Collisional quantum interference （CQI） in the intramolecular rotational energy transfer was observed in experiment by Sha and co-workers. The interference angle, which measuring the degree of the coherence, were mea...Collisional quantum interference （CQI） in the intramolecular rotational energy transfer was observed in experiment by Sha and co-workers. The interference angle, which measuring the degree of the coherence, were measured in the experiment of the static cell. Based on the first Born approximation of time dependent perturbation theory, taking into accounts the anisotropic Lennard-Jones interaction potentials, this paper describes the theoretical model of CQI in intramolecular rotational energy transfer in an atom-diatom collision system. In the model, the differential interference angle for the experiment of the molecular beam is calculated, the changing tendencies of the differential interference angle with the impact parameter and collision partners are obtained. This theoretical model is important for understanding or performing this kind of experiments.展开更多
Collisional quantum interference （CQI） was observed in the intramolecular rotational energy transfer in the experiment of the static cell, and the integral interference angles were measured. To observe more precise ...Collisional quantum interference （CQI） was observed in the intramolecular rotational energy transfer in the experiment of the static cell, and the integral interference angles were measured. To observe more precise information, the experiment in the molecular beam should be taken,from which the relationship between the differential interference angle and the scattering angle can be obtained. In this paper, the theoretical model of CQI is described in an atom-diatom system in the condition of the molecular beam, based on the first-Born approximation of time-dependent perturbation theory, taking into accounts the long-range interaction potential. The method of observing and measuring correctly the differential interference angle is presented. The changing tendency of the differential interference angle with the impact parameter and relative velocity is discussed. The changing tendencies of the differential interference angle with the parameter of experiment in the molecular beam, including the impact parameter and the velocity are discussed. This theoretical model is important to understand or perform the experiment in the molecular beam.展开更多
FOXL 2 and CYP 19 B are crucial transcription factors in vertebrates and invertebrates that play pivotal roles in sex differentiation and gonadal development.The potential roles of the foxl 2 and cyp 19 b genes in sex...FOXL 2 and CYP 19 B are crucial transcription factors in vertebrates and invertebrates that play pivotal roles in sex differentiation and gonadal development.The potential roles of the foxl 2 and cyp 19 b genes in sex determination and gonadal development in Cyprinus carpio var.koi were explored using a non-invasive RNA interference(RNAi)method,histopathological observation and qPCR.Results demonstrate that foxl 2 exhibited a sexually dimorphic expression pattern in gonads,with a notable expression in ovaries;cyp 19 b was expressed in all peripheral tissues,with a particularly prominent expression in brain and gonads.The knockdown of foxl 2 by RNAi resulted in delay in the development of the female gonads.Conversely,no notable alterations were discerned in the gonads of C.carpio var.koi following the knockdown of cyp 19 b.The upregulation of sox 9 a,amh,and cyp 19 b following foxl 2 knockdown indicates that foxl 2 may play a pivotal role in gonadal development.Nevertheless,further investigation is required to ascertain the potential role of cyp 19 b.This study elucidated the role of foxl 2 and enhanced the understanding of the mechanisms of sex determination and gonadal development in C.carpio var.koi.展开更多
The principles and applications of laser real-time holographic interferometry （LRTHI） and radar differential interferometry （RDI） technologies are described in this paper, respectively. By using LRTHI, we can obse...The principles and applications of laser real-time holographic interferometry （LRTHI） and radar differential interferometry （RDI） technologies are described in this paper, respectively. By using LRTHI, we can observe the deformation of samples under pressure in the lab and study the anomaly characteristics relating to different strain fields in different fracture-developing areas; while by using RDI, we can observe the landform and surface deformation. The results of deformation observed before and after the Ms=7.9 Mani earthquake （Tibet） and Ms=6.2 Shangyi-Zhangbei earthquake in China are obtained. It is pointed out that LRTHI and RDi are similar, which study the characteristics of anomalous deformation field by fringe variations for both of them. Therefore, the observation of deformation field in the seismogenic process, especially in the period impending an earthquake by RDI, and the comparative study in the lab by LRTHI are of great significance.展开更多
This paper gives theoretical analysis of visibility of fringes, which is influenced by distances, temporal and spatial coherence of source, in hard x-ray differential phase-contrast imaging with microfocus x-ray sourc...This paper gives theoretical analysis of visibility of fringes, which is influenced by distances, temporal and spatial coherence of source, in hard x-ray differential phase-contrast imaging with microfocus x-ray source. According to the character of longitudinal periodicity of the interferogram, the setup is insensitive to mechanical drift and vibrations. The effect of temporal coherence of x-ray source is investigated and its related bandwidth is derived. Based on the theory of partially coherent light, it shows that the requirement for the spatial coherence of x-ray source is not strict and can be met by the general microfocus x-ray tube for x-ray differential phase-contrast imaging.展开更多
Fully differential cross sections （FDCS） are calculated within a four-body model for single ionization of helium by C6＋ impact at the incident energy of 100 MeV/a.u. （atomic unit）. The results are compared with e...Fully differential cross sections （FDCS） are calculated within a four-body model for single ionization of helium by C6＋ impact at the incident energy of 100 MeV/a.u. （atomic unit）. The results are compared with experimental data and other theoretical predictions. It is shown that our results are in very good agreement with experiment for three small momentum transfers in the scattering plane; however, some significant discrepancies are still present at the largest momentum transfer in both the scattering plane and the perpendicular plane. In actuality, the problem has not been explained by the theory during the last decade. Accordingly, the contributions of different scattering amplitudes to FDCS are analyzed. It is found that for the largest momentum transfer the cross section arising from a destructive interference of the three amplitudes is much smaller than the experimental data. However, the cross section due to the constructive interference of two scattering amplitudes between projectile-ionized electron interaction and projectile-passive electron interaction almost approaches the experimental data.展开更多
In order to study the collisional quantum interference （CQI） on rotational energy transfer in atom-diatom system, we have studied the relation of the integral interference angle and differential interference angle i...In order to study the collisional quantum interference （CQI） on rotational energy transfer in atom-diatom system, we have studied the relation of the integral interference angle and differential interference angle in Naq-Na2 （A1 ∑u^＋,v=8-b^3∏0u,v=14） collision system. In this paper, based on the first-Born approximation of timedependent perturbation theory and taking into accounts the anisotropic effect of Lennard-Jones interaction potentials, we present a theoretical model of collisional quantum interference in intramolecular rotational energy transfer, and a relationship between differential and integral interference angles.展开更多
The four-body model has been used to calculate the fully differential cross-sections （FDCS） for the single ionization of helium by 100 MeV/amu Ca^＋ impact in geometries. By comparing with experimental data and othe...The four-body model has been used to calculate the fully differential cross-sections （FDCS） for the single ionization of helium by 100 MeV/amu Ca^＋ impact in geometries. By comparing with experimental data and other theories, we find the results of four-body model are in very good agreement in the scattering plane, but poor agreement out of the scattering plane. Accordingly, the contributions of different scattering amplitudes to FDCS are analyzed. It is found that the cross sections due to the interference of the scattering amplitudes between projectile-target nucleus interaction and projectile-ejected electron interaction almost tend to experimental results around the recoil region in geometries. In particular in the perpendicular plane, the cross section originating from interference of the scattering amplitudes between projectile-target nucleus and projectile-ejected electron interactions yields an experimental double-peak structure in the angular distribution. However, this feature could not be presented by the interference of the three amplitudes. Thus, the failure of the fourbody model predicting the feature in this geometry may be attributed to an inappropriate weighting of the three amplitudes.展开更多
Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the...Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the Differential Pulse Polarography (DPP) method is that has a high sensitivity for the determination of vitamin B12. This determination was possible with cobalt present in vitamin B12 structure. Since Co(III) is formed from the oxidation of the vitamin, its polarographic behavior had to be determined in various electrolytes such as acetate, borate, phosphate and ammonia. The polarograms of Co(III) were taken in these electrolytes in which 1.0 M NH3/ (pH = 9.8) and 1.0 M AcOH/AcO- (pH = 4.0) were found as the most suitable electrolytes. This method was successfully applied vitamin of B12 determination in a 1 mL ampoule with high precision. The LOD was found as 3.7 × 10-7 for instead of (S/N = 3). Besides Co(III), interference effects of Zn(II), Ni(II), Cr(III), Fe(III), Cu(II), Cd(II) and Se(IV) were also studied. It was found that only Zn(II) peak had an overlap Co(III) peak in ammonium buffer. This problem could be solved by working in 1.0 M AcOH/AcO- (pH = 4.0) buffer. B12, which is 1000 μg in 1 mL vitamin ampoule, was found for 4 measurements as 999 ± 15 μg as a result of 95% confidence interval.展开更多
Noncoherent communication receivers (differential-detectors) have simple design, however, they always incur bit error rate (BER) performance loss up to 3dB compared to coherent receivers. In this paper, a differential...Noncoherent communication receivers (differential-detectors) have simple design, however, they always incur bit error rate (BER) performance loss up to 3dB compared to coherent receivers. In this paper, a differential-detector is proposed for impulse radio ultra wideband (IR-UWB) communication systems. The system employs bit-level differential phase shift keying (DPSK) combined with code division (CD) for IR-UWB signals to support multiple-access (MA). It is analyzed under additive white Gaussian noise (AWGN) corrupted by multiple-access interference (MAI) channel. Its BER performance is compared against a reference coherent receiver using Monte-Carlo simulation method. A closed form expression for its average probability of error is derived analytically. Simulation results and theoretical analysis confirm the applicability of the proposed differential-detector for IR-UWB communication systems.展开更多
本文针对高压直流输电(high-voltage direct current,HVDC)工程中交流滤波电容器桥差保护电流表测量值异常偏大的问题展开研究。理论分析与现场实测表明,因电流表测量导线与电容器塔、导线与地面以及导线之间存在杂散电容,且导线对地布...本文针对高压直流输电(high-voltage direct current,HVDC)工程中交流滤波电容器桥差保护电流表测量值异常偏大的问题展开研究。理论分析与现场实测表明,因电流表测量导线与电容器塔、导线与地面以及导线之间存在杂散电容,且导线对地布线存在物理不对称,引起差模干扰,导致不平衡电流测量值大于真实值。研究建立了杂散电容的等效电路模型,推导了测量误差的计算公式,并分析了杂散电容对测量结果的影响程度。为精确量化杂散电容参数,基于COMSOL Multiphysics软件构建了电容器塔与测量导线的高保真三维静电场模型,为误差分析提供了关键输入。最后结合新疆哈密某±800 kV特高压直流工程实例,通过现场试验验证了理论分析的正确性,并提出以采集电压替代电流的方案,实现不平衡电流的等效测量。展开更多
Objective： To investigate the characteristics of CGI-100- knockdown K562 cells and the effect of CGI-100 RNA interference （RNAi） on matrine-treated K562 cells. Methods： Three oligonucleotides targeting CGI-100 ge...Objective： To investigate the characteristics of CGI-100- knockdown K562 cells and the effect of CGI-100 RNA interference （RNAi） on matrine-treated K562 cells. Methods： Three oligonucleotides targeting CGI-100 gene and a pair of negative control containing the same nucleotide composition with a different sequence were devised and chemically synthesized. The inhibition efficiency of CGI-100 expression by shRNA-CGI-100 in K562 cells was determined using semiquantitative RT-PCR and dot blot hybridization. The effect of CGI-100 RNAi on the growth of K562 cells was examined using MTT assay and cell differentiation was measured by distinct approaches including flow cytometry, benzidine staining and electron microscope. After CGI-100-konckdown K562 cells were incubated with 0.2 mg/ml of matrine or 30 Ixmol/L of hemin for 48 h, the expression levels of Glycophorin A（GPA）（CD235a） and Growth factor independence-lB mRNA（Gfi-IB mRNA） were measured by RT-PCR and the protein levels of GPA, CD14 and CD15 were detected by flow cytometry. Results： The eukaryotic expression vectors of CGI-100 RNAi were successfully constructed. The K562/shRNA-CGI-100 cell line was established in which the inhibition efficiency of CGI-100 gene expression by shRNA-CGI-100 was 54%. CGI-100-knockdown inhibited the proliferation and induced erythroid differentiation in K562 cells. Compared with the control K562 cells, the K562/shRNA-CGI-100 cells showed decreased absorbance value detected by MTT assay, decreased enchromation, increased heterochromation, increased percentage of G0/Gx phase cells, decreased population of S phase cells, decreased PI （proliferation index of cells）, and elevated percentage of benzidine-positive cells. Moreover, the sensitivity of K562/shRNA-CGI-100 cells to either matrine or hemin was enhanced and the sensitivity of these cells to matrine was higher than that to hemin. Compared with the control K562 cells, matrine treatment in K562/shRNA-CGI-100 cells resulted in increased inhibitory rate of proliferation, elevated percentage of be nzidine-positive cells, obviously up-regulated mRNA expressions of GPA and Gfi-IB, and increased mean fluorescence intensity （MFI） of GPA. No CD14 expression was detected and no statistical significance was found for the detected CD15. Finally, the MFI of GPA increased in K562/shRNA-CGI-100 cells treated with hemin and was 1.7 times less than that in cells exposed to matrine. Conclusion： These results suggest that the function of CGI-100 gene is correlated with the deregulated proliferation and the block of erythroid differentiation in K562 cells and may also be involved in matrine-induced erythroid differentiation in K562 ceils.展开更多
Objective:To investigate the effect on erythroid differentiation and proliferation of K562 cells by IER3IP1-knockdown with RNA interference targeting at IER3IP1 gene.Methods:The shRNA eukaryotic expression vectors tar...Objective:To investigate the effect on erythroid differentiation and proliferation of K562 cells by IER3IP1-knockdown with RNA interference targeting at IER3IP1 gene.Methods:The shRNA eukaryotic expression vectors targeting at IER3IP1 gene were designed and constructed.Inhibitory effect was detected by semiquantitative RT-PCR.The impacts on K562 cells by RNAi were studied by MTT assay,benzidine staining,light microscope and electron microscopy observation,cell cycles analysis,colony formation assay and RT-PCR.The expressions of erythroid differentiation correlated genes Gfi-lB,GPA and 7-globin were studied after being exposed to 0.2μmol/L imatinib for two days.Results:The shRNA eukaryotic expression vectors were successfully constructed.The expression of IER3IP1 gene was significantly inhibited with an inhibition efficiency of 76%(P〈0.01).Compared with the control groups,bcr/abl mRNA level was increased in K562/shRNA-IER3IP1 group(P〈0.01).The proliferation ability was enhanced(P〈0.01)and the proportion of cells at G0/G1 phase decreased but S phase increased(P〈0.05)in K562/shRNA-IER3IP1 group.Under electron microscopy,the amount of euchromatin increased but heterochromatin decreased.There were structural abnomalities in endocytoplasmic reticulum and clusters of vesicular.The percentage of benzidine staining positive cells and mRNA expression levels of Gfi-1B,GPA andγ-globin were all decreased after being exposed to 0.2μmol/L STI571 for two days in K562/shRNA-IER3IP1 group(P〈0.01).Conclusion:IER3IP1-knockdown can hinder the erythroid differentiation and elevate the proliferation level of K562 cells.IER3IP1 may play a role in erythroid differentiation and proliferation of K562 cells.展开更多
A reduction in the track width of magnetic recording systems results in a welcome increase in Areal Density(AD),but can severely deteriorate system performance in the unfortunate appearance of extreme Inter-Track Inte...A reduction in the track width of magnetic recording systems results in a welcome increase in Areal Density(AD),but can severely deteriorate system performance in the unfortunate appearance of extreme Inter-Track Interference(ITI).The effect of severe ITI may be mitigated by using coding schemes.In this paper,therefore,we present a rate-5/62-Dimensional(2D)modulation code based on a proposed Single-Reader/Two-track Reading(SRTR)technique to cope with this serious problem in staggered Bit-Pattemed Magnetic Recording(BPMR)systems.We then evaluate the Bit-Error Rate(BER)performance of the proposed system in the presence of media noises,e.g.,position and size fluctuations.Our simulation results indicate that,at the same User Density(UD),the proposed system performs better than an uncoded system by about 1.0 dB at the BER of 105 and is also superior to the conventional recording system.展开更多
基金Project supported by the Research Foundation of Department of Education of Liaoning Province (Grant No 20060347)the NNSFC (Grant No 10374040)
文摘Collisional quantum interference （CQI） in the intramolecular rotational energy transfer was observed in experiment by Sha and co-workers. The interference angle, which measuring the degree of the coherence, were measured in the experiment of the static cell. Based on the first Born approximation of time dependent perturbation theory, taking into accounts the anisotropic Lennard-Jones interaction potentials, this paper describes the theoretical model of CQI in intramolecular rotational energy transfer in an atom-diatom collision system. In the model, the differential interference angle for the experiment of the molecular beam is calculated, the changing tendencies of the differential interference angle with the impact parameter and collision partners are obtained. This theoretical model is important for understanding or performing this kind of experiments.
基金The project supported by National Natural Science Foundation of China under Grant No. 10374040 and Fund of the Department of Education of Liaoning Province of China under Grant No. 2004 F 004 . Thanks are given to Dr. Sun Meng-Tao （Department of Chemical Physics, Lund University, Lund, Sweden） due to his help in this work.
文摘Collisional quantum interference （CQI） was observed in the intramolecular rotational energy transfer in the experiment of the static cell, and the integral interference angles were measured. To observe more precise information, the experiment in the molecular beam should be taken,from which the relationship between the differential interference angle and the scattering angle can be obtained. In this paper, the theoretical model of CQI is described in an atom-diatom system in the condition of the molecular beam, based on the first-Born approximation of time-dependent perturbation theory, taking into accounts the long-range interaction potential. The method of observing and measuring correctly the differential interference angle is presented. The changing tendency of the differential interference angle with the impact parameter and relative velocity is discussed. The changing tendencies of the differential interference angle with the parameter of experiment in the molecular beam, including the impact parameter and the velocity are discussed. This theoretical model is important to understand or perform the experiment in the molecular beam.
基金Supported by the Qingdao Aquarium Technology Collaborative Innovation Center Cooperation Project(No.20210021)the Researching Key Technologies for Selecting Excellent Koi Carp Germplasm(No.20223702032291)the Qingdao Agricultural University Tangwang Koi Carp Joint R&D Center Collaborative Project(No.20220271)。
文摘FOXL 2 and CYP 19 B are crucial transcription factors in vertebrates and invertebrates that play pivotal roles in sex differentiation and gonadal development.The potential roles of the foxl 2 and cyp 19 b genes in sex determination and gonadal development in Cyprinus carpio var.koi were explored using a non-invasive RNA interference(RNAi)method,histopathological observation and qPCR.Results demonstrate that foxl 2 exhibited a sexually dimorphic expression pattern in gonads,with a notable expression in ovaries;cyp 19 b was expressed in all peripheral tissues,with a particularly prominent expression in brain and gonads.The knockdown of foxl 2 by RNAi resulted in delay in the development of the female gonads.Conversely,no notable alterations were discerned in the gonads of C.carpio var.koi following the knockdown of cyp 19 b.The upregulation of sox 9 a,amh,and cyp 19 b following foxl 2 knockdown indicates that foxl 2 may play a pivotal role in gonadal development.Nevertheless,further investigation is required to ascertain the potential role of cyp 19 b.This study elucidated the role of foxl 2 and enhanced the understanding of the mechanisms of sex determination and gonadal development in C.carpio var.koi.
基金Joint Seismological Science Foundation of China (201012).
文摘The principles and applications of laser real-time holographic interferometry （LRTHI） and radar differential interferometry （RDI） technologies are described in this paper, respectively. By using LRTHI, we can observe the deformation of samples under pressure in the lab and study the anomaly characteristics relating to different strain fields in different fracture-developing areas; while by using RDI, we can observe the landform and surface deformation. The results of deformation observed before and after the Ms=7.9 Mani earthquake （Tibet） and Ms=6.2 Shangyi-Zhangbei earthquake in China are obtained. It is pointed out that LRTHI and RDi are similar, which study the characteristics of anomalous deformation field by fringe variations for both of them. Therefore, the observation of deformation field in the seismogenic process, especially in the period impending an earthquake by RDI, and the comparative study in the lab by LRTHI are of great significance.
文摘This paper gives theoretical analysis of visibility of fringes, which is influenced by distances, temporal and spatial coherence of source, in hard x-ray differential phase-contrast imaging with microfocus x-ray source. According to the character of longitudinal periodicity of the interferogram, the setup is insensitive to mechanical drift and vibrations. The effect of temporal coherence of x-ray source is investigated and its related bandwidth is derived. Based on the theory of partially coherent light, it shows that the requirement for the spatial coherence of x-ray source is not strict and can be met by the general microfocus x-ray tube for x-ray differential phase-contrast imaging.
基金supported by the National Natural Science Foundation of China(Grant No.11274215)the Natural Science Foundation of Shanxi Province,China(Grants Nos.20051008 and 2010011009)the Technology Project of Shanxi Provincial Education Department,China(Grant No.20111011)
文摘Fully differential cross sections （FDCS） are calculated within a four-body model for single ionization of helium by C6＋ impact at the incident energy of 100 MeV/a.u. （atomic unit）. The results are compared with experimental data and other theoretical predictions. It is shown that our results are in very good agreement with experiment for three small momentum transfers in the scattering plane; however, some significant discrepancies are still present at the largest momentum transfer in both the scattering plane and the perpendicular plane. In actuality, the problem has not been explained by the theory during the last decade. Accordingly, the contributions of different scattering amplitudes to FDCS are analyzed. It is found that for the largest momentum transfer the cross section arising from a destructive interference of the three amplitudes is much smaller than the experimental data. However, the cross section due to the constructive interference of two scattering amplitudes between projectile-ionized electron interaction and projectile-passive electron interaction almost approaches the experimental data.
基金Supported by the National Natural Science Foundation of China under Grant No.10374040the Foundation of the Educational Department of Liaoning Province under Grant Nos.2008290 and 20060347
文摘In order to study the collisional quantum interference （CQI） on rotational energy transfer in atom-diatom system, we have studied the relation of the integral interference angle and differential interference angle in Naq-Na2 （A1 ∑u^＋,v=8-b^3∏0u,v=14） collision system. In this paper, based on the first-Born approximation of timedependent perturbation theory and taking into accounts the anisotropic effect of Lennard-Jones interaction potentials, we present a theoretical model of collisional quantum interference in intramolecular rotational energy transfer, and a relationship between differential and integral interference angles.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China （No.11274215）, the Natural Science Foundation of Shanxi Province, China （No.20051008 and No.2010011009）, and the Technology Project of Shanxi Provincial Education Department, China （No.20111011）.
文摘The four-body model has been used to calculate the fully differential cross-sections （FDCS） for the single ionization of helium by 100 MeV/amu Ca^＋ impact in geometries. By comparing with experimental data and other theories, we find the results of four-body model are in very good agreement in the scattering plane, but poor agreement out of the scattering plane. Accordingly, the contributions of different scattering amplitudes to FDCS are analyzed. It is found that the cross sections due to the interference of the scattering amplitudes between projectile-target nucleus interaction and projectile-ejected electron interaction almost tend to experimental results around the recoil region in geometries. In particular in the perpendicular plane, the cross section originating from interference of the scattering amplitudes between projectile-target nucleus and projectile-ejected electron interactions yields an experimental double-peak structure in the angular distribution. However, this feature could not be presented by the interference of the three amplitudes. Thus, the failure of the fourbody model predicting the feature in this geometry may be attributed to an inappropriate weighting of the three amplitudes.
基金the Gazi University research fund for the financial support of this research.
文摘Vitamin B12 is a type of vitamin also known by the name cobalamin. B12 is involved in many metabolism activities, including DNA synthesis, nervous system, red blood formation and immune system. Therefore, we chose the Differential Pulse Polarography (DPP) method is that has a high sensitivity for the determination of vitamin B12. This determination was possible with cobalt present in vitamin B12 structure. Since Co(III) is formed from the oxidation of the vitamin, its polarographic behavior had to be determined in various electrolytes such as acetate, borate, phosphate and ammonia. The polarograms of Co(III) were taken in these electrolytes in which 1.0 M NH3/ (pH = 9.8) and 1.0 M AcOH/AcO- (pH = 4.0) were found as the most suitable electrolytes. This method was successfully applied vitamin of B12 determination in a 1 mL ampoule with high precision. The LOD was found as 3.7 × 10-7 for instead of (S/N = 3). Besides Co(III), interference effects of Zn(II), Ni(II), Cr(III), Fe(III), Cu(II), Cd(II) and Se(IV) were also studied. It was found that only Zn(II) peak had an overlap Co(III) peak in ammonium buffer. This problem could be solved by working in 1.0 M AcOH/AcO- (pH = 4.0) buffer. B12, which is 1000 μg in 1 mL vitamin ampoule, was found for 4 measurements as 999 ± 15 μg as a result of 95% confidence interval.
文摘Noncoherent communication receivers (differential-detectors) have simple design, however, they always incur bit error rate (BER) performance loss up to 3dB compared to coherent receivers. In this paper, a differential-detector is proposed for impulse radio ultra wideband (IR-UWB) communication systems. The system employs bit-level differential phase shift keying (DPSK) combined with code division (CD) for IR-UWB signals to support multiple-access (MA). It is analyzed under additive white Gaussian noise (AWGN) corrupted by multiple-access interference (MAI) channel. Its BER performance is compared against a reference coherent receiver using Monte-Carlo simulation method. A closed form expression for its average probability of error is derived analytically. Simulation results and theoretical analysis confirm the applicability of the proposed differential-detector for IR-UWB communication systems.
文摘本文针对高压直流输电(high-voltage direct current,HVDC)工程中交流滤波电容器桥差保护电流表测量值异常偏大的问题展开研究。理论分析与现场实测表明,因电流表测量导线与电容器塔、导线与地面以及导线之间存在杂散电容,且导线对地布线存在物理不对称,引起差模干扰,导致不平衡电流测量值大于真实值。研究建立了杂散电容的等效电路模型,推导了测量误差的计算公式,并分析了杂散电容对测量结果的影响程度。为精确量化杂散电容参数,基于COMSOL Multiphysics软件构建了电容器塔与测量导线的高保真三维静电场模型,为误差分析提供了关键输入。最后结合新疆哈密某±800 kV特高压直流工程实例,通过现场试验验证了理论分析的正确性,并提出以采集电压替代电流的方案,实现不平衡电流的等效测量。
基金supported by the National Natural Science Foundation of China(No.30171150)
文摘Objective： To investigate the characteristics of CGI-100- knockdown K562 cells and the effect of CGI-100 RNA interference （RNAi） on matrine-treated K562 cells. Methods： Three oligonucleotides targeting CGI-100 gene and a pair of negative control containing the same nucleotide composition with a different sequence were devised and chemically synthesized. The inhibition efficiency of CGI-100 expression by shRNA-CGI-100 in K562 cells was determined using semiquantitative RT-PCR and dot blot hybridization. The effect of CGI-100 RNAi on the growth of K562 cells was examined using MTT assay and cell differentiation was measured by distinct approaches including flow cytometry, benzidine staining and electron microscope. After CGI-100-konckdown K562 cells were incubated with 0.2 mg/ml of matrine or 30 Ixmol/L of hemin for 48 h, the expression levels of Glycophorin A（GPA）（CD235a） and Growth factor independence-lB mRNA（Gfi-IB mRNA） were measured by RT-PCR and the protein levels of GPA, CD14 and CD15 were detected by flow cytometry. Results： The eukaryotic expression vectors of CGI-100 RNAi were successfully constructed. The K562/shRNA-CGI-100 cell line was established in which the inhibition efficiency of CGI-100 gene expression by shRNA-CGI-100 was 54%. CGI-100-knockdown inhibited the proliferation and induced erythroid differentiation in K562 cells. Compared with the control K562 cells, the K562/shRNA-CGI-100 cells showed decreased absorbance value detected by MTT assay, decreased enchromation, increased heterochromation, increased percentage of G0/Gx phase cells, decreased population of S phase cells, decreased PI （proliferation index of cells）, and elevated percentage of benzidine-positive cells. Moreover, the sensitivity of K562/shRNA-CGI-100 cells to either matrine or hemin was enhanced and the sensitivity of these cells to matrine was higher than that to hemin. Compared with the control K562 cells, matrine treatment in K562/shRNA-CGI-100 cells resulted in increased inhibitory rate of proliferation, elevated percentage of be nzidine-positive cells, obviously up-regulated mRNA expressions of GPA and Gfi-IB, and increased mean fluorescence intensity （MFI） of GPA. No CD14 expression was detected and no statistical significance was found for the detected CD15. Finally, the MFI of GPA increased in K562/shRNA-CGI-100 cells treated with hemin and was 1.7 times less than that in cells exposed to matrine. Conclusion： These results suggest that the function of CGI-100 gene is correlated with the deregulated proliferation and the block of erythroid differentiation in K562 cells and may also be involved in matrine-induced erythroid differentiation in K562 ceils.
基金supported by the National Natural Science Foundation of China(No.30171150)
文摘Objective:To investigate the effect on erythroid differentiation and proliferation of K562 cells by IER3IP1-knockdown with RNA interference targeting at IER3IP1 gene.Methods:The shRNA eukaryotic expression vectors targeting at IER3IP1 gene were designed and constructed.Inhibitory effect was detected by semiquantitative RT-PCR.The impacts on K562 cells by RNAi were studied by MTT assay,benzidine staining,light microscope and electron microscopy observation,cell cycles analysis,colony formation assay and RT-PCR.The expressions of erythroid differentiation correlated genes Gfi-lB,GPA and 7-globin were studied after being exposed to 0.2μmol/L imatinib for two days.Results:The shRNA eukaryotic expression vectors were successfully constructed.The expression of IER3IP1 gene was significantly inhibited with an inhibition efficiency of 76%(P〈0.01).Compared with the control groups,bcr/abl mRNA level was increased in K562/shRNA-IER3IP1 group(P〈0.01).The proliferation ability was enhanced(P〈0.01)and the proportion of cells at G0/G1 phase decreased but S phase increased(P〈0.05)in K562/shRNA-IER3IP1 group.Under electron microscopy,the amount of euchromatin increased but heterochromatin decreased.There were structural abnomalities in endocytoplasmic reticulum and clusters of vesicular.The percentage of benzidine staining positive cells and mRNA expression levels of Gfi-1B,GPA andγ-globin were all decreased after being exposed to 0.2μmol/L STI571 for two days in K562/shRNA-IER3IP1 group(P〈0.01).Conclusion:IER3IP1-knockdown can hinder the erythroid differentiation and elevate the proliferation level of K562 cells.IER3IP1 may play a role in erythroid differentiation and proliferation of K562 cells.
基金This work was patially supported by the Thailand Research Fund under the grant number RSA6080051,College of Advanced Manufacturing Innovation(AMD),and King Mongkut's Institute of Technology Ladkrabang(KMIIL),Thailand.
文摘A reduction in the track width of magnetic recording systems results in a welcome increase in Areal Density(AD),but can severely deteriorate system performance in the unfortunate appearance of extreme Inter-Track Interference(ITI).The effect of severe ITI may be mitigated by using coding schemes.In this paper,therefore,we present a rate-5/62-Dimensional(2D)modulation code based on a proposed Single-Reader/Two-track Reading(SRTR)technique to cope with this serious problem in staggered Bit-Pattemed Magnetic Recording(BPMR)systems.We then evaluate the Bit-Error Rate(BER)performance of the proposed system in the presence of media noises,e.g.,position and size fluctuations.Our simulation results indicate that,at the same User Density(UD),the proposed system performs better than an uncoded system by about 1.0 dB at the BER of 105 and is also superior to the conventional recording system.
文摘利用全球导航卫星系统(Global Navigation Satellite System,GNSS)双频差分信号进行电离层电子含量反演是一种常用的电离层探测手段,但GNSS信号在强电磁干扰环境下,被淹没于电磁噪声中而无法被提取,影响电离层总电子含量(total electron content,TEC)反演系统的可靠性。采用传统调零抗干扰阵列天线方案能解决干扰源剥离的问题,但调零信号的天线相位中心不稳定导致高精度的相位平滑伪距和精密单点定位(precise point positioning,PPP)算法无法收敛。针对强干扰环境下的电离层监测需求,本文提出一种抗干扰TEC数据反演手段,通过对阵列天线通道幅相一致性进行校正,保证相位中心的稳定性,从而推算出准确的电离层TEC信息,提高了系统的可靠性和抗干扰能力。
