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Search Results: 1 - 10 of 250650 matches for " 张炯 "
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时代呼唤新的目录学著作

图书情报工作 , 2005,
Abstract: ?指出我国当代目录学著作的数量呈下降趋势,在出版时间和出版内容上明显滞后以及形式不够生动、新颖等现状,认为其中既有目录学教育体制和出版发行方面的客观原因,也有目录学家和目录学工作者的主观原因。提出设立目录学研究基金、推出个性化的目录学著作、争取多个领域分工合作及培养目录学接班人等几点建议。
射频消融辅助治疗剖宫产切口部位早孕1例
,王云
第三军医大学学报 , 2010,
Abstract:
蛇床子素通过抑制线粒体介导的凋亡信号途径减轻脑缺血再灌注损伤
Osthole alleviates cerebral ischemia-reperfusion injury by suppressing mitochondrial mediating apoptosis

,,,
- , 2017, DOI: 10.7652/jdyxb201701028
Abstract: 摘要:目的 观察蛇床子素(Osthole)对大鼠脑缺血再灌注损伤的作用及机制。方法 将50只SD大鼠随机分成假手术组、模型组和蛇床子素(25、50、100mg/kg)组(n=10)。利用物理法评估大鼠脑梗死范围、脑含水量和神经症状,试剂盒检测活性氧自由基(ROS)和ATP酶活性,流式细胞仪检测线粒体膜电位,免疫蛋白印迹法检测Caspase3、Clevage-Caspase3、Caspase9、Clevage-Caspase9、Bcl-2、Bax、细胞质中凋亡诱导因子(AIF)和cytochrome C的表达水平。结果 与假手术组相比,模型组脑梗死范围、脑含水量、神经症状以及ROS、Cleaved-Caspase3、Cleaved-Caspase9、Bax、细胞质中AIF和cytochrome C的表达明显增加,而Caspase3、Caspase9和Bcl-2表达以及线粒体膜电位和ATP酶的活性明显降低。与模型组相比,蛇床子素组脑梗死范围、脑含水量、神经症状以及ROS、Cleaved-Caspase3、Cleaved-Caspase9、Bax、细胞质中AIF和cytochrome C的表达明显减少,而Caspase3、Caspase9和Bcl-2表达以及线粒体膜电位和ATP酶的活性明显增加。结论 蛇床子素预处理可减轻脑缺血再灌注损伤,其机制可能与抑制线粒体介导的凋亡信号途径相关。
ABSTRACT: Objective To observe the influence of Osthole on cerebral ischemia-reperfusion injury and its acting mechanism. Methods We randomly divided 50 SD rats into sham (Sham) group, ischemia-reperfusion injury (IRI) group and Osthole (25, 50, and 100mg/kg) (Osthole) groups (n=10). The neurological symptoms, extent of cerebral infarction and cerebral water content were evaluated by physical approach. The activities of ROS and ATP were examined by the kit; the mitochondrial membrane potential (MMP) was measured by flow cytometry. The expressions of Bax, Bcl-2, Caspase3, clevage-Caspase3, Caspase9, clevage-Caspase9, cytoplasmic AIF and cytochrome C were measured by Western blotting. Results Compared with those in sham group, the extent of cerebral infarction and cerebral water content, changes of neurological symptoms, activities of ROS, and expressions of clevage-Caspase3, clevage-Caspase9, Bax, cytoplasmic AIF and cytochrome C in IRI group were significantly increased (P<0.05). However, the activities of ATP, expressions of Caspase3, Caspase9, Bcl-2 and MMP, and ATP activity were decreased (P<0.05). Compared with those in IRI group, the extent of cerebral infarction and cerebral water content, changes of neurological symptoms, activities of ROS, and expressions of clevage-Caspase3, clevage-Caspase9, Bax, cytoplasmic AIF and cytochrome C in Osthole group were significantly decreased (P<0.05). But the activities of ATP, expressions of Caspase3, Caspase9, Bcl-2 and MMP, and ATP activities were increased (P<0.05). Conclusion Osthole pretreatment can attenuate cerebral ischemia-reperfusion injury, which is associated with suppressing mitochondria-mediated apoptosis
原子核空间结构表述的一种新方法——金刚石结构
A New Method of the Expression of the Atomic Nucleus Space Structure—The Diamond Structure
 [PDF]

, 李冬晓, 朱永强
Modern Physics (MP) , 2013, DOI: 10.12677/MP.2013.34021
Abstract: 本文揭示了原子核空间表述的一种新方法即原子核中每一个中子和质子都有它们的空间位置:一般质子处在金刚石结构中体心位置而中子处在面心位置,它们靠核力键相互顶紧,并以它们的质心位置无序地旋转,从而来确定每一种原子核的结合能、质量、大小和电荷分布。原子核的空间结构还可以决定哪些原子核具有转动能级、振动能级、超变和电四极矩等性质。
This paper reveals that the new method is one of the express of the space structure of the atomic nucleus and that any neutron and proton have their space place in atomic nucleus: generally speaking, the proton has the place of the body-centre and the neutron has the place of the face-centre in the diamond structure. They withstand each other by nuclear force’s bond, and they are un-orderly spinning with the place of their mass centre, with the result that it can decide the binding energy, mass, body and distribution of the nuclear charge for any atomic nucleus. And the space structure of the atomic nucleus can decide which atomic nucleus has spinning energy level, vibration energy level, hyperchange, electric quadrupole moment and so on.
连铸中间包水口吹氩对堵塞的影响数值模拟
Numerical Simulation of Influence of Argon Flowrate on Tundish Nozzle Clogging during Continuous Casting
 [PDF]

袁方明, 王新华, , 张立
International Journal of Fluid Dynamics (IJFD) , 2014, DOI: 10.12677/IJFD.2014.24009
Abstract:
本文采用数值模拟方法,对水口吹氩量和水口开度影响水口沉积速率的规律作了分析研究。结果表明,吹氩量对水口内的压力存在较大的影响,压力在滑动水口处存在突降。使水口滑板处保持正压的吹氩量随着开度的减小而增大。水口开度从66.45%减小至42.82%时,使水口滑板处保持正压的吹氩量从10 L?min?1增加至25~30 L?min?1。吹氩量对水口内沉积速率的影响规律与滑板开度有关。大开度时,较小吹氩量2.5~5 L?min?1可以使沉积速率降至最低,但随着吹氩量进一步增大时,沉积速率反而增加,至最大值后再次下降。小开度时,随着吹氩量的增加,沉积速率均为下降趋势,但吹氩量大于15~20 L?min?1以后,增大吹氩量对降低沉积速率的效果并不明显。综合考虑吹气量对水口内压力和对沉积速率的影响,大开度下(>60%)合适的吹气量应为10 L?min?1。考虑大吹气量带来的危害,小开度下(<60%)合适的吹气量应为15~20 L?min?1
Influence of argon flowrate and slide gate opening ratio on deposition rate was researched by the method of numerical simulation. Flowrate of argon had influence markedly upon pressure in the nozzle, and the pressure dropped suddenly after molten steel flowing through the slide gate. To keep positive pressure at slide gate for avoiding inspiration of air, minimum flowrate of argon was increased from about 10 L?min?1 to 25~30 L?min?1 as slide gate opening ratio decreasing from 66.45%to 42.82% when casting speed was 1.2 m?min?1. Influence of argon flowrate on the deposition rate of alumina was related to the slide gate opening ratio. When the slide gate opening ratio was big, such as 66.45%, the deposition rate of alumina occurred maximum and minimum values as the argon flowrate increased step by step. When the opening ratio was small, such as 50.46% and 42.82%, the deposition rate of alumina was decreased all along as the argon flowrate increased, and the effect of argon flowrate on decreasing alumina deposition rate was not obvious when the argon flowrate was more than 15~20 L?min?1. Considering the influence of flowrate upon to static pressure in nozzle and deposition rate, the appropriate argon flowrate was 10 L?min?1 as big opening ratio of slide gate (>60%). Due to the disadvantage of high flowrate, the appropriate argon flowrate was 15~20 L?min?1 as small opening ratio (<60%).
THE APPLICATION OF SYNCHROTRON RAIATION IN DIFFRACT ON DATA COLLECTION OF D-GLYCERALDEHYDE-3-PHOSPHAIE DEHVDROGENASE AND IT''S DERIVATIVES
同步辐射在D-甘油醛-3-磷酸脱氢酶及其系列衍生物高分辨率衍射数据收集中的应用

发明,林政
生物物理学报 , 1990,
Abstract: Helo - D - glyceraldehyde - 3 - phosphate dehyregenase HOLO - GAPDUwas purified frorr P. versicolor lobster muscle. It's active site Cys-149 carboxymethy and den-vative CM-GAPDH) and the fluorescent NAD derivative IRR-GAPDH were prepared. Using I (NH4) 2SO4 as precipitating agent, the three forms of the en me were crystallized by vapour diffusion method. The diffraction data of these three forms of the enzyme were collected with synchrotron radiation-Fuji imaging plate -weisse berg cam-era system at BL-6A2 of Photon Factory at 1.8A resolution. Rmerge factor of HOLO-GAPDH, CM-GAPDH and IRR-GAPDH are 4.93%, 6.22% and 5.77% respectively. The diffraction intensity difference between the native enzyme and it's derivatives and its structural implication arc discussed.
一种基于词聚类的文本特征描述方法
,永奎
计算机系统应用 , 2011,
Abstract: 针对文本挖掘中存在的特征空间高维性问题,提出了一种基于词聚类的文本特征描述方法,旨在通过机器学习的方法挖掘词汇之间的语义关联,动态构造特定领域的概念词典,借助构造的概念来描述文本的特征,该方法不借助主题词典,先从训练语料中对词的共现情况进行分析,用词聚类(word clustering)生成由种子词(seedwords)表示的代表某一主题概念的词类,然后用种子词作为文本的特征项。实验表明,该方法不仅压缩了特征空间的维数,也克服了HowNet 中概念信息的局限性,提高了文本分类的精确度。
黄河下游游荡段河床调整对于水沙组合的复杂响应
,欧阳
地理学报 , 2000, DOI: 10.11821/xb200003003
Abstract: 以黄河资料为基础,揭示了包括非高含沙水流和高含沙水流在内的河道挟沙水流的复杂冲淤行为。由于这种复杂冲淤行为的作用和高含沙水流特殊能耗特征的影响,使得河床横断面形态及平面形态对于水沙组合的响应出现非线性特征,这可视为流水地貌系统复杂响应的又一表现形式。
基于Log-Gabor特征的非局部均值去噪算法及其加速方案研究*
,景华
模式识别与人工智能 , 2015, DOI: 10.16451/j.cnki.issn1003-6059.201503011
Abstract: 非局部均值是一种基于像素长程相似性的图像空域去噪算法,它一般采用灰度块特征估计图像像素间的相似度.文中首先使用基于Log-Gabor特征的像素间相似度估计获得较好的去噪效果.然后将Log-Gabor几何特征与灰度特征相融合,所形成的混合相似度具有更佳的图像局部自适应性,去噪性能也得到进一步提升.最后基于Johnson-Lindenstrauss引理研究利用随机降维方法降低相似度计算的复杂度,并对该加速方案的效果,包括降维前后运行时间对比、降维程度以及随机矩阵生成方法对去噪性能的影响,进行详细试验分析,结果证明基于随机降维的加速方案的有效性.
黄河流域产水产沙、输移和沉积系统的划分
欧阳,
地理研究 , 2002, DOI: 10.11821/yj2002020007
Abstract: 根据Schumm提出的河流系统的理论对黄河流域地貌系统进行了划分。结果表明,整个黄河流域地貌系统可以很明确地分为产水产沙系统、输移系统和沉积系统,其模式与Schumm的理想流域模式非常吻合,同时又表现出其特殊性。以河口镇为界,黄河流域上游和中下游两部分分别具有对应的产水系统、产沙系统和河道输移系统,各子系统处于动态变化过程中,存在一种强耦合关系,这种特点主要是由黄河流域的历史发育过程决定的。
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