A recently released XMM-Newton note revealed a significant calibration issue between nuclear spectroscopic telescope array(NuSTAR)and XMM-Newton European Photon Imaging Camera(EPIC)and provided an empirical correction...A recently released XMM-Newton note revealed a significant calibration issue between nuclear spectroscopic telescope array(NuSTAR)and XMM-Newton European Photon Imaging Camera(EPIC)and provided an empirical correction to the EPIC effective area.To quantify the bias caused by the calibration issue in the joint analysis of XMM-NuSTAR spectra and verify the effectiveness of the correction,in this work,we perform joint-fitting of the NuSTAR and EPIC-pn spectra for a large sample of 104 observation pairs of 44 X-ray bright active galactic nuclei(AGN).The spectra were extracted after requiring perfect simultaneity between the XMM-Newton and NuSTAR exposures(merging good time intervals(GTIs)from two missions)to avoid bias due to the rapid spectral variability of the AGN.Before the correction,the EPIC-pn spectra are systematically harder than the corresponding NuSTAR spectra by■subsequently yielding significantly underestimated cutoff energy E_(cut)and the strength of reflection component R when performing joint-fitting.We confirm that the correction is highly effective and can commendably erase the discrepancy in best-fitΓ,E_(cut),and R.We thus urge the community to apply the correction when joint-fitting XMM-NuSTAR spectra,but note that the correction is limited to 3–12 keV and therefore not applicable when the soft X-ray band data are included.Besides,we show that as merging GTIs from two missions would cause severe loss of NuSTAR net exposure time,in many cases,joint-fitting yields no advantage compared with utilizing NuSTAR data alone.Finally,We present a technical note on filtering periods of high background flares for XMM-Newton EPIC-pn exposures in the small window(SW)mode.展开更多
To investigate the chemical constituents of the roots ofPolygala sibirica L. The separation and purification were performed by solvent extraction and repeated chromatography with silica gel, Sephadex LH-20, ODS column...To investigate the chemical constituents of the roots ofPolygala sibirica L. The separation and purification were performed by solvent extraction and repeated chromatography with silica gel, Sephadex LH-20, ODS columns, and semiprep. HPLC. The structures were elucidated by spectral analysis. Twelve known compounds were isolated and identified as tenuifoliside A (1), tenuifoliside B (2), glomeratose A (3), 3',6-disinapoyl sucrose (4), sibiricose A5 (5), sibiricose A6 (6), sibiricose A1 (7), sibiricose A2 (8), polygalatenoside E (9), 1-O-L-arabinopyranosyl-O-(6→1)-β-D-glucopyranosyl-salicylate (10), canthoside A (11), and methyl- 3,4,5-trimethoxycinnamate (12). Compound 11 was obtained from genus Polygala for the first time, and compounds 2, 9, 10 and 12 were isolated from this plant for the first time.展开更多
Because the modified remote user authentication scheme proposed by Shen, Lin and Hwang is insecure, the Shen-Lin-Hwang' s scheme is improved and a new secure remote user authentication scheme based on the bi- linear ...Because the modified remote user authentication scheme proposed by Shen, Lin and Hwang is insecure, the Shen-Lin-Hwang' s scheme is improved and a new secure remote user authentication scheme based on the bi- linear parings is proposed. Moreover, the effectiveness of the new scheme is analyzed, and it is proved that the new scheme can prevent from all kinds of known attack. The one-way hash function is effective in the new scheme. The new scheme is proved that it has high effectiveness and fast convergence speed. Moreover, the ap- plication of the new scheme is easy and operational.展开更多
With the increasing civil aviation passengers and the rapid development of aviation logistics,the study on remotely piloted operation(RPO)mode has received extensive attention.RPO mode constructs the piloting decision...With the increasing civil aviation passengers and the rapid development of aviation logistics,the study on remotely piloted operation(RPO)mode has received extensive attention.RPO mode constructs the piloting decisionmaking mode which involves the tripartite collaboration among airborne automatic/autonomous system,remote ground-based crews and air traffic control.In this paper,we describe the organizing architecture for commercial remotely piloted aircraft(CRPA)system and its components.Compared with the current operation mode,the new air-ground collaborative decision-making mode has been established with six different situations based on the type of the flight and the condition of the remote pilot.Taking airport surface operation as an experimental example,we model the airport surface operation process and compare the advantages and disadvantages between RPO mode and the current dual-pilot mode from the perspectives of time and operation coverage,and draw conclusions that RPO mode can basically cover the flight operations of the dual-pilot,improve the accuracy of pilot operations and greatly reduce response time by 48%in pre-flight inspection.The above research would be the foundation for the RPO development of commercial aircraft in China.展开更多
With the scale extending of mining, the landslide disaster in the earth’s surface will become more and more serious, and these landslide disasters are being threatened to the sustainable safe mining of the undergroun...With the scale extending of mining, the landslide disaster in the earth’s surface will become more and more serious, and these landslide disasters are being threatened to the sustainable safe mining of the underground mine and the open-pit mine. Based on the theory that sliding force is greater than the shear resistance (resisting force) at the potential slip surface is the necessary and sufficient condition to occur the landslide as the sliding criterion, the principle and method for sliding force remote monitoring is presented, and the functional relationship between the human mechanical quantity and the natural sliding force is derived, hereby, the natural sliding force can be calculated according to the human mechanical quantity. Based on above principle and method, a new system of landslide remote monitoring is designed and 53 systems are installed on the landslide body in the Luoshan mining area, which make up the landslide remote monitoring network. According to the results of field test around 8 months, monitoring curves between sliding force and time are obtained, which can describe and forecast the develop trend of landslide. According to above analysis, the results show that this system has some following advantages: (1) real-time monitoring; (2) remote intelligent transmission; (3) landslides early warning.展开更多
In this paper, we make a comparison of haptic control schemes (position-position and position-force control schemes) for two haptic teleoperation systems by QoE (quality of experience) assessment. One is a remote ...In this paper, we make a comparison of haptic control schemes (position-position and position-force control schemes) for two haptic teleoperation systems by QoE (quality of experience) assessment. One is a remote control system with haptic media and video. In the system, we can write characters by controlling a haptic interface device at a remote place with another haptic interface device while watching video. The other is a remote instruction system with haptic media, video and voice. By using the system, a teacher can actively write characters and teach a student how to write the characters. The student can also write characters actively, and the teacher can confirm how the student writes the characters. We investigate the influences of network delay on QoE for the two systems with the two haptic control schemes.展开更多
The paper analyze and design and implement a remote control system based on embedded web server network. A computer network remote control system mainly includes server, client and the control information. Server regi...The paper analyze and design and implement a remote control system based on embedded web server network. A computer network remote control system mainly includes server, client and the control information. Server registration information realize the user command; client provides network hardware, software and other system resources, the system response message and then feedback service instruction. The research results show that, the embedded web server can be assigned to the field device user information through the browser, field device data also can access to the browser through the web server. In order to achieve remote monitoring, control, diagnostics and configuration of the equipment.展开更多
The modem distance education along with one new educational mode that the development of enterprise group has, it takes the modem distance education as the principal means that, imparts and studies independently throu...The modem distance education along with one new educational mode that the development of enterprise group has, it takes the modem distance education as the principal means that, imparts and studies independently through the correspondence course and other educational modes, can effectively take advantage of the educational resources. In the era of knowledge economy, the high-quality and perfect educational system is the biggest resources. But the educational quality has decided the altitude of education. But the research distance learning service enhances the student degree of satisfaction and promotion service level to have the high research value regarding the distance learning organization. Based on our country modem distance education development level, should be centered on improving the grade of service, strengthens the teaching service concept that realizes multi-resource sharing the strategic concept.展开更多
The aim of this study was to isolate the chemical constituents of the aerial parts of Polygala tenuifolia Willd. and to determine their antioxidant activities. Ten flavonoids were isolated and purified by silica gel, ...The aim of this study was to isolate the chemical constituents of the aerial parts of Polygala tenuifolia Willd. and to determine their antioxidant activities. Ten flavonoids were isolated and purified by silica gel, Sephadex LH-20, and ODS column chromatography, and semi-preparative HPLC. Their structures were elucidated by spectroscopic analysis and identified as isorhamnetin-3-O-13-D-glucopyranoside (1), isorhamnetin-3-O-13-D-galactopyranoside (2), quercetin-3-O-13-o-glucopyranosyl (1--*2)-I^-D-galactopyranoside (3), quercetin-3-O-13-O-glucopyranosyl (1---~2)-13-D-glucopyranoside (4), linarin (5), quercetin-3-O- 13-D-glucopyranoside (6), 5,7-dihydroxy-8-methxoyflavone-7-O-13-o-glucuronoside (7), isorhamnetin (8), kaempferol (9) and quercetin (10). All these compounds were isolated from this plant for the first time, and compounds 1-5 and 7 were isolated from the genus of Polygala for the first time. The antioxidant activities of the isolated compounds were evaluated by DPPH free radical scavenging assay, and compounds 3, 4, 6, 8, 9 and 10 showed potent antioxidant activities.展开更多
Abstract: To investigate the chemical constituents of the roots of Polygala wattersii Hance, the separation and purification were performed by solvent extraction and repeated column chromatography (CC) on silica ge...Abstract: To investigate the chemical constituents of the roots of Polygala wattersii Hance, the separation and purification were performed by solvent extraction and repeated column chromatography (CC) on silica gel, Sephadex LH-20 and macroporous resin D101, preparative TLC and semi-preparative HPLC. The structures were identified by spectroscopic analysis and comparison of their 1H and 13C NMR data with those reported in literatures. Twenty-three known compounds, including eleven xanthones (1-11), nine sugar esters (12-20), two triterpenoid saponins (21 and 22) and one phenylpropanoid (23) were isolated and their structures were identified as 1,3-dihydroxyxanthone (1), 1-hydroxy-3-methoxyxanthone (2), 1,3-dihydroxy-2-methoxyxanthone (3), 1,3,7-trihydroxy-2- methoxyxanthone (4), 1,3,6-trihydroxy-2,7-dimethoxyxanthone (5), 1,6,7-trihydroxy-2,3-dimethoxyxanthone (6), 1,7-dihydroxy- 2,3-methylenedioxyxanthone (7), 1,7-dimethoxyxanthone (8), 1,2,3-trimethoxyxanthone (9), 1-methoxy-2,3-methylenedioxyxanthone (10), 6-hydroxy-0-methoxy-2,3-methylenedioxyxanthone (11), 3'-O-feruloyl-6-O-acetyl sucrose (12), arillatose B (13), sibricose A5 (14), sibricose A6 (15), 3',6-di-O-sinapoyl sucrose (16), tenufoliside A (17), 3'-O-3,4,5-trimethoxycinnamoyl-6-O-p-methoxybenzoyl sucrose (18), glomeratose A (19), 1-O-p-coumaroyl-D-glucopyranose (20), bayogenin-3-O-glucoside (21), tenufolin (22), and sinapic acid (23). Among them, compounds 2 and 12 were obtained from genus Polygala for the first time, and except compound 16, all others were isolated from this species for the first time.展开更多
A simple,low-cost and effective reverse flow-high performance capillary electrophoresis(RF-HPCE)method was developed for the separation and determination of tenuifolin in Polygalae Radix.Through optimization of sepa...A simple,low-cost and effective reverse flow-high performance capillary electrophoresis(RF-HPCE)method was developed for the separation and determination of tenuifolin in Polygalae Radix.Through optimization of separation conditions, a buffer of 50 mmol/L borax containing methanol(65:35,v/v)was selected for the separation of analytes.Regression equation revealed good linear relationship between peak area and concentration of the analyte in the range of 0.0563-0.9000 mg/mL (r=0.9988).The recoveries ranged from 99.50%-104.7%.The results indicated that this method is simple,rapid and accurate. It can be used for the quality control of Polygalae Radix.展开更多
This paper first reviews an EUV normal incidence solar telescope that we have developed in our lab. The telescope is composed of four EUV telescopes and the operation wavelengths are 13.0 nm, 17.1 nm, 19.5 nm, and 30....This paper first reviews an EUV normal incidence solar telescope that we have developed in our lab. The telescope is composed of four EUV telescopes and the operation wavelengths are 13.0 nm, 17.1 nm, 19.5 nm, and 30.4 nm. These four wavelengths, fundamental to the research of the solar activity and the atmosphere dynamics, are always chosen by the EUV normal incidence solar telescope. In the EUV region, almost all materials have strong absorption, so optics used in this region must be coated by the multilayer. The Mo/Si multilayers used for the EUV normal incidence solar telescope are designed and fabricated by the magnetron sputtering coating machine. The characteristics of these multilayers, such as reflectivity and thermal stability at wavelengths of 13.0 nm, 17.1 nm, 19.5 nm and 30.4 nm, are also described. All the multilayers were measured by a hard X-ray diffractometer (XRD) and an EUV/soft X-ray reflectometer (EXRR) before and after heating (in a vacuum chamber) at 100℃ for 24 hours and at 200℃ for 1 hour and 4 hours. The results show that Mo/Si multilayers have high reflectivity at 13.0 nm, 17.1 nm, and 19.5 nm but low at 30.4 nm. We found no change in the reflectivity and center wavelength of these multilayers by comparing the reflectivity curves before and after heating. This suggests the thermal stability of Mo/Si multilayers may meet our requirement in future solar observation missions.展开更多
Programmable metasurface enables controlling electromagnetic (EM) waves in real time. By programming the states of active device embedded in metasurface element, the EM properties of the digital metasurface can be cha...Programmable metasurface enables controlling electromagnetic (EM) waves in real time. By programming the states of active device embedded in metasurface element, the EM properties of the digital metasurface can be changed quickly without redesigning their structures. However, large numbers of long-distance wires are required to connect the programmable metasurface to provide the coded signals from field programmable gate array (FPGA) when controlling the metasurface at a long distance, which is complicated and inconvenient. Here, we propose an infrared-controlled programmable metasurface that can be programmed remotely. The infrared transceiver is able to switch the coding sequences stored in the FPGA controller, thus controlling the voltage on the varactors integrated in the metasurface. Experiment is performed at microwave frequencies, and the measured results verify that the scattering beams of the metasurface sample can be changed remotely by using infrared ray. The proposed infrared-controlled programmable metasurface opens up avenues for constructing a new class of remotely-tuning dynamic metasurfaces.展开更多
基金supported by the National Natural Science Foundation of China(12033006,12192221,123B2042).
文摘A recently released XMM-Newton note revealed a significant calibration issue between nuclear spectroscopic telescope array(NuSTAR)and XMM-Newton European Photon Imaging Camera(EPIC)and provided an empirical correction to the EPIC effective area.To quantify the bias caused by the calibration issue in the joint analysis of XMM-NuSTAR spectra and verify the effectiveness of the correction,in this work,we perform joint-fitting of the NuSTAR and EPIC-pn spectra for a large sample of 104 observation pairs of 44 X-ray bright active galactic nuclei(AGN).The spectra were extracted after requiring perfect simultaneity between the XMM-Newton and NuSTAR exposures(merging good time intervals(GTIs)from two missions)to avoid bias due to the rapid spectral variability of the AGN.Before the correction,the EPIC-pn spectra are systematically harder than the corresponding NuSTAR spectra by■subsequently yielding significantly underestimated cutoff energy E_(cut)and the strength of reflection component R when performing joint-fitting.We confirm that the correction is highly effective and can commendably erase the discrepancy in best-fitΓ,E_(cut),and R.We thus urge the community to apply the correction when joint-fitting XMM-NuSTAR spectra,but note that the correction is limited to 3–12 keV and therefore not applicable when the soft X-ray band data are included.Besides,we show that as merging GTIs from two missions would cause severe loss of NuSTAR net exposure time,in many cases,joint-fitting yields no advantage compared with utilizing NuSTAR data alone.Finally,We present a technical note on filtering periods of high background flares for XMM-Newton EPIC-pn exposures in the small window(SW)mode.
基金Program for Changjiang Scholar and Innovative Team in University(Grant No.985-2-063-112)Program for New Century Excellent Talents in University(Grant No.985-2-102-113).
文摘To investigate the chemical constituents of the roots ofPolygala sibirica L. The separation and purification were performed by solvent extraction and repeated chromatography with silica gel, Sephadex LH-20, ODS columns, and semiprep. HPLC. The structures were elucidated by spectral analysis. Twelve known compounds were isolated and identified as tenuifoliside A (1), tenuifoliside B (2), glomeratose A (3), 3',6-disinapoyl sucrose (4), sibiricose A5 (5), sibiricose A6 (6), sibiricose A1 (7), sibiricose A2 (8), polygalatenoside E (9), 1-O-L-arabinopyranosyl-O-(6→1)-β-D-glucopyranosyl-salicylate (10), canthoside A (11), and methyl- 3,4,5-trimethoxycinnamate (12). Compound 11 was obtained from genus Polygala for the first time, and compounds 2, 9, 10 and 12 were isolated from this plant for the first time.
基金Supported by the National Science Foundation for Young Scholars of China(61001091)~~
文摘Because the modified remote user authentication scheme proposed by Shen, Lin and Hwang is insecure, the Shen-Lin-Hwang' s scheme is improved and a new secure remote user authentication scheme based on the bi- linear parings is proposed. Moreover, the effectiveness of the new scheme is analyzed, and it is proved that the new scheme can prevent from all kinds of known attack. The one-way hash function is effective in the new scheme. The new scheme is proved that it has high effectiveness and fast convergence speed. Moreover, the ap- plication of the new scheme is easy and operational.
基金supported by the National Program on Key Basic Research Project (No. 2014CB744903)the National Natural Science Foundation of China(Nos. 61973212,61673270)+3 种基金the Shanghai Industrial Strengthening Project (No. GYQJ-2017-5-08)the Shanghai Science and Technology Committee Research Project (No. 17DZ1204304)the Civil Aviation Pre-Research ProjectsShanghai Engineering Research Center of Civil Aircraft Flight Testing.
文摘With the increasing civil aviation passengers and the rapid development of aviation logistics,the study on remotely piloted operation(RPO)mode has received extensive attention.RPO mode constructs the piloting decisionmaking mode which involves the tripartite collaboration among airborne automatic/autonomous system,remote ground-based crews and air traffic control.In this paper,we describe the organizing architecture for commercial remotely piloted aircraft(CRPA)system and its components.Compared with the current operation mode,the new air-ground collaborative decision-making mode has been established with six different situations based on the type of the flight and the condition of the remote pilot.Taking airport surface operation as an experimental example,we model the airport surface operation process and compare the advantages and disadvantages between RPO mode and the current dual-pilot mode from the perspectives of time and operation coverage,and draw conclusions that RPO mode can basically cover the flight operations of the dual-pilot,improve the accuracy of pilot operations and greatly reduce response time by 48%in pre-flight inspection.The above research would be the foundation for the RPO development of commercial aircraft in China.
基金Project 2006CB202200 supported by the National Basic Research Program of China
文摘With the scale extending of mining, the landslide disaster in the earth’s surface will become more and more serious, and these landslide disasters are being threatened to the sustainable safe mining of the underground mine and the open-pit mine. Based on the theory that sliding force is greater than the shear resistance (resisting force) at the potential slip surface is the necessary and sufficient condition to occur the landslide as the sliding criterion, the principle and method for sliding force remote monitoring is presented, and the functional relationship between the human mechanical quantity and the natural sliding force is derived, hereby, the natural sliding force can be calculated according to the human mechanical quantity. Based on above principle and method, a new system of landslide remote monitoring is designed and 53 systems are installed on the landslide body in the Luoshan mining area, which make up the landslide remote monitoring network. According to the results of field test around 8 months, monitoring curves between sliding force and time are obtained, which can describe and forecast the develop trend of landslide. According to above analysis, the results show that this system has some following advantages: (1) real-time monitoring; (2) remote intelligent transmission; (3) landslides early warning.
文摘In this paper, we make a comparison of haptic control schemes (position-position and position-force control schemes) for two haptic teleoperation systems by QoE (quality of experience) assessment. One is a remote control system with haptic media and video. In the system, we can write characters by controlling a haptic interface device at a remote place with another haptic interface device while watching video. The other is a remote instruction system with haptic media, video and voice. By using the system, a teacher can actively write characters and teach a student how to write the characters. The student can also write characters actively, and the teacher can confirm how the student writes the characters. We investigate the influences of network delay on QoE for the two systems with the two haptic control schemes.
文摘The paper analyze and design and implement a remote control system based on embedded web server network. A computer network remote control system mainly includes server, client and the control information. Server registration information realize the user command; client provides network hardware, software and other system resources, the system response message and then feedback service instruction. The research results show that, the embedded web server can be assigned to the field device user information through the browser, field device data also can access to the browser through the web server. In order to achieve remote monitoring, control, diagnostics and configuration of the equipment.
文摘The modem distance education along with one new educational mode that the development of enterprise group has, it takes the modem distance education as the principal means that, imparts and studies independently through the correspondence course and other educational modes, can effectively take advantage of the educational resources. In the era of knowledge economy, the high-quality and perfect educational system is the biggest resources. But the educational quality has decided the altitude of education. But the research distance learning service enhances the student degree of satisfaction and promotion service level to have the high research value regarding the distance learning organization. Based on our country modem distance education development level, should be centered on improving the grade of service, strengthens the teaching service concept that realizes multi-resource sharing the strategic concept.
基金New-Century Talent Program, Ministry of Education of China (Grant No.985-2-102-113)National Science Fund for Excellent Young Scholars (Grant No. 81222051)National Key Technology R&D Program "New Drug Innovation" of China (Grant No. 2012ZX09304-005, 2012ZX09301002-002)
文摘The aim of this study was to isolate the chemical constituents of the aerial parts of Polygala tenuifolia Willd. and to determine their antioxidant activities. Ten flavonoids were isolated and purified by silica gel, Sephadex LH-20, and ODS column chromatography, and semi-preparative HPLC. Their structures were elucidated by spectroscopic analysis and identified as isorhamnetin-3-O-13-D-glucopyranoside (1), isorhamnetin-3-O-13-D-galactopyranoside (2), quercetin-3-O-13-o-glucopyranosyl (1--*2)-I^-D-galactopyranoside (3), quercetin-3-O-13-O-glucopyranosyl (1---~2)-13-D-glucopyranoside (4), linarin (5), quercetin-3-O- 13-D-glucopyranoside (6), 5,7-dihydroxy-8-methxoyflavone-7-O-13-o-glucuronoside (7), isorhamnetin (8), kaempferol (9) and quercetin (10). All these compounds were isolated from this plant for the first time, and compounds 1-5 and 7 were isolated from the genus of Polygala for the first time. The antioxidant activities of the isolated compounds were evaluated by DPPH free radical scavenging assay, and compounds 3, 4, 6, 8, 9 and 10 showed potent antioxidant activities.
基金The National Key Technology R&D Program"New Drug Innovation"of China(Grant No.2012ZX09301002-002-002,2012ZX09304-005)special funds for scientific research on traditional Chinese medicine(Grant No.201307002)National Science Fund for Excellent Young Scholars(Grant No.81222051)
文摘Abstract: To investigate the chemical constituents of the roots of Polygala wattersii Hance, the separation and purification were performed by solvent extraction and repeated column chromatography (CC) on silica gel, Sephadex LH-20 and macroporous resin D101, preparative TLC and semi-preparative HPLC. The structures were identified by spectroscopic analysis and comparison of their 1H and 13C NMR data with those reported in literatures. Twenty-three known compounds, including eleven xanthones (1-11), nine sugar esters (12-20), two triterpenoid saponins (21 and 22) and one phenylpropanoid (23) were isolated and their structures were identified as 1,3-dihydroxyxanthone (1), 1-hydroxy-3-methoxyxanthone (2), 1,3-dihydroxy-2-methoxyxanthone (3), 1,3,7-trihydroxy-2- methoxyxanthone (4), 1,3,6-trihydroxy-2,7-dimethoxyxanthone (5), 1,6,7-trihydroxy-2,3-dimethoxyxanthone (6), 1,7-dihydroxy- 2,3-methylenedioxyxanthone (7), 1,7-dimethoxyxanthone (8), 1,2,3-trimethoxyxanthone (9), 1-methoxy-2,3-methylenedioxyxanthone (10), 6-hydroxy-0-methoxy-2,3-methylenedioxyxanthone (11), 3'-O-feruloyl-6-O-acetyl sucrose (12), arillatose B (13), sibricose A5 (14), sibricose A6 (15), 3',6-di-O-sinapoyl sucrose (16), tenufoliside A (17), 3'-O-3,4,5-trimethoxycinnamoyl-6-O-p-methoxybenzoyl sucrose (18), glomeratose A (19), 1-O-p-coumaroyl-D-glucopyranose (20), bayogenin-3-O-glucoside (21), tenufolin (22), and sinapic acid (23). Among them, compounds 2 and 12 were obtained from genus Polygala for the first time, and except compound 16, all others were isolated from this species for the first time.
基金Natural Science Foundation of Shanxi Province (Grant No.200801107-1)
文摘A simple,low-cost and effective reverse flow-high performance capillary electrophoresis(RF-HPCE)method was developed for the separation and determination of tenuifolin in Polygalae Radix.Through optimization of separation conditions, a buffer of 50 mmol/L borax containing methanol(65:35,v/v)was selected for the separation of analytes.Regression equation revealed good linear relationship between peak area and concentration of the analyte in the range of 0.0563-0.9000 mg/mL (r=0.9988).The recoveries ranged from 99.50%-104.7%.The results indicated that this method is simple,rapid and accurate. It can be used for the quality control of Polygalae Radix.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40774098 and 10878004)
文摘This paper first reviews an EUV normal incidence solar telescope that we have developed in our lab. The telescope is composed of four EUV telescopes and the operation wavelengths are 13.0 nm, 17.1 nm, 19.5 nm, and 30.4 nm. These four wavelengths, fundamental to the research of the solar activity and the atmosphere dynamics, are always chosen by the EUV normal incidence solar telescope. In the EUV region, almost all materials have strong absorption, so optics used in this region must be coated by the multilayer. The Mo/Si multilayers used for the EUV normal incidence solar telescope are designed and fabricated by the magnetron sputtering coating machine. The characteristics of these multilayers, such as reflectivity and thermal stability at wavelengths of 13.0 nm, 17.1 nm, 19.5 nm and 30.4 nm, are also described. All the multilayers were measured by a hard X-ray diffractometer (XRD) and an EUV/soft X-ray reflectometer (EXRR) before and after heating (in a vacuum chamber) at 100℃ for 24 hours and at 200℃ for 1 hour and 4 hours. The results show that Mo/Si multilayers have high reflectivity at 13.0 nm, 17.1 nm, and 19.5 nm but low at 30.4 nm. We found no change in the reflectivity and center wavelength of these multilayers by comparing the reflectivity curves before and after heating. This suggests the thermal stability of Mo/Si multilayers may meet our requirement in future solar observation missions.
基金This work was supported by the National Key Research and Development Program of China(2017YFA0700201,2017YFA0700203 and 2016YFC0800401)National Natural Science Foundation of China(61890544,61522106,61631007,61571117,61731010,61735010,61722106,61701107,and 61701108)+3 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX19_0081)Scientific Research Foundation of Graduate School of Southeast University(YBPY1938)Foundation of National Excellent Doctoral Dissertation of China(201444)the 111 Project(111-2-05).
文摘Programmable metasurface enables controlling electromagnetic (EM) waves in real time. By programming the states of active device embedded in metasurface element, the EM properties of the digital metasurface can be changed quickly without redesigning their structures. However, large numbers of long-distance wires are required to connect the programmable metasurface to provide the coded signals from field programmable gate array (FPGA) when controlling the metasurface at a long distance, which is complicated and inconvenient. Here, we propose an infrared-controlled programmable metasurface that can be programmed remotely. The infrared transceiver is able to switch the coding sequences stored in the FPGA controller, thus controlling the voltage on the varactors integrated in the metasurface. Experiment is performed at microwave frequencies, and the measured results verify that the scattering beams of the metasurface sample can be changed remotely by using infrared ray. The proposed infrared-controlled programmable metasurface opens up avenues for constructing a new class of remotely-tuning dynamic metasurfaces.