Rutile U-Pb age for the ultrahigh pressure eclogite from the Dabie Mountains,central China: Evidence for rapid cooling

The U-Pb isotope compositions of rutile, omphacite and garnet in the eclogite from the Jinheqiao area in the Southern Dabie ultrahigh-pressure metamorphic zone were analyzed. The consistent high precision U-Pb age (218 ± 1.2) Ma of rutile in eclogite from the Dabie Mountains was obtained by two ways of isochron and common Pb correction based on the composition of omphacite. This proves that the omphacite in eclogite has a U/Pb ratio (m = 2.8) low enough to be used for common Pb correction in the analyses of rutile. Under the rapid cooling condition (40℃/Ma) the closure temperature for U-Pb diffusion in rutile is about 470℃. Thus, this U-Pb age of rutile proves that 218 Ma should be the cooling age of eclogite at 470℃ instead of the peak metamorphic age.     

Mutations in Rab3a alter circadian period and homeostatic response to sleep loss in the mouse

Rab3a is the most abundant Rab (ras-associated binding) protein in the brain and has a regulatory role in synaptic vesicle trafficking. Mice with a targeted loss-of-function mutation in Rab3a have defects in Ca(2+)-dependent synaptic transmission: the number of vesicles released in response to an action potential is greater than in wildtype mice, resulting in greater synaptic depression and the abolishment of CA3 mossy-fiber long term potentiation. The effect of these changes on behavior is unknown. In a screen for mouse mutants with abnormal rest-activity and sleep patterns, we identified a semidominant mutation, called earlybird, that shortens the circadian period of locomotor activity. Sequence analysis of Rab3a identified a point mutation in the conserved amino acid (Asp77Gly) within the GTP-binding domain of this protein in earlybird mutants, resulting in significantly reduced levels of Rab3a protein. Phenotypic assessment of earlybird mice and a null allele of Rab3a revealed anomalies in circadian period and sleep homeostasis, providing evidence that Rab3a-mediated synaptic transmission is involved in these behaviors.     

基于MATLAB的信号与系统软件实验平台

基于MATLAB软件的信号与系统实验平台,弥补了教学中的不足,通过实验,加强学生对信号与系统课程的理解和掌握。     

新型苯并呋喃新木脂素类化合物的合成研究

以对羟基苯甲醛和丙二酸为原料,经Knoevenagel缩合反应,酯化、仿生氧化偶联、DDQ脱氢、还原和水解等反应步骤,合成了6种未见文献报道的苯并二氢呋喃新木脂素和苯并呋喃新木脂素类化合物(1~6).其中两分子对羟基苯丙烯酸甲酯仿生氧化偶联为它的二聚体(1)和DDQ脱氢反应是整个合成路线的关键步骤.DDQ脱氢反应可成功实现由苯二氢呋喃向苯并呋喃环转化,这为合成苯并呋喃新木脂素类化合物提供了一种新方法.     

矩菜缺素症状及焉耆垦区甜菜营养生理性病害的诊断

1998－2000年通过室内溶液培养和田间调查分析，对甜菜缺素症状与田间诊断进行了研究。结果表明，甜菜缺乏必须营养元素会表现出其特有的缺素症状，但甜菜营养生理性病害的田间诊断不仅要通过缺素症状进行形态诊断，还应结合化学诊断来综合判断其发生原因。     

Catastrophe mechanism and classification of discontinuity behavior in thermal science (I)

The mechanism of discontinuity behavior has important significance in the study of thermal science, such as fire, combustion, explosion and heat transfer. This sort of discontinuity behavior and the catastrophe caused by system nonlinearity may be equivalently classified according to the catastrophe model promulgated by catastrophe theory. Under the conditions of uniform temperature and thermal isolation, the self-ignition behavior of a Semenov System can be viewed as a result of the fold catastrophe of the system.     

白花夏枯草对高原家兔骨髓各级幼红细胞Feret直径的研究

本文应用透射电镜技术对平原移居高原（海拔３９００米）实验家兔骨髓内各级红系细胞电镜照片的费莱特直径（Ｆeret)进行了研究，实验分平原对照组，高原给药及高原对照三个组，实验结果：高原给药组骨髓原红，早、中，晚幼红细胞Ｆeret直径均低于高原对照组，差别有显著性，结果提示白花夏枯草可降低由低氧引起的各级幼红细胞胸体增大，从而降低血液的粘滞性，改善血循环。     

清末新军建设述评

从20世纪中国军队近代化的宏观角度看,清末新军建设不仅编练了一支新型的近代化军代,而且带来了中国军事制度的根本性变革,堪称中国军事近代化的肇端.但从清王朝练军自求的微观角度看,新军却变成了王朝的掘墓了,不能说新军建设不是一次惨重的失败.封建主义的国家机体难以移植资本主义的军事制度;落后的农业经济承受不起近代化军队建设的重负;动荡的末代政局无法保障军制改革和军队建设的顺利进行,是新军建设失败的3个重要原因.     

固载杂多酸PW12/SiO2催化合成烷基糖苷的研究

以固载杂多酸Pw