检索结果-南通市图书馆

Chemical Research in Chinese Universities 2006年第5期22卷 556-559页

作者： wang Xiu-li ZHAO Hai-yan wang yi-fei Faculty of Chemistry and Chemical Engineering Bohai University Jinzhou 121000 P. R. China

A kind of inorganic-organic hybrid semiconductor composite nanoparticles： Dawson-type phosphomolybdate- doped polypyrrole （P2Mo18-PPy） was designed and prepared using microemulsion oxidation-polymerization at room temperature and characterized by TEM and IR. The P2Mo18-PPy was used as a bulk-modifier to fabricate a chemically modified carbon paste electrode（CPE） by direct mixing, which represents the example of polyoxometalates（ POMs）- doped semiconductor polymer nanoparticles modified electrode. Both the advantage of POMs-doped polymer and the surface-renewal property of the CPE were fully utilized. The electrochemical behavior of the P2Mo18-PPY bulk-modified CPE（P2Mo18-PPy-CPE） was investigated with cyclic voltammetry. Three couples of reversible redox peaks were observed in the range from ＋ 800 to 0 mV, which corresponded to the reduction and oxidation through two-, four- and six-electron processes, respectively. The P2 Mo18-PPY-CPE showed a high electrocatalytic activity for the reduction of nitrite, which expanded the application of POMs-doped semiconductor polymer nanoparticles.

关键词： Dawson-type phosphomolybdate Polypyrrole Composite nanoparticles Bulk-modified Carbon paste electrode Electrocatalysis

Preparation of AlN thin films for film bulk acoustic resonator application by radio frequency sputtering

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) 2009年第3期10卷 464-470页

作者： Kan LI Hao JIN De-miao wang yi-fei TANG Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China

Aluminum nitride （AlN） thin films with high c-axis orientation have been prepared on a glass substrate with an Al bottom electrode by radio frequency （RF） reactive magnetron sputtering. Based on the analysis of Berg＇s hysteresis model, the improved sputtering system is realized without a hysteresis effect. A new control method for rapidly depositing highly c-axis oriented AlN thin films is proposed. The N2 concentration could be controlled by observing the changes in cathode voltage, to realize the optimum processing condition where the target could be fixed stably in the transition region, and both stoichiometric film composition and a high deposition rate could be obtained. Under a 500 W RF power of a target with a 6 cm diameter, a substrate temperature of 450 ℃, a target-substrate distance of 60 mm and a N2 concentration of 25%, AlN thin film with preferential （002） orientation was deposited at 2.3 μm/h which is a much higher rate than previously achieved. Through X-ray diffraction （XRD） analysis, the full width at half maximum （FWHM） of AlN （002） was shown to be about 0.28°, which shows the good crystallinity and crystal orientation of AlN thin film. With other parameters held constant, any increase or decrease in N2 concentration results in an increase in the FWHM of AlN.

关键词： Aluminum nitride (A1N) Piezoelectric thin film Radio frequency (RF) reactive sputtering Preferred orientation,Film bulk acoustic resonator (FBAR)

SYNERGISTIC EFFECTS OF NOVOLAC-BASED CHAR FORMER WITH A PHOSPHORUS/NITROGEN-CONTAINING FLAME RETARD ANT IN POLYAMIDE 6

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2012年第1期30卷 72-81页

作者： Wei-cheng Xiong Li Chen De-yi wang fei Song Yu-zhong wang Center for Degradation an-d Flame--Retardant Polymeric Materials College of-Chemistry State Key Laboratory of Polymer Materials Engineering National Engineering Laboratory of Eco-Friendly Polymeric Materials （Sichuan） Sichuan University Chengdu 610064 China

The synergistic effect of phosphorus oxynitride（PON） with a novolac-based char former modified by salification （NA-metal salt） on the flame retardance of polyamide 6（PA6） was *** this purpose,various flame-retardant PA6 systems were melt-compounded with PON,PON/NA,PON/NA-V_2O_5 and PON/NA-Fe_2O_3,and their flame retardance was evaluated by measuring the limiting oxygen index（LOI） values and UL-94 vertical burning *** results showed that,compared with the PA6/PON/NA system,the combination of two char formers（NA-V_2O_5,NA-Fe_2O_3） with PON could obviously improve the char formation and flame retardance of *** flame retardance and cone calorimetric analyses showed the stronger synergism as well as the better flame retardant performance of PON/NA-Fe_2O_3 flame retardant system. The effects of different char formers on the flame retardance and thermal stability of this system were also discussed.

关键词： Polyamide Flame retardance Novolac resin Synergistic effect

Wave Attenuation and Turbulence Driven by Submerged Vegetation Under Current-Wave Flow

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2024年第4期38卷 602-611页

作者： HUANG Yu-ming Ding Lei wang yi-fei CHEN Ben YANG Xiao-yu DOU Xi-ping School of Water Resources and Hydropower Engineering Wuhan UniversityWuhan430072China Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China

A set of laboratory experiments are carried out to investigate the effect of following/opposing currents on wave *** vegetation canopies with aligned and staggered configurations were tested under the condition of various regular wave heights and current velocities,with the constant water depth being 0.60 m to create the desired submerged *** show that the vegetation-induced wave dissipation is enhanced with the increasing incident wave height.A larger velocity magnititude leads to a greater wave height attenuation for both following and opposing current ***,there is a strong positive linear correlation between the damping coefficientβand the relative wave height H_(0)/h,especially for pure wave *** the velocity profile,the distributions of U_(min)and U_(max)show different patterns under combined wave and *** time-averaged turbulent kinetic energy(TKE)vary little under pure wave and U_(c)=±0.05 m/s *** the increase of flow velocity amplitude,the time-averaged TKE shows a particularly pronounced increase trend at the top of the *** vegetation drag coefficients are obtained by a calibration *** empirical relations of drag coefficient with Reynolds and Keulegane-Carpenter numbers are proposed to further understand the wave-current-vegetation interaction mechanism.

关键词： wave attenuation rigid vegetation following and opposing currents turbulent kinetic energy

Study on Volume Variation and Stability of Riverbed in the Yangtze Estuary

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2023年第3期37卷 433-446页

作者： DING Lei JIAO Jian TONG Chao-feng wang yi-fei CHEN Ben SUN Jie-ying DOU Xi-ping Key Laboratory of Port Waterway and Sedimentation Engineering of MOTNanjing Hydraulic Research InstituteNanjing 210029China College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210098China State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan UniversityChengdu 610065China

In recent years,regional floods and typhoons have occurred in the Yangtze *** dynamic conditions and dramatic reduction of sediment discharge in the basin are affecting the dynamic equilibrium pattern of the Yangtze *** on the field measurement data and theoretical derivation,this paper analyzed the changing process of runoff-sediment discharge into the sea after the operation of the Three Gorges Project(TGP),and the tidal dynamics and sediment variation characteristics of the Yangtze *** erosion of South Branch mainly occurs in the channel below-10 m contour,and the riverbed volume below contours 0 m and-10 m has a good correlation with the sediment discharge of Datong Station in the previous *** this basis,the ratio of the horizontal distance from the starting point to the section centroid below the average water level(B_c)and the water depth at the section centroid(H_c)was proposed to describe the change of the section *** relationships between the water-diverting ratio,the sediment-diverting ratio and the water-diverting angle,the conditions of runoff and sediment discharge from the upper reach and the characteristics of the riverway section were established,and the theoretical calculation equations of the water-diverting ratio,the sediment-diverting ratio and the diverting angle of each bifurcation were also established.

关键词： Yangtze Estuary volume variation section shape riverbed stability

Microwave Assisted Sintering and Photoluminescence Properties of BaaSi6OleNe：Eu^2＋ Green Phosphors

在线全文

学校读者我要写书评

暂无评论

无机材料学报 2015年第3期30卷 330-336页

作者： HAN Bin wang yi-fei LIU Qian HUANG Qing Structural and Functional Integration of Ceramics Group the Division of Functional Materials and Nanodevices Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo 315201 China Institute of Materials Shanghai University Shanghai 200072 China State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shang- hai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China

Eu^2＋-doped Ba3Si6012N2 green phosphors were prepared by microwave assisted sintering method at 1275℃ for 4 h, while the counterparts using conventional solid-state reaction method were synthesized at temperature higher than 1300℃ and for to 10 h. Microwave assisted sintering could reduce the activation energy and enhance the diffu- sion rate, thus greatly improved the sintering. Moreover, the influence of Si3N4 content on phase formation, morphol- ogy, absorption, and quantum efficiency, and photoluminescence properties of phosphors were studied. As a result, the Ba3Si6OI2N2：Eu^2＋ samples sintered by microwave assisted sintering method have a higher phase purity and photo- luminescence intensity under ultraviolet excitation as compared with samples sintered in the conventional tube furnace The proposed method is a potential preparation method for the oxynitride phosphors with strong photoluminescence and high phase purity.

关键词： Ba3S16012N2:Eu^2+ phosphors oxynitride microwave assisted sintering photoluminescence

IGF-1 Accelerates Cell Aging by Inhibiting POLD1 Expression

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2022年第11期35卷 981-991页

作者： HOU Yu Li wang yi fei SONG Qiao ZHANG Xiao Min LIU Jing wang Ya Qi CUI Yu Ting FU Jing Xuan FENG Zi yi ZHANG Chi wang Pei Chang Department of Clinical Laboratory Xuanwu HospitalNational Clinical Research Center for Geriatric DiseasesCapital Medical UniversityBeijing 100053China Clinical Laboratory Diagnostics Capital Medical UniversityBeijing 100053China

Objective The individual cascades of the insulin-like growth factor-1(IGF-1)signaling pathway and the molecular mechanism of aging have not been fully *** the current study,we explored the effect of DNA polymerase delta 1(POLD1)on the IGF-1 signaling pathway in cell *** First,we analyzed the relationship between IGF-1 and POLD1 expression in *** investigate the effect of IGF-1 on POLD1 expression and aging,the 2BS cells were incubated with youngage or old-age human serum,IGF-1 protein,or ***,the effect of IGF-1 on aging was examined in the 2BS cells with increased or decreased POLD1 expression to clarify the molecular *** In this study,we found that IGF-1 expression increased and POLD1 expression decreased with aging in human serum and hippocampal tissues of SAMP8 mice,and a negative relationship between IGF-1 and POLD1 expression was ***,the cells cultured with old-age human serum or IGF-1 showed lower POLD1 expression and more pronounced senescence characteristics,and the effect could be reversed by treatment with linsitinib or overexpression of POLD1,while the effect of linsitinib on cell aging could be reversed with the knockdown of *** Taken collectively,our findings demonstrate that IGF-1 promotes aging by binding to IGF-1R and inhibiting the expression of *** findings offer a new target for anti-aging strategies.

关键词： Insulin-like growth factor-1 DNA polymerase delta 1 Aging Linsitinib

Old canalicular laceration repair:a retrospective study of the curative effects and prognostic factors

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2017年第6期10卷 902-907页

作者： Fang Bai Hai Tao Yan Zhang Peng wang Cui Han yi-fei Huang Ye Tao The Lacrimal Center of Ophthalmology Armed Police General Hospital of China Beijing 100039 China

AIM： To investigate the epidemiology and surgical outcomes of old canalicular laceration and analyze the variables impacting on the prognosis of reparation. METHODS： A retrospective review of all old canalicular laceration repairs from Jan. 1, 2008 to Dec. 30, 2015 was performed. Analyzed data included demographics, mechanisms of injury, the time from injury to repair, causes for delayed repair, old associated injuries, the types of surgery, and the effects of repair using canaliculus anastomosis combined with bicanalicular stent intubation. RESULTS： Totally 148 patients with old canalicular laceration received surgical repair and were enrolled. The mean age at presentation was 32.52 years old （ranged from 3 to 63 years old）. The 110 patients （74.32%） were male and 127 patients （85.81%） were adults （__.18 years old）. The old upper, lower, and bicanalicular lacerations were found in 5 （3.38%）, 39 （26.35%）, and 104 patients （70.27%）, respectively. The mechanism of old injury was primarily due to motor vehicle accidents （n=53, 35.81%）. The mean time from injury to repair was 43.61mo （ranged from 1 to 360mo）. Associated old ocular and orbit injuries were found in 65 patients （43.92%）, and chronic dacryocystitis in 18 patients （12.16%）. The main cause of delayed repair was that doctors or patients didn＇t pay attention to the canalicular laceration because of the concurrent severe injuries （n=71, 47.97%）. Totally 136 patients （91.89%） with old canalicular laceration underwent canaliculus anastomosis combined with bicanalicular stent intubation. In all of them, 20 patients （13.51%） were combined with dacryocystorhinostomy. In these cases, 132 patients （97.06%） attained anatomic success, 121 patients （88.97%）reported no epiphora （functional success）, 11 patients （8.09%） reported significant epiphora anesis （functional improvement）, and 4 （2.94%） reported no significant anesis （functional failure）. Rates of anatomic success and functional success were significantly correla

关键词： old canalicular laceration canalicular repair bicanalicular stent

Simultaneous immobilization of multiple heavy metal(loid)s in contaminated water and alkaline soil inoculated Fe/Mn oxidizing bacterium

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

Journal of Environmental Sciences 2025年第1期147卷 370-381页

作者： yi Wu Shengli wang Jun Xu fei Zang Song Long yining Wu Yuqing wang Zhongren Nan Technology Research Center for Pollution Control and Remediation of Northwest Soil and Groundwater College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China State Key Laboratory of Grassland Agro-ecosystems College of Pastoral Agriculture Science and TechnologyLanzhou UniversityLanzhou 730000China

Two strains of Fe/Mn oxidizing bacteria tolerant to high concentrations of multiple heavy metal(loid)s and efficient decontamination for them were *** surface of the bio-Fe/Mn oxides produced by the oxidation of Fe(II)and Mn(II)by Pseudomonas taiwanensis(marked as P4)and Pseudomonas plecoglossicida(marked as G1)contains rich reactive oxygen functional groups,which play critical roles in the removal efficiency and immobilization of heavymetal(loid)s in co-contamination *** isolated strains P4 and G1 can growwell in the following environments:pH 5-9,NaCl 0-4%,and temperature 20-30℃.The removal efficiencies of Fe,Pb,As,Zn,Cd,Cu,and Mn are effective after inoculation of the strains P4 and G1 in the simulated water system(the initial concentrations of heavy metal(loid)were 1 mg/L),approximately reaching 96%,92%,85%,67%,70%,54%and 15%,*** exchangeable and carbonate bound As,Cd,Pb and Cu are more inclined to convert to the Fe-Mn oxide bound fractions in P4 and G1 treated soil,thereby reducing the phytoavailability and bioaccessible of heavy metal(loid)*** research provides alternatives method to treat water and soil containing high concentrations of multi-heavy metal(loid)s.

关键词： Bio-Fe/Mn oxides Pseudomonas Heavy metal(loid)s Removal and immobilization

Denoising of SAR Images Based on Lifting Scheme Wavelet Packet Transform

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

Geo-Spatial Information Science 2008年第4期11卷 257-261页

作者： wang Wenbo yi Xuming fei Pusheng School of Mathematic Wuhan University Luojia Hill Wuhan 430072 China

According to the different characteristics that signal and noise exhibit during wavelet decomposition, a new denoising method based on the lifting scheme wavelet packet decomposition is presented. In this method, the SAR images are decom- posed by using the best wavelet packet and the norm of each sub-band are calculated; signals and noise can be discriminated based on the norm and soft-threshold method, and the images can be denoised. Experiments show that the proposed algorithm has excellent performance in denoising SAR images, and can remove most noise of images with well-kept texture detail informa- tion. The calculating speed of the method is twice the speed of the general wavelet packet transform algorithm.

关键词： lifting scheme wavelet packet decomposition SAR image image denoising