检索结果-南通市图书馆

Journal of Ocean University of China 2024年第2期23卷 467-476页

作者： SUN Wenting HU Yangdong ZHENG Jiahuan SUN Qichao Chen Xia ding jiakun ZHANG Weitao WU Lianying College of Chemistry and Chemical Engineering Ocean University of ChinaQingdao 266100China Institute of Chemical Engineering Guangdong Academy of Science Guangzhou 510665China

Studying the relationship between ionic interactions and salt solubility in seawater has implications for seawater desalination and mineral *** this paper,a new method of expressing ion-to-ion interaction is proposed by using molecular dynamics simulation,and the relationship between ion-to-ion interaction and salt solubility in a simulated seawater water-salt system is *** analyzing the variation of distance and contact time between ions in an electrolyte solution,from both spatial and temporal perspectives,new parameters were proposed to describe the interaction between ions:interaction distance(ID),and interaction time ratio(ITR).The best correlation between characteristic time ratio and solubility was found for a molar ratio of salt-to-water of 10:100 with a correlation coefficient of *** the same salt,a positive correlation was found between CTR and the molar ratio of salt and *** type 1-1,type 2-1,type 1-2,and type 2-2 salts,the correlation coefficients between CTR and solubility were 0.93,0.96,0.92,and 0.98 for a salt-to-water molar ratio of 10:100,*** solubility of multiple salts was predicted by simulations and compared with experimental values,yielding an average relative deviation of 12.4%.The new ion-interaction parameters offer significant advantages in describing strongly correlated and strongly hydrated electrolyte solutions.

关键词： molecular dynamics simulation interaction distance interaction time rate electrolyte aqueous solutions solubility

Research on anti-attack performance of a private cloud safety computer based on the Markov-Percopy dynamic heterogeneous redundancy structure

在线全文

学校读者我要写书评

暂无评论

Transportation Safety and Environment 2023年第4期5卷 107-116页

作者： jiakun Wen Zhen Liu Huan ding CRSC Research&Design Institute Group Co.Ltd Beijing 100070China

With the increasing computing demand of train operation control systems,the application of cloud computing technology on safety computer platforms of train control system has become a research hotspot in recent *** to improve the safety and availability of private cloud safety computers is the key problem when applying cloud computing to train operation control *** the cloud computing platform is in an open network environment,it can face many security loopholes and malicious network ***,it is necessary to change the existing safety computer platform structure to improve the attack resistance of the private cloud safety computer platform,thereby enhancing its safety and ***,a private cloud safety computer platform architecture based on dynamic heterogeneous redundant(DHR)structure is proposed,and a dynamic migration mechanism for heterogeneous executives is ***,a generalized stochastic Petri net(GSPN)model of a private cloud safety computer platform based on DHR is established,and its steady-state probability is solved by using its isomorphism with the continuous-time Markov model(CTMC)to analyse the impact of different system structures and executive migration mechanisms on the system's anti-attack ***,through experimental verifcation,the system structure proposed in this paper can improve the anti-attack capability of the private cloud safety computer platform,thereby improving its safety and reliability.

关键词： Safety computer logical monitoring method continuous time Markov modelling,cloud computing anti-attack analysis

改性的光棒废料粉末填充EVA的复合材料性能研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

无机盐工业 2018年第10期50卷 58-61页

作者：石从云丁家坤王金峰向军陈红祥王潇杨明月强敏武汉科技大学化学与化工学院湖北武汉430081

为了探索光纤预制棒废料(主要成分为二氧化硅)在聚乙烯-聚醋酸乙烯酯(EVA)材料领域的应用,将经过烘干、研磨和煅烧处理后的废料分别由A-151改性和聚甲基丙烯酸甲酯(PMMA)包覆改性制备了纳米粉末Si O2/A-151和Si O2/PMMA,然后把制得的改... 详细信息

为了探索光纤预制棒废料(主要成分为二氧化硅)在聚乙烯-聚醋酸乙烯酯(EVA)材料领域的应用,将经过烘干、研磨和煅烧处理后的废料分别由A-151改性和聚甲基丙烯酸甲酯(PMMA)包覆改性制备了纳米粉末Si O2/A-151和Si O2/PMMA,然后把制得的改性纳米粉末与EVA熔融共混制备Si O2/A-151/EVA和Si O2/PMMA/EVA纳米复合材料,研究了复合材料的磨耗和拉伸性能(拉伸强度和断裂伸长率)与粉末质量分数的关系。疏水性测试结果表明改性后的粉末疏水性好。关于磨耗性能,粉末填充质量分数为1%~2%时两种复合材料较纯EVA都有显著提高,其中质量分数都为1%时提高最多。关于拉伸性能,填充质量分数为1%~4%的Si O2/A-151粉末和1%~3%的Si O2/PMMA粉末都能提升EVA的拉伸强度和断裂伸长率;两种复合材料的拉伸性能都随粉末质量分数的增大先增大后减小;Si O2/A-151、Si O2/PMMA粉末填充质量分数分别为1%、2%时,复合材料的拉伸强度达到最大值,二者填充质量分数在3%时断裂伸长率都达到最大。

关键词：光纤预制棒废料改性粉末 EVA 纳米复合材料二氧化硅

湖羊瘤胃微生物GH9家族葡聚糖酶基因IDSGLUC9-25的表达与功能表征

在线全文

学校读者我要写书评

暂无评论

微生物学报 2024年第3期64卷 755-766页

作者：徐晓锋韩俊彦丁钰杰廖静高德英张骥王佳堃尹尚军王谦徐洁皓浙江万里学院生物与环境学院浙江宁波315100 浙江大学动物科学学院奶业科学研究所浙江杭州310058 杭州云心质力生物科技有限公司浙江杭州310018

【目的】葡聚糖酶是饲用添加剂的重要成分,本研究旨在从湖羊消化道微生物中挖掘性质优良的GH9家族葡聚糖酶基因,用于研发新型饲用酶制剂。【方法】从湖羊瘤胃微生物cDNA中扩增IDSGLUC9-25基因,在大肠杆菌中进行异源表达,对重组蛋白进行... 详细信息

【目的】葡聚糖酶是饲用添加剂的重要成分,本研究旨在从湖羊消化道微生物中挖掘性质优良的GH9家族葡聚糖酶基因,用于研发新型饲用酶制剂。【方法】从湖羊瘤胃微生物cDNA中扩增IDSGLUC9-25基因,在大肠杆菌中进行异源表达,对重组蛋白进行诱导表达和纯化,研究重组蛋白的酶学性质和底物水解模式。【结果】IDSGLUC9-25基因编码527个氨基酸,包含一个CelD_N结构和一个GH9家族催化结构域;重组蛋白rIDSGLUC9-25分子量约为62.7 kDa,最适反应温度和pH分别为40℃和6.0,在30–50℃下活性较高,在pH 4.0–8.0范围内能够保持较高的稳定性,经pH4.0–8.0缓冲液处理1h后残余活性均大于90%;底物谱分析表明,rIDSGLUC9-25能催化大麦β-葡聚糖、苔藓地衣多糖、魔芋胶和木葡聚糖,比活性分别为(443.55±24.48)、(65.56±5.98)、(122.37±2.85)和(159.16±7.73)U/mg;利用薄层色谱法(thinlayer chromatography,TLC)和高效液相色谱法(high performance liquid chromatography,HPLC)分析水解产物发现,rIDSGLUC9-25降解大麦葡聚糖主要生成纤维三糖(占总还原糖64.19%±1.19%)和纤维四糖(占总还原糖26.24%±0.12%),催化地衣多糖主要生成纤维三糖(占总还原糖78.46%±0.89%)。【结论】本研究报道了一种来自密螺旋体属细菌的内切β-1,4-葡聚糖酶IDSGLUC9-25(EC3.***.1.4),能高效催化多糖底物生成纤维三糖和纤维四糖,为研发饲用酶制剂和制备低聚寡糖建立基础。

关键词：湖羊消化道微生物葡聚糖酶 IDSGLUC9-25 纤维寡糖

湖羊瘤胃微生物来源的低温葡聚糖酶的表达与功能表征

在线全文

学校读者我要写书评

暂无评论

浙江大学学报（农业与生命科学版） 2024年第4期50卷 531-541页

作者：丁钰杰徐晓锋韩俊彦周叶波麻子莹沈桢祎钱国英王佳堃徐洁皓王谦浙江万里学院生物与环境学院浙江宁波315100 浙江大学奶业科学研究所浙江杭州310058

葡聚糖酶作为添加剂在饲料、食品和纺织工业中具有重要的应用价值。本研究从湖羊瘤胃微生物c DNA中扩增IDSGH5-50基因,通过大肠埃希菌BL21(DE3)进行异源表达,研究重组蛋白rIDSGH5-50的酶学性质和水解产物。结果表明:IDSGH5-50编码690个... 详细信息

葡聚糖酶作为添加剂在饲料、食品和纺织工业中具有重要的应用价值。本研究从湖羊瘤胃微生物c DNA中扩增IDSGH5-50基因,通过大肠埃希菌BL21(DE3)进行异源表达,研究重组蛋白rIDSGH5-50的酶学性质和水解产物。结果表明:IDSGH5-50编码690个氨基酸,蛋白质分子量为75.78 kDa,等电点为4.75;重组蛋白rIDSGH5-50的最适反应条件为温度30℃、pH 6.0,且能在4~20℃下保持较高活性(>70%),在pH 5.0~8.0范围内稳定性较高。rIDSGH5-50的活性底物谱分析显示,rIDSGH5-50能催化大麦β-葡聚糖、地衣多糖、罗望子木葡聚糖和魔芋胶,对应的比活性分别为(10.42±0.16)、(7.12±0.08)、(7.03±0.38)、(5.94±0.65) U/mg。薄层色谱分析表明,在rIDSGH5-50催化下,大麦β-葡聚糖主要降解成纤维四糖和纤维五糖,地衣多糖主要降解成纤维三糖和纤维五糖,魔芋胶主要降解成纤维五糖,罗望子木葡聚糖主要降解成聚合度>5的寡糖。本研究报道了一种来自瘤胃球菌属的低温内切β-1,4-葡聚糖酶IDSGH5-50,为饲料、食品酶制剂开发奠定了基础。

关键词：湖羊瘤胃葡聚糖酶低温冷适应底物水解

Preliminary investigation on electrothermal instabilities in early phases of cylindrical foil implosions on primary test stand facility

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第2期28卷 352-357页

作者： Guanqiong Wang Delong Xiao jiakun Dan Yang Zhang Ning ding Xianbin Huang Xiaoguang Wang Shunkai Sun Chuang Xue Xiaojian Shu Institute of Applied Physics and Computational Mathematics Institute of Fluid Physics Chinese Academy of Engineering Physics

Recent experiments on the implosions of 15-mm long and 2-μm thick aluminum liners having a diameter of 12.8 mm have been performed on the primary test stand(PTS) facility. The stratified structures are observed as alternating dark and light transverse stripes in the laser shadowgraph images. These striations perpendicular to the current flow are formed early in the implosion, i.e., at the stage when the bulk of the material mass was almost at rest. A two-dimensional(2 D)magnetohydrodynamics(MHD) code is employed to simulate the behavior of liner dynamics in the early phases. It is found that the striations may be produced by the electrothermal instability(ETI) that results from non-uniform Joule heating due to the characteristic relation between the resistivity and the temperature. In 2 D simulations, the stratified structures can be seen obviously in both density and temperature contours as the liner expands rapidly. By analyzing instability spectrum, the dominant wavelengths of the perturbations are 8.33 μm–20.0 μm, which agree qualitatively with the theoretical *** is also interesting to show that ETI provides a significant seed to the subsequent magneto Rayleigh–Taylor(MRT)instability.

关键词： Z-pinch electrothermal instability magnetohydrodynamics(MHD) simulations

Optimal Trade-Off Between Regulation and Wind Curtailment in the Economic Dispatch Problem

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2015年第4期1卷 52-60页

作者： Jinghua Li jiakun Fang Jinyu Wen Yi Pan Qiang ding State Key Laboratory of Advanced Electromagnetic Engineering and Technology Huazhong University of Science and TechnologyWuhan 430074China the department of electrical engineering Guangxi UniversityNanning 530004China China Electric Power Research Institute Beijing 100192China

Generator regulation and wind power curtailment are two conflicting ways to deal with the inaccurate prediction and volatility of wind *** study focuses on planning the day-ahead schedule based on optimal trade-off between regulation of generators and wind *** to traditional economic dispatch methods,the proposed schedule is more robust and adaptive to multiple forecast scenarios instead of a single forecast *** works of this paper are as follows:First,an economic dispatch problem based on multiple scenarios is formulated with the objective of minimizing both generator regulation and wind ***,a forecast method for wind power scenarios is ***,the proposed model is verified by comparing with other dispatch models that are based on single forecast *** simulation results demonstrate the effectiveness of the proposed method with less wind curtailment,generator regulation,and operational *** addition,the penalty factors are set as parameters and the influences on the generators’regulation and wind curtailment are analyzed,providing the reference for system operators with different regulatory purposes.

关键词： Economic dispatch forecasting regulation uncertainty wind curtailment wind power scenarios

基于实时细胞分析技术的中药挥发性组分抗人腺病毒3型毒/效整合评价的高通量筛选新策略

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中华中医药学刊 2024年第9期42卷 171-175,I0037-I0039页

作者：刘芳彤李彦青王含雪林佳坤刘孝云叶冬雪容蓉杨勇山东中医药大学山东济南250355 中医药经典理论教育部重点实验室山东济南250355 中医药基础研究山东省重点实验室山东济南250355 山东省中医药抗病毒工程研究中心山东济南250355

目的基于实时细胞分析(real time cell analysis,RTCA)技术对中药挥发性组分的细胞毒性及抗人腺病毒3型(human adenovirus 3,HAdV-3)的作用进行毒/效整合分析,构建抗病毒药物高通量筛选的新策略。方法采用RTCA技术动态监测不同接种密度... 详细信息

目的基于实时细胞分析(real time cell analysis,RTCA)技术对中药挥发性组分的细胞毒性及抗人腺病毒3型(human adenovirus 3,HAdV-3)的作用进行毒/效整合分析,构建抗病毒药物高通量筛选的新策略。方法采用RTCA技术动态监测不同接种密度的A549细胞48 h生长曲线及10倍梯度稀释的HAdV-3感染A549细胞生长曲线,获得A549细胞最佳接种密度及HAdV-3最佳稀释浓度用于后续实验。以利巴韦林为阳性对照,基于RTCA技术采用曲线下面积(Area Under the Curve,AUC)方法对5种中药挥发性组分的细胞毒性及抗HAdV-3的作用进行毒/效整合分析,并与传统终点法数据处理进行对比。结果终点法中艾叶、柴胡、薄荷、荆芥、牛蒡子、酸枣仁和利巴韦林对细胞的保护率分别为0.73%、12.50%、20.99%、44.50%、27.99%、51.50%和82.70%;AUC法中艾叶、柴胡、薄荷的选择性指数(Selective Index,SI)为负数,分别为-0.57、-0.21和-0.08。荆芥、牛蒡子、酸枣仁和利巴韦林的SI值分别为0.14、0.40、0.72和5.33。以利巴韦林的抗病毒活性为参照,终点法中酸枣仁、牛蒡子和荆芥的抗病毒活性为利巴韦林抗病毒活性的62.27%、33.85%和53.81%;AUC法中酸枣仁、牛蒡子和荆芥的抗病毒活性为利巴韦林抗病毒活性的13.51%、7.50%和2.63%。结论传统终点法与研究采用的AUC法计算结果有较大的差异。传统的抗病毒活性筛选研究多采用终点法检测受试药物对病毒感染细胞的保护作用,无法反映整个感染周期的变化,缺乏细胞毒的数据也会对结果的判断产生偏差。研究提示基于RTCA技术对中药挥发性组分开展抗HAdV-3的毒/效整合评价,采用AUC方法计算药物的选择性指数作为高通量筛选新策略,能快速、精准地判断受试药物的抗病毒活性,具有准确性高、重复性好的优势。

关键词： RTCA技术挥发性组分 HAdV-3 毒/效整合高通量筛选

维普期刊数据库博看期刊

基于RGB图像的刺槐季节变化监测适用指数研究

在线全文

学校读者我要写书评

暂无评论

遥感技术与应用 2018年第3期33卷 476-485页

作者：滕佳昆刘宇丁明涛西南科技大学环境与资源学院四川绵阳621010 中国科学院地理科学与资源研究所中国科学院生态系统网络监测与模拟重点实验室北京100101

随着普通数字相机的广泛使用,利用普通数字相机拍摄获得的RGB图像提取植被生长的特征时间点是监测植被季节变化的一种有效方式。为此提出了多个为量化特征时间点的提供数据基础的颜色指标,但其有效性仍是这一植被监测方法的制约因素。... 详细信息

随着普通数字相机的广泛使用,利用普通数字相机拍摄获得的RGB图像提取植被生长的特征时间点是监测植被季节变化的一种有效方式。为此提出了多个为量化特征时间点的提供数据基础的颜色指标,但其有效性仍是这一植被监测方法的制约因素。以黄土高原广布的刺槐为对象,利用缩时相机获取的数字照片为基本数据。通过提取绝对绿度指数(Green Excess Index,ExG)、相对绿度指数(Green Chromatic Coordinate,Gcc)、绿红植被指数(Green Red Vegetation Index,GRVI)和色相指数(Hue based on HSL,Hue)等颜色指数,比较了上述4个颜色指数在平均值法和最大亮度法两种分析方法下提取植被生长过程时间节点的效果,与实际观测结果相比较,遴选最佳指数。结果表明:基于平均值法的ExG指数的提取的生长期开始(Start of the Seasonality,SOS)、生长期结束(End of the Seasonality,EOS)最接近实测值,ExG可以较好地拟合出刺槐生长过程中的关键时间节点。该方法实现了对植被生长状况主要时间节点的自动提取,弥补了遥感监测和人工物候观测的不足,为生态系统植被生长变化研究补充了新的数据来源。

关键词：数字相机植被变化颜色指数刺槐

在线全文

学校读者我要写书评

暂无评论

转轴径向运动误差干涉测量的信号处理方法

红外与激光工程 2022年第12期51卷 185-191页

作者：丁要文李家琨马栋张海峰冯其波北京交通大学发光与光信息教育部重点实验实北京100044

转轴径向运动误差是转轴的重要误差项之一,严重影响数控机床等转轴相关设备的精度和性能。利用激光干涉配合伺服转轴可以实现转轴径向运动误差的测量,但由于待测转轴和伺服转轴的自身转速不匀、伺服响应延迟、跟踪不稳等原因,干涉测量... 详细信息

转轴径向运动误差是转轴的重要误差项之一,严重影响数控机床等转轴相关设备的精度和性能。利用激光干涉配合伺服转轴可以实现转轴径向运动误差的测量,但由于待测转轴和伺服转轴的自身转速不匀、伺服响应延迟、跟踪不稳等原因,干涉测量信号存在持续微幅相位抖动,进而造成非线性误差难以有效修正,相位解算精度不高,测量误差大。针对这一问题,提出一种零值截取-阈值判定的干涉信号处理方法,成功消除了相位抖动的影响。设计并搭建了一套转轴径向运动误差的激光干涉测量装置,针对实测信号的处理结果表明,相比于传统修正方法,文中提出的修正方法使得转轴径向运动误差干涉测量信号解算的重复性由4.8μm减小到0.2μm,与标准仪器的对比误差由3.5μm降为2μm。

关键词：转轴径向运动误差相位抖动非线性修正