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Equilibrator-based measurements of dissolved methane in the surface ocean using an integrated cavity output laser absorption spectrometer 被引量:4
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作者 LI Yuhong ZHAN Liyang +1 位作者 ZHANG Jiexia CHEN Liqi 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第6期34-41,共8页
A new off-axis integrated cavity output spectroscopy (ICOS) is coupled to Weiss equilibrator for continuous high- resolution dissolved methane measurement in the surface ocean. The time constant for the equilibrator... A new off-axis integrated cavity output spectroscopy (ICOS) is coupled to Weiss equilibrator for continuous high- resolution dissolved methane measurement in the surface ocean. The time constant for the equilibrator in freshwater at room temperature is determined via dis-equilibration and re-equilibration experiments. The constant for methane is about 40 min. The system is calibrated using a standard gas of 3.980×10-6, and the precision of the ICOS for methane is 0.07%. This system is equipped onboard to measure the spatial distribution in methane concentrations of South Yellow Sea (SYS) along the cruise track from Shanghai to Qingdao. Result shows that the methane concentration varies from 2.79 to 36.36 nmol/L, reveals a significant pattern of methane source in SYS, and a distinct decreasing trend from south to north. The peak value occurs at the coast area outside mouth of the Changjiang River, likely to be affected by the Changjiang diluted water mass dissolving a large amount of rich in methane. Moreover, all the surface waters are oversaturated, air-to-sea fluxes range from 98.59 to 5 485.35 μmol/(m2·d) (average value (1 169.74±1 398.46) μmol/(m2·d)), indicating a source region for methane to the atmosphere. Key words: methane, equilibrator, off-axis integrated cavity output spectroscopy (ICOS), South Yellow Sea 展开更多
关键词 METHANE equilibrator off-axis integrated cavity output spectroscopy (ICOS) South Yellow Sea
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Equalized Electronegativity Based on the Valence Electrons and Its Application 被引量:2
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作者 武亚新 曹晨忠 袁华 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2011年第1期31-39,I0003,共10页
We take the contribution of all valence electrons into consideration and propose a new valence electrons equilibration method to calculate the equalized electronegativity including molecular electronegativity, group e... We take the contribution of all valence electrons into consideration and propose a new valence electrons equilibration method to calculate the equalized electronegativity including molecular electronegativity, group electronegativity, and atomic charge. The ionization potential of alkanes and mono-substituted alkanes, the chemical shift of 1H NMR, and the gas phase proton affinity of aliphatic amines, alcohols, and ethers were estimated. All the expressions have good correlations. Moreover, the Sanderson method and Bratsch method were modified on the basis of the valence electrons equilibration theory. The modified Sanderson method and modified Bratsch method are more effective than their original methods to estimate these properties. 展开更多
关键词 Electronegativity equalization Valence electrons equilibration method Molecular electronegativity Group electronegativity Atomic charge
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Diabetic retinopathy:Role of inflammation and potential therapies for anti-inflammation 被引量:7
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作者 Gregory I Liou 《World Journal of Diabetes》 SCIE CAS 2010年第1期12-18,共7页
Diabetic retinopathy is a leading cause of blindness among working-age adults.Despite many years of research,treatment options for diabetic retinopathy remain limited and with adverse effects.Discovery of new molecula... Diabetic retinopathy is a leading cause of blindness among working-age adults.Despite many years of research,treatment options for diabetic retinopathy remain limited and with adverse effects.Discovery of new molecular entities with adequate clinical activity for diabetic retinopathy remains one of the key research priorities in ophthalmology.This review is focused on the therapeutic effects of cannabidiol(CBD),a nonpsychoactive native cannabinoid,as an emerging and novel therapeutic modality in ophthalmology based on systematic studies in animal models of inflammatory retinal diseases including diabetic retinopathy-a retinal disease associated with vascular-neuroinflammation.Special emphasis is placed on novel mechanisms which may shed light on the pharmacological activity asso c iated with CBD preclinically.These include a selfdefence system against inflammation and neurodegeneration mediated by inhibition of equilibrat ive nucleoside transporter and activation of adenosine receptor by treatment with CBD. 展开更多
关键词 CANNABIDIOL ANTI-INFLAMMATION Diabetic RETINOPATHY Retinal MICROGLIA ADENOSINE receptors Equilibrative NUCLEOSIDE transporters
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Identification of AtENT3 as the main transporter for uridine uptake in Arabidopsis roots 被引量:7
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作者 Kun Ling Chen Min Xin Xu +6 位作者 Guang Yong Li Hui Liang Zong Liang Xia Xin Liu Ji Shu Zhang Ai Min Zhang Dao Wen Wang 《Cell Research》 SCIE CAS CSCD 2006年第4期377-388,共12页
Previous studies have shown that Arabidopsis equilibrative nucleoside transporters (AtENTs) possess transport activities when produced in yeast cells and are differentially expressed in Arabidopsis organs. Herein, w... Previous studies have shown that Arabidopsis equilibrative nucleoside transporters (AtENTs) possess transport activities when produced in yeast cells and are differentially expressed in Arabidopsis organs. Herein, we report further analysis on the nucleoside transport activities and transcriptional patterns of AtENT members. The recombinant proteins of AtENTs 3, 6, and 7, but not those of AtENTs 1, 2, 4, and 8, were found to transport thymidine with high affinity. Contrary to previ- ous suggestion that AtENT 1 may not transport uridine, this work showed that recombinant AtENT 1 was a pH-dependent and high-affinity transporter of uridine. When grown on MS plates, the AtENT3 knockout plants were more tolerant to the cytotoxic uridine analog 5-fluorouridine than wild-type plants and the knockout plants ofAtENT 1 or AtENT6. Con- sistent with this observation, the AtENT3 knockout line exhibited a significantly decreased ability to take up [^3H]uridine via the roots when compared with wild-type plants and the plants with mutated AtENT 1 or AtENT6. This indicates that AtENT3, but not AtENTs 1 and 6, is the main transporter for uridine uptake in Arabidopsis roots. The transcription of AtENTs 1, 3, 4, 6, 7, and 8 was regulated in a complex manner during leaf development and senescence. In contrast, the six AtENT members were coordinately induced during seed germination. This work provides new information on the transport properties of recombinant AtENT proteins and new clues for future studies of the in vivo transport activities and physiological functions of the different ENT proteins in Arabidopsis plants. 展开更多
关键词 ARABIDOPSIS equilibrative nucleoside transporter expression pattern nucleoside transport functional analysis
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The influence of moisture on the permeability of crushed shale samples 被引量:3
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作者 Mercy Achang Jack C.Pashin Eliot A.Atekwana 《Petroleum Science》 SCIE CAS CSCD 2019年第3期492-501,共10页
Shale cuttings and cores recovered from the subsurface and stored for hours to decades tend to dry out and lose moisture and hydrocarbons,leading to an increase in the effective matrix permeability.Moisture loss in sh... Shale cuttings and cores recovered from the subsurface and stored for hours to decades tend to dry out and lose moisture and hydrocarbons,leading to an increase in the effective matrix permeability.Moisture loss in shale samples is a fundamental sample preservation problem which can be solved by applying a standard moisture equilibration procedure to restore lost moisture.Our aim was to investigate the relationship between permeability and variable moisture as-received,as-received moisture-equilibrated and saturated moisture-equilibrated samples.Samples were crushed to a series of particle sizes(0.6-2.0)mm and moisture equilibrated at 97% relative humidity.Results show that moisture equilibration in the samples was achieved after 72 h.The permeability of the saturated moisture-equilibrated and as-received moisture-equilibrated samples decreased exponentially with increase in moisture content.The high correlation coefficient between permeability and particle size(r = 0.96 and 0.97)for moisture-equilibrated samples compared to 0.76 for as-received samples indicates that moisture equilibration improves permeability measurements in crushed shale samples.Furthermore,permeability measurements are repeatable for moisture-equilibrated samples compared to samples that were not equilibrated(as-received).We conclude that moisture content affects permeability and moisture equilibration normalizes and improves the repeatability of permeability measurements in crushed shale. 展开更多
关键词 CRUSHED SHALE Matrix PERMEABILITY MOISTURE EQUILIBRATION
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Henry's Law constant for phosphine in seawater:determination and assessment of influencing factors 被引量:2
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作者 付梅 俞志明 +1 位作者 卢光远 宋秀贤 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第4期860-866,共7页
The Henry's Law constant (k) for phosphine in seawater was determined by multiple phase equilibration combined with headspace gas chromatography. The effects of pH, temperature, and salinity on k were studied. The ... The Henry's Law constant (k) for phosphine in seawater was determined by multiple phase equilibration combined with headspace gas chromatography. The effects of pH, temperature, and salinity on k were studied. The k value for phosphine in natural seawater was 6.415 at room temperature (approximately 23℃). This value increases with increases in temperature and salinity, but no obvious change was observed at different pH levels. At the same temperature, there was no significant difference between the k for phosphine in natural seawater and that in artificial seawater. This implies that temperature and salinity are major determining factors for k in marine environment. Double linear regression with Henry's Law constants for phosphine as a function of temperature and salinity confirmed our observations. These results provide a basis for the measurement of trace phosphine concentrations in seawater, and will be helpful for future research on the status of phosphine in the oceanic biogeochemical cycle of phosphorus. 展开更多
关键词 PHOSPHINE Henry's Law constant seawater influencing factors multiple phase equilibration
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Proposals for Fabrication of Long-Period Grating in LiNbO3 Strip Waveguides 被引量:1
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作者 张德龙 杨庆忠 潘裕斌 《Chinese Physics Letters》 SCIE CAS CSCD 2008年第8期2904-2907,共4页
The structure of a strip LiNbO3 waveguide clad with a planar LiNbOa waveguide is proposed to fabricate a long-period waveguide grating (LPWG). It is shown theoretically that an LPWG device based on such a special Li... The structure of a strip LiNbO3 waveguide clad with a planar LiNbOa waveguide is proposed to fabricate a long-period waveguide grating (LPWG). It is shown theoretically that an LPWG device based on such a special LiNbOa waveguide structure is of the merit of thermal stability. The methods for fabrication of planar waveguide, channel waveguide and grating are suggested and discussed. Detailed design consideration is exemplified based on a soft-proton-exchange planar waveguide clad Ti-diffused LiNbOa (Z-cut) strip waveguide. 展开更多
关键词 VAPOR TRANSPORT EQUILIBRATION FIELD DISTRIBUTION LITHIUM-NIOBATE TEMPERATURE WAVELENGTH
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Translational research in pancreatic ductal adenocarcinoma: current evidence and future concepts 被引量:1
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作者 Stephan Kruger Michael Haas +5 位作者 Steffen Ormanns Sibylle Bchmann Jens T Siveke Thomas Kirchner Volker Heinemann Stefan Boeck 《World Journal of Gastroenterology》 SCIE CAS 2014年第31期10769-10777,共9页
Pancreatic ductal adenocarcinoma(PDA) is one of the major causes for cancer death worldwide. Treatment of metastatic disease remains challenging as only certain patients benefit from advances made with the intensified... Pancreatic ductal adenocarcinoma(PDA) is one of the major causes for cancer death worldwide. Treatment of metastatic disease remains challenging as only certain patients benefit from advances made with the intensified chemotherapy regimen folinic acid, irinotecan and oxaliplatin, the epidermal growth factor receptor inhibitor erlotinib or the recently FDA-approved nab-paclitaxel. Up to date, no established approach for prediction of treatment response or specific treatment allocation exists. Translational research was able to identify a number of potential biomarkers that might help to improve the dismal prognosis of PDA by facilitating upfront treatment allocation. This topic highlight is focused on current evidence on potential biomarkers for tumor biology, prognosis and prediction of treatment efficacy. 展开更多
关键词 Biomarker ERLOTINIB GEMCITABINE Human equilibrative nucleoside transporter 1 KRAS NAB-PACLITAXEL p53 Pancreatic cancer SMAD4 SPARC
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Experimental Study on Load Equilibration and Vibration Reduction in 3-Ring-Gear Reducer 被引量:1
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作者 王世彤 闫换新 +1 位作者 刘荣强 李华敏 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1997年第3期43-47,共5页
Following the principle of elastic floating compensation, this paper presents a new metal elastic ring for load equilibration and vibration reduction in 3-ring-gear reducer, and design and fabrivcation of a metal elas... Following the principle of elastic floating compensation, this paper presents a new metal elastic ring for load equilibration and vibration reduction in 3-ring-gear reducer, and design and fabrivcation of a metal elastic ring for SCH 3-ring-gear reducer. Comparison tests run with 3-ring-gear reducers without or with the metal elastic ring show satisfactory load equilibration and vibration reduction can be achieved with the metal elastic ring, and the metal elastic ring is a good solution for the problem of unequilibrated load and excessive vibration from which 3-ring-gear reducers suffered long.- This will further the improvement of design and application of 3-ring-gear reducers in both theory and practice. 展开更多
关键词 3-ring-gear REDUCER LOAD EQUILIBRATION vibration reduction
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Effect of Sources and Concentrations of Soybean Phosphatidylcholine on Diluted Goat Semen Equilibrated at 4 ℃ 被引量:1
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作者 N. Phutikanit E. Sangkrachang J. Suwimonteerabutr J. Singlor 《Journal of Agricultural Science and Technology(A)》 2011年第8期1170-1173,共4页
The objective of the present study was to determine the proper sources and concentrations of soybean lecithin (phosphatidylcholine, PC) to be used as substitute for hen egg yolk in extender for preserving goat semen... The objective of the present study was to determine the proper sources and concentrations of soybean lecithin (phosphatidylcholine, PC) to be used as substitute for hen egg yolk in extender for preserving goat semen. Two sources of soybean lecithin (20% and 95% soybean phosphatidylcholine; PC20 and PC95) and three concentrations (1%, 2% and 3% v/v) of PC20 and PC95 supplemented in Tris-citric acid-fructose (TCF) extender were tested. The TCF extender supplemented with 20% hen egg yolk was used as a control. Fresh semen samples were collected from 3 goats by artificial vagina. Seminal plasma was removed by centrifugation and sperm pellets were pooled together and divided into 7 groups according to types of extender. The diluted semen samples were kept at 4 ℃ (equilibration). The semen qualities including progressive motility, sperm viability, sperm plasma membrane integrity and tail abnormalities were evaluated before dilution and after 4 hrs equilibration. It was found that the progressive motility of equilibrated semen in egg yolk and PC20 extenders were higher than those in PC95 extender (P 〈 0.05). Sperm viability was lower in 1% and 2% PC95 extender compared to other extenders (P 〈 0.05). PC20 extender maintained the sperm membrane integrity and normal tail morphology at low temperature better than egg yolk and PC95 (P 〈 0.05). It can be concluded that 20% soybean phosphatidylcholine supplemented in TCF extender at 1%-3% (v/v) is as effective as hen egg yolk to preserve goat semen during equilibration at 4 ℃ for 4 hrs . 展开更多
关键词 Goat semen semen extender soybean lecithin PHOSPHATIDYLCHOLINE EQUILIBRATION
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Soil Water Hysteresis at Low Potential
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作者 L.PRUNTY J.BELL 《Pedosphere》 SCIE CAS CSCD 2007年第4期436-444,共9页
Knowledge of the soil water characteristic curve is fundamental for understanding unsaturated soils.The objective of this work was to find scanning hysteresis loops of two fine textured soils at water potentials below... Knowledge of the soil water characteristic curve is fundamental for understanding unsaturated soils.The objective of this work was to find scanning hysteresis loops of two fine textured soils at water potentials below wilting point.This was done by equilibration over NaCl solutions with water potentials of-6.6 to-18.8 MPa at 25℃.When cycled repeatedly through a series of potentials in the range noted previously both soils exhibited a hysteresis effect.The experimental differences in water content between the drying and wetting soils at the same water potential were much too large to be accounted for by failure to allow sufficient time to attain equilibrium as predicted by the exponential decay model.The wetting versus drying differences were relatively small,however,at only 4 mg g-1 or less in absolute terms and about 3% of the mean of wetting and drying,in relative terms.Hysteresis should be a consideration when modeling biological and physical soil processes at water contents below the wilting point,where small differences in water content result in large potential energy changes. 展开更多
关键词 ADSORPTION dry soil EQUILIBRATION matric potential soil water characteristic
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SYNTHESIS AND CHARACTERIZATION OF NOVEL REACTIVE POLYORGANOSILOXANE CONTAINING NITRO GROUPS
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作者 Chun-qing Liu Yang Liu Ping Xie Rong-ben Zhang Chao-bin He Neal Tai-shung Chung 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2001年第1期1-6,共6页
A novel reactive polyorganosiloxane containing nitro groups was first prepared by acid-catalyzed equilibration polymerization. The monomer, 3-(4-nitrophenoxy)propylmethyldichlorosilane (NPPMS), was synthesized by hydr... A novel reactive polyorganosiloxane containing nitro groups was first prepared by acid-catalyzed equilibration polymerization. The monomer, 3-(4-nitrophenoxy)propylmethyldichlorosilane (NPPMS), was synthesized by hydrosilylation reaction with dicyciopentadienylplatinum(II) chloride (Cp2PtCl2) catalyst in high yield. The synthesized polynitroorganosiloxane, which has potential application as a precursor for synthesizing advanced functional polymers, was characterized by FTIR, H-1-NMR, C-13-NMR, Si-29-NMR, vapor pressure osmometry (VPO) and gel permeation chromatography(GPC). 展开更多
关键词 polyorganosiloxane equilibration polymerization HYDROSILYLATION CHARACTERIZATION
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Study on Analytical Methods for Hydrogen and Oxygen Isotope in Water Sample
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作者 ZHANG Lin LIU Fuliang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第S1期175-175,共1页
1 Introduction The stable isotopes of hydrogen and oxygen(δ2H andδ18O)are excellent tracers for studies on the natural water cycle.The isotopic signature of different water bodies
关键词 hydrogen isotope oxygen isotope equilibration technique metal chromium
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Chemical Indicator of Spinel During Partial Melting and Subsolidus Equilibration of Mantle Peridotite:Experimental Study and Application to Natural Rocks
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作者 Jacques Kornprobst Daniel Vielzeuf 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1995年第4期420-435,共16页
Systematic experimental studies on partial melting and subsolidus equilibration of three reconstituted spinel-peridotites have been carried out at temperatures ranging from 1000 to 1380℃ and pressures of 1.0 and 1.5 ... Systematic experimental studies on partial melting and subsolidus equilibration of three reconstituted spinel-peridotites have been carried out at temperatures ranging from 1000 to 1380℃ and pressures of 1.0 and 1.5 GPa. The results shows (1) during partial melting, Mg# [=Mg/(Mg+Fe)]and Cr# [=Cr/(Cr-Al)]of spinel increase with an increase in degrees of melting) (2) during subsolidus equilibration, with increasing temperatures, Mg# of spinel increases but Cr# of spinel remains almost unchanged in dunite and increases slightly in Iherzolite and harzburgite. The negative and quasi-linear Mg# -Cr# correlation of spinel represents an isotherm of total non-equilibrium. The same results have been obtained by means of mathematical modelling. It is also proved by Mg# -Cr# correlation of spinel in natural peridotites. As a result of the spinel subsolidus equilibration, only variation of Cr# of spinel is limited, and then Cr# of spinel can be used to estimate the relative degree of melting undergone by host rocks. The bigger Cr# of spinel is, the higher the degree of melting will be. By contrast, during crystallization magma, Mg# and Cr# of spinel decrease with decreasing temperatures. Likewise, Cr# of spinel in basalts may be used to indicate the feature of Cr2O3/Al2O3 of magma, and the compositional zoning of spinel may be used to study the evolution of magma (cooling rate and contamination). 展开更多
关键词 PERIDOTITE SPINEL partial melfing subsolidus equilibration experimental study and application
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Oxygen Potentials and Oxygen-potential Diagrams for Buffer Gas System at Normal Pressure
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作者 方正 张全茹 +1 位作者 张平民 陈新民 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1992年第1期35-43,共9页
The principles of chemical equilibrium were used to derive a new set of formulae representing the oxygen potentials for five buffer gas mixtures at normal pressure.Various sorts of classical formulae for them are on- ... The principles of chemical equilibrium were used to derive a new set of formulae representing the oxygen potentials for five buffer gas mixtures at normal pressure.Various sorts of classical formulae for them are on- ly a particular representation under ignoring the effects of oxygen,thereby being unavailable for accurate cal- culation of oxygen potentials.In this paper,the oxygen potentials set by CO_2-H_2 gas mixtures and the mis- takes and errors of the classical expressions for them were discussed emphatically.The deviation in partial pressures of oxygen in some of previous experiments under the oxygen potentials controlled by CO_2-H_2 gas mixtures was explained quantitatively.The oxygen-potential diagrams predicting the equilibrated gas com- positions from the initial conditions have been also given. 展开更多
关键词 oxygen potential oxygen-potential diagram buffer gas gas equilibration
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THE EXTENDING OF JOUKOWSKY'S LEVER METHOD AND ITS APPLICATIONS IN LINKAGE PROBLEMS
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作者 陈人哲 章文俊 《Journal of Donghua University(English Edition)》 EI CAS 1989年第Z1期37-45,共9页
Joukowsky’s Lever Method is the method used to find out the equilibrant and balancingmoment of various mechanisms.The advantage of this method is to save the complicated processof finding out the reactional forces in... Joukowsky’s Lever Method is the method used to find out the equilibrant and balancingmoment of various mechanisms.The advantage of this method is to save the complicated processof finding out the reactional forces in kinematic pairs.But,the method is only limited to thosemechanisms composed of rigid bar linkages and with negligible friction.In practical cases,hydropneumatic elements and spring constraints may be included in the mechanism;and alsowith the development of high load,high speed and high accuracy of mechanism,the friction maynot be neglected.So,the authors have tried to develop the Generalized Joukowsky’s LeverMethod,which can be used to find out the equilibrant and balancing moment of the mechanismwhen the hydropneumatic elements and spring constraints are included and the friction inkinematic pairs has to be considered.Three examples are here analyzed to show the applicationsof this method. 展开更多
关键词 LINKAGE equilibrant frictional FORCE SPRING ELEMENT hydropneumation ELEMENT balancing MOMENT LINKAGE mechanism
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Comparison of ZnO Films Grown on before- and after-vapor Transport Equilibration (VTE) LiAlO_2 Substrates by Pulsed Laser Deposition (PLD)
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作者 Jun ZOU Shengming ZHOU Jun XU 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第3期333-335,共3页
About φ45 mm LiAlO2 single crystal was grown by Czochralski (Cz) technique. However, the full-width at half-maximum (FWHM) value was high to 116.9 arcsec. After three vapor transport equilibration (VTE) process... About φ45 mm LiAlO2 single crystal was grown by Czochralski (Cz) technique. However, the full-width at half-maximum (FWHM) value was high to 116.9 arcsec. After three vapor transport equilibration (VTE) processes, we can obtain high-quality LiAlO2 slice with the FWHM value of 44.2 arcsec. ZnO films were fabricated on as-grown slices and after-VTE ones by pulsed laser deposition (PLD). It was found that ZnO films on the two slices have similar crystallinity, optical transmittance and optical band gap at room temperature. These results not only show that LAO substrate is suitable for ZnO growth, but also prove that the crystal quality of LAO substrate slightly affects the structural and optical properties of ZnO film. 展开更多
关键词 Crystal structure Pulsed laser deposition ZnO films Vapor transport equilibration (VTE)
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THE INFLUENCE OF SUBSTITUENT ELECTRONIC EFFECT ON ETHYLENE OLIGOMERIZATION ACTIVITIES OF BIS(IMINO)PYRIDYL Fe(Ⅱ) CATALYSTS:A COMBINED MOLECULAR MECHANICS AND CHARGE EQUILIBRATION METHOD
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作者 李化毅 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2009年第5期711-717,共7页
Bis(imino)pyridyl Fe(Ⅱ) complexes are important catalysts in ethylene oligomerization for preparingα-olefins. The metal net charge-activity relationship of bis(imino)pyridyl Fe(Ⅱ) complexes was investigated by mole... Bis(imino)pyridyl Fe(Ⅱ) complexes are important catalysts in ethylene oligomerization for preparingα-olefins. The metal net charge-activity relationship of bis(imino)pyridyl Fe(Ⅱ) complexes was investigated by molecular mechanics (MM) and net charge equilibration(QEq) method with modified Dreiding force field.It was found that metal net charge was in reverse ratio to ethylene oligomerization activity.Electron-donor substituents with less steric hindrance to the central metal were favorable to Fe complex act... 展开更多
关键词 Ethylene OLIGOMERIZATION Fe catalyst Molecular mechanics(MM) Net charge equilibration(QEq).
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Equilibrating Pressure with Auto-Control Valve in Water Distribution Networks
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作者 张宏伟 闫晓强 张丽 《Transactions of Tianjin University》 EI CAS 2003年第4期334-339,共6页
This paper probes into the feasibility of equilibrating pressure of water distribution network through (using auto-control valves) in theory and in the economy. An optimal valve control model is designed to minimize t... This paper probes into the feasibility of equilibrating pressure of water distribution network through (using auto-control valves) in theory and in the economy. An optimal valve control model is designed to minimize the sum of squares of residual pressure in the network. Such an analog simulation has been performed on the year 2003 programming network of a certain littoral district in North China, through which this paper confirms that it is feasible to equilibrate pressure with auto-control valves in theory. The research work has brought about a discovery of applicable conditions of valves in economic feasibility, which avoids a great economic loss due to the wild use of auto-control valve. In addition, simulated annealing algorithm is applied to optimize valve settings and shown to identify global optimum or near-optimum. 展开更多
关键词 auto-control valve water distribution networks equilibrating pressure simulated annealing
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Role of human nucleoside transporters in pancreatic cancer and chemoresistance
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作者 Carly Jade Carter Ahmed H Mekkawy David L Morris 《World Journal of Gastroenterology》 SCIE CAS 2021年第40期6844-6860,共17页
The prognosis of pancreatic cancer is poor with the overall 5-year survival rate of less than 5%changing minimally over the past decades and future projections predicting it developing into the second leading cause of... The prognosis of pancreatic cancer is poor with the overall 5-year survival rate of less than 5%changing minimally over the past decades and future projections predicting it developing into the second leading cause of cancer related mortality within the next decade.Investigations into the mechanisms of pancreatic cancer development,progression and acquired chemoresistance have been constant for the past few decades,thus resulting in the identification of human nucleoside transporters and factors affecting cytotoxic uptake via said transporters.This review summaries the aberrant expression and role of human nucleoside transports in pancreatic cancer,more specifically human equilibrative nucleoside transporter 1/2(hENT1,hENT2),and human concentrative nucleoside transporter 1/3(hCNT1,hCNT3),while briefly discussing the connection and importance between these nucleoside transporters and mucins that have also been identified as being aberrantly expressed in pancreatic cancer.The review also discusses the incidence,current diagnostic techniques as well as the current therapeutic treatments for pancreatic cancer.Furthermore,we address the importance of chemoresistance in nucleoside analogue drugs,in particular,gemcitabine and we discuss prospective therapeutic treatments and strategies for overcoming acquired chemoresistance in pancreatic cancer by the enhancement of human nucleoside transporters as well as the potential targeting of mucins using a combination of mucolytic compounds with cytotoxic agents. 展开更多
关键词 Pancreatic cancer GEMCITABINE Human nucleoside transporters Human equilibrative nucleoside transporters Human concentrative nucleotide transporters MUCINS
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