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和量法解题探讨
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作者 吴振强 《中学化学》 2001年第5期27-27,共1页
关键词 和量法 解题 化学 教学 解题 化学方程式 中学
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MULTI-CLASS TRAFFIC QOS ROUTING FOR LEO SATELLITE NETWORKS 被引量:3
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作者 蒋文娟 宗鹏 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第3期254-262,共9页
Due to the diversified demands of quality of service(QoS) in volume multimedia application, QoS routings for multiservice are becoming a research hotspot in low earth orbit(LEO) satellite networks. A novel QoS sat... Due to the diversified demands of quality of service(QoS) in volume multimedia application, QoS routings for multiservice are becoming a research hotspot in low earth orbit(LEO) satellite networks. A novel QoS satellite routing algorithm for multi-class traffic is proposed. The goal of the routing algorithm is to provide the distinct QoS for different traffic classes and improve the utilization of network resources. Traffic is classified into three classes and allocated priorities based on their QoS requirements, respectively. A priority queuing mechanism guarantees the algorithm to work better for high-priority classes. In order to control the congestion, a blocking probability analysis model is built up based on the Markov process theory. Finally, according to the classification link-cost metrics, routings for different classes are calculated with the distinct QoS requirments and the status of network resource. Simulations verify the performance of the routing algorithm at different time and in different regions, and results demonstrate that the algorithm has great advantages in terms of the average delay and the blocking probability. Meanwhile, the robustness issue is also discussed. 展开更多
关键词 low earth orbit satellite networks traffic classification routing algorithm quality of service traffic and topology model
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碱金属常用计算技巧例谈
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作者 高琪 《中学生理科应试》 2004年第1期38-39,共2页
关键词 碱金属 计算技巧 中学化学 和量法 极端假设 平均式 元素守恒 设“1”
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Analysis of the Conditional Correlations from Different Genetic Systems Between the Protein Content and the Appearance Quality Traits of Indica Rice 被引量:4
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作者 葛国科 郑希 +2 位作者 吴建国 叶子弘 石春海 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第2期129-137,共9页
A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines (A) and 5 restorer lines (R) along with their F1 (A × R) and F2 populations. The unconditional and conditio... A factorial mating design in two environments was conducted using 7 cytoplasmic male sterile lines (A) and 5 restorer lines (R) along with their F1 (A × R) and F2 populations. The unconditional and conditional analyses of genetic models and the corresponding statistic methods, including endospermic, cytoplasmic, and maternal plant genetic systems, were used to analyze the genetic relationships between protein content (PC) and the appearance quality traits of indica rice (Oryza sativa L.). The results from unconditional analysis indicated that PC was significantly correlated with the appearance quality traits of rice, except for the brown rice thickness (BRT). Only the genetic covariance between PC and the brown rice width (BRW) was positively correlative, whereas all the other pairwise traits were negatively correlative. The results from conditional analysis revealed that the weight of brown rice (WBR) or the amylose content (AC) could significantly affect the relationships between PC and the appearance quality traits of indica rice. The conditional analysis showed that WBR might negatively affect the relationships between PC and the brown rice length (BRL), BRW, or BRT through the geuotype x environmental (GE) interaction effects, but positively affected the relationships between PC and the ratio of brown rice length to width (RLW) or the ratio of brown rice length to thickness (RLT). The amylase content could positively affect the relationships between PC and BRL, RLW, RLT through the cytoplasmic effects and maternal additive effects, but negatively affected the relationships between PC and BRW. 展开更多
关键词 indica rice (Oryza sativa L.) COVARIANCE unconditional and conditional analysis methods protein content amylose content appearance quality
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Adsorption of Rhenium(Ⅶ) with Anion Exchange Resin D318 被引量:11
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作者 舒增年 杨明华 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第3期372-376,共5页
The adsorption and mechanism of Re(Ⅶ)on resin D318 were studied using chemical methods and IR spectrometry.At pH 5.2,the static and dynamic saturation adsorption capacities were 351.4 and 366.5 mg·g-1,respective... The adsorption and mechanism of Re(Ⅶ)on resin D318 were studied using chemical methods and IR spectrometry.At pH 5.2,the static and dynamic saturation adsorption capacities were 351.4 and 366.5 mg·g-1,respectively.The adsorption behavior obeyed the Freundlich empirical equation and the adsorption rate constant k298 was 6.37×10-4s-1.The desorption percentage was up to 99.7%when 2.0 mol·L-1KSCN was used for dynamic desorption. 展开更多
关键词 RHENIUM resin D318 ADSORPTION DESORPTION
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Ethanol-Water Near-Azeotropic Mixture Dehydration by Compound Starch-Based Adsorbent 被引量:1
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作者 孙津生 师明 王文平 《Transactions of Tianjin University》 EI CAS 2015年第5期427-432,共6页
Ethanol-water near-azeotropic mixture dehydration was investigated by formulated compound starchbased adsorbent(CSA), which consists of corn, sweet potato and foaming agent. The net retention time and separation facto... Ethanol-water near-azeotropic mixture dehydration was investigated by formulated compound starchbased adsorbent(CSA), which consists of corn, sweet potato and foaming agent. The net retention time and separation factor of water over ethanol were measured by inverse gas chromatography(IGC). Results indicated that water has a longer net retention time than ethanol and that low temperature is beneficial to this dehydration process. Orthogonal test was conducted under different vapor feed flow rates, bed temperatures and bed heights, to obtain optimal fixed-bed dehydration condition. Dynamic saturated adsorbance was also studied. It was found that CSA has the same water adsorption capacity(0.15 g/g)as some commercial molecular sieves. Besides, this biosorptive dehydration process was found to be the most energy-efficient compared with other ethanol purification processes. 展开更多
关键词 starch-based adsorbent adsorption ethanol-water near-azeotropic mixture DEHYDRATION
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Factors controlling the latent and sensible heat FLuxes over Erhai Lake under different atmospheric surface layer stability conditions 被引量:3
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作者 MENG Xiaoni LIU Huizhi +2 位作者 DU Qun LIU Yang XU Lujun 《Atmospheric and Oceanic Science Letters》 CSCD 2020年第5期400-406,共7页
The stratification of the atmospheric surface layer(ASL)plays an important role in regulating the water vapor and heat exchange across the lake–air interface.Based on one year of data measured by the eddy covariance ... The stratification of the atmospheric surface layer(ASL)plays an important role in regulating the water vapor and heat exchange across the lake–air interface.Based on one year of data measured by the eddy covariance technique over Erhai Lake in 2015,the ASL stability(ζ)was divided into six ranges,including unstable(-1ζ<-0:1),weakly unstable(-0:1ζ<-0:01),near-neutral1(-0:01ζ<0),near-neutral2(0ζ<0:01),weakly stable(0:01ζ<0:1),and stable(0:1ζ<1).The characteristics of ASL stability conditions and factors controlling the latent(LE)and sensible heat(H)fluxes under different stability conditions were analyzed in this study.The stability conditions of Erhai Lake have noticeably seasonal and diurnal variation,with the nearneutral and(weakly)stable stratification usually occurring before July,with frequencies of 51.7%and 23.3%,respectively,but most of the(weakly)unstable stratification was observed after July,with a frequency of 59.8%.Large evaporation occurred even in stable atmospheric conditions,due to the coupled effects of the relatively larger lake–air vapor pressure difference and wind speed.The relative controls of LE and H by different atmospheric variables are largely dependent on the stability conditions.In stable and unstable ranges,LE is closely correlated with the vapor pressure difference,whereas in weakly unstable to weakly stable ranges,it is primarily controlled by wind speed.H is related to wind speed and the lake–air temperature difference under stable conditions,but shows no obvious relationship under unstable conditions. 展开更多
关键词 Atmospheric surface layer stability eddy covariance Erhai Lake latent and sensible heat fluxes
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Spatiotemporal interpolation of precipitation across Xinjiang, China using space-time CoKriging 被引量:1
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作者 HU Dan-gui SHU Hong 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第3期684-694,共11页
In various environmental studies, geoscience variables not only have the characteristics of time and space, but also are influenced by other variables. Multivariate spatiotemporal variables can improve the accuracy of... In various environmental studies, geoscience variables not only have the characteristics of time and space, but also are influenced by other variables. Multivariate spatiotemporal variables can improve the accuracy of spatiotemporal estimation. Taking the monthly mean ground observation data of the period 1960–2013 precipitation in the Xinjiang Uygur Autonomous Region, China, the spatiotemporal distribution from January to December in 2013 was respectively estimated by space-time Kriging and space-time CoKriging. Modeling spatiotemporal direct variograms and a cross variogram was a key step in space-time CoKriging. Taking the monthly mean air relative humidity of the same site at the same time as the covariates, the spatiotemporal direct variograms and the spatiotemporal cross variogram of the monthly mean precipitation for the period 1960–2013 were modeled. The experimental results show that the space-time CoKriging reduces the mean square error by 31.46% compared with the space-time ordinary Kriging. The correlation coefficient between the estimated values and the observed values of the space-time CoKriging is 5.07% higher than the one of the space-time ordinary Kriging. Therefore, a space-time CoKriging interpolation with air humidity as a covariate improves the interpolation accuracy. 展开更多
关键词 space-time CoKriging product-sum model VARIOGRAM PRECIPITATION interpolation
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Numerical simulation on melt flow with bubble stirring and temperature field in aluminum holding furnace 被引量:1
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作者 张家奇 周乃君 周善红 《Journal of Central South University》 SCIE EI CAS 2011年第5期1726-1732,共7页
The numerical model for predicting the flow and temperature fields of the melt in holding furnace with porous brick purging system were set up using Euler-Lagrange approach.In this model,bubbles coalescence and disint... The numerical model for predicting the flow and temperature fields of the melt in holding furnace with porous brick purging system were set up using Euler-Lagrange approach.In this model,bubbles coalescence and disintegration were ignored based on the dimensionless analysis,and the bubble size was assumed to be obedient to Rosin-Rammler distribution with a mean size of 0.6 mm.The results show that on reference operating condition,during the heating and agitation process,melt mixes well in the furnace,and the melt velocity increases with the increase of gas flux.Holding the melt for 30 min causes the max temperature in the bulk melt to increase to 60 K.After holding the heat,the agitation processing restarts,and it takes 10 min for the stratified melt to retrieve the homogeneous temperature field when the gas flux is 10 L/min,which shows deficient alloying and degassing in the melt.With the increase of gas flux from 10 to 20,30 and 40 L/min,the necessary recovery time decreases from 10 to 6,5 and 4 min gradually,which shows the improvement of the stirring efficiency.Depending on the processing purposes,for both good degassing performance and gas saving,proper operating strategy and parameters (gas flux,primarily) could be adjusted. 展开更多
关键词 aluminum holding furnace porous brick bubble agitation computational fluid dynamic method
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Quantitative Surface Chirality Detection with Sum Frequency Generation Vibrational Spectroscopy: Twin Polarization Angle Approach
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作者 Feng Wei Yan-yan Xu +2 位作者 Yuan Guo Shi-lin Liu Hong-fei Wang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2009年第6期592-600,J0001,共10页
Here we report a novel twin polarization angle (TPA) approach in the quantitative chirality detection with the surface sum-frequency generation vibrational spectroscopy (SFG-VS). Generally, the achiral contributio... Here we report a novel twin polarization angle (TPA) approach in the quantitative chirality detection with the surface sum-frequency generation vibrational spectroscopy (SFG-VS). Generally, the achiral contribution dominates the surface SFG-VS signal, and the pure chiral signal is usually two or three orders of magnitude smaller. Therefore, it has been difficult to make quantitative detection and analysis of the chiral contributions to the surface SFG- VS signal. In the TPA method, by varying together the polarization angles of the incoming visible light and the sum frequency signal at fixed s or p polarization of the incoming infrared beam, the polarization dependent SFG signal can give not only direct signature of the chiral contribution in the total SFG-VS signal, but also the accurate measurement of the chiral and achiral components in the surface SFG signal. The general description of the TPA method is presented and the experiment test of the TPA approach is also presented for the SFG-VS from the S- and R-limonene chiral liquid surfaces. The most accurate degree of chiral excess values thus obtained for the 2878 cm^-1 spectral peak of the S- and R-limonene liquid surfaces are (23.7±0.4)% and (-25.4±1.3)%, respectively. 展开更多
关键词 Sum-frequency generation vibrational spectroscopy Twin polarization angle approach SURFACE CHIRALITY LIMONENE
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Self-normalized moderate deviations for independent random variables 被引量:2
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作者 JING BingYi LIANG HanYing ZHOU Wang 《Science China Mathematics》 SCIE 2012年第11期2297-2315,共19页
Let X1,X2,... be a sequence of independent random variables (r.v.s) belonging to the domain of attraction of a normal or stable law. In this paper, we study moderate deviations for the self-normalized sum n X ∑^n_i... Let X1,X2,... be a sequence of independent random variables (r.v.s) belonging to the domain of attraction of a normal or stable law. In this paper, we study moderate deviations for the self-normalized sum n X ∑^n_i=1Xi/Vm,p ,where Vn,p (∑^n_i=1|Xi|p)^1/p (P 〉 1).Applications to the self-normalized law of the iteratedlogarithm, Studentized increments of partial sums, t-statistic, and weighted sum of independent and identically distributed (i.i.d.) r.v.s are considered. 展开更多
关键词 self-normalized sum moderate deviation t-statistic LIL INCREMENT
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Constructions on Approximately Mutually Unbiased Bases by Galois Rings 被引量:3
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作者 LI Jin FENG Keqin 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第6期1440-1448,共9页
Several new series of approximately mutually unbiased bases are constructed by using Gauss sums and Jacobi sums over Galois rings GR(p2, r), and the tensor method.
关键词 MUB Galois rings Gauss sums Jacobi sums tensor method
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Clinical observation on the time-effect relationship of moxibustion for primary dysmenorrhea due to stagnation and congelation of cold-damp 被引量:4
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作者 Xue Xiao Liu Xin +5 位作者 Liu Yu Peng Guo-ran Wang Qian Chen Chun Li Yun Wang Pan-an 《Journal of Acupuncture and Tuina Science》 CSCD 2021年第1期62-66,共5页
Objective:To observe the time-effect relationship of moxibustion for primary dysmenorrhea(PD)due to stagnation and congelation of cold-damp,thus explore the optimal choice of moxibustion duration,and provide evidence ... Objective:To observe the time-effect relationship of moxibustion for primary dysmenorrhea(PD)due to stagnation and congelation of cold-damp,thus explore the optimal choice of moxibustion duration,and provide evidence for achieving satisfactory efficacy in moxibustion treatment.Methods:A total of 90 patients with PD due to stagnatin and congelation of cold-damp were divided into three groups by the random number table method,with 30 cases in each group.All the patients in the three groups were given moxibustion treatment at Guanyuan(CV 4),20 min in group A,40 min in group B and 60 min in group C.The changes in the pain measurement score in the three groups were observed after treatment.Results:After treatment,there were significant differences in the clinical efficacy among the three groups(P<0.05);the clinical efficacy was better in group B and group C than that in group A(P<0.05),and that in group B was better than that in group C(P<0.05).Besides,the pain measurement score changed significantly after treatment in the three groups(all P<0.05),and the between-group differences were also statistically significant(P<0.05);the pain measurement scores in group B and group C were lower than that in group A(P<0.05),and that in group B was lower than that in group C(P<0.05).Conclusion:Given the same stimulating frequency and intervention time of moxibustion,40-minute duration demonstrates relatively better efficacy for PD due to stagnation and congelation of cold-damp. 展开更多
关键词 Moxibustion Therapy Moxa Stick Moxibustion Mild Moxibustion Dose Response Relationship Acupuncture-moxibustion:Pain Measurement Cold-dampness Dysmenorrhea
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Synthesis of functionalized triphenylene discotic liquid crystals and the influence of unsaturated periphery on mesomorphism 被引量:1
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作者 ZHAO KeQing ZHOU Hui +4 位作者 YU WenHao HU Ping WANG BiQin MONOBE Hirosato SHIMIZU Yo 《Science China Chemistry》 SCIE EI CAS 2011年第10期1576-1583,共8页
Twelve triphenylene discogens with unsaturated periphery (abbreviated as C18H6(OC5H11)6-x(OR)x(x=1,2,3), R=-C3H6CH==CH2(a),-C3H6C≡CH(b),-C2H4OCH==CH2(c)) were synthesized and characterized. The thermotropic liquid cr... Twelve triphenylene discogens with unsaturated periphery (abbreviated as C18H6(OC5H11)6-x(OR)x(x=1,2,3), R=-C3H6CH==CH2(a),-C3H6C≡CH(b),-C2H4OCH==CH2(c)) were synthesized and characterized. The thermotropic liquid crystal prop-erties were studied by using polarized optical microscopy, differential scanning calorimetry and X-ray diffractometry. The results showed that all triphenylenes exhibited hexagonal columnar mesophase. The thermotropic studies showed that series a (alkene periphery) exhibited higher clearing points than the corresponding series b (alkyne periphery), while series c (vinyloxy periphery) exhibited highest clearing points and widest mesophase temperature ranges. We also found that the symmetric discogens sym-C18H6(OC5H11)3(OR)3 displayed higher melting points and clearing points than the asymmetric ones asym-C18H6(OC5H11)3(OR)3. 展开更多
关键词 discotic liquid crystal TRIPHENYLENE functional periphery hexagonal columnar mesophase mesomorphism engineering
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