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371.
谷氨酸离子交换过程动态穿透曲线的分析 总被引:3,自引:0,他引:3
介绍了一种新的分析离子交换过程穿透曲线的方法,该方法采用特定的函数来描述穿透曲线以求出在不同实验条件下的离子交换过程的传质参数。该特定函数建立在吸附区传质概率的基础上,因此传质机制可以用函数的常数来表示,无需识别传质机理。采用该方法建立了NH4+型阳离子交换树脂吸附谷氨酸的穿透曲线模型,以得到离子交换过程的传质参数。 相似文献
372.
申福祥 《南京理工大学学报(自然科学版)》1984,(Z2)
本文在技术经济学领域提出并系统论述了经济效益保证体系的概念。估计了体系工作误差和损失。在此基础上给出体系的有效性概念及其公式。作为一个系数,它有助于修正计算总产值和其他经济效益指标的工作。 相似文献
373.
申建华 《湖南师范大学自然科学学报》1996,19(3):13-16
研究某类不连续初始函数空间上有限时滞泛函微分方程解的存在唯一性,并应用它来讨论脉冲泛函数微分方程的某些局部理论。 相似文献
374.
375.
WANGZhen MENGXianmin CAOHuiqing LIUDongqing FENGYan YOUXin WANGYin GUOLianjun QUShen 《科学通报(英文版)》2004,49(23):2487-2490
The interaction of nelin, a cardiac-specific expressed protein of human novel gene nelin, with F-actin was studied by both F-actin cosedimentation in vitro and colocalization assays. The results showed that nelin is a new F-actin binding protein and is colocolized with F-actin in cytoplasm of cells. Three new nelin binding proteins, filamin C subtype, titin N2B subtype and inter-alpha trypsin inhibitor heavy chain precursor (ITIH), were identified from human heart cDNA library using yeast two-hybrid screening. The binding activity of filamin C with nelin was confirmed by coimmunoprecipitation. Filamin C binds to nelin through its C-terminal region. It is indicated that nelin is a cytoskeleton associated protein and acts as a membrane-cytoskeleton associated protein involved in the formation of focal adhesions. 相似文献
376.
QISuwei YANGPingfang JINGYuxiang SHENShihua YANGSusheng 《科学通报(英文版)》2004,49(17):1828-1833
Sinorhizobium fredii RT19, a strain of freeliving bacteria, was subjected to salt shock and its protein expression profiles were analyzed by differential display proteome approaches. The results of separation by two-dimensional polyacrylamide gel electrophoresis (2D PAGE) showed that the number of resolved proteins was 481, 465 and 424, corresponding to salt-free control, 5 and 50 min 1 mol/L salt treatment, respectively. Among the resolved proteins, 82 in total had altered expression in response to salt-shock stress. 26 out of the 82 proteins were induced and 23 were completely inhibited, while 12 were up-regulated and 21 down-regulated in response to salt shock. In addition, the appearance of differentially displayed proteins responding to different salt shock periods is also reported. The identity of the 26 induced proteins was revealed by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) followed by database searching. Among them, 20 were assigned to proteins with known functions. Their roles in response to salt shock stress are discussed. 相似文献
377.
Characterization of MASDs of surface soils in north China and its influence on estimating dust emission 总被引:2,自引:0,他引:2
MEI Fanmin ZHANG Xiaoye LU Huayu SHEN Zhenxing & WANG Yaqiang . State Key Laboratory of Loess Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xian China . Xian University of Engineering Science Technology Xian China 《科学通报(英文版)》2004,49(20):2169-2176
Inordertoquantitivelyevaluateeffectsofdustaerosolonradiativeforcing[1],andtounderstandtheprocessofatmosphericchemistryandbiogeochemistry[2,3],modelingthedustemissionfluxisakindoffundamentalwork.TheDPMmodel[4—6]isidealforpredictingdustemission[7—10]becauseitconsiderseffectsofsurfacefea-tures(MASDofsurfacesoil,roughnesslengthandsoilmoisture,etc)andsandblastingprocess.Italsoprovidesanexplicitphysicalmechanismthatisvalidatedbywindtunnelandfieldexperiments[7—10].Themeandiameterofsurfacesoilsi… 相似文献
378.
一种基于需求景气分析和“幼稚预测”思想的需求预测模型 总被引:1,自引:0,他引:1
根据汽车生产企业和宾馆企业需求预测问题的基本特点,利用需求时间序列及其变化曲线,提出了一种基于需求景气分析和"幼稚"预测思想的定量预测模型,即首先划分产品的景气变化模式,然后寻找当前点状态的最佳历史匹配,并据此给出需求预测值.本文给出了模型的相关定义及算法,并以宾馆和汽车生产企业的实际需求数据为应用对象,检验了该模型的预测性能.试验结果表明,该方法具有较理想的预测精度. 相似文献
379.
Wet periods in northeastern Brazil over the past 210 kyr linked to distant climate anomalies 总被引:1,自引:0,他引:1
Wang X Auler AS Edwards RL Cheng H Cristalli PS Smart PL Richards DA Shen CC 《Nature》2004,432(7018):740-743
The tropics are the main source of the atmosphere's sensible and latent heat, and water vapour, and are therefore important for reconstructions of past climate. But long, accurately dated records of southern tropical palaeoclimate, which would allow the establishment of climatic connections to distant regions, have not been available. Here we present a 210,000-year (210-kyr) record of wet periods in tropical northeastern Brazil--a region that is currently semi-arid. The record is obtained from speleothems and travertine deposits that are accurately dated using the U/Th method. We find wet periods that are synchronous with periods of weak East Asian summer monsoons, cold periods in Greenland, Heinrich events in the North Atlantic and periods of decreased river runoff to the Cariaco basin. We infer that the wet periods may be explained with a southward displacement of the Intertropical Convergence Zone. This widespread synchroneity of climate anomalies suggests a relatively rapid global reorganization of the ocean-atmosphere system. We conclude that the wet periods probably affected rainforest distribution, as plant fossils show that forest expansion occurred during these intermittent wet intervals, and opened a forest corridor between the Amazonian and Atlantic rainforests. 相似文献
380.
An improved double-threshold method based on gradient histogram 总被引:2,自引:0,他引:2
YANGShen CHENShu-zhen ZHANGBing 《武汉大学学报:自然科学英文版》2004,9(4):473-476
This paper analyzes the characteristics of the output gradient histogram and shortages of several traditional automatic threshold methods in order to segment the gradient image better. Then an improved double-threshold method is proposed, which is combined with the method of maximum classes variance, estimatingarea method and double-threshold method. This method can automatically select two different thresholds to segment gradient images. The computer simulation is performed on the traditional methods and this algorithm and proves that this method can get satisfying result. 相似文献