FAAS测定嫩、老荷叶中7种营养元素含量

采用火焰原子吸收光谱法对嫩、老(成熟)荷叶中K、Ca、Mg、Mn、Fe、Zn、Cu7种营养元素的含量进行测定。结果表明,嫩、老荷叶中7种营养元素含量高低顺序一致,依次为KCaMgMnFeZnCu,但成熟荷叶中钙、锰含量明显高于嫩荷叶,约为嫩荷叶的两倍,铁含量稍高于嫩荷叶,钾、镁、锌、铜含量略低于嫩荷叶。其中成熟荷叶中锰的含量为738.04μg.g-1,比一般中药高出近20倍,荷叶的多种药用价值可能与富含微量元素锰有密切关系。     

Near-infrared reflectance spectroscopy as a fast and non-destructive tool to predict foliar organic constituents of several woody species

Near-infrared reflectance spectroscopy (NIRS) was used to estimate N, neutral detergent fibre (NDF), acid detergent fibre (ADF), lignin and cellulose contents in leaves of a heterogeneous group of 17 woody species from the Central Western region of the Iberian Peninsula. The sample set consisted of 182 samples of leaves of deciduous and evergreen species, showing a wide range of concentrations determined by reference methods: 6.60–35.2 g kg⁻¹ (N), 15.5–66.0% (NDF), 10.2–57.3% (ADF), 3.45–27.4% (lignin) and 5.79–31.3% (cellulose). Reflectance spectra, obtained for samples of dried and ground leaves, were recorded as log1/R (R=reflectance) from 1,100 to 2,500 nm. NIRS calibrations were developed using multiple linear (MLR) and partial least-squares (PLSR) regressions, and tested by external validation. Spectral data were transformed to the first and second derivative (1D, 2D). The PLSR method and derivative transformations provided the best statistics and showed lower standard errors of calibration (SEC) and higher coefficients of multiple determination (R ²). In the external validation the standard errors of prediction (SEP) were 0.76 g kg⁻¹ (N), 2.11% (NDF), 1.47% (ADF), 0.85% (lignin) and 0.86% (cellulose). The results obtained show that NIRS is very effective for the estimation of these organic constituents in leaf tissue of woody species. This technique can be used in ecological or ecophysiological studies as an alternative to the more time-consuming standard methods.     

云南省玉米灰斑病菌孢子相关生物学特性研究

为探明玉米灰斑病在云南省发病较重的原因,该试验在田间条件下,采用人工喷雾接种玉米灰斑病菌,研究玉米灰斑病潜育期、病斑产孢、孢子飞散以及菌龄、温度、湿度和光照对孢子萌发的影响.结果表明:昆明地区玉米灰斑病在感病品种会单4号上的潜育期为12～13d;病斑产孢量随显症天数的增加呈单峰曲线,显症后24～27d病斑产孢量达到最大值;玉米灰斑病菌孢子主要在夜间飞散,风或雨有助于孢子的飞散与传播;菌龄对孢子萌发影响较大,随菌龄的增长,孢子萌发率降低;在10～30℃时,分生孢子均能萌发,但以22℃最适,35℃以上或4℃时均不能萌发;水滴有利于孢子萌发,光照对孢子萌发影响较小.     

豫皖地区旅游景点公示语英译的问题及对策——以开封市和亳州市为例

国内旅游业的迅速发展,各地区的旅游业的跟进,旅游景点面临着精细化的机遇和挑战。旅游景点的公示语,作为推动、吸引、帮助游客畅游的标示性平台,成为衡量景点服务水平的重要指标。以豫皖地区具有丰富历史文化底蕴的开封和亳州为中心,发现旅游景点公示语存在的各种问题,并结合英译实践,提出若干改进旅游景点公示语英译的对策。     

A fast luminosity monitor for BEPCⅡ

The fast luminosity monitor counting the γ photons above a given energy threshold emitted from radiative Bhabha scattering has been operated in the BEPC Ⅱ to measure the relative luminosity bunch by bunch for the first time and used successfully in beam tuning of BEPC Ⅱ. In the relative mode the monitor is able to deliver the relative luminosities with an accuracy of 0.8 %. By steering the electron beam while observing the counting rate changes of the monitor the horizontal and vertical sizes of the bunch spots can be estimated as： Sxe＋ =Sxe =0.356 mm, Sye＋ =Sye- =0.011 mm.     

云南不同茶树品种(系)叶性状及变异性

叶性状研究是探讨不同类群植物的适应策略和机理提供快捷简便的方法,是提供有关植物生长和适应环境的重要信息,但关于茶树叶性状的研究却鲜有报道。以云南30种茶树品种(系)为研究对象,对其叶面积(AR)、叶鲜重(FW)、叶干重(DW)、叶厚度(TH)、叶绿素含量(CClC)、叶缘锯齿数、侧脉数、叶长(LL)、叶宽(WD)等进行测量,得到不同茶树的比叶面积(SLA)、叶干物质含量(DMC)等叶性状指标。研究结果如下：(1)各因子变化范围：AR(8.58-48.72cm₂)、FW(0.233-1.656g)、DW(0.090-0.605g)、CClC(60.89-163.49CCI)、TH(0.17-0.34mm)、SLA(60.69-133.06cm₂.g_-1)、DMC(0.350-0.557g.g_-1),其中云南茶树叶片叶绿素含量平均110.81CCI,最高值高达163.49CCI,极显著高于其他地区植物;(2) 叶性状因子相关性结果表明： SLA与DMC之间呈极显著负相关(p＜0.01),SLA与TH、DW、CClC呈极显著负相关(p＜0.01),AR与LL、FW、DW、WD、CClC呈极显著正相关(p＜0.01),FW、DW两个因子与AR、LL、WD、TH均为极显著正相关关系(p＜0.01),TH与CClC呈极显著正相关(p＜0.01);(3) 基于叶面积仪测量法将云南30种茶树划分为大、中、小叶种,这与此前分类有所出入;(4) 30种茶树品种(系)的叶性状变异范围为9.26-40.27%,排序为FW＞ 枯落叶干重＞DW＞AR＞ LL ＞CClC＞MX WD＞AV WD＞ SLA＞TH＞DMC,云南30种茶树叶性状较其他地区相比整体变异性较小,大部分为低变异系数(9.26-40.27%),其中SLA和DMC变异系数分别为16.18%和9.26%。     

前馈控制算法在DRC型点焊监控系统上的应用

在DRC型监控器上应用时间前馈、阈值前馈网压前馈控制算法与反馈调节算法相结合,使DRC型监控系统在干扰频繁的电阻点焊生产环境中工作可靠。     

Polynomial kernels for 3-leaf power graph modification problems

A graph G=(V,E) is a 3-leaf power iff there exists a tree T the leaf set of which is V and such that uv∈E iff u and v are at distance at most 3 in T. The 3-leaf power graph edge modification problems, i.e. edition (also known as the closest 3-leaf power), completion and edge-deletion are FPT when parameterized by the size of the edge set modification. However, polynomial kernels were known for none of these three problems. For each of them, we provide kernels with O(k³) vertices that can be computed in linear time. We thereby answer an open problem first mentioned by Dom et al. (2004) [8].     

雾玻璃上的彩色环

向一个冷玻璃上哈气,在玻璃表面会形成水雾.透过起雾的玻璃去观察白光光源,会看到有多层彩色环(内层蓝色,外层红色),并且在中央会出现白色亮斑.利用散射光干涉的模型解释了彩色圆环的成因.     

激光能量叠加过程中对准精度对焦斑的影响

利用多光束激光输出耦合叠加是一种提高激光器输出功率的有效方法。采用两束矩形激光对准系统,分析两光束不同对准情况下的焦斑特性。完全对准的情况下,两束光的远场焦斑重合在一起,焦斑能量是两光束能量之和。在实际光束对准系统中,讨论了三种常见的对准误差,并比较了这些误差对焦斑特性的影响。利用ZEMAX软件对设计系统进行了模拟分析,并进行了实验验证。结果表明,元件的位置误差会使远场焦斑能量集中度降低,焦斑半径增大。