8β-hydroxyeremophil-7(11)-ene-12,8α(4β,6α)-diolide分子的晶体结构

运用层析法、结晶法从狭苞橐吾全草中分离得到艾里莫芬烷型倍半萜8β-hydroxyeremophil-7(11)-ene-12,8α(4β,6α)-diolide化合物,并通过质谱、核磁共振氢谱和碳谱、氢核-氢核相关谱、异核多量子相干谱和异核多键相干谱进行结构鉴定．其单晶经X射线衍射测试表明,其晶体属正交晶系,空间群为P212121,晶胞参数为: a=6．8519(5),b=10．7191(8),c=18．5942(14)A,V=1365．67(18) A3,Z=4,Dc=1．354 mg／m3．F(000)=592,μ=0．101 mm-1     

4,4,5,5-四甲基-1,3,2-二氧硼戊环的11B NMR及1H-11B HMQC研究

以4,4,5,5-四甲基-1,3,2-二氧硼戌环分子为研究对象,对碳硼烷类化合物的核磁共振(NMR)检测方法进行了研究.除了采用常规的核磁共振碳谱(~(13)C NMR)、氢谱(~1H NMR)及其二维相关谱外,引入核磁共振硼谱(~(11)B NMR)与二维异核多量子相关谱(~1H-~(11)B HMQC),对含硼类化合物结构进行了测定,该方法对于准确解析硼烷类化合物的结构具有较好的参考意义.     

2-甲基-6-(2-甲苯基)-2-庚烯的波谱学研究

采用色谱法从蒲儿根花部位中分离得到2-甲基-6-(2-甲苯基)-2-庚烯,该化合物第一次以单体的形式得到,通过测定氢-氢相关谱(1H-1H COSY)、DEPT谱、异核单量子相关谱(HSQC)及异核多键相关谱(HMBC)等二维谱确定了该化合物的结构,并对该化合物的1H NMR和13C NMR谱进行了归属.     

1,2-二氢-4-(4-羟基苯基)(2H)二氮杂萘-1-酮的NMR研究

应用多种二维核磁共振谱,即：2D同核化学位移全相关谱(TOCSY),2D NOESY谱,2D 异核多量子相关谱(HMQC)和2D异核¹³C-¹H多键 相关谱(HMBC),对化合物1,2-二氢-4-(4-羟基苯基)(2H)二氮杂萘-1-酮的¹H和¹³C NMR 谱线进行了完整归属,从而系统地分析和讨论了该化合物的结构特征.     

三苯基锡4-吡啶甲酸酯的合成和晶体结构研究

利用三苯基氢氧化锡与4-吡啶甲酸在乙醇溶液中以摩尔比1:1反应,合成了有机锡化合物[Ph3SnO2CC5H4NH2O]n.通过元素分析、红外光谱、核磁共振氢谱和X-射线单晶衍射对其结构进行了表征.该化合物为正交晶系,空间群P212121,a=1.22176(19),b=1.4971(2),c=2.4313(4)nm,Z=8,V=4.4471(12)nm3,Dc=1.464g/cm3,μ=1.172mm-1,F(000)=1968,R=0.0437,wR=0.0674.该化合物中心锡原子为五配位三角双锥构型,并且通过4-吡啶甲酸配体的氮原子桥联作用形成一维无限链状结构.     

三维超分子化合物(C_(20)O_2H_(14))(C_(12)N_2H_8)的合成、晶体结构与荧光性质

合成了一个三维超分子化合物(C20O2H14)(C12N2H8)(命名为BP1),通过元素分析、红外光谱、核磁共振氢谱和X射线单晶衍射对其结构进行了表征,结果表明分子之间通过氢键和π-π堆积弱的相互作用形成超分子化合物。对所有合成的超分子化合物进行了紫外光谱和荧光光谱的测试。在室温DMSO溶液中,当激发波长为342 nm时,化合物在373 nm处有一强发射峰,呈现紫色荧光,这可以归属于分子内的π*→π跃迁。X射线单晶衍射分析结果表明,该超分子化合物属于三斜晶系,P1空间群,晶胞参数a=1.087 8(2)nm,b=1.125 2(2)nm,c=1.168 0(2)nm,α=97.89(3)°,β=110.91(3)°,γ=109.62(3)°,V=1.203 2(4)nm3,Z=2,R1=0.053 1,wR2=0.163 4,GOF值为1.034。     

1,3,5,7-四甲基-2,6,8-三乙基吡咯甲川-BF2络合物的合成及晶体结构

合成了标题化合物 ,借助于元素分析、红外光谱、核磁共振氢谱、质谱以及X 射线单晶衍射等分析方法确定了它的结构。该化合物属于三斜晶系 ,空间群为P-1(No 2 ) ,化学式 :C19H2 7BF2 N2 。晶胞参数 :a =1 2 2 5 7( 2 ) ,b=1 7830 ( 8) ,c=0 8877( 2 )nm ,α =10 0 2 6 ( 2 ) ,β =10 7 5 7( 1) ,γ =76 96 ( 2 )°,V =1 7892( 9)nm3 ,Mr=332 2 4,Z =4,Dc=1 2 33g·cm-3 ,μ(MoKα) =0 86cm-1,F( 0 0 0 ) =712 0 0 ,R =0 0 5 1,Rw=0 0 6 0。化合物中除 2 ,6 ,8位的三个甲基 (C( 12 ) ,C( 15 ) ,C( 18) )和氟原子 (F( 1) ,F( 2 ) )外 ,其余非氢原子近似组成一个大平面结构。在对其晶体结构进行详细分析的基础上 ,我们还初步讨论了它的分子结构与光谱及激光性能的关系。     

3S-7-羟基蜂蜜曲霉素分子的晶体结构

从红树林内生真菌Xylariasp．2508中分离到一个新的蜂蜜曲霉素型化合物3S-7-羟基蜂蜜曲霉素,这是首次从海洋真菌中获得该类结构的化合物并测定其晶体结构．通过核磁共振谱、红外光谱、质谱进行结构鉴定．其单晶经X射线衍射测试表明,该化合物晶体属单斜晶系,空间群为P21,化学式为C10H12O5,Mr=212．20．晶胞参数为:a=10．8884(19)(A|。),b=7.2284(13)(A|。),c=13．398(2)(A|。),β=104．217(3)°,V=1022．2(3)(A|。)3,Z=4,Dc=1．379 mg／m3, F(000)=448,μ=0．112 mm-1．结构由直接法解出,用全矩阵最小二乘法修正,最终偏离因子R=0．0498,wR=0．101．该分子由一个苯并吡喃环组成．通过与文献中已知3R-7-羟基蜂蜜曲霉素的熔点及旋光度对照,确定其绝对构型为3S．其初步抑菌实验结果表叫,3S-7-羟批蜂蜜曲霉素菌在每纸片200μg的剂量下对金黄色葡萄球菌(Staphylococcus aureus)没有表现出抑菌活性．     

绣线菊碱Ⅲ的结构研究

利用核磁共振谱对绣线菊碱Ⅲ(Spirasine Ⅲ)结构中的碳,氢信号作了归属,用同核相关谱和异核相关谱分析了噁唑烷环存在带来的双信号问题,指认出C_1,R,S两种构型的信号并对噁唑烷环的ABXY体系做了模拟。     

Formation of [3]Pseudorotaxanes from β-cyclodextrin and a Series of Dicarboxylic Acids with Their Corresponding α,ω-alkanedicarboxylate Anions

通过研磨法和共沉淀法成功制得β-环糊精与碳原子数11~15的脂肪族二元酸包合物，并通过傅立叶变换红外光谱(FTIR)、差热分析(DTA)以及X射线衍射(XRD)的方法确证了该包合物为[3]准轮烷结构．上述包合物通过与NaOH作用得到了β-环糊精与脂肪族二元酸双负离子的包合物并通过核磁共振氢谱(1H-NMR)及二维NOSEY谱确认了该包合物同样具有[3]准轮烷结构．     

Self-organization of five species in a cyclic competition game

Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.     

Experimental study on downstep in Chinese intonation

Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.     

Contrastive analysis on tone between Putonghua and Taiwan Mandarin

The differences of the pitch and duration of Chinese syllables between Putonghua （PTH） and Taiwan Mandarin （TM） were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that： For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.     

Abelian-Higgs phase of SU(2) QCD and glueball energy

It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].     

High efficiency filtering using two-dimensional photonic crystal coupled cavity structures

Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.     

Signal generation in an isotropic medium in scanning electron acoustic microscope

Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122： 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM （Scanning Electron Acoustic Microscopy） signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α （α is the radius of the focused electron beam）. Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.     

Real-time restoration of rotational blurred image using gradient-loading

The key to the restoration of rotational motion blurred image is how to restore the image under a low cost and to correct the irreversibility of the degradation function matrix.Based on the special qualities of degradation function matrix and precise deduction in space-domain, we present a new approach using gradient-loading for restoration of rotational blurred image.By easily adding a gradient operator, the irreversibility of the original matrix is corrected and can be applied for inverse filtering then.Gradientloading is the optimized approach which combines the advantages of both the approaches using constrained least square filtering and traditional diagonal-loading.Compared with the approach using least square filtering, its peak signal-to-noise ratio (PSNR) is improved from 3.18 to 6.46dB, while the computing time is reduced to 1/2-1/3.Experimental results demonstrate the effectiveness, noise-resistibility, robustness, and low complexity of this approach, which make it more suitable for real-time environment.     

All-Optical Logic Device Using Bent Nonlinear Tapered Y-Junction Waveguide Structure

We propose an all-optical logic device made of a bent tapered Y-junction waveguide with a Kerr-type nonlinear interface. It could provide an AND gate, OR gate, and exclusive-OR (XOR) gate. We could obtain different transmission results by adjusting the bending angle. The numerical simulation results show that the device functions as AND, OR, and XOR gates.