南瓜生长过程中多糖含量的测定

苯酚-硫酸分光光度法测定了南瓜中多糖含量。测定波长为485nm,多糖换算因子f=2.97,在5.00—70.00μg/mL范围内呈良好的线性关系,相关系数r=0.9998,方法的回收率在96.0%—101.7%之间,相对标准偏差RSD在2.07%—3.12%之间。结果表明,南瓜多糖在南瓜生长40天后几乎不再发生变化。本法简便、准确、重现性行好,可作为南瓜中多糖含量的测定方法。     

褐蘑菇多糖提取及含量的测定

采用水提醇沉法从褐蘑菇中提取水溶性多糖,通过苯酚-硫酸比色法在490nm波长处测定多糖含量。在5.00—40.00μg/mL范围内,葡萄糖质量浓度与吸光度呈良好线性关系,相关系数r=0.9981,回收率在97.82%—103.09%之间,相对标准偏差RSD为2.24%（n=5）,褐蘑菇多糖含量为3.01%。方法操作简单、显色稳定、准确度高,可作为褐蘑菇多糖工业化生产的常规检测方法。     

新疆锁阳多糖的提取及含量测定

采用分光光度法测定新疆锁阳多糖的含量,以葡萄糖为对照品,以蒽酮-浓硫酸为显色剂,在625nm处测定样品溶液的吸光度。在40.00—200.00μg/mL范围内,葡萄糖质量浓度与吸光度呈良好线性关系,相关系数r=0.9998,回收率在96.15%—102.85%之间,相对标准偏差RSD为2.814%（n=5）,新疆锁阳多糖含量为2.39%。本方法操作简单,灵敏度高,可作为锁阳多糖的含量测定方法。     

7种常见食用菌中多糖的提取和测定

采用热水提取、乙醇沉淀的方法从7种食用菌中提取出了水溶性多糖,采用蒽酮-硫酸法在波长620nm处进行了糖含量的测定,求得其校准曲线的回归方程为y=0.0094x+0.0057,相关系数r为0.9998。平均回收率为98.3%—102.7%,RSD为2.1%—3.2%。结果显示粗多糖的提取率为4.44%—16.75%,多糖含量为3.48%—6.91%。     

分光光度法测定沙棘叶多糖含量

经苯酚-硫酸显色,用分光光度法测定沙棘叶多糖含量。测定波长490nm,葡萄糖含量在10.0—71.0μg/mL范围内与吸光度呈良好的线性关系,r=0.9981,多糖换算因子f为3.271。测得不同月份同一片植株沙棘叶多糖含量分别为:5月份3.39%,7月份3.94%,9月份4.42%,平均回收率为99.07%,RSD为3.22%。     

雷蘑深层发酵胞外多糖含量测定方法的确定

从雷蘑(Clitocybe Gigantean)AS 5.105深层发酵的滤液中分离得到胞外多糖(CGP),用苯酚-硫酸分光光度法在室温下测定胞外多糖含量,测定波长490nm,在5.00-40μg·mL-1范围内吸光度与被测物含量呈良好的线性关系,相关系数r=0.9957,方法的回收率在97.8%-104.6%之间.测定结果表明,雷蘑在出发培养基深层发酵过程中合成了胞外多糖,含量为0.54mg·mL-1.     

新疆人工栽培阿魏菇多糖含量的测定

采用可见分光光度法测定阿魏菇多糖的含量.以葡萄糖为对照品,以蒽酮-浓硫酸为显色剂,在625nm处测定样品溶液的吸光度.在0.00-20.00μg/mL范围内,葡萄糖质量浓度与吸光度呈良好线性关系,相关系数r=0.9995.回收率在98.3%-104.5%之间.相对标准偏差RSD为2.17%(n=5),新疆阿魏菇多糖含量...     

蒙成药敖西根多糖的提取及含量测定

本文用热水提取了蒙成药敖西根中水溶性多糖,并用硫酸-苯酚法在波长为490nm处测定敖西根中多糖的含量,求得其标准曲线的回归方程为A=0.0140C-0.1500,r=0.9992,粗多糖产率为14.28%,平均回收率为99.8%,RSD 0.86%,糖含量为89.2%.     

氢化物发生原子荧光光谱法测定螺旋藻中无机硒和有机硒

螺旋藻试样经硝酸、高氯酸消解,原子荧光光谱法测定总硒含量;用水浸提螺旋藻试样,经环己烷萃取后,水相采用硝酸、高氯酸消解后,原子荧光光谱法测定无机硒含量,间接测定螺旋藻中有机硒含量。总硒测定精密度在1.05%—2.10%之间,加标回收率在96.6%—102.3%之间;无机硒的浸提率在95.1%—100.7%之间,测定精密度在2.37%—3.70%之间,加标回收率在93.6%—98.4%之间,检出限为0.47mg/kg,满足螺旋藻中有机硒含量的测定。     

蒙药苘麻子中多糖的提取纯化及含量测定

采用热水提取-乙醇沉淀法从苘麻子中提取多糖,Sevag法除蛋白,苘麻子多糖经大孔树脂分离、透析得两种多糖,即QMZP-1和QMZP-2,采用分光光度法(λ=486nm)测定两种多糖含量,分别为1.8%和0.75%,求得校准曲线的回归方程为y=0.00435x+0.561,相关系数为r=0.9998,平均回收率为100.1%,RSD=0.71%(n=5)。     

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.     

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.     

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.     

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].     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

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.     

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.