检索结果-南通市图书馆

Influence of longitudinal-torsional ultrasonic-assisted vibration on micro-hole drilling Ti-6Al-4V

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2021年第9期34卷 247-260页

作者： Guofu GAO Ziwen xia Zhaojie yuan Daohui xiaNG Bo ZHAO School of Mechanical and Power Engineering Henan Polytechnic UniversityJiaozuo 454000China

As Ti-6 Al-4 V is a typical hard to machine material,especially in micro drilling aviation parts,chip breaking difficulty is of increasing interest to explore its further *** this study,Longitudinal-Torsional Ultrasonic Assisted Drilling(LTUAD)was employed to machine Ti-6 Al-4 V,and its feasibility was evaluated by comparing with Conventional Drilling(CD).By combining periodical characteristics and vibration models(the separated or the unseparated ultrasonic elliptical vibration),the influence of ultrasonic frequency on the intersection characteristics of trajectories were *** the intersection characteristics were divided into four categories:even periodicity,odd periodicity,non-odd and even periodicity and composite periodicity,indicating different capability for chip *** applying the longitudinal-torsional compound vibration horn,the micro-hole drilling experiment was carried out on machining *** chip morphology,the thrust force,and the burr height were *** results showed that the morphology of chips presented as smaller and more fragmentary ones in LTUAD compared with continuous helical conical ones and fold-shaped ones in *** with CD,the average values of the thrust force in LTUAD reduced by 1.98%to 24.9%.According to the burr around the hole exit in both LTUAD and CD,the height of the latter was greatly affected by the drilling *** the burr around the exit of the hole were distributed rather evenly with smaller extension in ***,the LTUAD employed in micro-hole drilling was effective.

关键词： Capability for chip breaking Longitudinal-torsional ultrasonic assisted drilling Micro-hole drilling Periodical characters Ti-6Al-4V

Hydrogen-rich surface of MoC catalysts for efficient CO_(2) hydrogenation induced by a coupled hydrogen donator

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第8期17卷 7762-7767页

作者： Dong Xu Si-yuan xia Qi-yuan Li Jie-Sheng Chen Xin-Hao Li School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Jiao Tong UniversityShanghai 200240China

Direct CO_(2) hydrogenation offers an important strategy for promoting the global carbon balance,but high thermodynamic and kinetic stability of CO_(2) has restricted its applicability to only a handful of industrial ***,we introduce a proof-of-concept application of the electron-rich Pt surface to promote hydrogen donation for electron-rich MoC particles acting as hydrogen acceptors,thereby constructing hydrogen-rich surface of MoC active ***,the formed hydrogen-rich and electronrich surface could greatly decrease reaction activation energy to boost the efficient CO_(2) hydrogenation into formic acid over the MoC *** optimized MoC@NC/Pt-0.1(NC:nitrogen-doped carbon)catalyst exhibits a high turnover frequency(TOF)value of 1.2 h^(−1) at a lower temperature of 60℃and a TOF of 24.2 h^(−1) under standard reaction conditions widely used in the literature,exceeding 7 times of MoC@NC catalyst and surpassing the benchmark classical non-noble metal active center-based heterogeneous catalyst.

关键词： electron-rich Pt nanoparticles hydrogen donation hydrogen-rich MoC nanoparticles CO_(2) hydrogenation formic acid

Electro-generation of TGA by Ni-mSA-mCS bipolar membrane

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 2007年第11期18卷 1411-1415页

作者： Zhen xia Huang Xi Zheng ri Yao Chen xiao Chen Zhen Chen Experiment Center College of Chemistry and Materials Science Fujian Normal University Fuzhou 350007 China

Ni-mSA-mCS bipolar membrane （BM） was prepared by sodium alginate （SA） and chitosan （CS）, which were modified by Ca^2＋ and glutaraldehyde as linking reagents, respectively, mSA-mCS membrane was characterized by FTIR, SEM, TG and used as a separator in the electrolysis cell to produce thioglycolic acid （TGA）. The experiment results show that TGAwas prepared effectively by electro-reduction of dithiodiglycolic acid （DTDGA） with the mixture of TGA and DTDGA in the cathodic chamber. The current efficiency was up to 66.7% at the room temperature （25 ℃） during the current density of 10 mA/cm^2. Compared with the traditional metal reduction method, the electro-reduction technology saves the zinc powder and eliminates the pollution to environment.

关键词： Bipolar membrane Modified sodium alginate Modified chitosan Thioglycolic acid Dithiodiglycolic acid

Accurate all-electron calculation on the vibrational and rotational spectra of ground states for O2 and its ions

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第7期28卷 193-197页

作者： Qiao-xia Wang Yu-Min Wang ri Ma Bing Yan Key Laboratory of Applied Atomic and Molecular Spectroscopy Jilin Province Institution of Atomic and Molecular PhysicsJilin University

The potential energy curves, spectroscopic constants, and low-lying vibration–rotation levels of ground-state O2 and its cation O2+ and anion O2- were calculated with the explicitly correlated multireference configuration interaction *** zeroth-order reference wavefunction was treated with the complete active space multiconfigurational self-consistent field method, in which the active space was carefully selected, and an additional molecular orbital πu was added into the full valence active *** electron correlation of the 1s core in the oxygen atom was considered in the *** Davidson correction on molecular energy was considered to account for higher electron *** relativistic effects, including the scalar relativistic effect and spin–orbit coupling, were considered in the computation of potential energy *** physical effects on the spectroscopic constants were *** low-lying levels of vibration–rotation spectra of O2 and its ions were determined based on the computed potential energy *** with available experiments were made and excellent agreement was obtained for the vibrational and rotational *** spectroscopic constants and vibration–rotation spectrum of O2-, which is sparse in experiments, were *** study will shed some light on further theoretical and experimental studies on these simple but important molecular systems.

关键词： O2 molecule/molecular ion explicitly correlated multireference configuration interaction spectroscopic constant vibration–rotation spectrum

Enhanced conductivity and stability of Prussian blue cathodes in sodium-ion batteries by surface vapor-phase molecular selfassembly

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第5期17卷 4221-4230页

作者： Tao yuan xiaopan Fu yuan Wang Mingjie Li Shuixin xia Yuepeng Pang Shiyou Zheng School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China

With many merits such as facile synthesis,economy,and relatively high theoretical capacity,Prussian blue analogs(PBAs)are considered promising cathode materials for sodium-ion batteries(SIBs).However,their practical applications still suffer from a low actual specific capacity and inferior stability owing to the imperfect crystallinity,irreversible phase transition,and low intrinsic ***,a surface-modification technique for vapor-phase molecular self-assembly was developed to prepare Fe-based PBAs,specifically sodium iron hexacyanoferrate(NaFeHCF),with a uniform conductive polymer protective layer of polypyrrole(PPy)on the surface,resulting in NaFeHCF@*** incorporation of a PPy protective layer not only improves the electronic conductivity of NaFeHCF@PPy,but also effectively mitigates the dissolution of Fe-ions during ***,this advanced vapor-phase technique avoids Fe^(2+)oxidation and Na^(+)loss during liquid-phase surface *** NaFeHCF@PPy exhibited a remarkably enhanced cycling performance,with capacity retentions of 85.6%and 69.1%over 500 and 1000 cycles,respectively,at 200 mA/g,along with a superior rate performance up to 5 A/g(fast kinetics).Additionally,by adopting this strategy for Mn-based PBAs(NaMnHCF@PPy),we further demonstrated the universality of this method for PBA cathodes in SIBs.

关键词： sodium-ion battery cathode Prussian blue analogs surface modification vapor-phase molecular self-assembly

Inhibitory effects of apigenin on the growth of gastric carcinoma SGC-7901 cells

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第29期11卷 4461-4464页

作者： Kun Wu Lin-Hong yuan Wei xia Department of Nutrition and Food Hygiene Public Health College Harbin Medical University Harbin 150001 Heilong jiang Province China

AIM： To explore the growth inhibition and apoptosisinducing effect of apigenin on human gastric carcinoma SGC-7901 cells. METHODS： The effects of apigenin on the growth, clone formation and proliferation of human gastric carcinoma SGC-7901 cells were observed by N-rr, done-forming assay, and morphological observation. Fluorescent staining and flow cytometry analysis were used to detect apoptosis of cells. RESULTS： Apigenin obviously inhibited the growth, clone formation and proliferation of SGC-7901 cells in a dosedependent manner. Inhibition of growth was observed on d 1 at the concentration of 80 μmol/L, while after 4 d, the inhibition rate （IR） was 90%. The growth IRs at the concentration of 20, 40, and 80 μmol/L were 38%, 71%, and 99% respedJvely on the 7^th d. After the cells were treated with apigenin for 48 h, the number of clone-forming in control, 20, 40, and 80 μmol/L groups was 217±16.9, 170±11.1 （P〈0.05）, 98±11.1 （P〈0.05）, and 25±3.5 （P〈0.05） respectively. Typical morphological changes of apoptosis was found by fluorescent staining. The cell nuclei had lost its smooth boundaries, chromatin was condensed, and cell nuclei were broken. Flow cytometry detected typical apoptosis peak. After the cells were treated with apigenin for 48 h, the apoptosis rates were 5.76%, 19.17%, and 29.30% respectively in 20, 40, and 80 μmol/L groups. CONCLUSION： Apigenin shows obvious inhibition on the growth and clone formation of SGC-7901 cells by inducing apoptosis.

关键词： Apigenin Apoptosis Anti-cancer effect Gastric carcinoma

Anti-apoptotic effects of recombinant human granulocyte colony-stimulating factor in focal cerebral ischemic rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2011年第11期6卷 839-844页

作者： xia yuan Shiming Zhang Wanli Dong Qi Fang Department of Neurology First Affiliated Hospital of Soochow University Suzhou 215006 Jiangsu Province China Department of Neurosurgery First Affiliated Hospital of Soochow University Suzhou 215006 Jiangsu Province China

The neuroprotective effects of granulocyte colony-stimulating factor in cerebral ischemia/reperfusion injury are currently contentious. The present study examined the effects of subcutaneous injection of recombinant human granulocyte colony-stimulating factor （50 pg/kg） over 5 days in a model of cerebral ischemia/reperfusion with intraluminal filament occlusion in rats. The results indicated that recombinant human granulocyte colony-stimulating factor reduced brain infarct volume following cerebral ischemia/reperfusion injury in rats, down-regulated the expression of caspase-3 mRNA （a key protease for apoptosis in the cerebral ischemia zone）, lowered the rate of neuronal apoptosis in the cerebral ischemia zone, and notably ameliorated neurological function. These results indicate that recombinant human granulocyte colony-stimulating factor has anti-apoptotic effects on neurons following focal cerebral ischemia/reperfusion injury, and exerts neuroprotective effects.

关键词： recombinant human granulocyte colony-stimulating factor cerebral ischemia/ reperfusion injury anti-apoptosis neural regeneration

Rational Fabrication and Biomedical Application of Biomolecule-Conjugated AIEgens through Click Reaction

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2019年第10期37卷 1072-1082页

作者： Qiming yuan Yong Cheng xiaoding Lou Fan xia Engineering Research Center of Nano-Geomaterials of Ministry of Education Faculty of Materials Science and ChemistryChina University of GeosciencesWuhanHubei 430074China State Key Laboratory of Material Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhanHubei 430074China Zhejiang Institute China University of GeosciencesHangzhouZhejiang 311305China【摘要】Contents

Recently,the issue of cancer has attracted extensive *** diagnosis and timely therapy are important for cancer *** lots of advanced fluorescent probes have been applied to cancer ***,the further development of these probes is limited by the disadvantages of poor targeting,weak sensitivity and ***,the emergence of biomolecule-conjugated fluorescent probes with aggregationinduced emission properties has taken innovative impetus to the cancer *** review summarizes the rational fabrication and biomedical applications of biomolecule-conjugated A1E luminogens(AIEgens)based on"click reaction"over the past *** the meantime,the challenges of biomolecule-conjugated AIEgens in the field of biomedicine are also discussed.

关键词： AIE diagnosis Rational

Fusion and Classification of Beijing-1 Small Satellite Remote Sensing Image for Land Cover Monitoring in Mining Area

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 Geographical Science 2011年第6期21卷 656-665页

作者： DU Peijun yuan Linshan xia Junshi HE Jianguo Department of Geoinformatics Nanjing University Nanjing 210093 China Key Laboratory for Land Environment andDisaster Monitoring of SBSM China University of Mining and Technology Xuzhou 221116 China East China Mineral Exploration and Development Bureau Nanjing 210007 China）

In order to promote the application of Beijing-1 small satellite(BJ-1) remote sensing data,the multispectral and panchromatic images captured by BJ-1 were used for land cover classification in Pangzhuang Coal *** improved Intensity-Hue-Saturation(IHS) fusion algorithm is proposed to fuse panchromatic and multispectral images,in which intensity component and panchromatic image are combined using the weights determined by edge pixels in the panchromatic image identified by grey absolute correlation *** improved IHS fusion algorithm outper-forms traditional IHS fusion method to a certain extent,evidenced by its ability in preserving spectral information and enhancing spatial ***-Shafer(D-S) evidence theory was adopted to combine the outputs of three member classifiers to generate the final classification map with higher accuracy than that by any individual *** on this study,we conclude that Beijing-1 small satellite remote sensing images are useful to monitor and analyze land cover change and ecological environment degradation in mining areas,and the proposed fusion algorithms at data and decision levels can integrate the advantages of multi-resolution images and multiple classifiers,improve the overall accuracy and produce a more reliable land cover map.

关键词： grey absolute correlation degree Intensity-Hue-Saturation (IHS) transformation D-S evidence theory Beijing- 1 small satellite