检索结果-南通市图书馆

Synthetic Control Method for Crystallite Size of MOF-5

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2014年第3期30卷 356-361页

作者： HAN Pengfei YUAN Changfu XU junyi liu Jin School of Metallurgy and Environment Central South University Changsha 410083 t~ R. China

We reported a dripping solvothermal method for synthesizing metal-organic framework-5（MOF-5）. It started from separately dissolving Zn（NO3）2 and terephthalic acid（H2BDC） in dimethyl formamide（DMF）, and then dripping one solution into the other. Results of SEM, XRD and laser particle size distribution show that regular cubic-shaped and micro-crystallite powder of MOF-5 can be obtained. The d0.5（volume-median-diameter） values are 4.32 μm for particles prepared by dripping Zn（NO3）2 into H2BDC（ZH） and 9.32 μm for those prepared by dripping H2BDC into Zn（NO3）2（HZ）, much smaller than 22,7 μm that of particles prepared by the traditional adding water solvothermal method（L）. The standard deviations of the particle size distributions fitted by the GaussAmp model are 2.49, 4.38 and 15.4 respectively for ZH, HZ and L, further revealing narrower size distributions of particles prepared by the dripping method. In addition, the Langmuir specific surface areas are 923 m^2/g for ZH and 868 m^2/g for HZ. The TGA results present mass losses of 4.18% and 3.62% at 105 ℃, 17.19% and 14.78% at 245 ℃, 39.04% and 34.85% at 600℃ separately for ZH and HZ, which correspond to the removal of H20, DMF and the decomposition of MOF-5. This indicates that MOF-5 has a strong adsorption ability for small molecules. Besides, the mass loss of 48.39%（ZH） and 41.02%（HZ）between 400 ℃ and 600 ℃ are less than the theoretical value of 57.81% for MOF-5 decomposition to ZnO, suggesting that an impure phase with an extra amount of ZnO may exist in the cavities of MOF-5.

关键词： Metal-organic framework-5(MOF-5) Dripping solvothermal method Size distribution

Phosphatidylmannoside prevents obesity induced by high-fat feeding

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Food Bioscience 2022年第2期46卷 274-281页

作者： Yanjun liu Ziwei Li junyi liu Jie Xu Yuanfa liu Changhu Xue State Key Laboratory of Food Science and Technology School of Food Science and TechnologyNational Engineering Research Center for Functional FoodNational Engineering Laboratory for Cereal Fermentation TechnologyCollaborative Innovation Center of Food Safety and Quality Control in Jiangsu ProvinceJiangnan University1800 Lihu RoadWuxi 214122JiangsuChina College of Food Science and Engineering Ocean University of China5 Yushan Road266003QingdaoShandong ProvinceChina Qingdao National Laboratory for Marine Science and Technology 266235QingdaoShandong ProvinceChina

Emerging evidence suggests that dietary D-mannose,enriched naturally in many plants and fruits,show benefits in patients with bacterial urinary tract infection,diabetes,and ***,it is noteworthy that the physiological level of D-mannose in the blood is relatively *** on the study that D-mannose could be a safe and beneficial dietary supplement to obese,here phosphatidylation of mannose was proposed as a way to increase the physiological level of D-mannose and enhance the modulatory effect of mannose on *** this study,phosphatidylmannoside(PtdMan)was synthesized via the approach of phospholipase D mediated *** vivo,we show that phosphatidylation of mannose enhanced the physiological level of mannose in *** benefits of PtdMan and D-mannose in high-fat diet-induced obesity were then *** with D-mannose supplementary,increased physiological level of PtdMan enhanced the expression of fatty acid oxidation-related genes in liver and PPARγtargeted genes in adipose tissue,thus protecting from high-fat diet induced obesity,glucose tolerance,and insulin ***,our findings reveal the possibility that phosphatidylation of mannose could be used as a dietary approach to prevent obesity-associated diseases via its enhanced mannose bioavailability.

关键词： Mannose Phosphatidylmannoside Phosphatidylation Obesity Bioavailability

Design, Synthesis and Activities of Aziridine Derivatives of N^5-Methyltetrahydrofolate Against Methionine Synthase

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2015年第5期31卷 742-745页

作者： DENG Xiling GUO Ying TIAN Chao liu junyi WANG Xiaowei ZHANG Zhili School of Pharmaceutical Sciences Beijing 100191 P R. China State Key Laboratory of Natural and Biomimetic Drugs Peking University Beijing 100191 P R. China School of Pharmaceutical Sciences Shihezi University Shihezi 832000 P R. China

Aziridine derivatives of N^5-methyltetrahydrofolate were designed and synthesized based on the mechanism of methionine synthase, and their biological activities were investigated as well. The aziridine derivatives 1 and 6 exhibited superior inhibitory activities（IC50：5.05 and 4.15 μmol/L, respectively） compared to the corresponding chain analogue 4（IC55=24.42 μmol/L）. The results suggest that the aziridine derivatives can get potential activities against nucleophilic methionine synthase.

关键词： Aziridine Methionine synthase Ring closure reaction N^5-Methyltetrahydrofolate

Large scale fabrication of graphene for oil and organic solvent absorption

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2016年第3期26卷 319-323页

作者： Chenxi Fu Zifeng Wang junyi liu Hongbo Jiang Guangming Li Chunyi Zhi Department of Physics and Materials Science City University of Hong Kong School of Mechanical Electrical & Information Engineering Shandong University

A simple method for synthesizing highly wrinkled and less layered structure of graphene sheets by using a mechano-thermal exfoliation method was developed. During this process, graphite and ammonium chloride（NH;Cl） powders were loaded by milling and followed with heating at a quartz tube under a nitrogen gas flow. The method is facile and easy for scaling up. Consequently, such microstructure merits of structure endowed graphene super strong adsorption ability, which should have great potential for water purification and treatment.

关键词： Graphene Ball-milling Oil absorption

The impact of COVID-19 on stock markets

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Economic and Political Studies 2020年第3期8卷 275-288页

作者： Qing He junyi liu Sizhu Wang Jishuang Yu China Financial Policy Research Centre and School of Finance Renmin University of ChinaBeijingP.R.China Department of Economics Soka University of AmericaAliso ViejoUSA School of Finance Renmin University of ChinaBeijingP.R.China

This paper attempts to explore the direct effects and spill-overs of COVID-19 on stock *** conventional t-tests and nonparametric Mann–Whitney tests,we empirically analyse daily return data from stock markets in the People’s Republic of China,Italy,South Korea,France,Spain,Germany,Japan and the United States of *** empirical results show that(i)COVID-19 has a negative but short-term impact on stock markets of affected countries and that(ii)the impact of COVID-19 on stock markets has bidirectional spill-over effects between Asian countries and European and American ***,there is no evidence that COVID-19 negatively affects these countries’stock markets more than it does the global *** findings contribute to the research on economic impact of the pandemic by providing empirical evidence that COVID-19 has spill-over effects on stock markets of other *** results also provide a basis for assessing trends in international stock markets when the situation is alleviated worldwide.

关键词： COVID-19 coronavirus disease stock markets spillover effect

Syntheses and Antiproliferative Evaluation of 6-Thienyl, 6-Polyphenyl Aryl and 6-Naphthyl Derivatives of 2,4-Diaminopyrido [3,2-d] pyramidine as Non-classical Antifolate Targeting DHFR

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2017年第4期33卷 559-568页

作者： YANG Jiajia WANG Meng LI Xia FAN Ningning XUE Liangmin LI Hao TIAN Chao WANG Xiaowei liu junyi ZHANG Zhili Department of Chemical Biology School of Pharmaceutical Sciences Peking University Beijing 100191 P. R. China State Key Laboratory of Natural and Biomimenc Drugs Peking University Beijing 100191 P. R. China Marine College Shandong University Weihai 264209 P. R. China

A series of 6-thienylethenyl, 6-polyphenyl arylethenyl, 6-thienylethyl and 6-polyphenyl arylethyl deriva- tives of 2,4-diaminopyrido[3,2-d]pyrimidine for targeting dihydrofolate reductase（DHFR） was designed and synthe- sized as non-classical antifolates in order to overcome drug resistance. The compounds were evaluated for in vitro antitumor activities, rhDHFR and antimicrobial activities. All the compounds exhibited antitumor activities, with ICs0 values in the range of 0.13--17.8 gmol/L against HL-60, HeLa and A549. Both the types of aryl groups and the orientation of polyphenyl aryl made an impact on the biological activities. 6-Naphthylethyl derivatives 5c and 5d were proved to be the most active Dt-IFR inhibitors, which were more potent than 6-phenylethyl, 6-thienylethyl and 6-biphenylethyl derivatives. Docking studies reveal that flexible saturated carbon-carbon bond of C9--C10 is essential for biological activities in molecular backbone. Antimicrobial test shows that most of the compounds exhibit antibacterial activities.

关键词： Non-classical antifolate Dihydrofolate reductase(DHFR) Antitumor Antimicrobial

Mode-division multiplexed transmission of wavelength-division multiplexing signals over a 100-km single-span orbital angular momentum fiber

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2020年第7期8卷 1236-1242页

作者： Junwei Zhang junyi liu Lei Shen Lei Zhang Jie Luo Jie liu Siyuan Yu State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510006China State Key Laboratory of Optical Fiber and Cable Manufacture Technology Yangtze Optical Fiber and Cable Joint Stock Limited CompanyWuhan 430073China Photonics Group Merchant Venturers School of EngineeringUniversity of BristolBristol BS81UBUK

We experimentally demonstrate mode-division multiplexed(MDM)transmission using eight orbital angular momentum(OAM)modes over a single span of 100-km low-attenuation and low-crosstalk ring-core fiber(RCF).Each OAM mode channel carries 10 wavelength-division multiplexing(WDM)signal channels in the C band,with each WDM channel in turn transmitting 16-GBaud quadrature phase-shift keying *** aggregate capacity of 2.56 Tbit/s and an overall spectral efficiency of 10.24 bit/(s·Hz)are *** capacity-distance product of 256(Tbit/s)·km is the largest reported so far for OAM fiber communications systems to the best of our *** the low crosstalk between the OAM mode groups in the RCF,the scheme only requires the use of modular 4×4 multiple-input multiple-output processing,and it can therefore be scaled up in the number of MDM channels without increasing the complexity of signal processing.

关键词： OAM crosstalk mode

Object-level change detection based on full-scale image segmentation and its application to Wenchuan Earthquake

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2008年第S2期51卷 110-122页

作者： GONG JianYa,SUI HaiGang,SUN KaiMin,MA GuoRui & liu junyi State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan 430072,China State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing Wuhan University Wuhan China

Aiming at object fragmentation and poor detection results caused by discontinuous segmentation scale in object-level change detection,a new object-level change detection method based on the full-scale object tree is presented in this *** core idea of this new algorithm is to establish the full-scale object tree based on convexity model theory and integrate full-scale image segmentation techniques and change detection into the whole *** Wenchuan Earthquake images are taken as an example to discuss the new method for earthquake damage detection and evaluation in urban area,landslide detection,and extraction of barrier lake *** application shows that the new method is robust and it provides an advanced tool for the quantitative detection and evaluation of earthquake damage.

关键词： change detection convexity model image segmentation full-scale object tree Wenchuan Earthquake

1-Pbps orbital angular momentum fibre-optic transmission

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2022年第8期11卷 1823-1833页

作者： junyi liu Jingxing Zhang Jie liu Zhenrui Lin Zhenhua Li Zhongzheng Lin Junwei Zhang Cong Huang Shuqi Mo Lei Shen Shuqing Lin Yujie Chen Ran Gao Lei Zhang Xiaobo Lan Xinlun Cai Zhaohui Li Siyuan Yu State Key Laboratory of Optoelectronic Materials and Technologies School of Electronics and Information TechnologySun Yat-Sen UniversityGuangzhou510006China Yangtze Optical Fibre and Cable Joint Stock Limited Company State Key Laboratory of Optical Fibre and Cable Manufacture TechnologyNo.9 Guanggu AvenueWuhanHubeiChina School of Information and Electronics Beijing Institute of TechnologyBeijing100081China

Space-division multiplexing(SDM),as a main candidate for future ultra-high capacity fibre-optic communications,needs to address limitations to its scalability imposed by computation-intensive multi-input multi-output(MIMO)digital signal processing(DSP)required to eliminate the crosstalk caused by optical coupling between multiplexed spatial *** exploiting the unique propagation characteristics of orbital angular momentum(OAM)modes in ring core fibres(RCFs),a system that combines SDM and C+L band dense wavelength-division multiplexing(DWDM)in a 34 km 7-core RCF is demonstrated to transport a total of 24960 channels with a raw(net)capacity of 1.223(1.02)Peta-bit s−1(Pbps)and a spectral efficiency of 156.8(130.7)bit s−1 Hz−*** for such a high channel count,the system only uses fixed-size 4×4 MIMO DSP modules with no more than 25 time-domain *** ultra-low MIMO complexity is enabled by the simultaneous weak coupling among fibre cores and amongst non-degenerate OAM mode groups within each core that have a fixed number of 4 *** results take the capacity of OAM-based fibre-optic communications links over the 1 Pbps milestone for the first *** also simultaneously represent the lowest MIMO complexity and the 2nd smallest fibre cladding diameter amongst reported few-mode multicore-fibre(FM-MCF)SDM systems of>1 Pbps *** believe these results represent a major step forward in SDM transmission,as they manifest the significant potentials for further up-scaling the capacity per optical fibre whilst keeping MIMO processing to an ultra-low complexity level and in a modularly expandable fashion.

关键词： fibre momentum coupling