连续自然数的平方和 sum from s=0 to n (a+i)~2=a^2+(a+1)~2+(a+2)~2+…+(a+n)~2 (1) 其中,a=1,2,…,当n取不同的自然数时,有一个共同的性质:对某些自然数n,(1)式可以等于两个连续自然数的平方差 sum from s=0 to n (a+i)
Throughout history, Silk Road played an important role with connecting more than 50 countries between its endpoints. Reviving this ancient trade route is a contemporary discussion among politicians. There are many pro...Throughout history, Silk Road played an important role with connecting more than 50 countries between its endpoints. Reviving this ancient trade route is a contemporary discussion among politicians. There are many projects realized and proposed for the resurgence of the modem Silk Road, including the railroad project connecting Baku, Tiflis and Kars of Azerbaijan, Georgia, and Turkey; the undersea rail tunnel under the Bosphorus strait, Marmaray; the Silk Road Economic Belt proposed by China; and the Maritime Silk Road, again proposed by China. Just like the original Silk Road, it was not only a route for caravans or trade, but it was a meeting point for cultural, religious, and philosophical exchanges that served humanity for centuries; today＇s modem Silk Road initiatives should be considered as bridges between Eastern and Western civilizations that will serve the same purpose of its ancient predecessor. The revived Silk Road will facilitate strengthening of relationships in between countries that experienced harmony in history. The railways, transportation facilities, transnational gates, energy corridors, and natural gas pipelines that constitute the Silk Road will transform the region with improving its economy and bringing peace and economic prosperity. With recent developments, it witnesses the importance of geopolitical and historical ties in establishing contemporary alliances. Although there are great expectations with the revival of the modern Silk Road, authors would like to emphasize that it should be an agreement to foster shared interests rather than the interest of bigger partners.展开更多
The captopril/Chitosan-gelatin net-polymer microspheres(CTP/CGNPMs) were prepared using Chitosan(CTS) and gelatin(GT) by the methods of emulsification,cross-linked reagent alone or in combination and microcrystalline ...The captopril/Chitosan-gelatin net-polymer microspheres(CTP/CGNPMs) were prepared using Chitosan(CTS) and gelatin(GT) by the methods of emulsification,cross-linked reagent alone or in combination and microcrystalline cellulose(MCC) added in the process of preparation of microspheres,which aimed to eliminate dose dumping and burst phenomenon of microspheres for the improvement of the therapeutic efficiency and the decrease of the side effects of captopril(CTP). The results indicated that CTP/CGNPMs had a spherical shape,smooth surface and integral structure inside but no adhesive phenomena in the preparation. The size distribution ranged from 220 μm to 280 μm. The CTP release test in vitro demonstrated that CTP/CGNPMs played the role of retarding the release of CTP compared with ordinary CTP tablets. The release behaviors of CGNPMS were influenced by preparation conditions such as experimental material ratio(EMR) and composition of cross linking reagents. Among these factors,the EMR(1/4),CLR(FA+SPP) and 0.75% microcrystalline cellulose(MCC) added to the microspheres constituted the optimal scheme for the preparation of CTP/CGNPMs. The ER,DL and SR of CTP/CGNPMs prepared according to the optimal scheme were 46.23±4.51%,9.95±0.77% and 261±42%,respectively. The CTP/CGNPMs had the good characteristics of sustained release of drug and the process of emulsification and cross-linking were simple and stable. The CGNPMs are likely to be an ideal sustained release formulation for water-soluble drugs.展开更多
We present a systematic study on the formation of ultra-slow bright and dark optical solitons in highly resonant media. By investigating four life-time broadened atomic systems, i.e., three-state A-type and cascade-ty...We present a systematic study on the formation of ultra-slow bright and dark optical solitons in highly resonant media. By investigating four life-time broadened atomic systems, i.e., three-state A-type and cascade-type schemes, and four-state N-type and cascade-type schemes, we show that the formation of such ultra-slow solitons in cold atomic systems is a fairly universal phenomenon.展开更多
文摘连续自然数的平方和 sum from s=0 to n (a+i)~2=a^2+(a+1)~2+(a+2)~2+…+(a+n)~2 (1) 其中,a=1,2,…,当n取不同的自然数时,有一个共同的性质:对某些自然数n,(1)式可以等于两个连续自然数的平方差 sum from s=0 to n (a+i)
文摘Throughout history, Silk Road played an important role with connecting more than 50 countries between its endpoints. Reviving this ancient trade route is a contemporary discussion among politicians. There are many projects realized and proposed for the resurgence of the modem Silk Road, including the railroad project connecting Baku, Tiflis and Kars of Azerbaijan, Georgia, and Turkey; the undersea rail tunnel under the Bosphorus strait, Marmaray; the Silk Road Economic Belt proposed by China; and the Maritime Silk Road, again proposed by China. Just like the original Silk Road, it was not only a route for caravans or trade, but it was a meeting point for cultural, religious, and philosophical exchanges that served humanity for centuries; today＇s modem Silk Road initiatives should be considered as bridges between Eastern and Western civilizations that will serve the same purpose of its ancient predecessor. The revived Silk Road will facilitate strengthening of relationships in between countries that experienced harmony in history. The railways, transportation facilities, transnational gates, energy corridors, and natural gas pipelines that constitute the Silk Road will transform the region with improving its economy and bringing peace and economic prosperity. With recent developments, it witnesses the importance of geopolitical and historical ties in establishing contemporary alliances. Although there are great expectations with the revival of the modern Silk Road, authors would like to emphasize that it should be an agreement to foster shared interests rather than the interest of bigger partners.
文摘The captopril/Chitosan-gelatin net-polymer microspheres(CTP/CGNPMs) were prepared using Chitosan(CTS) and gelatin(GT) by the methods of emulsification,cross-linked reagent alone or in combination and microcrystalline cellulose(MCC) added in the process of preparation of microspheres,which aimed to eliminate dose dumping and burst phenomenon of microspheres for the improvement of the therapeutic efficiency and the decrease of the side effects of captopril(CTP). The results indicated that CTP/CGNPMs had a spherical shape,smooth surface and integral structure inside but no adhesive phenomena in the preparation. The size distribution ranged from 220 μm to 280 μm. The CTP release test in vitro demonstrated that CTP/CGNPMs played the role of retarding the release of CTP compared with ordinary CTP tablets. The release behaviors of CGNPMS were influenced by preparation conditions such as experimental material ratio(EMR) and composition of cross linking reagents. Among these factors,the EMR(1/4),CLR(FA+SPP) and 0.75% microcrystalline cellulose(MCC) added to the microspheres constituted the optimal scheme for the preparation of CTP/CGNPMs. The ER,DL and SR of CTP/CGNPMs prepared according to the optimal scheme were 46.23±4.51%,9.95±0.77% and 261±42%,respectively. The CTP/CGNPMs had the good characteristics of sustained release of drug and the process of emulsification and cross-linking were simple and stable. The CGNPMs are likely to be an ideal sustained release formulation for water-soluble drugs.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 60478029, 90503010, 10575040 and 10125419 and the National Fundamental Research Program of China under Grant Nos. 2005CB724508 and 2001CB309310
文摘We present a systematic study on the formation of ultra-slow bright and dark optical solitons in highly resonant media. By investigating four life-time broadened atomic systems, i.e., three-state A-type and cascade-type schemes, and four-state N-type and cascade-type schemes, we show that the formation of such ultra-slow solitons in cold atomic systems is a fairly universal phenomenon.
