In classical physics, time and space are absolute and independent, so time and space can be treated separately. However, in modern physics, time and space are relative and dependent: time and space must be treated tog...In classical physics, time and space are absolute and independent, so time and space can be treated separately. However, in modern physics, time and space are relative and dependent: time and space must be treated together. In 4-d s-t frames, we treat time and space independently, then add a constraint to link them together. In teaching, there is a big gap between classical and modern physics. We hope that we are able to find a frame connecting them to make learning simpler. 3-d s-t frame is the best candidate to serve this purpose: time and space are able to be treated dependently by defining the unit of time as T and the unit of space as λ in this frame. Furthermore, the ratio, λ/T, is the velocity, c, of the medium. This paper shows the equivalence between a 4-d s-t frame and a 3-d s-t frame by properly converting coordinates of two frames.展开更多
In Newton’s classical physics, space and time are treated as absolute, independent quantities and can be discussed separately. In Special Relativity, Einstein proved that space and time are relative and dependent and...In Newton’s classical physics, space and time are treated as absolute, independent quantities and can be discussed separately. In Special Relativity, Einstein proved that space and time are relative and dependent and therefore must not be treated separately. Minkowski adopted four-dimensional space-time frames (4-d s-t frames), which indirectly revealed the dependency of space and time with the addition of a constraint for an event interval. We are not able to visualize 4-d s-t frames. Since space and time are inseparable, three-dimensional space-time frames (3-d s-t frames) can be constructed by embedding time into space to directly show the interdependency of space and time. Time contraction and length contraction can also be depicted graphically using 3-d s-t frames. We have much better understanding reality of space and time in 3-d s-t frames. This will lead to Contextual Reality for better understanding the universe.展开更多
A novel phenolic glucoside was isolated from stem barks of Alangium plantanifolium, its structure was elucidated to be 1-O-[2-(1-hydroxy-6-oxocyclohex-2-ene-1-carboxymethyl) -phenyl]-4, 6-O-[(S)-4, 4', 5, 5', ...A novel phenolic glucoside was isolated from stem barks of Alangium plantanifolium, its structure was elucidated to be 1-O-[2-(1-hydroxy-6-oxocyclohex-2-ene-1-carboxymethyl) -phenyl]-4, 6-O-[(S)-4, 4', 5, 5', 6, 6'-hexahydroxydi-phenoyl]-beta -D-glucopyranose 1 by spectroscopic methods including 2D NMR techniques.展开更多
目的研究甘草Glycyrrhizae Radix et Rhizoma黄酮类化学成分。方法采用HP-20大孔树脂、硅胶、ODS、凝胶等多种柱色谱,结合制备液相等方法进行分离和纯化,根据理化性质及波谱数据对化学成分进行结构鉴定。结果从甘草70%乙醇提取物中分离...目的研究甘草Glycyrrhizae Radix et Rhizoma黄酮类化学成分。方法采用HP-20大孔树脂、硅胶、ODS、凝胶等多种柱色谱,结合制备液相等方法进行分离和纯化,根据理化性质及波谱数据对化学成分进行结构鉴定。结果从甘草70%乙醇提取物中分离得到10个黄酮类化合物,分别鉴定为4′,6,7-三羟基-2′-甲氧基查耳酮(1)、3′,4′,5,7-四羟基-8-(3-羟基-3-甲基丁基)-异黄酮(2)、异甘草素(3)、异甘草苷(4)、刺甘草查耳酮(5)香豌豆酚(6)、芒柄花苷(7)、2(S)-3′,5′,7-三羟基二氢黄酮(8)、南酸枣苷(9)、4′,7-二羟基黄酮(10)。结论化合物1和2为新化合物,分别命名为异甘草查耳酮B和甘草异黄酮G,化合物9为首次从该属植物中分离得到。展开更多
文摘In classical physics, time and space are absolute and independent, so time and space can be treated separately. However, in modern physics, time and space are relative and dependent: time and space must be treated together. In 4-d s-t frames, we treat time and space independently, then add a constraint to link them together. In teaching, there is a big gap between classical and modern physics. We hope that we are able to find a frame connecting them to make learning simpler. 3-d s-t frame is the best candidate to serve this purpose: time and space are able to be treated dependently by defining the unit of time as T and the unit of space as λ in this frame. Furthermore, the ratio, λ/T, is the velocity, c, of the medium. This paper shows the equivalence between a 4-d s-t frame and a 3-d s-t frame by properly converting coordinates of two frames.
文摘In Newton’s classical physics, space and time are treated as absolute, independent quantities and can be discussed separately. In Special Relativity, Einstein proved that space and time are relative and dependent and therefore must not be treated separately. Minkowski adopted four-dimensional space-time frames (4-d s-t frames), which indirectly revealed the dependency of space and time with the addition of a constraint for an event interval. We are not able to visualize 4-d s-t frames. Since space and time are inseparable, three-dimensional space-time frames (3-d s-t frames) can be constructed by embedding time into space to directly show the interdependency of space and time. Time contraction and length contraction can also be depicted graphically using 3-d s-t frames. We have much better understanding reality of space and time in 3-d s-t frames. This will lead to Contextual Reality for better understanding the universe.
文摘A novel phenolic glucoside was isolated from stem barks of Alangium plantanifolium, its structure was elucidated to be 1-O-[2-(1-hydroxy-6-oxocyclohex-2-ene-1-carboxymethyl) -phenyl]-4, 6-O-[(S)-4, 4', 5, 5', 6, 6'-hexahydroxydi-phenoyl]-beta -D-glucopyranose 1 by spectroscopic methods including 2D NMR techniques.
文摘目的研究甘草Glycyrrhizae Radix et Rhizoma黄酮类化学成分。方法采用HP-20大孔树脂、硅胶、ODS、凝胶等多种柱色谱,结合制备液相等方法进行分离和纯化,根据理化性质及波谱数据对化学成分进行结构鉴定。结果从甘草70%乙醇提取物中分离得到10个黄酮类化合物,分别鉴定为4′,6,7-三羟基-2′-甲氧基查耳酮(1)、3′,4′,5,7-四羟基-8-(3-羟基-3-甲基丁基)-异黄酮(2)、异甘草素(3)、异甘草苷(4)、刺甘草查耳酮(5)香豌豆酚(6)、芒柄花苷(7)、2(S)-3′,5′,7-三羟基二氢黄酮(8)、南酸枣苷(9)、4′,7-二羟基黄酮(10)。结论化合物1和2为新化合物,分别命名为异甘草查耳酮B和甘草异黄酮G,化合物9为首次从该属植物中分离得到。
