper is to solve the above-mentioned problem of falling into a local optimal solution by introducing a measure of diversity of population using the concept of information entropy. Thus, we can obtain a best approximate solution of the parts loading scheduling problem of FFM by using an advanced GA.     

Trajectory Design of Galvano Scanner Considering Voltage Constraint of Current Amplifier

This paper proposes a new method for designing feedforward inputs for Galvano scanners in laser drilling machines. The heat generated by current amplifiers becomes a problem as the positioning speed of the Galvano scanner is increased. The proposed method involves the use of a final‐state control that considers the voltage constraint of a current amplifier. By constraining the applied voltage to the motor, the power supply voltage of the current amplifier is reduced. Therefore, the electricity consumed and the heat generated by the current amplifier can be reduced. The effectiveness of the proposed method is shown through simulation and experimental results.     

SYNTHETIC INORGANIC ION-EXCHANGE MATERIALS XXX III. SELECTIVITIES OF ALKALI METAL IONS ON TIN(IV) ANTIMONATE CATION-EXCHANGER PREPARED AT DIFFERENT CONDITIONS

ABSTRACT

A tin(IV) antimonate(SnSbA) cation exchanger has been synthesized under different conditions; changes in the concentration, the molar ratio of Sb/Sn in the starting solution, and hydrolysis temperature. The products obtained were characterized by powdered X-ray diffraction and thermal analysis, and infrared spectra. The pH titration curves on SnSbA showed apparently mono-basic acid, but can be expected to the presence of the number of the functional groups with overlapping different pKa values. The increased acidities were observed with increasing the molar ratio (Sb/Sn) in the exchanger. The equilibrium distribution coefficients were determined at micro-amount of alkali metal ions in the hydrochloric acid solution. The SnSbA showed an unusual selectivity for alkali metal ions compared to cation exchange resins and other inorganic ion-exchangers.

The selectivity sequence shows; Na⁺ < K⁺ < Rb⁺ < Cs⁺ < Li⁺

An extremely high selectivity of lithium ions was found on the SnSbA hydrolyzed at relatively high temperature and with high Sb/Sn molar ratio     

A revised iterative algorithm for decomposition goal programming

The decomposition approach has received increasing attention in recent years not only as ft computational technique for large-scale management models but also as a systematic tool for designing organizational structure and information systems in decentralized organizations. In this paper, a revised iterative algorithm is developed for multicriteria decomposition in an organization by utilizing goal programming. The algorithm not only has the capability of dealing with multicriteria decomposition problems but is also useful for evaluating organizational effectiveness of a decentralized organization. A simple example is presented for an illustrative purpose of the algorithm application.