液态压铸锻造双控成形技术工艺优化

压铸锻造双控成形技术是结合了铸造和锻造两种成型工艺特点的一种新的成型工艺，其不仅可以像压铸一样控制零件形状和尺寸，由于锻造可以使零件产生塑性变形并消除压铸产生的气孔、疏松等缺陷．从而使强度得到较大提高．并且可以通过热处理提高强度．铸锻双控成形工艺主要适合生产形状复杂和高强度要求的汽车零部件和其它结构件。为实现其工业化应用，本文主要论述压铸锻造双控成形技术的工艺优化。     

Laser-assisted Grinding Wheel Dressing (Ⅱ)-Experimental Researches

Most of the mechanical dressing technologies for resin bonded superabrasive grinding wheels are time consumingand costly. Based on the outcomes of the simulations in the previous study, this paper demonstrates the comprehensive researches on the laser-ass     

Standardized Failure Compression Test of Protein Gels from a Collaborative Study

A failure compression test with a standardized procedure for protein gelation was developed. Using whey protein concentrate, egg white protein and soy protein isolate as representative proteins, a highly reproducible procedure for sample preparation and gel testing was developed after refinements. Gels of varying protein concentrations were prepared with 0.1 M NaCl at pH 7. Force (N) and strain (Δh/h) at failure were the main parameters measured. Variability of results was found due to uncontrolled conditions for protein hydration and pH adjustment and air incorporation during hydration. After corrective steps to avoid potential errors, the procedure was recommended for a routine analysis of failure properties of protein gels.     

Mackerel Cathepsins B and L Effects on Thermal Degradation of Surimi

During surimi processing, cathepsins B and L activities in minced, leached and NaCl-ground meats were 6.02, 5.23, and 4.07 units/g, respectively. About 80% activity remained in surimi after 8 wk storage at ?40°C suggesting that these proteinases were stable and difficult to remove. At 40°～ 55°C, pH 6.5 ～ 7.5, cathepsins B and L and purified cathepsin B had high hydrolytic activity on myosin heavy chain (MHC). The strength of surimi gel with cathepsins B and L or with purified B decreased (p < 0.05) after 2 hr incubation at 55°C. This suggested that the residual cathepsins B and L had MHC-degrading activity and consequently caused gel softening.     

Utilizing the R-Index Measure for Threshold Testing in Model Soy Isoflavone Solutions

ABSTRACT: Twenty-eight untrained panelists used the signal detection rating method to determine thresholds for daidzein and genistein. Five concentrations of genistein and daidzein were suspended in starch solutions. The starch solution represented the noise, and isoflavone suspensions represented the signal. Blindfolded panelists received 15 replicates of noise and signal. To determine group detection thresholds, the concentration at an R-index of 75% was calculated. The group thresholds for genistein and daidzein were 4.006 × 10⁻³ M and 2.921 × 10⁻³ M, respectively. These results indicate a much higher threshold value than reported in the literature and in soymilks. This strongly suggests that daidzein and genistein individually do not contribute to bitterness or astringency in soy food products.     

Strategy for Building Initial Trust in Click-Only Online Fashion Stores

The main purpose of this study is to propose practical and effective strategies for acquiring and building initial trust from online consumers that could be used by the Internet store selling fashion goods online. To achieve this purpose, this paper suggests a trust life cycle model, identifies various trusting cues by reviewing antecedent literature on trust, establishes an empirical research model based on the eleven cues identified, and tries to find the most salient trusting cues affecting the development of initial trust by empirically testing the model. The results show that the factors significant in developing initial trust in an Internet fashion store are perceived service reliability, perceived variety of options, perceived ease of use, and legal infrastructure.     

运用手性固定相研究外消旋布洛芬的光学分离

Ibprofen is widely used as a non-steroidal anti-inflammatory drug and poduced as racemic mixture.Its pharmacological activity resides only is S-( )-enantiomer,and R-(-)-enantiomer is not only inactive but also has many side effects.Thus it is necessary to separate Renantiomer from racemic ibuprofen.We studied optical separation of racemic Ibuprofen with chiral high performance liquid chromatography(HPLC).,Out of three different chiral stationary phases,which were selected on the basis of structure and availability,two were found to be effective.There was optimum eluent composition for each stationary phase for good resolution in optical separation.Resolution decreased with increase of eluent flow rate,but effect of injection volume on resolution was insignificant at high eluent flow rate.     

Characterizing the formation and growth of intermetallic compound in the solder joint

A solder/intermetallic layers/copper joint assembly was prepared by the dipping process and then aged thermally for an accelerating aging test. The phase transformation of the assembly was compared to the phase diagram of binary alloy, Cu–Sn, and it showed an agreement with the resultant intermetallic phases formed between the pure tin and pure copper. Two theoretical models proposed by Gösele and Shatynski were developed and then employed to characterize the assembly. The Gosele's model was used to predict whether the intermetallic layers grew or shrank during aging, while the Shatynski's model was employed to estimate the related reactive thicknesses and hence the ratios of the interdiffusivities in the joint assembly. After a series of calculations, the Gösele's model predicted that Cu6Sn5 and Cu3Sn intermetallic layers became thicker; the orders of the intermetallic interdiffusivities were also proven to approach theoretical values from the Shatynski's model.     

ON-LINE SIGNATURE VERIFICATION BASED ON LOGARITHMIC SPECTRUM

In this paper, an on-line signature verification scheme based on similarity measurement of logarithmic spectrum is proposed. The principal components of the logarithmic spectrum of each signature are extracted. We then compute the similarity of logarithmic spectrum between input signature and the reference template. By comparing the similarity of logarithmic spectrum with the verification threshold, we can determine the authenticity of the input signature. Based on the experimentation, the rates of false rejection errors and false acceptance errors are as low as 1.4 and 2.8%, respectively. This demonstrates the effectiveness of the proposed scheme.     

Quality Attributes of Cheddar Cheese Containing Added Lactobacilli

Various strains of homo- and heterofermentative lactobacilli isolated from cheddar cheese were added to milk with a commercial streptococci culture to produce cheddar cheese. The heterofermatative lactobacilli L. brevis and L. fermentum almost always led to the development of fruity flavors, openness and late-gassing within 10 months of aging. Cheddar cheese produced using combined cultures of heterofermentative lactobacilli and L. casei-casei or L. casei-pseudoplantarum did not exhibit gas formation and openness. The overall grading scores of cheese containing added lactobacilli were not higher than those for the control cheese (without lactobacilli). A definite correlation was found between the lactobacilli used and the flavors of the cheese. The controlled acidity development during cheese making, the fat and the salt in moisture content of the cheeses were not affected.