国产食用乳化剂Tween60对甜橙油—水界面性质的影响

本文研究了国产食用乳化剂Tween60对甜橙油—水界面性质的影响。测定了Tween60水溶液在不同浓度、不同pH值及不同的电解质(NaCl)浓度时,油—水两相间界面张力的变化,发现了一些影响界面张力的因素。当水溶液中Tween60的浓度是5.3%时,界面张力最小。同时,文中还讨论了Tween60分子在界面处的吸附作用机理,得到了一些很有意义的结论。     

乳化剂对甜橙油—水界面张力的影响

研究了乳化剂(吐温Tween、阿拉伯胶AG、低酯果胶FG)以及pH、电解质对于甜橙油—水界面张力γ的影响,对比了三种乳化剂的作用,结论认为:Tween降低γ的能力最强,且可调范围较宽,而FG的浓度可调范围小,降低γ的作用不强。     

松籽脱壳工艺及主要设备的工作原理

本文对松籽机械脱壳工艺，加工生产及其主要设备的工作原理进行了介绍．供有关科研和工程技术人员参考．     

Dendrite growth increased by visual activity requires NMDA receptor and Rho GTPases

Previous studies suggest that neuronal activity may guide the development of synaptic connections in the central nervous system through mechanisms involving glutamate receptors and GTPase-dependent modulation of the actin cytoskeleton. Here we demonstrate by in vivo time-lapse imaging of optic tectal cells in Xenopus laevis tadpoles that enhanced visual activity driven by a light stimulus promotes dendritic arbor growth. The stimulus-induced dendritic arbor growth requires glutamate-receptor-mediated synaptic transmission, decreased RhoA activity and increased Rac and Cdc42 activity. The results delineate a role for Rho GTPases in the structural plasticity driven by visual stimulation in vivo.     

CD1d-lipid-antigen recognition by the semi-invariant NKT T-cell receptor

The CD1 family is a large cluster of non-polymorphic, major histocompatibility complex (MHC) class-I-like molecules that bind distinct lipid-based antigens that are recognized by T cells. The most studied group of T cells that interact with lipid antigens are natural killer T (NKT) cells, which characteristically express a semi-invariant T-cell receptor (NKT TCR) that specifically recognizes the CD1 family member, CD1d. NKT-cell-mediated recognition of the CD1d-antigen complex has been implicated in microbial immunity, tumour immunity, autoimmunity and allergy. Here we describe the structure of a human NKT TCR in complex with CD1d bound to the potent NKT-cell agonist alpha-galactosylceramide, the archetypal CD1d-restricted glycolipid. In contrast to T-cell receptor-peptide-antigen-MHC complexes, the NKT TCR docked parallel to, and at the extreme end of the CD1d-binding cleft, which enables a lock-and-key type interaction with the lipid antigen. The structure provides a basis for the interaction between the highly conserved NKT TCR alpha-chain and the CD1d-antigen complex that is typified in innate immunity, and also indicates how variability of the NKT TCR beta-chain can impact on recognition of other CD1d-antigen complexes. These findings provide direct insight into how a T-cell receptor recognizes a lipid-antigen-presenting molecule of the immune system.     

利用光纤光栅实现压力和温度同时测量

结合光纤光栅弹簧管压力传感器的结构特点 ,在悬臂梁的上下两面分别粘贴两个应力和温度灵敏系数基本相同的光纤光栅 ,通过分别测量光纤光栅对的波长位移 ,实现了压力和温度的同时测量 ,压力和温度测量的分辨率分别为 0 .1 4 MPa和 0 .5℃ .     

现代地表移动监测网的布设研究

本文基于位移反分析方法，通过数值试验研究了地表移动监测网的网形和观测误差对力学模型参数反演结果的影响，为解决实际生产中的现代地表移动监测网设计提供了理论依据。     

12％Cr耐热钢件蠕变破断寿命的简单预测方法

在大量试验数据的基础上,本文研究了两种含碳量不同的12％Cr-Mo—V—Nb—N—B马氏体耐热钢在550℃～650℃下的蠕变破断应力与破断试样平均室温硬度的关系,证实两者在衡量耐热钢蠕变弱化倾向上是一致的。分析了蠕变过程中析出相和微观组织的变化。提出了一种采用蠕变破断试样室温硬度近似预测耐热钢件蠕变破断寿命的方法。