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Prediction of Henry's constant in polymer solutions using PCOR equation of state coupled with an activity coefficient model 被引量:2
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作者 Somayeh Tourani Alireza Behvandi Farhad Khorasheh 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第3期528-535,共8页
In this paper,the polymer chain of rotator(PCOR) equation of state(EOS) was used together with an EOS/G^E mixing rule(MHV1) and the Wilson's equation as an excess-Gibbs-energy model in the proposed approach to ext... In this paper,the polymer chain of rotator(PCOR) equation of state(EOS) was used together with an EOS/G^E mixing rule(MHV1) and the Wilson's equation as an excess-Gibbs-energy model in the proposed approach to extend the capability and improve the accuracy of the PCOR EOS for predicting the Henry's constant of solutions containing polymers.The results of the proposed method compared with two equation of state(van der Waals and GC-Flory) and three activity coefficient models(UNIFAC,UNIFAC-FV and Entropic-FV) indicated that the PCOR EOS/Wilson's equation provided more accurate results.The interaction parameters of Wilson's equation were fitted with Henry's constant experimental data and the property parameters of PCOR,a and b,were fitted with experimental volume data(Tait equation).As a result,the present work provided a simple and useful model for prediction of Henry's constant for polymer solutions. 展开更多
关键词 henry's constant Polymer solutions Equation of state Activity coefficient model
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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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Reinvestigation of the Henry's law constant for hydrogen peroxide with temperature and acidity variation 被引量:1
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作者 Daoming Huang,Zhongming Chen The State Key Laboratory of Environmental Simulation and Pollution Control,College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China. 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第4期570-574,共5页
Hydrogen peroxide is not only an important oxidant in itself; it also serves as both sink and temporary reservoir for other important oxidants including HOx (OH and HO2) radicals and O3 in the atmosphere. Its partit... Hydrogen peroxide is not only an important oxidant in itself; it also serves as both sink and temporary reservoir for other important oxidants including HOx (OH and HO2) radicals and O3 in the atmosphere. Its partitioning between gas and aqueous phases in the atmosphere, usually described by its Henry's law constant (KH), significantly influences its role in atmospheric processes. Large discrepancies between the KH values reported in previous work, however, have created uncertainty for atmospheric modelers. Based on our newly developed online instrumentation, we have re-determined the temperature and acidity dependence of KH for hydrogen peroxide at an air pressure of (0.960 ± 0.013) atm (1 atm = 1.01325 × 10^5 Pa). The results indicated that the temperature dependence of KH for hydrogen peroxide fits to the Van't Hoff equation form, expressed as lnKH = a/T - b, and a = -△H/R, where KH is in M/atm (M is mol/L), T is in degrees Kelvin, R is the ideal gas constant, and AH is the standard heat of solution. For acidity dependence, results demonstrated that the KH value of hydrogen peroxide appeared to have no obvious dependence on decreasing pH level (from pH 7 to pH 1). Combining the dependence of both temperature and acidity, the obtained a and b were 7024 ± 138 and 11.97 ± 0.48, respectively, AH was (58.40 ± 1.15) kJ/(K.mol), and the uncertainties represent σ. Our determined KH values for hydrogen peroxide will therefore be of great use in atmospheric models. 展开更多
关键词 hydrogen peroxide henry's law constant ATMOsPHERE ACIDITY
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Prediction of Henry Constants and Adsorption Mechanism of Volatile Organic Compounds on Multi-Walled Carbon Nanotubes by Using Support Vector Regression 被引量:1
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作者 程文德 蔡从中 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第4期143-146,共4页
Support vector regression (SVR) combined with particle swarm optimization for its parameter optimization is employed to establish a model for predicting the Henry constants of multi-walled carbon nanotubes (MWNTs)... Support vector regression (SVR) combined with particle swarm optimization for its parameter optimization is employed to establish a model for predicting the Henry constants of multi-walled carbon nanotubes (MWNTs) for adsorption of volatile organic compounds (VOCs). The prediction performance of SVR is compared with those of the model of theoretical linear salvation energy relationship (TLSER). By using leave-one-out cross validation of SVR test Henry constants for adsorption of 35 VOCs on MWNTs, the root mean square error is 0.080, the mean absolute percentage error is only 1.19~, and the correlation coefficient (R2) is as high as 0.997. Compared with the results of the TLSER model, it is shown that the estimated errors by SVR are ali smaller than those achieved by TLSER. It reveals that the generalization ability of SVR is superior to that of the TLSER model Meanwhile, multifactor analysis is adopted for investigation of the influences of each molecular structure descriptor on the Henry constants. According to the TLSER model, the adsorption mechanism of adsorption of carbon nanotubes of VOCs is mainly a result of van der Waals and interactions of hydrogen bonds. These can provide the theoretical support for the application of carbon nanotube adsorption of VOCs and can make up for the lack of experimental data. 展开更多
关键词 of is in sVR Prediction of henry constants and Adsorption Mechanism of Volatile Organic Compounds on Multi-Walled Carbon Nanotubes by Using support Vector Regression VOCs MWNTs by on
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Gedankenexperiment for Modified ZPE and Planck’s “Constant”, h, in the Beginning of Cosmological Expansion, Partly Due to NLED
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作者 Andrew Walcott Beckwith 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期180-184,共5页
We initially look at a non singular universe representation of entropy, based in part on what was brought up by Muller and Lousto. This is a gateway to bringing up information and computational steps (as defined by Se... We initially look at a non singular universe representation of entropy, based in part on what was brought up by Muller and Lousto. This is a gateway to bringing up information and computational steps (as defined by Seth Lloyd) as to what would be available initially due to a modified ZPE formalism. The ZPE formalism is modified as due to Matt Visser’s alternation of k (maximum) ~ 1/(Planck length), with a specific initial density giving rise to initial information content which may permit fixing the initial Planck’s constant, h, which is pivotal to the setting of physical law. The settings of these parameters depend upon NLED. 展开更多
关键词 ZPE Planck’s constant Gedankenexperiment NLED
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Determination of the Henry’s Law Constant of Hexane in High-Viscosity Polymer Systems
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作者 Qi Jibing Li Yuliang +4 位作者 Liu Youzhi Yang Tong Liu Yandong Yuan Zhiguo Yi Jianjun 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2023年第1期34-43,共10页
The Henry’s law constant of volatiles in polymer systems is a crucial parameter reflecting the gas-liquid equilibrium,which is very important for devolatilization.In this research,polyolefin elastomer(POE)-cyclohexan... The Henry’s law constant of volatiles in polymer systems is a crucial parameter reflecting the gas-liquid equilibrium,which is very important for devolatilization.In this research,polyolefin elastomer(POE)-cyclohexane and polydimethylsiloxane(PDMS)-hexane systems were studied,and the Henry’s law constant was obtained by measuring the gas phase equilibrium partial pressure when polymer solutions containing different mass fractions of volatiles reached a saturated state.The effects of temperature,type of volatiles,and polymer viscosity on the gas phase equilibrium partial pressure and Henry’s law constant of the volatiles were investigated.The results indicate that,with the increase of temperature and polymer viscosity,the gas phase equilibrium partial pressure and Henry’s law constant of volatiles increase.As temperature increases,the solubility of gas in liquid decreases.The relationship between the Henry’s law constant and temperature is consistent with the Arrhenius law.In the PDMS-hexane system,the gas phase equilibrium partial pressure and Henry’s law constant of n-hexane are higher than those of cyclohexane.The obtained Henry’s law constants can be used as a reference for perfecting the devolatilization process and improving the devolatilization effect. 展开更多
关键词 henrys law constant gas-liquid equilibrium method HEXANE polyolefin elastomer(POE) polydimethylsiloxane(PDMs)
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Stoichiometry and Stability Constant Values for Copper (II) Chelates with Ethylene Diamine in Deep Eutectic Solvents (DES) (Ethaline) Solutions
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作者 Khalid El Ttaib Abdolhadi Benhmid Rifat Hasan Omar 《Open Journal of Applied Sciences》 2024年第9期2592-2609,共18页
In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements ha... In this study we used the deep eutectic solvents (ionic liquids) to investigate the reaction between copper (II) with ethylene diamine (en). Two of the existing methods for analyzing spectrophotometric measurements have been applied for establishing, the stoichiometry and whenever possible, the stability constants of the chelates formed. The method of continuous variations was necessary to determine first whether, the metal ion and the ligand ethylene diamine form one or more than one chelate, when more than one chelate formed, the results obtained depend on the wavelength and for meaningful conclusions the wavelengths were carefully selected. The empirical formulae of the chelates were further substantiated by the molar ratio method. The effect of time and temperature on the formation and stability of these chelates in solution is also studied. The stability constants, K1 and K2 for the copper (II) chelates were calculated, though reliable, and are comparable to literature values. 展开更多
关键词 CU(II) Ethylene Diamine (en) Deep Eutectic solvents Job’s Method Ionic Liquids and stability constant
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洗车废水VOCs的特征、健康风险和异味活性
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作者 王亚玲 孙成一 +1 位作者 蒋宝 王海林 《环境科学研究》 北大核心 2025年第2期262-271,共10页
为了探索洗车废水中VOCs的污染特征和健康影响,对北京市某区随机抽取60家汽修企业,用气相色谱-质谱联用仪和气相色谱-离子迁移谱,对洗车废水中VOCs的组分特征、健康风险和异味指纹图谱进行了研究。结果表明:①洗车废水中总VOCs浓度范围... 为了探索洗车废水中VOCs的污染特征和健康影响,对北京市某区随机抽取60家汽修企业,用气相色谱-质谱联用仪和气相色谱-离子迁移谱,对洗车废水中VOCs的组分特征、健康风险和异味指纹图谱进行了研究。结果表明:①洗车废水中总VOCs浓度范围为11.60~1300.00μg/L,包括芳香烃类和卤代烃类。芳香烃类中检出率较高(>10%)的物质为甲苯、1,2,4-三甲基苯、邻二甲苯、间,对-二甲苯、1,3,5-三甲基苯,其浓度范围分别为1.00~683.00、1.60~84.00、2.00~38.00、3.00~62.00、3.50~15.30μg/L;卤代烃类中检出率较高(>10%)的物质为氯仿、二氯甲烷,其浓度范围分别为0.70~20.60、0.90~419.00μg/L。②经亨利常数计算废水释放到洗车间空气的VOCs与废水VOCs污染特征相似(矩阵相似度余弦值为0.945),洗车间空气ΣVOCs浓度为0.05~291.17 mg/m^(3),检出率和浓度较高的组分是甲苯(0.27~185.38 mg/m^(3))和二氯甲烷(0.12~55.70 mg/m^(3)),其他检出率较高的VOCs包括1,2,4-三甲基苯、邻-二甲苯、间,对-二甲苯、1,3,5-三甲基苯和氯仿,其浓度范围分别为0.40~21.15、0.42~8.05、0.88~18.20、1.25~5.48、0.11~3.09 mg/m^(3)。③8.3%~40.0%的企业甲苯、二甲苯和三甲苯具有非致癌风险(1.00~80.48),1.7%~10.0%的企业二氯甲烷、1,2-二氯乙烷、四氯乙烯、环氧氯丙烷、1,1,2,2-四氯乙烷和1,2,3-三氯丙烷的致癌风险(10^(-6)~5.45×10^(-5))需要引起关注,1.7%~43.3%的企业氯仿、氯乙烯、1,2-二氯乙烷、四氯乙烯、三氯乙烯的致癌风险(10^(-4)~1.79×10^(-2))需要重点关注。④本文构建了洗车废水20种异味风险较高的物质清单,主要为C2-C8含氧、含硫和含氮异味物质。研究显示,废水中VOCs释放将导致洗车间空气VOCs浓度水平较高,洗车废水具有健康风险和异味风险,需协同实施消费品VOCs含量限值和绿色产品全生命周期管控技术。 展开更多
关键词 洗车废水 亨利常数 健康风险 异味风险指数
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SP0810色谱柱上D-塔格糖和D-半乳糖Henry常数的测定 被引量:1
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作者 周慧君 孙玉高 +2 位作者 徐巍 来梦龙 徐进 《应用化工》 CAS CSCD 2013年第5期965-967,共3页
利用高效液相色谱测定在SP0810色谱柱上吸附的Henry常数,以超纯水作为流动相,在流速为0.5 mL/min,柱温为35℃,进样20μL的条件下,测定D-半乳糖的Henry常数为0.56,D-塔格糖Henry常数为1.28。此外,研究了柱温对Henry常数的影响,估算了D-... 利用高效液相色谱测定在SP0810色谱柱上吸附的Henry常数,以超纯水作为流动相,在流速为0.5 mL/min,柱温为35℃,进样20μL的条件下,测定D-半乳糖的Henry常数为0.56,D-塔格糖Henry常数为1.28。此外,研究了柱温对Henry常数的影响,估算了D-塔格糖及D-半乳糖的吸附焓。 展开更多
关键词 D-半乳糖 D-塔格糖 高效液相 henry常数
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Physical interpretation of Planck's constant based on the Maxwell theory 被引量:1
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作者 张东才 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第4期87-95,共9页
The discovery of the Planck relation is generally regarded as the starting point of quantum physics.Planck's constant h is now regarded as one of the most important universal constants.The physical nature of h,howeve... The discovery of the Planck relation is generally regarded as the starting point of quantum physics.Planck's constant h is now regarded as one of the most important universal constants.The physical nature of h,however,has not been well understood.It was originally suggested as a fitting constant to explain the black-body radiation.Although Planck had proposed a theoretical justification of h,he was never satisfied with that.To solve this outstanding problem,we use the Maxwell theory to directly calculate the energy and momentum of a radiation wave packet.We find that the energy of the wave packet is indeed proportional to its oscillation frequency.This allows us to derive the value of Planck's constant.Furthermore,we show that the emission and transmission of a photon follows the all-or-none principle.The "strength" of the wave packet can be characterized by ζ,which represents the integrated strength of the vector potential along a transverse axis.We reason that ζ should have a fixed cut-off value for all photons.Our results suggest that a wave packet can behave like a particle.This offers a simple explanation to the recent satellite observations that the cosmic microwave background follows closely the black-body radiation as predicted by Planck's law. 展开更多
关键词 Planck's constant Maxwell's theory de Broglie relation uncertainty principle wave packet PHOTON
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A New Labdane Diterpenoid from the Bark of Larix olgensis Henry var. koreana Nakai 被引量:1
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作者 BaoHuaYANG WeiDongZHANG ZhengBingGU TingZhaoLI ChuanZHANG YunZHOU 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第8期919-920,共2页
A new diterpenoid was isolated from the bark of Larix olgensis Henry var. koreana Nakai. Its structure was elucidated as 5S, 9S, 10R-labda-8 (17), 13-diene-6a, 15-diol l by spectroscopic methods.
关键词 Larix olgensis henry var. koreana Nakai DITERPENOID 5s 9s 10R- labda-8 (17) 13-diene-6α 15-diol.
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ASYMPTOTIC EQUIVALENCE OF ALTERNATELY ADVANCED AND DELAYED DIFFERENTIAL SYSTEMS WITH PIECEWISE CONSTANT GENERALIZED ARGUMENTS 被引量:1
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作者 Kuo-Shou CHIU 《Acta Mathematica Scientia》 SCIE CSCD 2018年第1期220-236,共17页
In this paper, we investigate the existence, uniqueness and the asymptotic equiv- alence of a linear system and a perturbed system of differential equations with piecewise alternately advanced and retarded argument of... In this paper, we investigate the existence, uniqueness and the asymptotic equiv- alence of a linear system and a perturbed system of differential equations with piecewise alternately advanced and retarded argument of generalized type (DEPCAG). This is based in the study of an equivalent integral equation with Cauchy and Green matrices type and in a solution of a DEPCAG integral inequality of Gronwall type. Several examples are also given to show the feasibility of results. 展开更多
关键词 piecewise constant argument of generalized type hybrid equations EQUIVALENCE asymptotic behavior Gronwall's inequality
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Stability constants of Sb^5+with Cl−and thermodynamics of Sb−S−Cl−H2O system involving complex behavior of Sb with Cl 被引量:1
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作者 Gang LI Yun-tao XIN +3 位作者 Xiao-dong Lü Qing-hua TIAN Kang YAN Long-gang YE 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第12期3379-3389,共11页
The stability constants of Sb^5+with Cl−as well as thermodynamics of the Sb−S−Cl−H2O system were calculated.The stability constants of Sb5+with Cl−were obtained by theoretical calculations of the absorbance of a Sb5+-... The stability constants of Sb^5+with Cl−as well as thermodynamics of the Sb−S−Cl−H2O system were calculated.The stability constants of Sb5+with Cl−were obtained by theoretical calculations of the absorbance of a Sb5+-containing solution at different Cl^−concentrations,which was detected by spectrophotometric analysis at certain wavelengths of light(380 nm).The logarithmic values versus 10 of stability constants of Sb^5+with Cl−were 1.795,3.150,4.191,4.955,5.427 and 5.511,respectively,and partly filled the data gaps in the hydrometallurgy of antimony.The presence and distribution of pentavalent antimony compounds under different conditions were analyzed based on equilibrium calculations.Thermodynamic equilibrium calculations were performed for Sb−S−Cl−H2O system,which included the complex behavior of Sb with Cl,and the equilibrium equations of related reactions in this system were integrated into the potential−pH diagram. 展开更多
关键词 complex behavior stability constant thermodynamics sb−s−Cl−H2O system
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Mass Constituents of a Flat Lattice Multiverse: Conclusion from Similarity between Two Universal Numbers, the Rocksalt-Type 2<i>D</i>Madelung Constant and the Golden Mean 被引量:2
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作者 Hans Hermann Otto 《Journal of Modern Physics》 2018年第1期1-13,共13页
In fairly good agreement with the consensus range of dark energy to matter this ratio of the critical density is suggested to be connected with the golden mean &phi;=0.6180339887, yielding for dark energy to matte... In fairly good agreement with the consensus range of dark energy to matter this ratio of the critical density is suggested to be connected with the golden mean &phi;=0.6180339887, yielding for dark energy to matter mass fractions .?Assuming the baryonic matter to be only 4.432%, the ratio of matter to baryonic matter would be , and further the ratio of dark matter to baryonic one . If one subtracts from the dark matter a contribution of antimatter with the same mass of baryonic matter, according to the antigravity theories of Villata respectively Hajdukovic, the remaining mass ratio would yield . Replacing the “Madelung” constant α of Villata’s “lattice universe” by &phi;, one reaches again 1 + &phi;as the ratio of the repulsive mass contribution to the attractive one. Assuming instead of a 3D lattice a flat 2D one of rocksalt type, the numerical similarity between the Madelung constant and φ&minus;1 could not be just coincidence. The proposed scaling of the cosmological mass fractions with the square of the most irrational universal number &phi;may indicate that the chaotic cosmological processes have reached a quite stable equilibrium. This may be confirmed by another, but similar representation of the mass constituents by the Archimedes’ constant &pi;, giving for respectively for the dark components . However, the intimate connection of φ with its reciprocal may ignite the discussion whether our universe is intertwined with another universe or even part of a multiverse with the dark constituents contributed from there. 展开更多
关键词 UNIVERsAL NUMBERs Fractal NUMBERs Golden Mean Archimedes constant Fibonacci NUMBERs Madelung constants sommerfeld’s Fine structure constant Euler Number LATTICE UNIVERsE Reciprocal UNIVERsE Cosmological MAss Fractions Hubble constant Gyromagnetic Factor
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Values of Siva’s Constant “<i>K</i>” for All Fundamental Forces—A Review on Spin, Threshold Time and Quantum Entanglement 被引量:2
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作者 Siva Prasad Kodukula 《Journal of Modern Physics》 2019年第4期466-476,共11页
Siva’s constant “K” has been explained in brief. Its numerical values have been calculated for each fundamental force of nature. Spin of quantum mechanics has been interpreted in terms of Sivas constant “K”. Thus... Siva’s constant “K” has been explained in brief. Its numerical values have been calculated for each fundamental force of nature. Spin of quantum mechanics has been interpreted in terms of Sivas constant “K”. Thus limitation to velocity of light and interrelation between relativity and quantum mechanics has been explained in a novel and profound way. Involvement of “physics of consciousness” in synchronizing relativity and quantum mechanics has been emphasized. Concept of “bio force” as fifth fundamental force in addition to other four fundamental forces, strong, weak, electromagnetic and gravitational forces also has been emphasized. Consciousness has been explained as entanglement between bio force particle named as “jeeton” and gravitational force particle “graviton”. Thus frequency mediated consciousness has been explained. 展开更多
关键词 siva’s constant “K” Bio Force Particle Jeeton sPIN Grand Unification QUANTUM Mechanics Relativity QUANTUM Entanglement
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Experimental Evidence for Variability in Planck’s Constant 被引量:3
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作者 Richard A. Hutchin 《Optics and Photonics Journal》 2016年第6期124-137,共14页
Annual variations of 1000 - 3000 ppm (peak-to-valley) have been observed in the decay rates of 8 radionuclides over a 20 year span by six organizations on three continents, including beta decay (weak interaction) and ... Annual variations of 1000 - 3000 ppm (peak-to-valley) have been observed in the decay rates of 8 radionuclides over a 20 year span by six organizations on three continents, including beta decay (weak interaction) and alpha decay (strong interaction). In searching for a common cause, we hypothesized that small variations in Planck’s constant might account for the observed synchronized variations in strong and weak decays. If so, then h would be a maximum around January-February of each year and a minimum around July-August of each year based on the 20 years of radioactive decay data. To test this hypothesis, a purely electromagnetic experiment was set up to search for the same annual variations. From Jun 14, 2011 to Jan 29, 2014 (941 days), annual variations in tunneling voltage through 5 parallel Esaki tunnel diodes were recorded. It found annual variations of 826 ppm peak-to-valley peaking around Jan 1. These variations lend support to the hypothesis that there is a gradient in h of about 21 ppm across the Earth’s orbit. 展开更多
关键词 Planck’s constant Variable Radioactive Decay Rate Variable Plank’s constant
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Henry David Thoreau's Spiritual World
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作者 马云 《英语广场(学术研究)》 2013年第11期14-16,共3页
Henry David Thoreau was wholeheartedly in love with nature and he devoted almost all his life time to observation,appreciation and study of nature.Thus he formed a deep understanding of nature.In 1845,Thoreau began a ... Henry David Thoreau was wholeheartedly in love with nature and he devoted almost all his life time to observation,appreciation and study of nature.Thus he formed a deep understanding of nature.In 1845,Thoreau began a two-year and twomonth residence at Walden Pond.His life was lonely but full of fragrance.He wanted to live meaningfully,confront the essential facts of life and live a simple life.Based on the review of the literature related to this topic,this paper aims to study Henry David Thoreau’s spiritual world,especially reflected in his famous book—Walden. 展开更多
关键词 LIFE henry David Thoreau’s spiritual World
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FLIP AND N-S BIFURCATION BEHAVIOR OF A PREDATOR-PREY MODEL WITH PIECEWISE CONSTANT ARGUMENTS AND TIME DELAY 被引量:1
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作者 尚随明 田玉 张雅静 《Acta Mathematica Scientia》 SCIE CSCD 2017年第6期1705-1726,共22页
In this paper, the stability and bifurcation behaviors of a predator-prey model with the piecewise constant arguments and time delay are investigated. Technical approach is fully based on Jury criterion and bifurcatio... In this paper, the stability and bifurcation behaviors of a predator-prey model with the piecewise constant arguments and time delay are investigated. Technical approach is fully based on Jury criterion and bifurcation theory. The interesting point is that the model will produce two different branches by limiting branch parameters of different intervals. Besides, image simulation is also given. 展开更多
关键词 piecewise constant arguments time delay flip bifurcation N-s bifurcation stability
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Newton Did Not Invent or Use the So-Called Newton’s Gravitational Constant;G, It Has Mainly Caused Confusion 被引量:1
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作者 Espen Gaarder Haug 《Journal of Modern Physics》 2022年第2期179-205,共27页
Newton did not invent or use the so-called Newton’s gravitational constant G. Newton’s original gravity formula was and not . In this paper, we will show how a series of major gravity phenomena can be calculated and... Newton did not invent or use the so-called Newton’s gravitational constant G. Newton’s original gravity formula was and not . In this paper, we will show how a series of major gravity phenomena can be calculated and predicted without the gravitational constant. This is, to some degree, well known, at least for those that have studied a significant amount of the older literature on gravity. However, to understand gravity at a deeper level, still without G, one needs to trust Newton’s formula. It is when we first combine Newton’s assumptionn, that matter and light ultimately consist of hard indivisible particles, with new insight in atomism that we can truly begin to understand gravity at a deeper level. This leads to a quantum gravity theory that is unified with quantum mechanics and in which there is no need for G and not even a need for the Planck constant. We claim that two mistakes have been made in physics, which have held back progress towards a unified quantum gravity theory. First, it has been common practice to consider Newton’s gravitational constant as almost holy and untouchable. Thus, we have neglected to see an important aspect of mass;namely, the indivisible particle that Newton also held in high regard. Second, standard physics have built their quantum mechanics around the de Broglie wavelength, rather than the Compton wavelength. We claim the de Broglie wavelength is merely a mathematical derivative of the Compton wavelength, the true matter wavelength. 展开更多
关键词 Newton Gravity Newton’s Gravitational constant schwarzschild Radius Quantum Gravity Planck Length
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硅和镁质量分数对Al-Si-Mg合金机械力学性能参数影响的计算分析 被引量:1
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作者 郭柔 刘文豪 +2 位作者 薛预超 马瑞杰 胡心平 《齐鲁工业大学学报》 CAS 2024年第4期30-35,共6页
基于第一性原理,利用CASTEP模块,通过虚拟晶体近似的方法建模,采用GGA+PBE泛函关联函数,研究了Al-Si7-Mg X(X=0.1~0.5)、Al-Si X-Mg0.3(X=6~9)合金中的Si、Mg质量分数的变化对机械力学性能参数的影响。研究表明,随着研究组元质量分数的... 基于第一性原理,利用CASTEP模块,通过虚拟晶体近似的方法建模,采用GGA+PBE泛函关联函数,研究了Al-Si7-Mg X(X=0.1~0.5)、Al-Si X-Mg0.3(X=6~9)合金中的Si、Mg质量分数的变化对机械力学性能参数的影响。研究表明,随着研究组元质量分数的增加,晶格常数有所减小,最大值与最小值相差约0.265%;弹性常数C_(11)、C_(12)、C_(44)满足结构稳定性条件;体积模量B、剪切模量G、杨氏模量E、泊松比u随着A356中Si、Mg质量分数变化而变化;Mg质量分数的变化对剪切模量G、杨氏模量E的影响比Si质量分数的变化更敏感。计算结果与现有实验数据对比表明,计算结果接近实验数据,第一性原理计算Al-Si-Mg合金材料参数可行。 展开更多
关键词 第一性原理 Al-si-Mg 晶格常数 弹性模量 泊松比
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