磁性隧道结中自旋相关输运的势垒影响

为了研究势垒对铁磁/绝缘层/半导体/绝缘层/铁磁(FM/I/SM/I/FM)双隧道结中自旋相关电子输运特性的影响,提出了在半导体层厚度合适的情况下,非对称势垒对于提高平行结构磁性双隧道结的自旋注入效率SIE(spin injection efficiency)更具优势.数值计算结果表明,当两势垒强度的比率达到合适数值时双结的SIE和隧穿磁电阻TMR(tunneling magnetore resistance)都将达到最大,这给提高从铁磁到半导体的SIE带来新选择.研究还表明,非对称势垒结构磁性隧道结中增大铁磁交换能对提高SIE和TMR都是有益的,而且铁磁交换能的增加对SIE的提高要比对TMR的提高更显著.     

红霉素发酵过程前期参数相关分析及调控

对红霉素发酵过程前期调控策略进行了研究,从宏观代谢流的变化着手,对表征细胞代谢特征的参数进行了相关分析,对发酵前期的摄氧率(OUR)、二氧化碳释放率(CER)及呼吸商(RQ)相关变化及红霉素发酵前期CER与pH的变化进行了分析,确定了合适的调控方式,在工业规模发酵罐上通过控制发酵过程前期补糖速率等措施,使发酵平均水平从原来的4500u／mL提高到了6000u／mL。     

试论环境地貌学的性质和应用

本文对环境地貌学的产生、学科性质、研究方法及果应用作了初步探讨、认为,随着人类改造自然的能力不断增长,地貌(?)环境意义急剧加大,环境地貌学也应运而生,它以统一的整体、环境观,把地貌作为人-地环境要素之一,对地貌的环境意义作理论探讨与实际应用.它运用传统的常规方法和新技术、新思想进行研究,其成果以各种地(?)图件和设计方案投入生产建设和环境整治.城市地貌研究集中体现了环境地貌学特点     

对苯二甲酸中微量杂质HPLC分析条件的优化

用离子交换高效液相色谱法分析对苯二甲酸中的微量杂质,并对该方法进行了系统的优化。通过选择流动相pH值使缓冲溶液的浓度降低至0．13mol／L,分析周期缩短至10min以下。结果表明：该方法的工作曲线相关系数在0．9998以上,回收率为98．7％～102．2％,相对标准偏差小于3．6％。     

斜螺旋面的近似展开

本文用计算法论述了斜螺旋面展开图的近似画法，为斜螺旋面展开图提供亍一个较简便的方法。     

TULA-2, a novel histidine phosphatase, regulates bone remodeling by modulating osteoclast function

Bone is a dynamic tissue that depends on the intricate relationship between protein tyrosine kinases (PTK) and protein tyrosine phosphatases (PTP) for maintaining homeostasis. PTKs and PTPs act like molecular on and off switches and help modulate differentiation and the attachment of osteoclasts to bone matrix regulating bone resorption. The protein T cell ubiquitin ligand-2 (TULA-2), which is abundantly expressed in osteoclasts, is a novel histidine phosphatase. Our results show that of the two family members, only TULA-2 is expressed in osteoclasts and that its expression is sustained throughout the course of osteoclast differentiation, suggesting that TULA-2 may play a role during early as well late stages of osteoclast differentiation. Skeletal analysis of mice that do not express TULA or TULA-2 proteins (DKO mice) revealed that there was a decrease in bone volume due to increased osteoclast numbers and function. Furthermore, in vitro experiments indicated that bone marrow precursor cells from DKO mice have an increased potential to form osteoclasts. At the molecular level, the absence of TULA-2 in osteoclasts results in increased Syk phosphorylation at the Y352 and Y525/526 residues and activation of phospholipase C gamma 2 (PLCγ2) upon engagement of immune-receptor-tyrosine-based-activation-motif (ITAM)—mediated signaling. Furthermore, expression of a phosphatase-dead TULA-2 leads to increased osteoclast function. Taken together, these results suggest that TULA-2 negatively regulates osteoclast differentiation and function.     

The biliary excretion of [3H] lysergic acid diethylamide in Wistar and Gunn rats.

The biliary excretion of [3H] LSD was studied in Wistar and homozygous Gunn rats. In Wistar rats approximately 46% of the given dose was recovered from bile in 2.5 h whilst in the homozygous Gunn rat 26% was recovered in the same time period. In both strains the main metabolites were glucuronides.     

Seasonal variations of cardiac output in rats.

Cardiac output of rats shows seasonal variations with low values in spring and summer and high ones in autumn and winter. The stroke volume was much more implicated in these changes than the heart rate. The seasonal changes of cardiac output are probably due to changes of thyroid function.