侧扁软柳珊瑚中的3个甾醇

从中国南海侧扁软柳珊瑚(Subergorgia suberos)乙酸乙酯萃取相中首次分离得到3个甾醇化合物,根据现代波谱技术(MS,1D NMR,2D NMR)鉴定它们的结构,分别为:孕甾-5-烯-3-醇-20-羧酸(1),胆甾-3β,5α,6β-三醇(2),胆甾-22-烯-3β,5α,6β-三醇(3)。肿瘤活性实验表明,甾醇3对7种肿瘤细胞株的IC50值分别为:14.51、19.82、10.22、16.49、29.16、41.72与50.12μg/mL。     

Solutions of the Second Pöschl–Teller Potential Solved by an Improved Scheme to the Centrifugal Term

Using an improved approximate formula to the centrifugal term, we present arbitrary l-state bound and scattering solutions of the second Pöschl–Teller potential. We find that our approximate formula is better than a previous one since the calculated results are in better agreement with numerically exact ones.     

Energy spectrum for a modified Rosen-Morse potential solved by proper quantization rule and its thermodynamic properties

We apply our recently proposed proper quantization rule, ò_xA^x_Bk(x) dx -ò_x0A^x_0Bk₀(x) dx=np{\int_{x_A}^{x_B}k(x) dx -\int_{x_{0A}}^{x_{0B}}k_0(x) dx=n\pi} , where _boxclose_boxclose_boxclose_boxclose_boxclose_boxclose_boxclose_boxclose/{k(x)=\sqrt{2 M [E-V(x) ]}/\hbar} to obtain the energy spectrum of the modified Rosen-Morse potential. The beauty and symmetry of this proper rule come from its meaning—whenever the number of the nodes of f(x){\phi(x)} or the number of the nodes of the wave function ψ(x) increases by one, the momentum integral ò_xA^x_B k(x)dx{\int_{x_A}^{x_B} k(x)dx} will increase by π. Based on this new approach, we present a vibrational high temperature partition function in order to study thermodynamic functions such as the vibrational mean energy U, specific heat C, free energy F and entropy S. It is surprising to note that the specific heat C (k = 1) first increases with β and arrives to the maximum value and then decreases with it. However, it is shown that the entropy S (k = 1) first increases with the deepness of potential well λ and then decreases with it.     

Mini-review of rare charmonium decays at BESⅢ

Recently, the LHCb experiment announced 3.5σ evidence for direct CP violation in D⁰ decay by looking at the difference between A_CP(D⁰→K⁺K^-) and A_CP(D⁰→π⁺π^-). This is the rst evidence of CP violation in a charm system, which may indicate new physics beyond the Standard Model. Motivated by this measurement, we review rare processes in charmonium decay, especially, the weak decay, C or P violated decay, and lepton avor violated decays. In case the new physics appears in charm sector, these rare decays of charmonium states will provide an opportunity to search for signi cant contributions from physics beyond the Standard Model. With huge J/ψ and ψ(2S) samples in BES0 experiment, the rare decays may be feasible.     

Synthesis and Crystal Structure of 3-(Pyrrole-2′-carboxamido)propanoic Acid·(1/2)H_2O

1 INTRODUCTION Pyrrole and its derivatives have attracted much attention due to their chemical properties as well as biological activities[1]. They have been widely used to produce pharmaceutical, essences, biochemicals, etc. It has been found that a great number of pyrrole derivatives present antitumor and antiviral activi- ties[2 ~ 5]. During our searches for bioactive com- pounds, a series of pyrrole derivatives were synthe- sized[6, 7]. We report here the synthesis of 3-(pyrrole- 2?-…     

Syntheses and Crystal Structures of Methyl 2-（4,5-Dibromo- 1-methylpyrrole-2-carbonylamino）-3-phenyl propanoate and 4,5-Dibromo-1-methyl-2-trichloroacetylpyrrole

1 INTRODUCTION Pyrrole and its derivatives have attracted much attention due to their chemical properties as well as biological activities[1]. They have been widely used as the materials to produce pharmaceutical, essences, biochemicals, etc. It has been found that a great deal of pyrrole derivatives present bioactivities, such as antitumor and antiviral activities[2~5]. Thus, due to the interest in exploring the syntheses of potential bioactive materials which contain pyrrole ring andna…     

Aldisin及其衍生物的合成和α-葡萄糖苷酶抑制活性研究

以三氯氧磷为环化试剂, 回流状态下, N-(2-吡咯甲酰基)-β-丙氨酸经分子内酰化环化反应, 合成了吡咯[2,3-c]氮杂二酮稠环化合物Aldisin及其衍生物1-Methylaldisin和3-Bromoaldisin, 通过¹H NMR, ¹³C NMR, IR, FABMS和元素分析对其结构进行了表征. 以X射线衍射法研究了3-Methylaldisin的晶体结构. 测定了三个化合物对α-葡萄糖苷酶的抑制作用.     

Energy spectrum of the trigonometric Rosen-Morse potential using an improved quantization rule

The improved quantization rule simplifies the calculation of the energy levels for the exactly solvable quantum system. In this Letter we calculate the energy levels of the Schrödinger equation with the symmetric and asymmetric trigonometric Rosen-Morse potentials by the improved quantization rule.     

傅里叶红外光谱法检验喷墨打印机墨水

本文收集了28种喷墨打印机墨水,应用红外光谱法进行了种类研究,根据红外光谱的吸收峰可将其分为6类。     

Entanglement measures of a new type pseudo-pure state in accelerated frames

In this work we analyze the characteristics of quantum entanglement of the Dirac field in noninertial reference frames in the context of a new type pseudo-pure state, which is composed of the Bell states. This will help us to understand the relationship between the relativity and quantum information theory. Some states will be changed from entangled states into separable ones around the critical value F = 1/4, but there is no such a critical value for the variable y related to acceleration a. We find that the negativity N_ABI (ρ^TA_ABI) increases with F but decreases with the variable y, while the variation of the negativity N_BIBII(ρ^TA_ABI) is opposite to that of the negativity N_ABI (ρ^TA_ABI). We also study the von Neumann entropies S(ρ_ABI) and S(ρ_BIBII). We find that the S(ρ_ABI) increases with variable y but S(ρ_BIBII) is independent of it. However, both S(ρ_ABI) and S(ρ_BIBII) first decreases with F and then increases with it. The concurrences C(ρ_ABI) and C(ρ_BIBII) are also discussed. We find that the former decreases with y while the latter increases with y but both of them first increase with F and then decrease with it.