花椰菜实用预冷保鲜技术研究

对花椰菜各种预冷方式进行了比较。结果表明,差压预冷法预冷效果最好,模拟运输后可最大限度地保持花椰菜的新鲜度,样品几乎无散花、变黄及腐烂现象。     

电控柴油机共轨管进出油口位置对喷油压力波动的影响

现代电控柴油机共轨内压力的瞬态波动会直接影响到燃油喷射系统喷油量的均衡．采用AVL公司的workspace4．0软件建立了燃油喷射系统模型,设定不同进出油口的连接方式,分析了电控柴油机共轨管进油口在不同位置时对喷射压力波动产生的影响．     

Pressure evaluation of 3D seamless knitted bras and conventional wired bras

Seamless knitting for making bras is a novel approach. The fitting evaluation of these products remains unknown and there is limited knowledge about the effects of knitting parameters on the bra tension. This study developed 3 styles of seamless knitted bras with various loop length and elastic yarn tension based on a 2² full factorial experimental design with one additional centre level. Therefore, a total of 3 × 5= 15 new seamless bra samples have been knitted. The skin pressure exerted by the new bras was compared with 4 commercial bras including 2 “cut and sewn” wired bras and 2 seamless knitted bras. Six women subjects of breast size 75B* in our newly developed breast sizing system were invited to wear all the bra samples. The skin pressure exerted by the bra was measured by the Novel pliance-X pressure sensors on 11 body positions. The results indicated that newly developed seamless bras showed lower pressure than the commercial bras, but had a considerably higher pressure at the cup base point. The new seamless bras with the largest loop length presented the lowest pressure values. Furthermore, empirical equations were established to predict 2 critical pressure points at “apex” and “side bottom band” from two major knitting parameters. This study provides the new knowledge of seamless knitted bra fitting and the resulted bra pressure, as well as some guidelines for seamless knitted product design and manufacturing.     

3，5，6-三氯吡啶-2-酚的合成优化

[目的]进一步优化三氯乙酰氯合成三氯吡啶酚的工艺。[方法]以三氯乙酰氯、丙烯腈为原料,在催化剂作用下,通过加成环化、芳构化2步法合成3,5,6-三氯吡啶-2-酚,考察溶剂类型、催化剂用量、助催化剂类型和反应压力对三氯吡啶酚收率的影响。[结果]三氯乙酰氯路线合成三氯吡啶酚的优化工艺为：三氯乙酰氯、丙烯腈为原料,1．3g／46g（三氯乙酰氯）氯化亚铜为催化剂,二氯苯为溶剂,此条件下三氯吡啶酚的收率可达55％。微负压条件有利于及时排除反应过程中产生的氯化氢,降低安全隐患,而添加助催化剂对反应效果无显著促进作用。[结论]该研究确定了三氯乙酰氯路线合成三氯吡啶酚的最佳工艺。     

研究生心理压力问题研究

目前,随着考研热的升温,研究生已经成为高校学生中的重要组成部分,而他们的心理压力问题也开始成为人们关注的焦点。通过对江西农业大学和渤海大学2所学校部分在读硕士研究生的随机抽样,采用调查问卷方式并结合数学中的统计分析手法——方差分析、回归分析,逐一将影响研究生心理压力的压力源（包括学习、人际交往、恋爱、性别差异、就业等）进行了解释与分析,并且针对研究生的不同心理压力问题提出相应的解决方法,以缓解由于心理压力而对研究生在学习、生活等各个方面造成的影响。     

Prediction of air filter efficiency and pressure drop in air filtration media using a stochastic simulation

In this paper, we discussed the relationship of filter efficiency and pressure drop with the porosity, fiber diameter and filter thickness by Geodict®. We found that filter efficiency has exponential relationship with filter porosity, fiber diameter and thickness. Furthermorethe pressure drop has a linear relationship with filter thickness and exponential relationship with filter porosity and fiber diameter, respectively. The influence of electrostatic charge on the particle deposition has been investigated. Simulation results were compared with the actual test results by TSI 3160.     

红麻料片的压缩特性及压力与压缩密度的数学模型

进行了红麻料片在闭式容器内的压缩试验。对红麻料片的压力－变形曲线分析表明：红麻料片的压缩过程存在松散、过渡和压紧３个阶段。进一步对试验数据进行统计分析,建立了红麻全秆料片的压力ｐ与压缩密度γ在松散阶段的数学模型为γ＝ａ＋ｂｐ,过渡和压紧阶段的数学模型γ＝ａｐ＾ｂ。在松散压缩阶段通过增加压力来提高红麻料片的压缩密度效果较好。     

食品超高静压处理中热效应问题的研究进展

在食品的超高静压处理中,由于压缩作功使其温度发生改变,温度随着压力的升高而增加(压致升温),所以不可避免地会产生热效应问题。该文主要综述了食品超高静压处理中温度压力随时间的变化规律,传压介质和食品成分对压致升温的影响,以及食品超高静压处理中的传热和压致升温对微生物的影响等问题。     

注水驱油过程中地层流体渗透各向同性时的压力分布

通过把渗流的偏微分方程变成其弱解积分形式,针对油田的某一井排油水井的分布情况,用有限元法计算了注水驱油过程中储层渗透各向同性时的油、水井稳态压力分布和瞬态压力分布。结果表明,在注水加压驱油时,压力有一个逐渐变化的过程,最后达到新的稳定压力平衡状态,并揭示了地层流体的非稳态渗流是稳态渗流的特例。     

Effects of retinal ganglion cell apoptosis on delayed rectifier K+ currents

AIM: To investigate the effects of rat retinal ganglion cell (RGC) apoptosis on delayed rectifier K⁺ currents (I_K). METHODS: The retinas of 2~3 d newborn Sprague-Dawley rats were dissociated into cell suspension by trypsin digestion. The RGCs were cultured and divided into control group, pressure 0.5 h group, pressure 1 h group, pressure 1.5 h group and pressure 2 h group. The cells were cultured regularly for 6 d in control group, and the cells in other groups were cultured regularly for 6 d and gave pressure of 80 mmHg for 0.5 h, 1 h, 1.5 h and 2 h, respectively. The rhodamine 123 fluorescence from labeled RGC mitochondrion was detected by continuous wavelength multifunctional microplate detection instrument. The membrane capacitance (C_m) in different groups and I_K in the pressure 1 h group were recorded from the RGCs by whole-cell patch-clamp technique. RESULTS: No difference of rhodamine 123 fluorescence in the RGC mitochondria between control group and pressure 0.5 h group was observed. Rhodamine 123 fluorescence in the other 3 groups was significantly lower than that in control group (P<0.05). No difference of the C_m between control group and pressure 0.5 h group was found, and the C_m in the other 3 groups was significantly lower than that in control group (P<0.05). The amplitudes of I_K were higher than that in control group. At the test potential from -10 mV to 60 mV, the current density in pressure 1 h group was significantly higher than that in control group (P<0.05). The maximal conduction (G_max) in pressure 1 h group was significantly higher than that in control group. The voltage for I_K channel half-activation (V_1/2) in pressure 1 h group declined comparison with control group (P<0.01), and the k value had no significant difference between the 2 groups. CONCLUSION: Retinal ganglion cell apoptosis accompanies with delayed rectifier K⁺ current enhancement.