Based on the field investigation in August 2001 and August 2002, digitalChina Vegetation Map in 2001 and Qinghai-Xizang (Tibet) Plateau Vegetation Regionalization Map in1996, vegetation characteristics along two sides...Based on the field investigation in August 2001 and August 2002, digitalChina Vegetation Map in 2001 and Qinghai-Xizang (Tibet) Plateau Vegetation Regionalization Map in1996, vegetation characteristics along two sides of Qinghai-Xizang highway and railway are studiedin this paper. Meanwhile, the impact of Qinghai-Xizang highway and railway constructions on thevegetation types are analyzed using ARCVIEW, ARC/INFO and PATCH ANALYSIS. It was found that: 1)Qinghai-Xizang highway and railway span 9 latitudes, 12 longitudes and 6 physical geographic regions(East Qinghai and Qilian mountain steppe region, Qaidam mountain desert region, SouthQinghai-Xizang alpine meadow steppe region, Qiangtang alpine steppe region, Golog-Nagqu alpine shrubmeadow region and South Xizang mountain shrub steppe region); 2) the construction of Qinghai-Xizanghighway and railway destroyed natural vegetation and landscape, especially in 50m-wide bufferregions along both sides of the roads, it was estimated that the net primary productivity deceasedby about 30 504.62t/a and the gross biomass deceased by 432 919.25-1 436 104.3t. The losing primaryproductivity accounted for 5.70% of the annual primary productivity within Ikm-wide buffer regions(535 005.07-535 740.11t/a), and only 0.80%-0.89% of that within 10km-wide buffer regions (3 408950.45-3 810 480.92t/a). The losing gross biomass was about 9.47%-17.06% of the gross biomass within1km-wide buffer regions (7 502 971.85-25 488 342.71t), and only 1.47%-2.94% of that within10km-wide buffer regions (43 615 065.35-164 150 665.37t).展开更多
Aim Aim To study the pathological features nasopharyngeal T-cell malignant lymphoma (NTCML) and the relationship between EBV and NTCML. Methods Eighteen cases of NTCML were observed by light microscopy, electronic mic...Aim Aim To study the pathological features nasopharyngeal T-cell malignant lymphoma (NTCML) and the relationship between EBV and NTCML. Methods Eighteen cases of NTCML were observed by light microscopy, electronic microscopy and immunohistochemistry. Epstein-Bars virus (EBV) DNA was determined by two temperature polymerase chain reaction (PCR) cycles in paraffin embedded tissue of 18 cases NTCML. Results The positive of EBV-DNA were determined from 15 cases out of 18 cases of NTCML and only one case of the 12 controls ( P < 0.05). Conclusion It is suggested that the finding fresher supports the view that the pathogenesis of NTCML may be associated with the infection of EBV. We also discussed the significance of the determination of EBV-DNA in the diagnosis of NTCML and the advantage of two temperature PCR.展开更多
Array calibration with angularly dependent gain and phase uncertainties has long been a difficult problem. Although many array calibration methods have been reported extensively in the literature, they almost all assu...Array calibration with angularly dependent gain and phase uncertainties has long been a difficult problem. Although many array calibration methods have been reported extensively in the literature, they almost all assumed an angularly independent model for array uncertainties. Few calibration methods have been developed for the angularly dependent array uncertainties. A novel and efficient auto-calibration method for angularly dependent gain and phase uncertainties is proposed in this paper, which is called ISM (Instrumental Sensors Method). With the help of a few well-calibrated instrumental sensors, the ISM is able to achieve favorable and unambiguous direction-of-arrivals (DOAs) estimate and the corresponding angularly dependent gain and phase estimate simultaneously, even in the case of multiple non-disjoint sources. Since the mutual coupling and sensor position errors can all be described as angularly dependent gain/phase uncertainties, the ISM proposed still works in the presence of a combination of all these array perturbations. The ISM can be applied to arbitrary array geometries including linear arrays. The ISM is computationally efficient and requires only one-dimensional search, with no high-dimensional nonlinear search and convergence burden involved. Besides, no small error assumption is made, which is always an essential prerequisite for many existing array calibration techniques. The estimation performance of the ISM is analyzed theoretically and simulation results are provided to demonstrate the effectiveness and behavior of the proposed ISM.展开更多
The presence of unknown mutual coupling between array elements is knownto significantly degrade the performance of most high-resolution direction of arrival (DOA)estimation algorithms. In this paper, a robust subspace...The presence of unknown mutual coupling between array elements is knownto significantly degrade the performance of most high-resolution direction of arrival (DOA)estimation algorithms. In this paper, a robust subspace-based DOA estimation and arrayauto-calibration algorithm is proposed for uniformly linear array (ULA), when the arraymutual coupling is present. Based on a banded symmetric Toeplitz matrix model for themutual coupling of ULA, the algorithm provides an accurate and high-resolution DOAestimate without any knowledge of the array mutual couplings. Moreover, a favorableestimate of mutual coupling matrix can also be achieved simultaneously for arrayauto-calibration. The algorithm is realized just via one-dimensional search or polynomialrooting, with no multidimensional nonlinear search or convergence burden involved. Theproblem of parameter ambiguity, statistically consistence and efficiency of the newestimator are also analyzed. Monte-Carlo simulation results are also provided todemonstrate the effectiveness and behavior of the proposed algorithm.展开更多
Poly(vinylidene fluoride-co-hexafluoropropyle- ne) (PVDF-HFP) is one of the most popular polymers for polymer electrolyte membranes because of its excellent oper- ating characteristics and superior electrochemical pro...Poly(vinylidene fluoride-co-hexafluoropropyle- ne) (PVDF-HFP) is one of the most popular polymers for polymer electrolyte membranes because of its excellent oper- ating characteristics and superior electrochemical properties. The electrochemical performances of polymer electrolyte membrane can be enhanced by evenly dispersing nano-meter SiO2 particles in the polymer. In this paper, non-woven fab- rics were immersed in the mixed solution of PVDF-HFP/ SiO2/butanone/butanol/plasticizer, and then dried in a vac- uum oven to remove the solvents and the plasticizer and to make porous composite polymer electrolyte membranes. The prepared composite membranes supported by non-woven fabrics boast good mechanical strength and excellent elec- trochemical properties: the electrochemical stability window is 4.8 V vs. Li+/Li, and the ionic conductivity is 3.35×10?4 S/cm (around 60% of that of a common PE membrane) at room temperature. The lithium-ion polymer battery assem- bled by the composite membrane exhibits high rate capabil- ity and excellent cycling performance.展开更多
A light-harvesting chlorophyll a/b-protein complex (LHCP) was isolated directly from thylakoid mem-branes of marine green alga, Bryopsis corticulans, by two consecutive runs of liquid chromatography. The trimeric form...A light-harvesting chlorophyll a/b-protein complex (LHCP) was isolated directly from thylakoid mem-branes of marine green alga, Bryopsis corticulans, by two consecutive runs of liquid chromatography. The trimeric form of the light-harvesting complex has been obtained by sucrose gradient ultracentrifugation. The result of SDS- PAGE shows that the light-harvesting complex is composed of at least five apoproteins in which a protein with apparent molecular weight of about 31 kD was never found in the ma-jor light-harvesting complex (LHC Ⅱ) from higher plants. The isolated Bryopsis corticulans light-harvesting complex contains a specific carotenoid, siphonaxanthin, as well as chlorophyll (Chl) a, Chl b, neoxanthin and violaxanthin. Si-phonaxanthin which is present in the light-harvesting sipho-naxanthin-chlorophyll a/b-protein complex of Bryopsis corticulans is responsible for enhanced absorption in the blue-green region (530 nm). Efficient energy transfer from both siphonaxanthin and Chl b to Chl a in Bryopsis corticu-lans LHCP, which has similar absorption and fluorescence emission spectra to those of the lutein-chlorophyll a/b-protein of higher plants, proved that molecular arrangement of the light-harvesting pigments was highly ordered in the Bryopsis corticulans LHCP. The siphonaxanthin-chlorophyll a/b-pro- teins allow enhanced absorption of blue-green light, the pre-dominant light available in deep ocean waters or shaded subtidal marine habitats.展开更多
This paper describes experience with the se- quencing of synthetic segment peptides of gp41 which are used in trimeric peptides as potential peptide-based vaccines and as inhibitors to mimic the fusion state of gp41 i...This paper describes experience with the se- quencing of synthetic segment peptides of gp41 which are used in trimeric peptides as potential peptide-based vaccines and as inhibitors to mimic the fusion state of gp41 in HIV infection using ESI/CID-FT-ICR MS. All b and y″ series ions are found in the CID spectra and the mass difference between the calculated and observed results is very slight. FT-ICR MS again shows its power in peptide sequencing, successfully helping us obtain the sequence of an unknown peptide.展开更多
文摘Based on the field investigation in August 2001 and August 2002, digitalChina Vegetation Map in 2001 and Qinghai-Xizang (Tibet) Plateau Vegetation Regionalization Map in1996, vegetation characteristics along two sides of Qinghai-Xizang highway and railway are studiedin this paper. Meanwhile, the impact of Qinghai-Xizang highway and railway constructions on thevegetation types are analyzed using ARCVIEW, ARC/INFO and PATCH ANALYSIS. It was found that: 1)Qinghai-Xizang highway and railway span 9 latitudes, 12 longitudes and 6 physical geographic regions(East Qinghai and Qilian mountain steppe region, Qaidam mountain desert region, SouthQinghai-Xizang alpine meadow steppe region, Qiangtang alpine steppe region, Golog-Nagqu alpine shrubmeadow region and South Xizang mountain shrub steppe region); 2) the construction of Qinghai-Xizanghighway and railway destroyed natural vegetation and landscape, especially in 50m-wide bufferregions along both sides of the roads, it was estimated that the net primary productivity deceasedby about 30 504.62t/a and the gross biomass deceased by 432 919.25-1 436 104.3t. The losing primaryproductivity accounted for 5.70% of the annual primary productivity within Ikm-wide buffer regions(535 005.07-535 740.11t/a), and only 0.80%-0.89% of that within 10km-wide buffer regions (3 408950.45-3 810 480.92t/a). The losing gross biomass was about 9.47%-17.06% of the gross biomass within1km-wide buffer regions (7 502 971.85-25 488 342.71t), and only 1.47%-2.94% of that within10km-wide buffer regions (43 615 065.35-164 150 665.37t).
文摘Aim Aim To study the pathological features nasopharyngeal T-cell malignant lymphoma (NTCML) and the relationship between EBV and NTCML. Methods Eighteen cases of NTCML were observed by light microscopy, electronic microscopy and immunohistochemistry. Epstein-Bars virus (EBV) DNA was determined by two temperature polymerase chain reaction (PCR) cycles in paraffin embedded tissue of 18 cases NTCML. Results The positive of EBV-DNA were determined from 15 cases out of 18 cases of NTCML and only one case of the 12 controls ( P < 0.05). Conclusion It is suggested that the finding fresher supports the view that the pathogenesis of NTCML may be associated with the infection of EBV. We also discussed the significance of the determination of EBV-DNA in the diagnosis of NTCML and the advantage of two temperature PCR.
文摘Array calibration with angularly dependent gain and phase uncertainties has long been a difficult problem. Although many array calibration methods have been reported extensively in the literature, they almost all assumed an angularly independent model for array uncertainties. Few calibration methods have been developed for the angularly dependent array uncertainties. A novel and efficient auto-calibration method for angularly dependent gain and phase uncertainties is proposed in this paper, which is called ISM (Instrumental Sensors Method). With the help of a few well-calibrated instrumental sensors, the ISM is able to achieve favorable and unambiguous direction-of-arrivals (DOAs) estimate and the corresponding angularly dependent gain and phase estimate simultaneously, even in the case of multiple non-disjoint sources. Since the mutual coupling and sensor position errors can all be described as angularly dependent gain/phase uncertainties, the ISM proposed still works in the presence of a combination of all these array perturbations. The ISM can be applied to arbitrary array geometries including linear arrays. The ISM is computationally efficient and requires only one-dimensional search, with no high-dimensional nonlinear search and convergence burden involved. Besides, no small error assumption is made, which is always an essential prerequisite for many existing array calibration techniques. The estimation performance of the ISM is analyzed theoretically and simulation results are provided to demonstrate the effectiveness and behavior of the proposed ISM.
文摘The presence of unknown mutual coupling between array elements is knownto significantly degrade the performance of most high-resolution direction of arrival (DOA)estimation algorithms. In this paper, a robust subspace-based DOA estimation and arrayauto-calibration algorithm is proposed for uniformly linear array (ULA), when the arraymutual coupling is present. Based on a banded symmetric Toeplitz matrix model for themutual coupling of ULA, the algorithm provides an accurate and high-resolution DOAestimate without any knowledge of the array mutual couplings. Moreover, a favorableestimate of mutual coupling matrix can also be achieved simultaneously for arrayauto-calibration. The algorithm is realized just via one-dimensional search or polynomialrooting, with no multidimensional nonlinear search or convergence burden involved. Theproblem of parameter ambiguity, statistically consistence and efficiency of the newestimator are also analyzed. Monte-Carlo simulation results are also provided todemonstrate the effectiveness and behavior of the proposed algorithm.
文摘Poly(vinylidene fluoride-co-hexafluoropropyle- ne) (PVDF-HFP) is one of the most popular polymers for polymer electrolyte membranes because of its excellent oper- ating characteristics and superior electrochemical properties. The electrochemical performances of polymer electrolyte membrane can be enhanced by evenly dispersing nano-meter SiO2 particles in the polymer. In this paper, non-woven fab- rics were immersed in the mixed solution of PVDF-HFP/ SiO2/butanone/butanol/plasticizer, and then dried in a vac- uum oven to remove the solvents and the plasticizer and to make porous composite polymer electrolyte membranes. The prepared composite membranes supported by non-woven fabrics boast good mechanical strength and excellent elec- trochemical properties: the electrochemical stability window is 4.8 V vs. Li+/Li, and the ionic conductivity is 3.35×10?4 S/cm (around 60% of that of a common PE membrane) at room temperature. The lithium-ion polymer battery assem- bled by the composite membrane exhibits high rate capabil- ity and excellent cycling performance.
文摘A light-harvesting chlorophyll a/b-protein complex (LHCP) was isolated directly from thylakoid mem-branes of marine green alga, Bryopsis corticulans, by two consecutive runs of liquid chromatography. The trimeric form of the light-harvesting complex has been obtained by sucrose gradient ultracentrifugation. The result of SDS- PAGE shows that the light-harvesting complex is composed of at least five apoproteins in which a protein with apparent molecular weight of about 31 kD was never found in the ma-jor light-harvesting complex (LHC Ⅱ) from higher plants. The isolated Bryopsis corticulans light-harvesting complex contains a specific carotenoid, siphonaxanthin, as well as chlorophyll (Chl) a, Chl b, neoxanthin and violaxanthin. Si-phonaxanthin which is present in the light-harvesting sipho-naxanthin-chlorophyll a/b-protein complex of Bryopsis corticulans is responsible for enhanced absorption in the blue-green region (530 nm). Efficient energy transfer from both siphonaxanthin and Chl b to Chl a in Bryopsis corticu-lans LHCP, which has similar absorption and fluorescence emission spectra to those of the lutein-chlorophyll a/b-protein of higher plants, proved that molecular arrangement of the light-harvesting pigments was highly ordered in the Bryopsis corticulans LHCP. The siphonaxanthin-chlorophyll a/b-pro- teins allow enhanced absorption of blue-green light, the pre-dominant light available in deep ocean waters or shaded subtidal marine habitats.
基金supported by the National Natural Science Foundation of China(Grant No.20075002)
文摘This paper describes experience with the se- quencing of synthetic segment peptides of gp41 which are used in trimeric peptides as potential peptide-based vaccines and as inhibitors to mimic the fusion state of gp41 in HIV infection using ESI/CID-FT-ICR MS. All b and y″ series ions are found in the CID spectra and the mass difference between the calculated and observed results is very slight. FT-ICR MS again shows its power in peptide sequencing, successfully helping us obtain the sequence of an unknown peptide.
