U型中深层地埋管换热器(U-bend Deep Borehole Heat Exchanger,UDBHE)具有广阔的应用前景。文章基于无限柱热源(Infinite Cylindrical Source,ICS)和无限线热源(Infinite Line Source,ILS)模型的G函数,建立了4种UDBHE传热模型,采用ICS或...U型中深层地埋管换热器(U-bend Deep Borehole Heat Exchanger,UDBHE)具有广阔的应用前景。文章基于无限柱热源(Infinite Cylindrical Source,ICS)和无限线热源(Infinite Line Source,ILS)模型的G函数,建立了4种UDBHE传热模型,采用ICS或ILS模型的G函数,考虑或忽略钻孔壁热流随时间变化,分别简称为ICS-q,ILS-q,ICS-c,ILS-c模型。通过与较为准确的二维数值模型及实验数据在2种边界条件下的对比,分析了这4种模型的准确性。结果表明:ILS-q模型在整体上最为准确,而ICS-q模型在分析UDBHE长期性能时最为准确;4种模型在前期均存在较大误差,但在足够长时间后,除了ILS-c和ICS-c模型在入口温度边界下仍有较大误差外,其他模型的误差均较小。研究结果可为UDBHE传热模型研究提供参考。展开更多
In this paper, we establish the following limiting weak-type behaviors of Littlewood-Paley g-function g_φ: for nonnegative function f∈ L^1(R^n),■and ■where f_t(x) =t^(-n)f(t^(-1) x) for t > 0. Meanwhile, the co...In this paper, we establish the following limiting weak-type behaviors of Littlewood-Paley g-function g_φ: for nonnegative function f∈ L^1(R^n),■and ■where f_t(x) =t^(-n)f(t^(-1) x) for t > 0. Meanwhile, the corresponding results for Marcinkiewicz integral and its fractional version with kernels satisfying L_α~q-Dini condition are also given.展开更多
In this paper a generalized tanh-function type method is proposed by using the idea of the transformed rational function method. We show that the (G'/G)?-expansion method is a special case of the generalized tanh-...In this paper a generalized tanh-function type method is proposed by using the idea of the transformed rational function method. We show that the (G'/G)?-expansion method is a special case of the generalized tanh-function type method, so the (G'/G)?-expansion method is considered as a special deformation application of the transformed rational function method. We demonstrate that all solutions obtained by the (G'/G)?-expansion method were found by the generalized tanh-function type method. As applications, we consider mKdV equation. Compared with the (G'/G) -expansion method, the generalized tanh-function type method gives new and more abundant solutions.展开更多
Membrane technology has been used for H_2 purification. In this paper, the systematic density functional simulations are conducted to study the separation of H_2 from the impurity gases(H_2, N_2, H_2 O, CO, Cl_2, and ...Membrane technology has been used for H_2 purification. In this paper, the systematic density functional simulations are conducted to study the separation of H_2 from the impurity gases(H_2, N_2, H_2 O, CO, Cl_2, and CH_4) by the bilayer porous graphitic carbon nitride(g-C_3 N_4) membrane. Theoretically, the bilayer g-C3 N4 membrane with a diameter of about3.25 A? should be a perfect candidate for H_2 purification from these mixed gases, which is verified by the high selectivity(S) for H_2 over other kinds of gases(3.43 × 1028 for H_2/N2; 1.40 × 1028 for H_262/H_2 O; 1.60 × 10 for H_2/CO; 4.30 × 10^(14) for H_2/Cl_2; 2.50 × 10^(55) for H_2/CH_4), and the permeance(P) of H_2(13 mol/m^2·s·Pa) across the bilayer g-C_3 N_4 membrane at 300 K, which should be of great potential in energy and environmental research. Our studies highlight a new approach towards the final goal of high P and high S molecular-sieving membranes used in simple structural engineering.展开更多
GPR126也称ADGRG6,是研究较为深入的黏附类G蛋白偶联受体(adhesion G protein-coupled receptors,aGPCRs)成员之一。最初,GPR126被认为是一种与肌肉发育相关的受体,主要在肌肉和骨骼系统中表达;随着研究的深入,人们发现GPR126在哺乳动...GPR126也称ADGRG6,是研究较为深入的黏附类G蛋白偶联受体(adhesion G protein-coupled receptors,aGPCRs)成员之一。最初,GPR126被认为是一种与肌肉发育相关的受体,主要在肌肉和骨骼系统中表达;随着研究的深入,人们发现GPR126在哺乳动物多个组织和器官中表达,并参与胚胎发育、神经系统发育和细胞外基质相互作用等多种生物学过程。GPR126具有典型的aGPCRs的七次跨膜螺旋结构,可介导跨膜信号转导,参与调控细胞增殖、分化和迁移等多种细胞过程。近年来,GPR126新配体的发现为探索其生理功能提供了有价值的工具。然而,目前GPR126在各类疾病中的生物学功能及其作为治疗靶点的潜力仍待进一步研究。该文重点描述GPR126的结构、物种间差异性与保守性、信号转导及其生物学功能,为未来GPR126的研究提供思路和参考。展开更多
Since the room-temperature detector CdZnTe(CZT) has advantages in terms of detection efficiency,energy resolution, and size, it has been extensively used to detect X-rays and gamma-rays. So far, nuclear radiation dete...Since the room-temperature detector CdZnTe(CZT) has advantages in terms of detection efficiency,energy resolution, and size, it has been extensively used to detect X-rays and gamma-rays. So far, nuclear radiation detectors such as cerium chloride doped with lanthanum bromide(LaBr_3(Ce)), thallium doped with cesium iodide(sI(Tl)), thallium doped with sodium iodide(NaI(Tl)),and high-purity germanium(HPGe) primarily use the spectroscopy-dose rate function(G(E)) to achieve the accurate measurement of air kerma rate(K_a) and ambient dose equivalent rate(H*(10)). However, the spectroscopy-dose rate function has been rarely measured for a CZT detector. In this study, we performed spectrum measurement using a hemispherical CZT detector in a radiation protection standards laboratory. The spectroscopy-dose rate function G(E) of the CZT detector was calculated using the least-squares method combined with the standard dose rate at the measurement position. The results showed that the hemispherical CZT detector could complete the measurement of air kerma rate(K_a) and ambient dose equivalent rate(H*(10)) by using the G(E) function at energies between 48 keV and 1.25 MeV, and the relative intrinsic errors were, respectively, controlled within ± 2. 3 and ± 2. 1%.展开更多
The explicit expression of the G3 basis function is presented in this paper. It is derived by constructing the conversion matrix between G3 basis function and Brzier representation. After the matrix decomposition, equ...The explicit expression of the G3 basis function is presented in this paper. It is derived by constructing the conversion matrix between G3 basis function and Brzier representation. After the matrix decomposition, equations for constructing G3 splines can be presented independently of geometric shape parameters＇ values. It makes the equation＇s solving easier. It is also known that the general form of the G3spline basis function is given in the first time. Its geometric construction method is presented.展开更多
Changes in the functional activity and levels of Gsa and Gia in heart failure have been studied predominantly in the end-stage failing heart.The objective of this study was to determine if levels and function of Gsa a...Changes in the functional activity and levels of Gsa and Gia in heart failure have been studied predominantly in the end-stage failing heart.The objective of this study was to determine if levels and function of Gsa and Gia2 in rat hearts change over time following acute myocar(lial infarction (MI) and if so,whether the changes in G proteins are associated with changes in heart function.As compared with sham-operated controls, Giα2, level of MI rats did not change at day l,increased by 64% at day 3 (P<0.01) and 55% at day 9 (P< 0.05)accompanied by reduced adenylyl cyclase activity,and returned to control by day 21. By contrast,Gsa level did not change at any time. Cardiac function in MI animals was markedly impaired at days 1,3 and 9 as evidenced by substantial elevation in LVEDP and reduction in +and -dp/dtmax,and partially restored at day 21. The increased Gia2level in MI rats at days 3 and 9 correlated positively to LVEDP(P< 0.05), and negatively to +and -dp/dtmax (p < 0. 01).The results show a three phase dynamic pattern in Gia2 level following acute MI:a lag phase, an increased expression phase associated with marked impairment of heart function,and a late phase in which the expression retums to control level accompanied by partially restored cardlac function.The results suggest that ② in G protein-mediated pathways,cardiac myocytes respond to MI Via regulating the gene expression of the inhibitory pathway, and ② up-regulation of Gia2 levels is related to the severity of impairment in cardiac function.展开更多
Magnesium(Mg) is crucial for the function of G proteins which play important roles in mediating the inotropic effects of β adrenergic agonists in the heart and are alteredin heart failure.This study was performed to ...Magnesium(Mg) is crucial for the function of G proteins which play important roles in mediating the inotropic effects of β adrenergic agonists in the heart and are alteredin heart failure.This study was performed to determine whether or not dietary Mg deficiency alters functional activity and levels of the two major ventricular G proteins, Gia and Gsa in the heart after myocardial infarction(MI).Six week old rats were fed a Mg adequate or deficient diet for 6 weeks.At the end of week 3,MI was induced by coronary artery ligation.A sham operation was performed as control.After surgery,surviving animals were maintained on their assigned diets for another 3 weeks.Then,cardiac function was measured.Severe hypomagnesemia and increased plasma catecholamine level were observed in all animals fed the Mg deficient diet.A significant reduction of ruyocardial Mg concentration accompanied by elevated plasma and myocardial calcium concentrations was observed in MI animals with existing Mg deficiency vs.animals fed the Mg adequate diet.Cardiac function was impaired in MI rats and further reduced in MI rats with existing Mg deficiency. Gia level was not altered by either Mg deficiency or MI alone,but was dramatically elevated in animals with combined Mg deficiency and MI (9. 9±0.7 arbitrary unit.mg-1 protein) as compared to MI alone (5.8±0. 6,P<0.05 )and Mg deficiency alone(6.1± 0.8,P<0.05 ). Gsa level did not differ between groups.Bacal,GppNHp-and forskolin-but not fluoride-, stimulated adenylyl cyclase activity was signifcantly reduced in MI animals with existing Mg deficiency indicating increased functional activity of Gia.The findings suggest that dietary Mg deficiency increases the expression and functional ac tivity of Gia in the heart after MI, while levels and function of Gsa are not compromised during dietary Mg deficiency either with or without MI.展开更多
文摘U型中深层地埋管换热器(U-bend Deep Borehole Heat Exchanger,UDBHE)具有广阔的应用前景。文章基于无限柱热源(Infinite Cylindrical Source,ICS)和无限线热源(Infinite Line Source,ILS)模型的G函数,建立了4种UDBHE传热模型,采用ICS或ILS模型的G函数,考虑或忽略钻孔壁热流随时间变化,分别简称为ICS-q,ILS-q,ICS-c,ILS-c模型。通过与较为准确的二维数值模型及实验数据在2种边界条件下的对比,分析了这4种模型的准确性。结果表明:ILS-q模型在整体上最为准确,而ICS-q模型在分析UDBHE长期性能时最为准确;4种模型在前期均存在较大误差,但在足够长时间后,除了ILS-c和ICS-c模型在入口温度边界下仍有较大误差外,其他模型的误差均较小。研究结果可为UDBHE传热模型研究提供参考。
文摘In this paper, we establish the following limiting weak-type behaviors of Littlewood-Paley g-function g_φ: for nonnegative function f∈ L^1(R^n),■and ■where f_t(x) =t^(-n)f(t^(-1) x) for t > 0. Meanwhile, the corresponding results for Marcinkiewicz integral and its fractional version with kernels satisfying L_α~q-Dini condition are also given.
文摘In this paper a generalized tanh-function type method is proposed by using the idea of the transformed rational function method. We show that the (G'/G)?-expansion method is a special case of the generalized tanh-function type method, so the (G'/G)?-expansion method is considered as a special deformation application of the transformed rational function method. We demonstrate that all solutions obtained by the (G'/G)?-expansion method were found by the generalized tanh-function type method. As applications, we consider mKdV equation. Compared with the (G'/G) -expansion method, the generalized tanh-function type method gives new and more abundant solutions.
基金Project supported by the Fundamental Research Funds for the Central Universities,China(Grant No.2018B19414)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20161501)+5 种基金the Six Talent Peaks Project in Jiangsu Province,China(Grant No.2015-XCL-010)the National Natural Science Foundation of China(Grant Nos.51776094 and 51406075)the Program of Henan Provincial Department of Education,China(Grant No.16A330004)the Special Fund of Nanyang Normal University,China(Grant No.ZX2016003)the Science and Technology Program of Henan Department of Science and Technology,China(Grant No.182102310609)the Scientific Research and Service Platform Fund of Henan Province,China(Grant No.2016151)
文摘Membrane technology has been used for H_2 purification. In this paper, the systematic density functional simulations are conducted to study the separation of H_2 from the impurity gases(H_2, N_2, H_2 O, CO, Cl_2, and CH_4) by the bilayer porous graphitic carbon nitride(g-C_3 N_4) membrane. Theoretically, the bilayer g-C3 N4 membrane with a diameter of about3.25 A? should be a perfect candidate for H_2 purification from these mixed gases, which is verified by the high selectivity(S) for H_2 over other kinds of gases(3.43 × 1028 for H_2/N2; 1.40 × 1028 for H_262/H_2 O; 1.60 × 10 for H_2/CO; 4.30 × 10^(14) for H_2/Cl_2; 2.50 × 10^(55) for H_2/CH_4), and the permeance(P) of H_2(13 mol/m^2·s·Pa) across the bilayer g-C_3 N_4 membrane at 300 K, which should be of great potential in energy and environmental research. Our studies highlight a new approach towards the final goal of high P and high S molecular-sieving membranes used in simple structural engineering.
文摘GPR126也称ADGRG6,是研究较为深入的黏附类G蛋白偶联受体(adhesion G protein-coupled receptors,aGPCRs)成员之一。最初,GPR126被认为是一种与肌肉发育相关的受体,主要在肌肉和骨骼系统中表达;随着研究的深入,人们发现GPR126在哺乳动物多个组织和器官中表达,并参与胚胎发育、神经系统发育和细胞外基质相互作用等多种生物学过程。GPR126具有典型的aGPCRs的七次跨膜螺旋结构,可介导跨膜信号转导,参与调控细胞增殖、分化和迁移等多种细胞过程。近年来,GPR126新配体的发现为探索其生理功能提供了有价值的工具。然而,目前GPR126在各类疾病中的生物学功能及其作为治疗靶点的潜力仍待进一步研究。该文重点描述GPR126的结构、物种间差异性与保守性、信号转导及其生物学功能,为未来GPR126的研究提供思路和参考。
基金supported by the National Key Scientific Instruments to Develop Dedicated(Nos.2013YQ090811 and 2016YFF0103800)
文摘Since the room-temperature detector CdZnTe(CZT) has advantages in terms of detection efficiency,energy resolution, and size, it has been extensively used to detect X-rays and gamma-rays. So far, nuclear radiation detectors such as cerium chloride doped with lanthanum bromide(LaBr_3(Ce)), thallium doped with cesium iodide(sI(Tl)), thallium doped with sodium iodide(NaI(Tl)),and high-purity germanium(HPGe) primarily use the spectroscopy-dose rate function(G(E)) to achieve the accurate measurement of air kerma rate(K_a) and ambient dose equivalent rate(H*(10)). However, the spectroscopy-dose rate function has been rarely measured for a CZT detector. In this study, we performed spectrum measurement using a hemispherical CZT detector in a radiation protection standards laboratory. The spectroscopy-dose rate function G(E) of the CZT detector was calculated using the least-squares method combined with the standard dose rate at the measurement position. The results showed that the hemispherical CZT detector could complete the measurement of air kerma rate(K_a) and ambient dose equivalent rate(H*(10)) by using the G(E) function at energies between 48 keV and 1.25 MeV, and the relative intrinsic errors were, respectively, controlled within ± 2. 3 and ± 2. 1%.
基金Supported by National Natural Science Foundation of China(Grants 61100129)Open Program of Key Laboratory of Intelligent Information Processing,Institute of Computing Technology,Chinese Academy of Sciences(IIP2014-7)
文摘The explicit expression of the G3 basis function is presented in this paper. It is derived by constructing the conversion matrix between G3 basis function and Brzier representation. After the matrix decomposition, equations for constructing G3 splines can be presented independently of geometric shape parameters＇ values. It makes the equation＇s solving easier. It is also known that the general form of the G3spline basis function is given in the first time. Its geometric construction method is presented.
文摘Changes in the functional activity and levels of Gsa and Gia in heart failure have been studied predominantly in the end-stage failing heart.The objective of this study was to determine if levels and function of Gsa and Gia2 in rat hearts change over time following acute myocar(lial infarction (MI) and if so,whether the changes in G proteins are associated with changes in heart function.As compared with sham-operated controls, Giα2, level of MI rats did not change at day l,increased by 64% at day 3 (P<0.01) and 55% at day 9 (P< 0.05)accompanied by reduced adenylyl cyclase activity,and returned to control by day 21. By contrast,Gsa level did not change at any time. Cardiac function in MI animals was markedly impaired at days 1,3 and 9 as evidenced by substantial elevation in LVEDP and reduction in +and -dp/dtmax,and partially restored at day 21. The increased Gia2level in MI rats at days 3 and 9 correlated positively to LVEDP(P< 0.05), and negatively to +and -dp/dtmax (p < 0. 01).The results show a three phase dynamic pattern in Gia2 level following acute MI:a lag phase, an increased expression phase associated with marked impairment of heart function,and a late phase in which the expression retums to control level accompanied by partially restored cardlac function.The results suggest that ② in G protein-mediated pathways,cardiac myocytes respond to MI Via regulating the gene expression of the inhibitory pathway, and ② up-regulation of Gia2 levels is related to the severity of impairment in cardiac function.
文摘Magnesium(Mg) is crucial for the function of G proteins which play important roles in mediating the inotropic effects of β adrenergic agonists in the heart and are alteredin heart failure.This study was performed to determine whether or not dietary Mg deficiency alters functional activity and levels of the two major ventricular G proteins, Gia and Gsa in the heart after myocardial infarction(MI).Six week old rats were fed a Mg adequate or deficient diet for 6 weeks.At the end of week 3,MI was induced by coronary artery ligation.A sham operation was performed as control.After surgery,surviving animals were maintained on their assigned diets for another 3 weeks.Then,cardiac function was measured.Severe hypomagnesemia and increased plasma catecholamine level were observed in all animals fed the Mg deficient diet.A significant reduction of ruyocardial Mg concentration accompanied by elevated plasma and myocardial calcium concentrations was observed in MI animals with existing Mg deficiency vs.animals fed the Mg adequate diet.Cardiac function was impaired in MI rats and further reduced in MI rats with existing Mg deficiency. Gia level was not altered by either Mg deficiency or MI alone,but was dramatically elevated in animals with combined Mg deficiency and MI (9. 9±0.7 arbitrary unit.mg-1 protein) as compared to MI alone (5.8±0. 6,P<0.05 )and Mg deficiency alone(6.1± 0.8,P<0.05 ). Gsa level did not differ between groups.Bacal,GppNHp-and forskolin-but not fluoride-, stimulated adenylyl cyclase activity was signifcantly reduced in MI animals with existing Mg deficiency indicating increased functional activity of Gia.The findings suggest that dietary Mg deficiency increases the expression and functional ac tivity of Gia in the heart after MI, while levels and function of Gsa are not compromised during dietary Mg deficiency either with or without MI.
