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Development and validation of HPLC methods for enantioseparation of mirtazapine enantiomers at analytical and semipreparative scale using polysaccharide chiral stationary phases

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Development and validation of HPLC methods for enantiosepara...

30th International Symposium on Capillary Chromatography、4th GC×GC Symposium、16th national Symposium and Exhibition on Chromatography,i.e. 1st Dalian International Symposium and Exhibition on Chromatography

作者： Zong-de Zhai~(1 2. Yan-Ping Shi~(1 *) 1.key laboratory for Natural Medicine of Gansu Province Lanzhou Institute of Chemical Physics {2. Lanzhou 730000 china 2.Graduate University of {2. beijing 100039 china

＜正＞Mirtazapine is a recent noradrenergic and specific serotonergic antidepressant（NaSSA）drug,and used to treat moderately and severely depressed hospitalized and *** HPLC methods were developed for the analytical and semipreparative resolution of new antidepressant drug mirtazapine *** analytical scale,the separation of the mirtazapine enantiomers was investigated using both cellulose and amylose tris（3,5- dimethylphenylcarbamate）（CDMPC and ADMPC）chiral stationary phases under normal-phases and polar organic *** good baseline enantioseparation was achieved in all ***,the elution order of mirtazapine enantiomic pairs was found reversed by changing the stationary phase from the amylose-based ADMPC-CSPs to its cellulose-based counterpart,*** validation of the analytical methods including linearity,limit of detection,limit of guantitation,recovery and precision,together with the semipreparative resolution of mirtazapine racemate were carried out using cellulose tris （3,5-dimethyiphenylcarbamate）chiral stationary phases and methanol as mobile phase without any basic additives under polar organic *** analytical scale,the elution times of both enantiomers were less than 6 min at room temperature and 1.0 ml/min,with the separation factor（α）1.99 and the resolution facotor（Rs）3.56. Then,the analytical methods were scaled up to semipreparative loading to obtain small amount of both mirtazapine *** semipreparative scale,about 16 mg/h enantiomers could be isolated and elution times of both enantiomers were less than 10 min at 2.0 ml/*** increase the throughput,the technique of boxcar injections was *** enantiomer（（-）-（R）-mirtazapine）was isolated with purity of ＞99.9% *** ＞98.0% yield and another（（+）-（S）-mirtazapine）was isolated with purity of ＞97.0% *** ＞99.0% *** addition,optical rotation and circular dichroism spectroscopy of both mirtazapine enantiomers isolated were also investi

关键词： Enantioseparation polysaccharide carbamate phase semipreparative HPLC optical rotation circular dichroism mirtazapine

Research progress of self-organized Ge quantum dots on Si substrate

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Progress in Natural Science:Materials International 2004年第5期 14-21页

作者： HUANG Changjun, YU Jinzhong and WANG Qiming(State key laboratory on Integrated Optoelectronics, Institute of Semiconductors, {2., beijing 100083, china) State key laboratory on Integrated Optoelectronics Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China

A review is presented on recent research development of self-organized Ge/Si quantum dots (QDs). Emphasis is put on the morphological evolution of the Ge quantum dots grown on Si (001) substrate, the structure analysis of multilayer Ge QDs, the optical and electronic properties of these nanostructures, and the approaches to fabricating ordered Ge quantum dots.

关键词： quantum dots Si-based optoelectronics SiGe material.

High performance liquid chromatographic separation of thirteen drugs collected in chinese Pharmacopoeia 2.10(Ch.P2.10) on cellulose ramification chiral stationary phase

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Journal of Pharmaceutical Analysis 2012年第1期2卷 48-55页

作者： Ying Zhoua,b, Chao Maa, Yan Wanga, Qi-Ming Zhangb, Yi-Ying Zhanga, Jie Fua, Hong Gaoc, Li-Xun Zhaoc aState key laboratory of Bioactive Substances and Functions of Natural Medicines, Institute of Materia Medica, {2. academy of Medical sciences & Peking Union Medical College, beijing 100050, china bnational Institute for the Control of Pharmaceutical and Biological Products, beijing 100050, china cInstitute of Medicinal Biotechnology, {2. academy of Medical sciences & Peking Union Medical College, beijing 100050, china State key laboratory of Bioactive Substances and Functions of Natural Medicines Institute of Materia Medica Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 100050 China. national Institute for the Control of Pharmaceutical and Biological Products Beijing 100050 China. Institute of Medicinal Biotechnology Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 100050 China.

The enantiomers separation of thirteen drugs collected in Ch.P2.10 was performed on chiral stationary phase of cellulose ramification (chiralpak OD and chiralpak OJ) by high performance liquid chromatographic (HPLC) methods, which included ibuprofen (C1), ketoprofen (C2., nitrendipine (C3), nimodipine (C4), felodipine (C5), omeprazole (C6), praziquantel (C7), propranolol hydrochloride (C8), atenolol (C9), sulpiride (C10), clenbuterol hydrochloride (C11), verapamil hydrochloride (C12., and chlorphenamine maleate (C13). The mobile phase consisted of isopropanol and n-hexane. The detection wavelength was set at 2.4 nm and the fiow rate was 0.7 mL/min. The enantiomers separation of these thirteen racemates on chiralpak OD column and chiralpak OJ column was studied, while the effects of proportion of organic additives, alcohol displacer and temperature on the separation were studied. And the mechanism of some of racemates was discussed. The results indicated that thirteen chiral drugs could be separated onchiral stationary phase of cellulose ramification in normal phase chromatographic system. The chromatographic retention and resolution of enantiomers could be adjusted by factors including column temperature and the concentration of alcohol displacer and organic alkaline modifier in mobile phase. It was shown that the resolution was improved with reducing concentration of alcohol displacer. When concentration of organic alkaline modifier was 0.2. (v/v), the resolution and the peak shape were fairly good. Most racemates mentioned above had better resolution at column temperature of 2. 1C. When racemates were separated, the temperature should be kept so as to obtain stable separation results.

关键词： HPLC Chiral stationary phase optical enantiomers Cellulose ramification

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The Unsymmetrical Delay Compensation in WDM Time Transmission Using optical Fiber

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The Unsymmetrical Delay Compensation in WDM Time Transmissio...

第三届中国卫星导航学术年会

作者： Li Xiaofeng 1,2.3 ,Liang Shuangyou 1,2.,Chen Faxi 1,2.,Zhao Kan 1,2.,Zhang Shougang 1,2.1 national Time Service Center,chinese academy of sciences.Xi’an,Shaanxi,710600, {2. 2.key laboratory of Time and Frequency Primary Standards,national Time Service Center, chinese academy of sciences.Xi’an,Shaanxi,710600,{2. 3 Graduate University of chinese academy of sciences.beijing,100049,{2.

The transmission of optical wave in fiber is analyzed,and the asymmetry of transmission delay which results from phenomena of chromatic dispersion is computed under the condition of DWDM（density WDM）and SWDM（sparse WDM）.Then we proposed a scheme of DWDM transmission delay compensation in time transmission using optical *** theoretical calculation shows that when calculated on 50km transmission range,the time difference when using two waves of wavelength difference of 1nm is nearly three orders of magnitude less than when using two waves of wavelength of 1550nm and 1310nm.

关键词： time transmission optical fiber time delay compensation WDM

GPS Ionospheric mapping and disturbances during geomagnetic storms and earthquakes

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GPS Ionospheric mapping and disturbances during geomagnetic ...

第十四届全国日地空间物理学术研讨会

作者： Shuanggen Jin ( Shanghai astronomical Observatory, chinese academy of sciences, Shanghai 2.0030, {2. ) ( Graduate University of the chinese academy of sciences, beijing 100049, {2.)

The total electron content (TEC) and electron density profiles are two key parameters in the ionosphere. Therefore, imaging the TEC and electron density profile is very crucial to determine the status of the ionospheric activities. In the past decades, different observing instruments have been developed and used to gather information on the ionosphere, such as ionosonde, scatter radars, topside sounders onboard satellites, in situ rocket and satellite observations and LEO (Low Earth Orbit) GPS occultation measurements. However, most instruments are expensive and also restricted to either the bottomside ionosphere or the lower part of the topside ionosphere (usually lower than 800 km), such as ground based radar measurements. Nowadays, GPS satellites in high altitude orbits (0,2.0 km) are capable of providing details on the structure of the entire ionosphere, even the plasmasphere. In this paper, a Regional Ionospheric Mapping and Tomography (RIMT) tool was developed, which can be used to retrieve 2.D TEC and 3-D ionospheric electron density profiles using ground-based or space-borne GPS measurements. Some results are presented from the RIMT tool using regional GPS networks in South Korea and validated using the independent ionosonde. GPS can provide time-varying ionospheric profiles and information at any specified grid related to ionospheric activities and states. For example, the responses of GPS-derived parameters at the ionospheric F2.layer to the 2. November 2.03 geomagnetic storm are investigated over South Korea. It has found that a fairly large increase in the electron density at the F2.layer peak (the NmF2. (positive storm) is observed during this storm, which is accompanied by a significant uplift in the height of the F2.layer peak (the hmF2.. The F2.layer peak height uplift and NmF2.increase are mainly associated with a strong eastward electric field, and are not associated with the increase of the O/N2.ratio obtained from the GUVI instruments aboard the

关键词： GPS ionosphere TEC electron density

Modeling of Dust Flux to Oceans from Asian Continent

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Modeling of Dust Flux to Oceans from Asian Continent

第三届中日韩气象学术会议

作者： Shen Yanbo~(1,2. Shi Guangyu~2.(1.laboratory for Climate Studies,national Climate Center,Center for Wind and Solar Energy Resources Assessment,{2. Meteorological Administration,beijing,100081 2.State key laboratory of Numerical Modeling for Atmospheric sciences and Geophysical Fluid Dynamics(LASG),Institute of Atmospheric Physics,chinese academy sciences,beijing,10002.)

＜正＞Plenty of dust aerosols are blown into atmosphere during the frequent Asian dust *** aerosols have not only direct and indirect climate effects through radiative processes,but also have important influences on the oceanic environment. As dust aerosols carrying nutriments like Fe fall into ocean,they will facilitate oceanic primary *** change in oceanic primary productivities will then cause the change in the flux ofradiatively active gases between ocean and atmosphere and result in the climate change *** the studying of these profound items, estimation of dust flux into oceans is an important *** this report,two schemes and relative observation data are combined to study the dust deposition flux and amount into seas near china from Asian continent during the spring of 2.06.

关键词： Dust aerosol chinese Seas Deposition Flux Numerical simulation Aerosol optical Depth

High Power VCSEL Device with Periodic Gain Active Region

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光机电信息 2007年第12期24卷 26-30,35页

作者： NING Yong-qiang1, QIN Li1, SUN Yan-fang1, LI Te1, CUI Jin-jiang1, PENG Biao1, LIU Guang-yu1, ZHANG Yan1, LIU Yun1, WANG Li-jun1, GUI Da-fu2. XU Zu-yan2.(1. key laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, {2., Changchun, 130033, china 2. Institute of Physics, {2., beijing, 100080, china) key laboratory of Excited State Processes Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of Sciences Changchun 130033 China Institute of Physics Chinese Academy of Sciences Beijing 100080 China

High power vertical cavity surface emitting lasers(VCSEKLs) with large aperture have been fabricated through improving passivation, lateral oxidation and heat dissipation techniques. Different from conventional three quantum well structures, a periodic gain active region with nine quantum wells was incorporated into the VCSEL structure, with which high efficiency and high power operation were expected. The nine quantum wells were divided into three groups with each of them located at the antinodes of the cavity to enhance the coupling between the optical field and the gain region. Large aperture and bottom-emitting configuration were used to improve the beam quality and the heat dissipation. A maximum output power of 1.4 W was demonstrated at CW operation for a 400 μm-diameter device. The lasing wavelength shifted to 995.5 nm with a FWHM of 2.nm at a current of 4.8 A due to the internal heating and the absence of active water cooling. A ring-shape far field pattern was induced by the non-homogeneous lateral current distribution in large diameter device. The light intensity at the center of the ring increased with increasing current. A symmetric round light spot at the center and single transverse mode operation with a divergence angle of 16° were observed with current beyond 4.8 A.

关键词： VCSEL large aperture high power periodic gain Al2.3

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一个边缘耀斑(后)环系速度场的近似计算

天体物理学报 2000年第4期20卷 414-422页

作者：顾啸马敦金平钟树华中国科学院云南天文台

利用“多云模型”方法，从云南天文台二维多波段太阳光谱仪观测到的Ｈβ光谱资料中导出１９８９年８月１７日太阳西边缘的一个大的耀斑环系不同时间的视向速度场．为了解释观测速度场的主要特征，本文采用如下假设和近似：环内物质在太... 详细信息

利用“多云模型”方法，从云南天文台二维多波段太阳光谱仪观测到的Ｈβ光谱资料中导出１９８９年８月１７日太阳西边缘的一个大的耀斑环系不同时间的视向速度场．为了解释观测速度场的主要特征，本文采用如下假设和近似：环内物质在太阳重力、磁场应力和环内气压梯度力联合作用下由环足沿螺旋磁力线上升运动．应用ＭＨＤ理论计算了它的理论速度场．通过两者的比较发现，计算出的速度场与第一时段的观测速度场基本相似，这似乎对耀斑物质蒸发模型提供了支持．

关键词：太阳耀斑速度场计算

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Nano-size Distribution of Aerosol from Agricultural Residues Burning Matched to optical Properties:A laboratory Study

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Nano-size Distribution of Aerosol from Agricultural Residues...

第五届全国环境化学大会

作者： Dawei Hu~1 Xingnan Ye~1 Hefeng Zhang~1 Tiantao Cheng~(1,2.) Jianmin Chen~(1*) Zhiwei Han~2.Renjian Zhang~2.(1.Center of Atmospheric Chemistry Study,Department of Environmental Science & Engineering, Fudan University,Shanghai 2.0433,china 2.key {2. of Regional Climate-Environment Research for Temperate East Asia,Institute of Atmospheric Physics,chinese academy of sciences, beijing 10002.,china)

＜正＞laboratory measurements were conducted with a chamber to determine the size distribution and scattering coefficient of aerosol emitted from the rice straw and corn stover burning,two major agricultural residues in *** size distributions of those rice-burned and corn-burned aerosols are well characterized by unimodal lognormal functions,with a remarkable feature of accumulation *** fresh smokes’ median diameters of number distribution centered at 0.15±0.03μm,0.2.±

关键词： Biomass burning Nano-size distribution optical properties Emission factors