检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

环戊二烯基有机金属化合物的摩擦化学特性

固体润滑 1991年第4期11卷 257-266页

作者： A.Kadmiri J.Amaudrut M.Camelot C.Roques-Carmes F.Louis T.mathia 周春红 ecole nationale superieure de Mecanique et des Microtechniques(enSMM 25030 Besancon Cedex France ecole Centrale 69131 Ecully CedexFrance

本文首先阐述了一些过渡金属配合物的摩擦学特性。根据配位化学的概念和有关配合物与金属表面间发生摩擦化学反应的假说,将所测试的有机金属配合物分成了3类。从摩擦学的要求来看,一些铌的硫代共价配合物显示了良好的摩擦学特性,可以与... 详细信息

本文首先阐述了一些过渡金属配合物的摩擦学特性。根据配位化学的概念和有关配合物与金属表面间发生摩擦化学反应的假说,将所测试的有机金属配合物分成了3类。从摩擦学的要求来看,一些铌的硫代共价配合物显示了良好的摩擦学特性,可以与二硫化钼及石墨之类的固体润滑剂相比。然后,利用红外吸收光谱和核磁共振波谱分别直接地和间接地分析了这些铌的硫代化合物的摩擦化学反应。红外光谱提供了所谓第三体(即润滑剂降解残留物)和转移膜分子结构的数据,核磁共振波谱给出了摩擦前原始分子的电离特性。转移膜的非腐蚀接枝与双核表面配合物的形成有关。依照Lewis酸碱规则,润滑剂的碱度是一个决定性的因素。

关键词：过渡金属配合物环戊二烯摩擦化学配位化学

Egg CD9 protein tides correlated with sperm oscillations tune the gamete fusion ability in mammal

在线全文

学校读者我要写书评

暂无评论

Journal of Molecular Cell Biology 2018年第6期10卷 494-502页

作者： Benjamin Ravaux Sophie Favier Eric Perez and Christine Gourier Laboratoire de Physique Statistique Ecole Normale Superieure/PSL Research UniversityUPMC Univ Paris 06Universite Paris DiderotCNRS75005 ParisFrance

Mammalian fertilization involves membrane events-adhesion,fusion,sperm engulfment,membrane block to polyspermy-whose causes remain largely ***,specific oscillations of the sperm in contact with the egg were shown to be necessary for *** a microfluidic chip to impose the venue for the encounter of two gametes allowed real-time observation of the membrane remodelling occurring at the sperm/egg *** spatiotemporal mapping of egg CD9 revealed that this protein concentrates at the egg/sperm interface as a result of sperm oscillations,until a CDg-rich platform is nucleated on which fusion immediately takes *** 2-5 min after fusion,most of the CD9 leaves the egg for the external aqueous *** an egg membrane wave engulfs the sperm head in^25 *** results show that sperm oscillations initiate the CD9 recruitment that causes gamete fusion after which CD9 and associated proteins leave the membrane in a process likely to contribute to block *** highlight that the gamete fusion story in mammals is an unexpected interplay between mechanical constraints and proteins.

关键词： mammalian fertilization membrane dynamics real-time imaging CDg sperm oscillations gamete fusion

Removal of Real Textile Dyes by Electrocoagulation/Electroflotation in a Pilot External-Loop Airlift Reactor

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2013年第10期5卷 1000-1006页

作者： H.Chenik M.Elhafdi A.Dassaa A.H.Essadki M.Azzi ecole superieure de Technologie Laboratoire de Genie des Procedes et EnvironnementCasablancaMorocco Faculte des Sciences Ain Chock Laboratoire Interface Materiau EnvironnementCasablancaMorocco

This paper studied the efficiency of electrocoagulation/electroflotation in removing colour from real textile wastewater by using aluminum and iron electrodes in an innovative pilot external-loop airlift reactor of 150 L. The reactor was designed to operate in batch and continuous modes. The real effluent contained 90% of disperse dye and 10% of reactive dye. A complete flotation of pollutants with acceptable mixing was achieved in this reactor using only the overall liquid recirculation induced by H2 microbubbles. The treatment of these discharges was easier using electrodes of iron rather than aluminum. The optimal initial pH was 10 for both aluminum and iron electrodes. By using iron electrodes, the maximum decolourisation efficiency and COD reduction efficiency reached respectively 96% and 65% for 90 minutes of treatment. Similarly, by using aluminum electrodes, the maximum decolourisation efficiency reached 90%, COD reduction reached 51% for 120 minutes of treatment. In the case of an initial pH slightly different to 10, the required time to reach 90% ranged from double to triple.

关键词： Pilot External Airlift Reactor Electrocoagulation Electroflotation Real Textile Dye

Recharge Estimation of Hard Rock Aquifers under Sahelian Climate Conditions Using Water Table Fluctuation:Case Study of Tougou Catchment,Burkina Faso

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2017年第12期9卷 1428-1448页

作者： Mahamadou Koita Wennegouda Jean Pierre Sandwidi Amagana Emmanuel Dara Institut International d’Ingenierie de l’Eau et de l’environnement OuagadougouBurkina Faso ecole nationale superieure d’Ingenieurs de Fada/Universite Ouaga I Professeur Joseph Ki Zerbo OuagadougouBurkina Faso

This study aims to characterize water table fluctuations and estimate groundwater recharge in the Tougou catchment located in the Sahel zone of Burkina Faso. Water table fluctuation and groundwater budget approaches are developed on an experimental site equipped with observation wells. The trends of water fluctuations in the different layers of the weathering profile are similar. There is a time-lag response of groundwater recharge to the daily precipitation occurrences. The interaction between the upper (clayey alteration) and lower (transition zone-fractured schist complex) parts of the weathering profile shows that generally the hydraulic head in the upper part is higher than that of the lower part due to difference in drainage porosity. The latter varies at the catchment scale between 0.006 and 0.009 and is inversely proportional to the saturated thickness of the clayey alteration layer. The groundwater recharge is annually estimated between 36 and 49 mm, which correspond to 6% and 9% of mean annual rainfall in the catchment. Annual evapotranspiration was estimated to be about 223 to 443 mm.

关键词： Recharge Aquifer Specific Yield Water Table Fluctuation WTF Groundwater Budget Sahel Tougou Burkina Faso

Epileptic seizure prediction based on EEG spikes detection of ictal-preictal states

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Journal of Biomedical Research 2020年第3期34卷 162-169页

作者： Itaf Ben Slimen Larbi Boubchir Hassene Seddik Centre de Recherche et de Production Research Lab. Ecole Nationale Superieure des Ingenieurs de TunisUniversity of TunisTunis 1008Tunisia Laboratoire d'Informatique Avancee de Saint-Denis Research Lab. University of Paris 8Saint-DenisCedex 93526France

Epileptic seizures are known for their unpredictable ***,recent research provides that the transition to seizure event is not random but the result of evidence ***,a reliable method capable to detect these indications can predict seizures and improve the life quality of epileptic *** periods are generally characterized by epileptiform discharges with different changes including spike rate variation according to the shapes,spikes,and the *** this study,spike rate is used as the indicator to anticipate seizures in electroencephalogram(EEG) *** detection step is used in EEG signal during interictal,preictal,and ictal periods followed by a mean filter to smooth the spike *** maximum spike rate in interictal periods is used as an indicator to predict *** the spike number in the preictal period exceeds the threshold,an alarm is *** the CHB-MIT database,the proposed approach has ensured92% accuracy in seizure prediction for all patients.

关键词： electroencephalogram epilepsy seizure prediction spikes detection

Multivariate Statistical Analysis of Saline Water——A Case Study:Sabkha Oum Le Khialate(Tunisia)

在线全文

学校读者我要写书评

暂无评论

Multivariate Statistical Analysis of Saline Water——A Case ...

作者： Nasri Nesrine Bouhlila Rachida Riadh Ahmed ecole nationale d’Ingénieurs de Tunis Laboratoire de Modélisation en Hydraulique et EnvironnementUniversité de Tunis ElManar Sté Chimique ALKIMIA

The hydrochemistry of the saline system in high arid environment is controlled by several processes including evaporation, water-rock interaction, precipitation/dissolution etc. Hydrochemical data of 80 wells from the catchment area of sabkha Oum le Khialate, southern Tunisia and 9 parameters(pH, TDS, Na, Ca, SO, Mg, K, Cl, HCO) show that the abundance of major ions from the sabkha is as follows: Na>Ca>Mg>K and SO>Cl>HCO3. Multivariate statistical analysis methods such us correlation analysis, principal component analysis(PCA) and hierarchical cluster analysis(HCA) were used to identify the geochemical processes controlling the chemistry of saline water in the catchment area of the sabkha. HCA reveals four major water groups(C1-C4). Samples of the sabkha from clusters C1, C2 to C3 have Na-SO-Cl, Na-SO and Na-ClSO water type respectively. Samples from C4 show Ca-HCOSO-Cl water type are located in recharge area. Using PCA, two factors account for 72.69 % of the total variance of the data set. Results of statistical analysis reveal that the major source of sulfate sodium deposit is the process of evaporation, cationic exchange between Ca and Na in clay formation and mineral precipitation.

关键词： Hydrochemistry saline system statistical analysis evaporation

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

幅度-频率域统计多分辨率分析

中国科学（E辑） 2004年第6期34卷 646-653页

作者：孙洪管鲍 H.Maitre 武汉大学电子信息学院 Departement TSI Ecole Nationale Superieure des TelecommunicationsParis 75013France

提出幅度.频率域统计多分辨率分析的概念,即在幅度域上对信号的统计特征作小波变换.根据广义的各态历经定理,给出幅频统计多分辨率分析的估计算法.描述了该分析方法用于合成孔径雷达图像处理的原理,应用结果表明,幅频统计多分辨率分析... 详细信息

提出幅度.频率域统计多分辨率分析的概念,即在幅度域上对信号的统计特征作小波变换.根据广义的各态历经定理,给出幅频统计多分辨率分析的估计算法.描述了该分析方法用于合成孔径雷达图像处理的原理,应用结果表明,幅频统计多分辨率分析为处理具有乘性模型的斑点噪声信号提供了一个有效的新途径.

关键词：统计信号分析多分辨率分析合成孔径雷达信号处理离散幅度小波变换

Firm Size, Innovation and Vertical Integration Incentives： The Case of Food Supply Chain

在线全文

学校读者我要写书评

暂无评论

Chinese Business Review 2016年第2期15卷 94-102页

作者： Amina Omrane Mohamed Amine Benmehaia Faculte des Sciences Economiques et de Gestion de Sfax (FSEGS) Sfax Tunisia ecole nationale superieure d'Agronomie Alger Algeria

This study aims to investigate and explore the relationship between vertical integration and the firm＇s innovativeness in food supply chain. For doing so, a two-stage least-squares model was used. It encompassed instrumental variables that attempt to describe the effective determinants of firm＇s vertical integration willingness. Results based on data concerning a set of 130 food-manufacturing firms, highlighted that vertical integration of a firm is strongly affected by internal incentives such as innovation rate and firm size. Moreover, it is simultaneously influenced by the economies of scale and some structure incentives. To conclude, results indicate globally that important and statistically significant differences exist across the studied firms and the small effective ones which acquire a high level of vertical integration.

关键词： vertical integration firm size performance innovation food supply chain

EEG epileptic seizure detection and classification based on dual-tree complex wavelet transform and machine learning algorithms

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

The Journal of Biomedical Research 2020年第3期34卷 151-161页

作者： Itaf Ben Slimen Larbi Boubchir Zouhair Mbarki Hassene Seddik Centre de Recherche et de Production Research Lab. Ecole Nationale Superieure des Ingenieurs de TunisUniversity of TunisTunis 1008Tunisia Laboratoire d^nfbrmatique Avancee de Saint-Denis Research Lab. University of Paris 8Saint-DenisCedex 93526France

The visual analysis of common neurological disorders such as epileptic seizures in electroencephalography(EEG) is an oversensitive operation and prone to errors,which has motivated the researchers to develop effective automated seizure detection *** paper proposes a robust automatic seizure detection method that can establish a veritable diagnosis of these *** proposed method consists of three steps:(i) remove artifact from EEG data using Savitzky-Golay filter and multi-scale principal component analysis(MSPCA),(ii) extract features from EEG signals using signal decomposition representations based on empirical mode decomposition(EMD),discrete wavelet transform(DWT),and dual-tree complex wavelet transform(DTCWT) allowing to overcome the non-linearity and non-stationary of EEG signals,and(iii) allocate the feature vector to the relevant class(i.e.,seizure class "ictal" or free seizure class "interictal") using machine learning techniques such as support vector machine(SVM),k-nearest neighbor(k-NN),and linear discriminant analysis(LDA).The experimental results were based on two EEG datasets generated from the CHB-MIT database with and without overlapping *** results obtained have shown the effectiveness of the proposed method that allows achieving a higher classification accuracy rate up to 100% and also outperforms similar state-of-the-art methods.

关键词： electroencephalography epileptic seizure detection feature extraction dual-tree complex wavelet transform machine learning