检索结果-南通市图书馆

Studies on sulfinatodehalogenation——ⅩⅪ.A new and convenient syntheses of 2-(F-alkyl)aldehydes,alcohols,acids and ketones

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 1991年第2期9卷 174-180页

作者： HUANG wei-yuan Shanghai Institute of Organic Chemistry The Chinese Academy of SciencesShanghai 200032

Reaction of perfluoroalkyl iodides(1a—e)with the unsaturated ethers such as 1-ethoxy-1- propene(2),1-methoxy-1-butene(3)under the sulfinatodehalogenation condition gave the correspon- ding 2-(F-alkyl)propanals(5a—e)and butanals(6c,d)very readily in high yield,which were converted to 2,4-dinitrophenylhydrazones(7a—e,8c,d)and *** reaction products 5 and 6 were oxidized with Jone's reagent and reduced with NaBH_4 in ethanol to give the corresponding acids (9,10)and alcohols(11,12)in good *** of compounds 5 and 6 with pyridine gave the dehydrofluorination products 13 and *** the same condition,perfluoroalkyl iodide reacted with 2-ethoxy-1-propene(4)only to form R_FSO_2Na and R_FH as the major products,but in aqueu- ous DMF(DMF:H_2O=5:1)to give the perfluoroalkylacetone(15)in good ***,the reac- tion provides a convenient,effective new method for syntheses of these useful organofluorine inter- mediates.

关键词： F-alkyl)aldehydes,alcohols,acids and ketones A new and convenient syntheses of 2

A new synthetic approach to phosphatidylethanolamine

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2012年第2期23卷 154-156页

作者： Yang Song wei yuan Yu Luo wei Lu Department of Chemistry East China Normal UniversityShanghai 200062China Institute of Drug Discovery and Development East China Normal UniversityShanghai 200062China

A new synthetic method for phosphatidylethanolamine head group was developed via ring-opening of cyclic dioxaphospholane 2 with sodium azide and subsequent *** advantage of this strategy included short reaction steps,... 详细信息

关键词： Phosphatidylethanolamine Synthesis

A Luminescent Dicyanodistyrylbenzene-based Liquid Crystal Polymer Network for Photochemically Patterned Photonic Composite Film

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2018年第6期36卷 776-782页

作者： Zhe-wei Zhang Jun-Tao Li Wan-yuan wei Jie wei Jin-Bao Guo Key Laboratory of Carbon Fibers and Functional Polymers Ministry of EducationBeijing Engineering Research Center for the Synthesis and Applications of Waterborne Polymers and College of Materials Science and EngineeringBeijing University of Chemical Technology

A novel photonic composite film based on a luminescent dicyanodistyrylbenzene-based liquid crystal polymer network（LCN） was fabricated by using a silica colloidal crystal as a template. The upper part of inverse opal structure and the luminescence characteristics of dicyanodistyrylbenzene-based moiety endowed the resulting bilayer photonic film with structural color arising from coherent Bragg reflection and fluorescence properties, respectively. A fluorescence enhancement phenomenon was observed in the photonic film due to the overlap between the reflection band and emission band of the fluorescent LCN. More importantly, the photo-induced irreversible Z/E photoisomerization of dicyanodistyrylbenzene-based moiety in the photonic film led to both a reflection spectral shift and an observable fluorescence variation. On the basis of this effective phototuning process, microscopic patterning of photonic film was developed under both fluorescence mode and reflection mode. The work demonstrated here provides a new route to construct photo-responsive photonic film.

关键词： Luminescent liquid crystal Polymer networks Photonic composite Photopatterning

Buckling response of offshore pipelines under combined tension, bending, and external pressure

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第8期12卷 627-636页

作者： Shun-feng GONG Lin yuan wei-liang JIN Institute of Structural Engineering Zhejiang University Hangzhou 310058 China

The buckle and collapse of offshore pipeline subjected to combined actions of tension, bending, and external pressure during deepwater installation has drawn a great deal of attention. Extended from the model initially proposed by Kyriakides and his co-workers, a 2D theoretical model which can successfully account for the case of simultaneous tension, bending, and external pressure is further developed. To confirm the accuracy of this theoretical method, numerical simulations are conducted using a 3D finite element model within the framework of ABAQUS. Excellent agreement between the results validates the effectiveness of this theoretical method. The model is then used to study the effects of several important factors such as load path, material prop-erties, and diameter-to-thickness ratio, etc., on buckling behaviors of the pipes. Based upon parametric studies, a few significant conclusions are drawn, which aims to provide the design guidelines for deepwater pipeline with solid theoretical basis.

关键词： Deepwater Offshore pipeline Buckle External pressure

Nonlinear Static and Dynamic Stiffness Characteristics of Support Hydraulic System of TBM

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2019年第6期32卷 26-34页

作者： Jianfeng Tao Junbo Lei Chengliang Liu wei yuan School of mechanical engineering Shanghai Jiaotong UniversityShanghai 200240China School of Electronic Information Jiangsu University of Science and TechnologyZhenjiang 212003China

Full-face hard rock tunnel boring machines(TBM)are essential equipment in highway and railway tunnel engineering *** the tunneling process,TBM have serious vibrations,which can damage some of its key *** support system,an important part of TBM,is one path through which vibrational energy from the cutter head is *** reduce the vibration of support systems of TBM during the excavation process,based on the structural features of the support hydraulic system,a nonlinear dynamical model of support hydraulic systems of TBM is *** influences of the component structure parameters and operating conditions parameters on the stiffness characteristics of the support hydraulic system are *** analysis results indicate that the static stiffness of the support hydraulic system consists of an increase stage,stable stage and decrease *** static stiffness value increases with an increase in the *** pre-compression length of the spring in the relief valve a ects the range of the stable stage of the static stiffness,and it does not a ect the static stiffness *** dynamic stiffness of the support hydraulic system consists of a U-shape and reverse *** bottom value of the U-shape increases with the amplitude and frequency of the external force acting on the cylinder body,however,the top value of the reverse U-shape remains *** study instructs how to design the support hydraulic system of TBM.

关键词： Tunnel boring machine Support hydraulic system Nonlinear model Static stiffness characteristics Dynamic stiffness characteristics

A pilot scale anoxic/oxic membrane bioreactor(A/O MBR) for woolen mill dyeing wastewater treatment

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2003年第4期15卷 449-455页

作者： ZHENG Xiang FAN Yao bo wei yuan song Department of Water Pollution Control Technology Research Center for Eco Environmental SciencesChinese Academy of SciencesBeijing 100085China.

A pilot scale(10 m 3/d) anoxic/oxic membrane bioreactor(A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was excellent, i.e. effluent COD less than 25 mg/L, BOD 5 under 5 mg/L, turbidity lower than 0 65 NTU, and colour less than 30 DT, and met with the reuse water standard of China. The removal rates of COD, BOD 5, colour, and turbidity were 92 4%, 98 4%, 74% and 98 9%, respectively. Constant flux operation mode was carried out in this study, and backwash was effective for reducing membrane fouling and maintaining constant flux. Membrane fouling had heavy impact on energy consumption. More attention should be paid on pipe selection and design for the sidestream MBR system, too.

关键词： activated sludge backwash constant flux dyeing wastewater treatment membrane bioreactor (MBR) woolen mill

Two-dimensional Conductive Metal-Organic Framework Nanowire Arrays for Highly Performed Soft Electrochemical Actuators

在线全文

学校读者我要写书评

暂无评论

材料导报 2021年第9期35卷 9001-9002页

作者： ZHAO Ruoqing WU Hao wei yuan WANG Xuewen Frontiers Science Center for Flexible Electronics(FSCFE)&Shaanxi Institute of Flexible Electronics(SIFE) Northwestern Polytechnical UniversityXi’an 710072China

Fig.1(a)Schematic illustration of the fabrication of a Ni-CAT NWAs/CNF hybrid membrane by the in situ hydrothermal growth of Ni-CAT NWAs on CNF;SEM images of(b)the pristine CNF nanomembrane and(c)Ni-CAT NWAs/CNF,and(d)size distribution statistics of the diameter of Ni-CAT NWAs/CNF;schematic illustrations of(e)the fabrication procedure for the Ni-CAT NWAs/CNF-based actuator,(f)Ni-CAT NWAs/CNF electrode surfaces and Ni-CAT along the c-axis(Color codes:O,red spheres;C,gray spheres;and Ni,blue spheres);(g)actuation performance of the Ni-CAT NWAs/CNF based actuator The demand for high-performance low-voltage driven electromechanical actuators is growing because of their potential applications,such as in soft robotics,artificial muscles,biomimetic flying insects,and micro/nano-electromechanical systems[1].Among these actuators,ionic-polymer metal composite actuators(IPMCs)are promising as they are capable of large actuation deformation under low operation voltages(only a few volts),and they operate best in a humid environment[2].However,although extensive efforts have been made in past decades,developing high-capacitance electrode materials that improve the performance of IPMCs is challenging.

关键词： composite illustration spheres

Spatiotemporal expression of leukemia inhibitory factor receptor protein during neural tube development in embryos with neural tube defects

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2020年第4期15卷 705-711页

作者： Dong An Xiao-wei wei He-Nan Zhang Dan Liu wei Ma Zheng-wei yuan Key Laboratory of Health Ministry for Congenital Malformation Shengjing HospitalChina Medical UniversityShenyangLiaoning ProvinceChina Department of Pediatrics The First Hospital of China Medical UniversityShenyangLiaoning ProvinceChina

Leukemia inhibitory factor receptor(LIFR),as a neuroregulatory cytokine receptor,generally shows a neuroprotective effect in central nervous system *** this study,to understand the effect of LIFR on pathogenesis of neural tube defects,we explored spatiotemporal expression of LIFR at different stages of fetal development in normal and neural tube defect *** bifida aperta was induced with all-trans retinoic acid on embryonic day 10 in rats,and the spatiotemporal expression of LIFR was investigated in spina bifida aperta rats and healthy rats from embryonic day 11 to *** time-polymerase chain reaction and western blot assay were used to examine mRNA and protein expression of LIFR in healthy control and neural tube defect *** of the animal experiment demonstrated that expression of LIFR protein and mRNA in the spinal cords of normal rat embryos increased with embryonic *** was significantly downregulated in the spinal cords of spina bifida aperta rats compared with healthy rats from embryonic days 11 to *** staining showed that the expression of LIFR in placenta and spinal cord in spina bifida aperta rat embryos was decreased compared with that in control embryos at embryonic day *** from human embryo specimens showed that LIFR mRNA expression was significantly down-regulated in spinal cords of human fetuses with neural tube defects compared with normal controls at a gestational age of 24 to 33 *** results were consistent with the down-regulation of LIFR in the animal *** study revealed spatiotemporal changes in expression of LIFR during embryonic ***,LIFR might play a specific role in neural tube *** animal and human experimental procedures were approved by the Medical Ethics Committee of Shengjing Hospital of China Medical University,China(approval No.2016PS106K)on February 25,2016.

关键词： amniotic fluid development embryogenesis leukemia inhibitory factor receptor nerve regeneration neural tube defect placenta spatiotemporal expression spina bifida aperta spinal cord serum

KMnO4-mediated direct selective radical cross-coupling：An effective strategy for C2 arylation of quinoline N-oxide with arylboronic acids

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2017年第5期28卷 981-985页

作者： Jin-wei yuan Ling-Bo Qu School of Chemistry & Chemical Engineering Henan University of TechnologyAcademician Workstation for Natural Medicinal Chemistry of Henan Province

Direct C—H functionalization of quinoline N-oxides with arylboronic acids is achieved using KMnOas the sole and efficient oxidative *** method provides an efficient protocol to construct regioselectively 2-arylquinol... 详细信息

关键词： Quinoline N-oxide Arylboronic acid KMnO_4-mediated Radical reaction Arylation