检索结果-南通市图书馆

胺源对“一锅法”合成聚硼硅氮烷结构及性能的影响

在线全文

学校读者我要写书评

暂无评论

高分子学报 2024年第2期55卷 161-171页

作者：陈楚童陈艳杰罗永明张宗波徐彩虹中国科学院化学研究所中国科学院极端环境高分子材料重点实验室北京100190 中国科学院大学化学与化工学院北京100049

以六甲基二硅氮烷(MMN)、四甲基二乙烯基二硅氮烷(MMNVi)和四甲基二硅氮烷(MMNH) 3种不同结构的二硅氮烷为胺源,通过与氯硅烷和三氯化硼反应,制备出具有不同封端结构的聚硼硅氮烷.其中,以MMN、MMNVi为胺源可获得液态产物;以MMNH为胺源时... 详细信息

以六甲基二硅氮烷(MMN)、四甲基二乙烯基二硅氮烷(MMNVi)和四甲基二硅氮烷(MMNH) 3种不同结构的二硅氮烷为胺源,通过与氯硅烷和三氯化硼反应,制备出具有不同封端结构的聚硼硅氮烷.其中,以MMN、MMNVi为胺源可获得液态产物;以MMNH为胺源时,因合成过程中发生活性基团间的过度交联导致产物凝胶.采用核磁共振波谱仪、红外光谱仪对液态前驱体聚合物及其热解产物的结构进行了表征.研究结果表明:通过“一锅法”制备的液态聚硼硅氮烷主链具有较多的支化和环状结构,随着封端结构中乙烯基含量的增加,所得前驱体的固化温度降低,固化反应活化能降低.与以MMN为胺源和封端剂合成的聚硼硅氮烷相比,以MMNVi为胺源所得前驱体固化前后陶瓷产率分别提高了14.9%及8.1%.并且,通过改变胺源的种类和比例可以调节热解产物的元素组成,合成的液态前驱体聚合物热解所得SiBCN陶瓷结晶温度高于1700℃.

关键词：前驱体转化法硅硼碳氮陶瓷聚硼硅氮烷 “一锅法”

A Novel Phenylpropanoid-substituted Catechin Glycoside and a New Dihydrochalcone from Sarcandra glabra

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第2期17卷 207-210页

作者： Yuan LI Dong ming ZHANG Shi Shah YU Jian Bei LI yong ming luo Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine Ministry of Education Institute of Materia Medica Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100050 Faculty of Pharmacy Jiangxi University of Traditional Chinese Medicine Nanchang 330006

A novel phenylpropanoid-substituted catechin glycoside glabraoside A 1 and a new dihydrochalcone 3＇-（7＂-allylphenyl）-2＇,4＇,4＂-trihydroxy-6＇-methoxydihydrochalcone 2 were isolated from the herbs of Sarcandra gl... 详细信息

关键词： Sarcandra glabra glabraoside A phenylpropanoid-substituted flavan-3-ols dihydrochalcone.

Two New Isosteroid Alkaloids from Fritillaria monatha Migo（Ⅲ）

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第5期17卷 631-634页

作者： Hong Ning LIU Fei LI yong ming luo Wei Feng ZHU Jiangxi University of Traditional Chinese Medicine Nanchang 330004

Two new isosteroid alkaloids, named pengbeimine A and pengbeimine C, were isolated from the fresh bulbs of FritiUaria monatha Migo. Their structures were determined by spectral methods, and were proved by X-ray diffra... 详细信息

关键词： Fritillaria monatha Migo isosteroid alkaloids pengbeimine A pengbeimine C.

Steroidal alkaloids from the bulbs of Fritillaria monatha

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2008年第5期19卷 544-546页

作者： Hong Ning Liu Fei Li yong ming luo Wei Feng Zhu Jiangxi University of Traditional Chinese Medicine Nanchang 330004 China

Two new Steroidal alkaloids, named pengbeisine A and pengbeisine B, were isolated from the fresh bulbs of Fritillaria monatha Migo. along with a known alkaloid. The structures were characterized as 22,26-imino-17, 23-oxido-5α-jerv-6-oxo-2α,3β-diol and 22, 26-imino-17, 23-oxido-5α-jerv-6-oxo-2β,3α-diol on the basis of spectroscopic methods.

关键词： Fritillaria monatha Migo Steroidal alkaloids Pengbeisine A Pengbeisine B

Effects of copper, lead and zinc in soil on egg development and hatching of Folsomia candida

在线全文

学校读者我要写书评

暂无评论

Insect Science 2009年第1期16卷 51-55页

作者： Jie Xu Yin Wang yong-ming luo Jing Song Xin Ke Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghal Soil and Environment Bioremediation Research Centre Institute of Soil Sciences Chinese Academy of Sciences Nanjing China

Effects of CaCl2, CuCl2, ZnCl2 and PbCl2 on development and hatching success of eggs of Folsomia candida （Collembola） were studied under laboratory conditions. Thousands of healthy eggs from synchronized cultures were incubated in soils treated with different concentrations of the metals. Compared with the water control, egg hatch significantly decreased when concentrations of Cu, Pb and Zn reached 400, 1 600 and 800 mg/kg dry soil, respectively. Values of EC50（hatching）, calculated according to the exponential model （with 95% confidence limits in brackets）, were 625 （407-875）, 2 361 （2 064-2 687） and 1 763 （1 548-2 000） mg/kg dry soils for Cu, Pb and Zn, respectively. When Cu concentration reached 1 600 mg/kg dry soil, eggs became green and the percentage of green eggs changed from 5%-20% after incubation for 2 days to 15%- 30% after incubation for 4 days. At 3 200 mg Cu/kg dry soil, tissues inside eggs were black and shrunken.

关键词： metal pollution soil springtail hatching success metamorphosis toxicity test,ultrathin sectioning

Realization of artificial skyrmion in CoCrPt/NiFe bilayers

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

Chinese Physics B 2018年第12期27卷 471-476页

作者： Yi Liu yong-ming luo Zheng-Hong Qian Jian-Guo Zhu College of Materials Science and Engineering Sichuan UniversityChengdu 610064China Center for Integrated Spintronic Device Hangzhou Dianzi UniversityHangzhou 310018China

Skyrmion, as a quasi-particle structure, has attracted much attention due to its potential applications in future spintronic devices. Artificial skyrmion structure has aroused great interest as it can be stabilized at room temperature, without needing to incorporate materials with Dzyaloshinskii–Moriya interaction(DMI) into it. In this paper, it is found that the artificial skyrmion structure can be realized in CoCrPt/NiFe bilayers by micromagnetic simulations. The critical magnetic field of the core decreases as the diameter of the NiFe soft magnetic layer increases. The artificial skyrmion has excellent topological protection, and the critical magnetic field of plane is about 76 mT(760 Oe, 1 Oe = 79.5775 A·m-1). The external magnetic field plays a key role in determining the core diameter of the skyrmion, and the artificial skyrmion can be realized in CoCrPt/Cu/CoCrPt/NiFe four-layer with a diameter of 13 nm.

关键词： bilayers artificial skyrmion micromagnetic simulations

Evaluation of growth and reproduction as indicators of soil metal toxicity to the Collembolan, Sinella curviseta

在线全文

学校读者我要写书评

暂无评论

Insect Science 2009年第1期16卷 57-63页

作者： Jie Xu Xin Ke Paul Henning Krogh Yin Wang yong-ming luo Jing Song Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China Department of Terrestrial Ecology National Environmental Research Institute University of Aarhus Vejlsevej 25 DK-8600 Silkeborg Denmark Soil and Environment Bioremediation Research Centre Institute of Soil Sciences Chinese Academy of Sciences Nanjing China

Laboratory studies evaluated the sensitivity of Sinella curviseta Brook （Collembola： Entomobryidae） to selected heavy metals （Cu, Pb and Zn）. Survival, reproduction and growth of S. curviseta were determined in a 4-week exposure test in an agricultural soil amended with metals to concentrations of 100, 200, 400, 800, 1 600 and 3 200 mg/kg. Results showed reduction in adult survival and reproductive failure at the highest concentrations （3 200 mg/kg） of Cu and Zn. EC50reproduction values for Cu and Zn were approximately 442 and 2 760 mg/kg, respectively. Application of Pb at all levels resulted in large numbers of progeny and no significant mortality compared to controls. Adult growth rate decreased for all metal treatments compared to the controls, suggesting that metals affect S. curviseta metabolism and result in slower growth. We showed that reproduction is a slightly more sensitive parameter than growth. Since a growth test needs fewer juveniles and takes less time than a reproduction test, we conclude that the two parameters are complementary and could be used for a better ecotoxicological evaluation of contaminant levels. However, relative growth and reproduction sensitivities should be tested with more chemicals before a growth test is accepted as a faster sublethal test than a reproduction test.

关键词： Collembolan copper growth lead reproduction Sinella curviseta soil pollution toxicity testing zinc

A New Route for Preparation of β-TCP/ PLLA Composite

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

Chinese Chemical Letters 2006年第6期17卷 833-836页

作者： Feng ZHANG Fang MEI Xin Zhi WANG Xiao Yang HU yong ming luo Xu Liang DENG School and Hospital of Stomatology Peking University Beijing 100081 Department of Histology and Embryology Health Science Center Peking University Beijing 100083 Department of Environmental Science and Engineering Kunming University of Science and Technology Kunming 650093 The 2nd Hospital of Beijing Armed Police Forces Beijing 100037

A new facile route for preparation of β-TCP/PLLA composites is reported in this letter. SEM images display that β-TCP particles with average diameter of 400 nm were well bonded and distributed within the pore walls of the PLLA scaffolds. The mixture of the novel complex and human dental pulp cells was transplanted subcutaneously into the dorsal surface of a nude mouse. Two months later histological examination showed that new collagen and new dentin formed. The results revealed that the new nano β-TCP/PLLA composite combined with human pulp cells could induce dentin formation offering a new way to dental tissue engineering.

关键词： β-TCP particles β-TCP/PLLA composite dental pulp cells dental tissue engineering.

Structural engineering of hard carbon through spark plasma sintering for enhanced sodium-ion storage

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第9期43卷 4274-4285页

作者： Hao-ming Xiao Heng Zheng Ping Yuan Jun-Hui luo Lin-Lin Shen Jie-Feng Tan Xian-You luo De Li yong Chen Guangdong Key Laboratory for Hydrogen Energy Technologies School of Materials Science and Hydrogen EnergyFoshan University State Key Laboratory of Marine Resource Utilization in South China Sea Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti ResourcesHainan University

Hard carbon （HC） has emerged as one of the superior anode materials for sodium-ion batteries （SIBs）,with its electrochemical performance significantly influenced by the presence of oxygen functional groups and its closed pore ***,current research on the structural adjustment of these oxygen functional groups and the closed pore architecture within HC remains ***,energy-efficient and contamination-free spark plasma sintering technology was employed to tune the structure of coconut-shell HC,resulting in significant adjustments to the content of carboxyl （decreasing from 5.71 at%to 2.12 at%） and hydroxyl groups （decreasing from 7.73 at % to 6.26 at%）.Crucially,these modifications reduced the irreversible reaction of oxygen functional groups with Na+.Simultaneously,a substantial number of closed pores with an average diameter of 1.22 nm were generated within the HC,offering an ideal environment for efficient Na+*** structural changes resulted in a remarkable improvement in the electrochemical performance of the modified *** reversible specific capacity of the modified HC surged from 73.89 mAh·g-1to an impressive 251.97 m Ah·g-1at a current density of 50 mA·*** at 400 mA·g-1,the reversible specific capacity increased significantly from 14.55 to 85.44 mAh·***,this study provides a novel perspective for designing tailored HC materials with the potential to develop high-performance SIBs.

关键词： Closed pores Hard carbon Oxygen functional groups Sodium-ion batteries Spark plasma sintering