The article develops a cosmological model based on a hypothesis that dark energy is a cosmological variable rather than a constant. A companion paper (DEH I) derives a formula for this variable cosmological parameter ...The article develops a cosmological model based on a hypothesis that dark energy is a cosmological variable rather than a constant. A companion paper (DEH I) derives a formula for this variable cosmological parameter as well as an argument that the early universe produces it and dark matter. The developed model leads to a series of self-consistent results including a prediction that provides a test for it. The results include comparisons of the DEH and the ΛCDM theory.展开更多
Time delay and integration (TDI) charge coupled device (CCD) noise sets a fundamental limit on image sensor performance, especially under low illumination in remote sensing applications. After introducing the comp...Time delay and integration (TDI) charge coupled device (CCD) noise sets a fundamental limit on image sensor performance, especially under low illumination in remote sensing applications. After introducing the complete sources of CCD noise, we study the effects of TDI operation mode on noise, and the relationship between different types of noise and number of the TDI stage. Then we propose a new technique to identify and measure sources of TDI CCD noise employing mathematical statistics theory, where theoretical analysis shows that noise estimated formulation converges well. Finally, we establish a testing platform to carry out experiments, and a standard TDI CCD is calibrated by using the proposed method. The experimental results show that the noise analysis and measurement methods presented in this paper are useful for modeling TDI CCDs.展开更多
As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry (GCxGC- TOFMS) has received much research attention. Here we present a ca...As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry (GCxGC- TOFMS) has received much research attention. Here we present a case study in the Junggar Basin of NW China. Results show that the hydrocarbons, including saturates and aromatics, were all well-separated without large co- elution, which cannot be realized by conventional one-dimensional GC-MS. The GC×GC technique is especially effective for analyzing aromatics and low-to-middle- molecular-weight hydrocarbons, such as diamondoids. The geochemical characteristics of crude oils in the study area were investigated through geochemical parameters extracted by GC×GC-TOFMS, improving upon the understanding obtained by GC-MS. Thus, the work here represents a new successful application of GC×GC- TOFMS, showing its broad usefulness in petroleum geochemistry.展开更多
The generalized master equation for the space-time coupled continuous time random walk is derived analytically, in which the space-time coupling is considered through the correlated function 9(t) ~ t^γ, 0 ≤ γ 〈...The generalized master equation for the space-time coupled continuous time random walk is derived analytically, in which the space-time coupling is considered through the correlated function 9(t) ~ t^γ, 0 ≤ γ 〈 2, and the probability density function ω(t) of a particle's waiting time t follows a power law form for large t: ω(t) ~t^-(1+α), 0 〈 α 〈 1. The results indicate that the expressions of the generalized master equation are determined by the correlation exponent 7 and the long-tailed index α of the waiting time. Moreover, the diffusion results obtained from the generalized master equation are in accordance with the previous known results and the numerical simulation results.展开更多
A regional air-sea coupled model, comprising the Regional Integrated Environment Model System (RIEMS) and the Princeton Ocean Model (POM) was developed to simulate summer climate features over East Asia in 2000. T...A regional air-sea coupled model, comprising the Regional Integrated Environment Model System (RIEMS) and the Princeton Ocean Model (POM) was developed to simulate summer climate features over East Asia in 2000. The sensitivity of the model's behavior to the coupling time interval (CTI), the causes of the sea surface temperature (SST) biases, and the role of air-sea interaction in the simulation of precipitation over China are investigated. Results show that the coupled model can basically produce the spatial pattern of SST, precipitation, and surface air temperature (SAT) with five different CTIs respectively. Also, using a CTI of 3, 6 or 12 hours tended to produce more successful simulations than if using 1 and 24 hours. Further analysis indicates that both a higher and lower coupling frequency result in larger model biases in air-sea heat flux exchanges, which might be responsible for the sensitivity of the coupled model's behavior to the CTI. Sensitivity experiments indicate that SST biases between the coupled and uncoupled POM occurring over the China coastal waters were due to the mismatch of the surface heat fluxes produced by the RIEMS with those required by the POM. In the coupled run, the air-sea feedbacks reduced the biases in surface heat fluxes, compared with the uncoupled RIEMS, consequently resulted in changes in thermal contrast over land and sea and led to a precipitation increase over South China and a decrease over North China. These results agree well observations in the summer of 2000.展开更多
An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation sin...An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation since November 1, 2007. In this paper we comprehensively present the simulation and verification of the system, whose distinguishing feature is that the wave-induced mixing is coupled in the circulation model. In particular, with nested technique the resolution in the China's seas has been updated to(1/24)° from the global model with(1/2)°resolution. Besides, daily remote sensing sea surface temperature(SST) data have been assimilated into the model to generate a hot restart field for OCFS-C. Moreover, inter-comparisons between forecasting and independent observational data are performed to evaluate the effectiveness of OCFS-C in upper-ocean quantities predictions, including SST, mixed layer depth(MLD) and subsurface temperature. Except in conventional statistical metrics, non-dimensional skill scores(SS) is also used to evaluate forecast skill. Observations from buoys and Argo profiles are used for lead time and real time validations, which give a large SS value(more than 0.90). Besides, prediction skill for the seasonal variation of SST is confirmed. Comparisons of subsurface temperatures with Argo profiles data indicate that OCFS-C has low skill in predicting subsurface temperatures between 100 m and 150 m. Nevertheless, inter-comparisons of MLD reveal that the MLD from model is shallower than that from Argo profiles by about 12 m, i.e., OCFS-C is successful and steady in MLD predictions. Validation of 1-d, 2-d and 3-d forecasting SST shows that our operational ocean circulation-surface wave coupled forecasting model has reasonable accuracy in the upper ocean.展开更多
The time delay integration charge coupled device(TDI CCD)is the key component in remote sensing systems.The paper analyzes the structure and the working principles of the device according to a customized TDI CCD chip....The time delay integration charge coupled device(TDI CCD)is the key component in remote sensing systems.The paper analyzes the structure and the working principles of the device according to a customized TDI CCD chip.Employing the special clock resources and large-scale phase locked logic(PLL)in field-programmable gate arrays(FPGA),a timing-driven approach is proposed,using which all timing signals including reset gate,horizontal and vertical timing signals,are implemented in one chip.This not only reduces printed circuit board(PCB)space,but also enhances the portability of the system.By studying and calculating CCD parameters thoroughly,load capacity and power consumption,package,etc,are compared between various candidates chips,and detailed comparison results are also listed in table.Experimental results show that clock generator and driving circuit satisfy the requirements of high speed TDI CCD.展开更多
The aim of the article is to construct exact solutions for the time fractional coupled Boussinesq-Burger and approximate long water wave equations by using the generalized Kudryashov method.The fractional differential...The aim of the article is to construct exact solutions for the time fractional coupled Boussinesq-Burger and approximate long water wave equations by using the generalized Kudryashov method.The fractional differential equation is converted into ordinary differential equations with the help of fractional complex transform and the modified Riemann-Liouville derivative sense.Applying the generalized Kudryashov method through with symbolic computer maple package,numerous new exact solutions are successfully obtained.All calculations in this study have been established and verified back with the aid of the Maple package program.The executed method is powerful,effective and straightforward for solving nonlinear partial differential equations to obtain more and new solutions with the integer and fractional order.展开更多
Curcumin,a safe natural yellow pigment with a wide range of pharmacological activities,is used both in herbal drugs and as a food coloring agents.Studies have shown that curcumin would suffer from extensive metabolism...Curcumin,a safe natural yellow pigment with a wide range of pharmacological activities,is used both in herbal drugs and as a food coloring agents.Studies have shown that curcumin would suffer from extensive metabolism in vivoand the predominant metabolic pathways are reduction and conjugation.In order to comprehensively study the metabolism and enrich the metabolic profile of cxurcumin in vivo,we carried out this research.A systematic method with highly sensitive UPLC-Q/TOF-MS was established to analyze different biological samples of rats after展开更多
文摘The article develops a cosmological model based on a hypothesis that dark energy is a cosmological variable rather than a constant. A companion paper (DEH I) derives a formula for this variable cosmological parameter as well as an argument that the early universe produces it and dark matter. The developed model leads to a series of self-consistent results including a prediction that provides a test for it. The results include comparisons of the DEH and the ΛCDM theory.
基金Project supported by the National High Technology Research and Development Program of China (Grant No. 2006AA06A208)
文摘Time delay and integration (TDI) charge coupled device (CCD) noise sets a fundamental limit on image sensor performance, especially under low illumination in remote sensing applications. After introducing the complete sources of CCD noise, we study the effects of TDI operation mode on noise, and the relationship between different types of noise and number of the TDI stage. Then we propose a new technique to identify and measure sources of TDI CCD noise employing mathematical statistics theory, where theoretical analysis shows that noise estimated formulation converges well. Finally, we establish a testing platform to carry out experiments, and a standard TDI CCD is calibrated by using the proposed method. The experimental results show that the noise analysis and measurement methods presented in this paper are useful for modeling TDI CCDs.
基金funded by the Major State Basic Research Development Program of China(973 project,Grant No.2012CB214803)National Science and Technology Major Project of China(Grant No. 2016ZX05003-005)National Natural Science Foundation of China(Grant Nos.41322017 and 41472100)
文摘As a new technology of analyzing crude oils, comprehensive two-dimensional gas chromatography cou- pled with time-of-flight mass spectrometry (GCxGC- TOFMS) has received much research attention. Here we present a case study in the Junggar Basin of NW China. Results show that the hydrocarbons, including saturates and aromatics, were all well-separated without large co- elution, which cannot be realized by conventional one-dimensional GC-MS. The GC×GC technique is especially effective for analyzing aromatics and low-to-middle- molecular-weight hydrocarbons, such as diamondoids. The geochemical characteristics of crude oils in the study area were investigated through geochemical parameters extracted by GC×GC-TOFMS, improving upon the understanding obtained by GC-MS. Thus, the work here represents a new successful application of GC×GC- TOFMS, showing its broad usefulness in petroleum geochemistry.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11605003 and 11547231
文摘The generalized master equation for the space-time coupled continuous time random walk is derived analytically, in which the space-time coupling is considered through the correlated function 9(t) ~ t^γ, 0 ≤ γ 〈 2, and the probability density function ω(t) of a particle's waiting time t follows a power law form for large t: ω(t) ~t^-(1+α), 0 〈 α 〈 1. The results indicate that the expressions of the generalized master equation are determined by the correlation exponent 7 and the long-tailed index α of the waiting time. Moreover, the diffusion results obtained from the generalized master equation are in accordance with the previous known results and the numerical simulation results.
基金supported by the National Basic Research Program under Grand No.2006CB400506
文摘A regional air-sea coupled model, comprising the Regional Integrated Environment Model System (RIEMS) and the Princeton Ocean Model (POM) was developed to simulate summer climate features over East Asia in 2000. The sensitivity of the model's behavior to the coupling time interval (CTI), the causes of the sea surface temperature (SST) biases, and the role of air-sea interaction in the simulation of precipitation over China are investigated. Results show that the coupled model can basically produce the spatial pattern of SST, precipitation, and surface air temperature (SAT) with five different CTIs respectively. Also, using a CTI of 3, 6 or 12 hours tended to produce more successful simulations than if using 1 and 24 hours. Further analysis indicates that both a higher and lower coupling frequency result in larger model biases in air-sea heat flux exchanges, which might be responsible for the sensitivity of the coupled model's behavior to the CTI. Sensitivity experiments indicate that SST biases between the coupled and uncoupled POM occurring over the China coastal waters were due to the mismatch of the surface heat fluxes produced by the RIEMS with those required by the POM. In the coupled run, the air-sea feedbacks reduced the biases in surface heat fluxes, compared with the uncoupled RIEMS, consequently resulted in changes in thermal contrast over land and sea and led to a precipitation increase over South China and a decrease over North China. These results agree well observations in the summer of 2000.
基金China-Korea Cooperation Project on the development of oceanic monitoring and prediction system on nuclear safetythe Project of the National Programme on Global Change and Air-sea Interaction under contract No.GASI-03-IPOVAI-05
文摘An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation since November 1, 2007. In this paper we comprehensively present the simulation and verification of the system, whose distinguishing feature is that the wave-induced mixing is coupled in the circulation model. In particular, with nested technique the resolution in the China's seas has been updated to(1/24)° from the global model with(1/2)°resolution. Besides, daily remote sensing sea surface temperature(SST) data have been assimilated into the model to generate a hot restart field for OCFS-C. Moreover, inter-comparisons between forecasting and independent observational data are performed to evaluate the effectiveness of OCFS-C in upper-ocean quantities predictions, including SST, mixed layer depth(MLD) and subsurface temperature. Except in conventional statistical metrics, non-dimensional skill scores(SS) is also used to evaluate forecast skill. Observations from buoys and Argo profiles are used for lead time and real time validations, which give a large SS value(more than 0.90). Besides, prediction skill for the seasonal variation of SST is confirmed. Comparisons of subsurface temperatures with Argo profiles data indicate that OCFS-C has low skill in predicting subsurface temperatures between 100 m and 150 m. Nevertheless, inter-comparisons of MLD reveal that the MLD from model is shallower than that from Argo profiles by about 12 m, i.e., OCFS-C is successful and steady in MLD predictions. Validation of 1-d, 2-d and 3-d forecasting SST shows that our operational ocean circulation-surface wave coupled forecasting model has reasonable accuracy in the upper ocean.
基金National High Technology Research and Development Program of China(863 Program)(No.2009AA7010102)
文摘The time delay integration charge coupled device(TDI CCD)is the key component in remote sensing systems.The paper analyzes the structure and the working principles of the device according to a customized TDI CCD chip.Employing the special clock resources and large-scale phase locked logic(PLL)in field-programmable gate arrays(FPGA),a timing-driven approach is proposed,using which all timing signals including reset gate,horizontal and vertical timing signals,are implemented in one chip.This not only reduces printed circuit board(PCB)space,but also enhances the portability of the system.By studying and calculating CCD parameters thoroughly,load capacity and power consumption,package,etc,are compared between various candidates chips,and detailed comparison results are also listed in table.Experimental results show that clock generator and driving circuit satisfy the requirements of high speed TDI CCD.
文摘The aim of the article is to construct exact solutions for the time fractional coupled Boussinesq-Burger and approximate long water wave equations by using the generalized Kudryashov method.The fractional differential equation is converted into ordinary differential equations with the help of fractional complex transform and the modified Riemann-Liouville derivative sense.Applying the generalized Kudryashov method through with symbolic computer maple package,numerous new exact solutions are successfully obtained.All calculations in this study have been established and verified back with the aid of the Maple package program.The executed method is powerful,effective and straightforward for solving nonlinear partial differential equations to obtain more and new solutions with the integer and fractional order.
基金partly supported by National Natural Science Foundation of China(No.81430095)also by Special National Program on Key Basic Research Project(No.2014CB560706)
文摘Curcumin,a safe natural yellow pigment with a wide range of pharmacological activities,is used both in herbal drugs and as a food coloring agents.Studies have shown that curcumin would suffer from extensive metabolism in vivoand the predominant metabolic pathways are reduction and conjugation.In order to comprehensively study the metabolism and enrich the metabolic profile of cxurcumin in vivo,we carried out this research.A systematic method with highly sensitive UPLC-Q/TOF-MS was established to analyze different biological samples of rats after