Prosaposin (Psap) has multiple cellular functions. It is involved in the development of the reproductive system, nervous system, and prostate cancer as well as in the regulation of sphingolipid catabolism by activat...Prosaposin (Psap) has multiple cellular functions. It is involved in the development of the reproductive system, nervous system, and prostate cancer as well as in the regulation of sphingolipid catabolism by activating several lysosomal hydrolases involved in the metabolism of various sphingolipids. In this research, it was found to be a novel interaction partner for Rhox5 using yeast two-hybrid screening. The interaction between Rhox5 and the full-length prosapsoin (the transcript without exon 8) as well as the C-terminal domain of prosaposin, was further confirmed in both yeast two hybrid analysis and in vitro assay. It suggested that the C-terminal domain of prosaposin may be critical for the Rhox5-prosaposin interaction. Given the important roles played by both Rhox5 and prosaposin in maintaining the differentiation of male reproductive organs, spermatogenesis, and fertilization, the interaction between Rhox5 and prosaposin might regulate the development of male reproductive organs dynamically.展开更多
The interaction functions of electrically coupled Hindmarsh–Rose(HR) neurons for different firing patterns are investigated in this paper.By applying the phase reduction technique,the phase response curve(PRC) of...The interaction functions of electrically coupled Hindmarsh–Rose(HR) neurons for different firing patterns are investigated in this paper.By applying the phase reduction technique,the phase response curve(PRC) of the spiking neuron and burst phase response curve(BPRC) of the bursting neuron are derived.Then the interaction function of two coupled neurons can be calculated numerically according to the PRC(or BPRC) and the voltage time course of the neurons.Results show that the BPRC is more and more complicated with the increase of the spike number within a burst,and the curve of the interaction function oscillates more and more frequently with it.However,two certain things are unchanged:Φ = 0,which corresponds to the in-phase synchronization state,is always the stable equilibrium,while the anti-phase synchronization state with Φ = 0.5 is an unstable equilibrium.展开更多
The influence of power-low long-range interactions (LRI) and helicoidal coupling (HC) on the properties of localized solitons in a DNA molecule when a ribonucleic acid polymerase (RNAP) binds to it at the physio...The influence of power-low long-range interactions (LRI) and helicoidal coupling (HC) on the properties of localized solitons in a DNA molecule when a ribonucleic acid polymerase (RNAP) binds to it at the physiological temperature is analytically and numerically investigated in this paper. We have made an analogy with the Heisenberg model Hamiltonian of an anisotropic spin ladder with ferromagnetic legs and anti-ferromagnetic rung coupling. When we limit ourselves to the second-order terms in the Taylor expansion, the DNA dynamics is found to be governed by a completely integrable nonlinear Schr?dinger (NLS) equation. In this case, results show that increasing the value of HC force or LRI parameter enhances the bubble height and reduces the number of base pairs which form the bubble. For the fourth-order terms in a Taylor expansion, results are closely resembling those of second-order terms, and are confirmed by numerical investigation. These results match with some experimental data and thus provide a better representation of the base pairs opening in DNA which is essential for the transcription process.展开更多
Attention deficit and hyperactivity disorder(ADHD) is a disorder characterized by behavioral symptoms including hyperactivity/impulsivity among children,adolescents,and adults.These ADHD related symptoms are influen...Attention deficit and hyperactivity disorder(ADHD) is a disorder characterized by behavioral symptoms including hyperactivity/impulsivity among children,adolescents,and adults.These ADHD related symptoms are influenced by the complex interaction of brain networks which were under explored.We explored age-related brain network differences between ADHD patients and typically developing(TD) subjects using resting state f MRI(rs-f MRI) for three age groups of children,adolescents,and adults.We collected rs-f MRI data from 184 individuals(27 ADHD children and 31 TD children;32 ADHD adolescents and 32 TD adolescents;and 31 ADHD adults and 31 TD adults).The Brainnetome Atlas was used to define nodes in the network analysis.We compared three age groups of ADHD and TD subjects to identify the distinct regions that could explain age-related brain network differences based on degree centrality,a well-known measure of nodal centrality.The left middle temporal gyrus showed significant interaction effects between disease status(i.e.,ADHD or TD) and age(i.e.,child,adolescent,or adult)(P 0.001).Additional regions were identified at a relaxed threshold(P 0.05).Many of the identified regions(the left inferior frontal gyrus,the left middle temporal gyrus,and the left insular gyrus) were related to cognitive function.The results of our study suggest that aberrant development in cognitive brain regions might be associated with age-related brain network changes in ADHD patients.These findings contribute to better understand how brain function influences the symptoms of ADHD.展开更多
The effects of exercise on decision-making performance have been studied using a wide variety of cognitive tasks and exercise interventions. Although the current literature supports a beneficial influence of acute exe...The effects of exercise on decision-making performance have been studied using a wide variety of cognitive tasks and exercise interventions. Although the current literature supports a beneficial influence of acute exercise on cognitive performance, the mechanisms underlying this phenomenon have not yet been elucidated. We review studies that used single-pulse transcranial magnetic stimulation (TMS) to probe the excitability of motor structures during whole-body exercise and present a framework to account for the facilitating effects of acute exercise on motor processes. Recent results suggest that, even in the absence of fatigue, the increase in corticospinal excitability classically reported during submaximal and exhausting exercises may be accompanied by a reduction in intracortical inhibition. We propose that reduced intracortical inhibition elicits an adaptive central mechanism that counteracts the progressive reduction in muscle responsiveness caused by peripheral fatigue. Such a reduction would render the motor cortex more sensitive to upstream influences, thus causing increased corticospinal excitability. Furthermore, reduction of intracortical inhibition may account for the more efficient descending drive and for the improvement of reaction time performance during exercise. The adaptive modulation in intracortical inhibition could be implemented through a general increase in reticular activation that would further account for enhanced sensory sensitivity.展开更多
Density functional theory calculations corrected by on-site Coulomb interactions were carried out o study the structures of polar CeO2 (100) surfaces as well as activities during catalytic CO oxidation. The stabilit...Density functional theory calculations corrected by on-site Coulomb interactions were carried out o study the structures of polar CeO2 (100) surfaces as well as activities during catalytic CO oxidation. The stabilities of various CeO2 (100) termination structures are discussed, and calculated energetics are presented. The most stable Ce〇2 (100) surface was obtained by removing half the outermost full layer of oxygen and the surface stability was found to decrease as the exposed oxygen concentration was increased. Assessing the reaction pathways leading to different final products during CO oxidation over the most stable CeO2 (100) surface, we determined that the formation of carbonate species competed with CO2 desorption. However, during CO oxidation on the less stable CeO2 (100) surfaces having more exposed oxygen, the CO is evidently able to react with surface oxygen, leading to CO2 formation and desorption. The calculation results and electronic analyses reported herein also indicate that the characteristic Ce 4/ orbitals are directly involved in deter-mining the surface stabilities and reactivities.展开更多
In recent years,many studies have focused on the interaction between host genes and microbiota and their mutual influence(Bonder et al.,2016;Goodrich et al.,2014;Rothschild et al.,2018;Wang et al.,2016;Zhang et al.,20...In recent years,many studies have focused on the interaction between host genes and microbiota and their mutual influence(Bonder et al.,2016;Goodrich et al.,2014;Rothschild et al.,2018;Wang et al.,2016;Zhang et al.,2019).Host genetic variation influences the composition of the microbial community,for instance in inflammatory bowel disease,host genetic susceptibilities induce pathological shifts in microbiome composition.展开更多
The potential energy curves (PECs) of the 3Π states of GaX (X=F, Cl, and Br) molecules are calculated using the multireference configuration interaction method with a large contracted basis set aug-cc-pV5Z. The P...The potential energy curves (PECs) of the 3Π states of GaX (X=F, Cl, and Br) molecules are calculated using the multireference configuration interaction method with a large contracted basis set aug-cc-pV5Z. The PECs are accurately fitted to analytical potential energy functions (APEFs) using the Murrell–Sorbie potential function. The spectroscopic parameters for the states are determined using the obtained APEFs, and compared with the theoretical and experimental data available presently in the literature.展开更多
The boundary element method(BEM) is a main method for analyzing the interactions between the waves and the marine structures. As with the BEM, a set of linear equations are generated with a full matrix, the required...The boundary element method(BEM) is a main method for analyzing the interactions between the waves and the marine structures. As with the BEM, a set of linear equations are generated with a full matrix, the required calculations and storage increase rapidly with the increase of the structure scale. Thus, an accelerated method with a low storage is desirable for the wave interaction with a very large structure. A systematic review is given in this paper for the BEM for solving the problem of the wave interaction with a large scale structure. Various integral equations are derived based on different Green functions, the advantages and disadvantages of different discretization schemes of the integral equations by the constant panels, the higher order elements, and the spline functions are discussed. For the higher order element discretization method, the special concerns are given to the numerical calculations of the single-layer potential, the double layer potential and the solid angle coefficients. For a large scale computation problem such as the wave interaction with a very large structure or a large number of bodies, the BEMs with the FMM and p FFT accelerations are discussed, respectively, including the principles of the FMM and the p FFT, and their implementations in various integral equations with different Green functions. Finally, some potential applications of the acceleration methods for problems with large scale computations in the ocean and coastal engineering are introduced.展开更多
The interannual atmosphere-ocean-sea ice interaction (AOSI) in high northern latitudes is studied with a global atmosphere-ocean-sea ice coupled model system, in which the model components of atmosphere and land sur...The interannual atmosphere-ocean-sea ice interaction (AOSI) in high northern latitudes is studied with a global atmosphere-ocean-sea ice coupled model system, in which the model components of atmosphere and land surface are from China National Climate Center and that of ocean and sea ice are from LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences. A daily flux anomaly correction scheme is employed to couple the atmosphere model and the ocean model with the effect of inhomogenity of sea ice in high latitudes is considered. The coupled model system has been run for 50 yr and the results of the last 30 years are analyzed. After the sea level pressure (SLP), surface air temperature (SAT), sea surface temperature (SST), sea ice concentration (SIC), and sea surface sensible heat flux (SHF) are filtered with a digital filter firstly, their normalized anomalies are used to perform the decomposition of combined complex empirical orthogonal function (CCEOF) and then they are reconstructed with the leading mode. The atmosphere-ocean-sea ice interactions in high northern latitudes during a periodical cycle (approximately 4 yr) are analyzed. It is shown that: (1) When the North Atlantic Oscillation (NAO) is in its positive phase, the southerly anomaly appears in the Greenland Sea, SAT increases, the sea loses less SHF, SST increases and SIC decreases accordingly; when the NAO is in its negative phase, the northerly anomaly appears in the Greenland Sea, SAT decreases, the sea loses more SHF, SST decreases and SIC increases accordingly. There are similar features in the Barents Sea, but the phase of evolution in the Barents Sea is different from that in the Greenland Sea. (2) For an average of multi-years, there is a cold center in the inner part of the Arctic Ocean near the North Pole. When there is an anomaly of low pressure, which is closer to the Pacific Ocean, in the inner part of the Arctic Ocean, anomalies of warm advection appear in the region near the Pacific Ocean and anomalies of cold advection appear in the region near the Atlantic Ocean. Accompanying with these anomalies of warm and cold advection in these two regions~ warm and cold anomalies appear respectively. Accordingly, SHF sent to the atmosphere from the sea surface decreases and increases, and SST increases and decreases~ SIC decreases and increases in these two regions. When there is an anomaly of high pressure in the inner part of the Arctic Ocean, the former relationships reverse. From these results~ it can be deduced that, during the interannual cycle of the coupled atmosphere-ocean system, the variability of large-scale atmospheric circulation plays a dominant role and variations of SST and SIC are mainly responding to that of atmospheric circulation.展开更多
The amount of carbon dioxide (CO2) absorption and calcium ion (Ca^2+) concentration besides the pH of aqueous solution were observed during the COz absorption to precipitate calcium carbonate (CaCO3) from calci...The amount of carbon dioxide (CO2) absorption and calcium ion (Ca^2+) concentration besides the pH of aqueous solution were observed during the COz absorption to precipitate calcium carbonate (CaCO3) from calcium hydroxide (Ca(OH)2). A reaction rate-limiting effect of an amount of CO2 absorption without any organic additives in the early stage of the precipitation was observed, which was attributed to an interruption effect of bicarbonate ion (HCO3) on the precipitation of CaCO3. The improvement for the reaction rate was achieved not only by amine additives but also by neutral additives such as ε-caprolactam or amine salt. When the hexamethylene diamine was dissolved in the solution, successive change of crystal forms of CaCO3 aragonite to calcite in aqueous suspensions, confirmed by Ca^2+ concentration change and X-ray diffraction, was concluded that a local environment around the amine group in aqueous solution and an interaction of the diamine with precipitated CaCO3 particles were important factors for these reactions.展开更多
A novel paradigm for fractal coding selectively corrects the fractal code for selected domain blocks with an image-adaptive VQ codebook. The codebook is generated from the initial uncorrected fractal code and is, ther...A novel paradigm for fractal coding selectively corrects the fractal code for selected domain blocks with an image-adaptive VQ codebook. The codebook is generated from the initial uncorrected fractal code and is, therefore, available at the decoder. An efficient trade-off is generated between incremental performance and bit rate.展开更多
Tag questions are a distinctive feature in spokenEnglish,but seldom used by the non-native speakers.Studies show that tags are employed by native speakersmainly to express their interactive and interpersonalmeaning.In...Tag questions are a distinctive feature in spokenEnglish,but seldom used by the non-native speakers.Studies show that tags are employed by native speakersmainly to express their interactive and interpersonalmeaning.In this paper,the writer explores the natureof tag questions,mainly their interactive and inter-personal functions in daily coversation.Suggestionsare made with regard to the teaching of tags in theclassroom.展开更多
基金This work was supported by the National Natural Sciences Foundation of China (No. 39770411) Doctoral Fund of Ministry of Education of China (No. 20060559006).
文摘Prosaposin (Psap) has multiple cellular functions. It is involved in the development of the reproductive system, nervous system, and prostate cancer as well as in the regulation of sphingolipid catabolism by activating several lysosomal hydrolases involved in the metabolism of various sphingolipids. In this research, it was found to be a novel interaction partner for Rhox5 using yeast two-hybrid screening. The interaction between Rhox5 and the full-length prosapsoin (the transcript without exon 8) as well as the C-terminal domain of prosaposin, was further confirmed in both yeast two hybrid analysis and in vitro assay. It suggested that the C-terminal domain of prosaposin may be critical for the Rhox5-prosaposin interaction. Given the important roles played by both Rhox5 and prosaposin in maintaining the differentiation of male reproductive organs, spermatogenesis, and fertilization, the interaction between Rhox5 and prosaposin might regulate the development of male reproductive organs dynamically.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11272065 and 11472061)
文摘The interaction functions of electrically coupled Hindmarsh–Rose(HR) neurons for different firing patterns are investigated in this paper.By applying the phase reduction technique,the phase response curve(PRC) of the spiking neuron and burst phase response curve(BPRC) of the bursting neuron are derived.Then the interaction function of two coupled neurons can be calculated numerically according to the PRC(or BPRC) and the voltage time course of the neurons.Results show that the BPRC is more and more complicated with the increase of the spike number within a burst,and the curve of the interaction function oscillates more and more frequently with it.However,two certain things are unchanged:Φ = 0,which corresponds to the in-phase synchronization state,is always the stable equilibrium,while the anti-phase synchronization state with Φ = 0.5 is an unstable equilibrium.
文摘The influence of power-low long-range interactions (LRI) and helicoidal coupling (HC) on the properties of localized solitons in a DNA molecule when a ribonucleic acid polymerase (RNAP) binds to it at the physiological temperature is analytically and numerically investigated in this paper. We have made an analogy with the Heisenberg model Hamiltonian of an anisotropic spin ladder with ferromagnetic legs and anti-ferromagnetic rung coupling. When we limit ourselves to the second-order terms in the Taylor expansion, the DNA dynamics is found to be governed by a completely integrable nonlinear Schr?dinger (NLS) equation. In this case, results show that increasing the value of HC force or LRI parameter enhances the bubble height and reduces the number of base pairs which form the bubble. For the fourth-order terms in a Taylor expansion, results are closely resembling those of second-order terms, and are confirmed by numerical investigation. These results match with some experimental data and thus provide a better representation of the base pairs opening in DNA which is essential for the transcription process.
基金supported by the Institute for Basic Science[grant No.IBS-R015-D1]the National Research Foundation of Korea(grant No.NRF-2016R1A2B4008545)
文摘Attention deficit and hyperactivity disorder(ADHD) is a disorder characterized by behavioral symptoms including hyperactivity/impulsivity among children,adolescents,and adults.These ADHD related symptoms are influenced by the complex interaction of brain networks which were under explored.We explored age-related brain network differences between ADHD patients and typically developing(TD) subjects using resting state f MRI(rs-f MRI) for three age groups of children,adolescents,and adults.We collected rs-f MRI data from 184 individuals(27 ADHD children and 31 TD children;32 ADHD adolescents and 32 TD adolescents;and 31 ADHD adults and 31 TD adults).The Brainnetome Atlas was used to define nodes in the network analysis.We compared three age groups of ADHD and TD subjects to identify the distinct regions that could explain age-related brain network differences based on degree centrality,a well-known measure of nodal centrality.The left middle temporal gyrus showed significant interaction effects between disease status(i.e.,ADHD or TD) and age(i.e.,child,adolescent,or adult)(P 0.001).Additional regions were identified at a relaxed threshold(P 0.05).Many of the identified regions(the left inferior frontal gyrus,the left middle temporal gyrus,and the left insular gyrus) were related to cognitive function.The results of our study suggest that aberrant development in cognitive brain regions might be associated with age-related brain network changes in ADHD patients.These findings contribute to better understand how brain function influences the symptoms of ADHD.
文摘The effects of exercise on decision-making performance have been studied using a wide variety of cognitive tasks and exercise interventions. Although the current literature supports a beneficial influence of acute exercise on cognitive performance, the mechanisms underlying this phenomenon have not yet been elucidated. We review studies that used single-pulse transcranial magnetic stimulation (TMS) to probe the excitability of motor structures during whole-body exercise and present a framework to account for the facilitating effects of acute exercise on motor processes. Recent results suggest that, even in the absence of fatigue, the increase in corticospinal excitability classically reported during submaximal and exhausting exercises may be accompanied by a reduction in intracortical inhibition. We propose that reduced intracortical inhibition elicits an adaptive central mechanism that counteracts the progressive reduction in muscle responsiveness caused by peripheral fatigue. Such a reduction would render the motor cortex more sensitive to upstream influences, thus causing increased corticospinal excitability. Furthermore, reduction of intracortical inhibition may account for the more efficient descending drive and for the improvement of reaction time performance during exercise. The adaptive modulation in intracortical inhibition could be implemented through a general increase in reticular activation that would further account for enhanced sensory sensitivity.
基金supported the National Natural Science Foundation of China(21421004,21573067)~~
文摘Density functional theory calculations corrected by on-site Coulomb interactions were carried out o study the structures of polar CeO2 (100) surfaces as well as activities during catalytic CO oxidation. The stabilities of various CeO2 (100) termination structures are discussed, and calculated energetics are presented. The most stable Ce〇2 (100) surface was obtained by removing half the outermost full layer of oxygen and the surface stability was found to decrease as the exposed oxygen concentration was increased. Assessing the reaction pathways leading to different final products during CO oxidation over the most stable CeO2 (100) surface, we determined that the formation of carbonate species competed with CO2 desorption. However, during CO oxidation on the less stable CeO2 (100) surfaces having more exposed oxygen, the CO is evidently able to react with surface oxygen, leading to CO2 formation and desorption. The calculation results and electronic analyses reported herein also indicate that the characteristic Ce 4/ orbitals are directly involved in deter-mining the surface stabilities and reactivities.
基金the National Key Research and Development Program of China (2018YFC2000504, 2017YFD0500503 and 2017YFD0501000)the National Natural Science Foundation of China (81770434 and 81370906)the National Program on Key Basic Research Project of China (973 Program) (2007CB513007 and 2013CB531406)。
文摘In recent years,many studies have focused on the interaction between host genes and microbiota and their mutual influence(Bonder et al.,2016;Goodrich et al.,2014;Rothschild et al.,2018;Wang et al.,2016;Zhang et al.,2019).Host genetic variation influences the composition of the microbial community,for instance in inflammatory bowel disease,host genetic susceptibilities induce pathological shifts in microbiome composition.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11174117 and 10974078)the Program for Scientific Research Innova-tion Team in Colleges and Universities of Shandong Province,China
文摘The potential energy curves (PECs) of the 3Π states of GaX (X=F, Cl, and Br) molecules are calculated using the multireference configuration interaction method with a large contracted basis set aug-cc-pV5Z. The PECs are accurately fitted to analytical potential energy functions (APEFs) using the Murrell–Sorbie potential function. The spectroscopic parameters for the states are determined using the obtained APEFs, and compared with the theoretical and experimental data available presently in the literature.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51379032,51490672 and 51479026)
文摘The boundary element method(BEM) is a main method for analyzing the interactions between the waves and the marine structures. As with the BEM, a set of linear equations are generated with a full matrix, the required calculations and storage increase rapidly with the increase of the structure scale. Thus, an accelerated method with a low storage is desirable for the wave interaction with a very large structure. A systematic review is given in this paper for the BEM for solving the problem of the wave interaction with a large scale structure. Various integral equations are derived based on different Green functions, the advantages and disadvantages of different discretization schemes of the integral equations by the constant panels, the higher order elements, and the spline functions are discussed. For the higher order element discretization method, the special concerns are given to the numerical calculations of the single-layer potential, the double layer potential and the solid angle coefficients. For a large scale computation problem such as the wave interaction with a very large structure or a large number of bodies, the BEMs with the FMM and p FFT accelerations are discussed, respectively, including the principles of the FMM and the p FFT, and their implementations in various integral equations with different Green functions. Finally, some potential applications of the acceleration methods for problems with large scale computations in the ocean and coastal engineering are introduced.
基金the National Natural Science Foundation of China under Grant No.40675065the National Basic Research Priorities Program of China under Grant No.2005CB32170X.
文摘The interannual atmosphere-ocean-sea ice interaction (AOSI) in high northern latitudes is studied with a global atmosphere-ocean-sea ice coupled model system, in which the model components of atmosphere and land surface are from China National Climate Center and that of ocean and sea ice are from LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences. A daily flux anomaly correction scheme is employed to couple the atmosphere model and the ocean model with the effect of inhomogenity of sea ice in high latitudes is considered. The coupled model system has been run for 50 yr and the results of the last 30 years are analyzed. After the sea level pressure (SLP), surface air temperature (SAT), sea surface temperature (SST), sea ice concentration (SIC), and sea surface sensible heat flux (SHF) are filtered with a digital filter firstly, their normalized anomalies are used to perform the decomposition of combined complex empirical orthogonal function (CCEOF) and then they are reconstructed with the leading mode. The atmosphere-ocean-sea ice interactions in high northern latitudes during a periodical cycle (approximately 4 yr) are analyzed. It is shown that: (1) When the North Atlantic Oscillation (NAO) is in its positive phase, the southerly anomaly appears in the Greenland Sea, SAT increases, the sea loses less SHF, SST increases and SIC decreases accordingly; when the NAO is in its negative phase, the northerly anomaly appears in the Greenland Sea, SAT decreases, the sea loses more SHF, SST decreases and SIC increases accordingly. There are similar features in the Barents Sea, but the phase of evolution in the Barents Sea is different from that in the Greenland Sea. (2) For an average of multi-years, there is a cold center in the inner part of the Arctic Ocean near the North Pole. When there is an anomaly of low pressure, which is closer to the Pacific Ocean, in the inner part of the Arctic Ocean, anomalies of warm advection appear in the region near the Pacific Ocean and anomalies of cold advection appear in the region near the Atlantic Ocean. Accompanying with these anomalies of warm and cold advection in these two regions~ warm and cold anomalies appear respectively. Accordingly, SHF sent to the atmosphere from the sea surface decreases and increases, and SST increases and decreases~ SIC decreases and increases in these two regions. When there is an anomaly of high pressure in the inner part of the Arctic Ocean, the former relationships reverse. From these results~ it can be deduced that, during the interannual cycle of the coupled atmosphere-ocean system, the variability of large-scale atmospheric circulation plays a dominant role and variations of SST and SIC are mainly responding to that of atmospheric circulation.
文摘The amount of carbon dioxide (CO2) absorption and calcium ion (Ca^2+) concentration besides the pH of aqueous solution were observed during the COz absorption to precipitate calcium carbonate (CaCO3) from calcium hydroxide (Ca(OH)2). A reaction rate-limiting effect of an amount of CO2 absorption without any organic additives in the early stage of the precipitation was observed, which was attributed to an interruption effect of bicarbonate ion (HCO3) on the precipitation of CaCO3. The improvement for the reaction rate was achieved not only by amine additives but also by neutral additives such as ε-caprolactam or amine salt. When the hexamethylene diamine was dissolved in the solution, successive change of crystal forms of CaCO3 aragonite to calcite in aqueous suspensions, confirmed by Ca^2+ concentration change and X-ray diffraction, was concluded that a local environment around the amine group in aqueous solution and an interaction of the diamine with precipitated CaCO3 particles were important factors for these reactions.
文摘A novel paradigm for fractal coding selectively corrects the fractal code for selected domain blocks with an image-adaptive VQ codebook. The codebook is generated from the initial uncorrected fractal code and is, therefore, available at the decoder. An efficient trade-off is generated between incremental performance and bit rate.
文摘Tag questions are a distinctive feature in spokenEnglish,but seldom used by the non-native speakers.Studies show that tags are employed by native speakersmainly to express their interactive and interpersonalmeaning.In this paper,the writer explores the natureof tag questions,mainly their interactive and inter-personal functions in daily coversation.Suggestionsare made with regard to the teaching of tags in theclassroom.