试论汉字教学与提高语文素养的关系

汉字教学在语文教学中是一块"鸡肋",存在着许多问题,有必要全面提升汉字教学的系统性和可操作性。本文试图从汉字本身的规律及其延伸拓展的作用方面,探讨汉字教学与语文素养之间的关系,进而促进汉字教学的发展。     

提高超声波测距精度的方法

基于宏晶公司新近推出的STC12C5410单片机,通过利用温度校正、标杆校正、软件校正的方法实现超声波测距精度由厘米级向毫米级跨进的方法。给出了硬件设计电路图及软件的流程图。在电路的实际测试过程中,成功地达到了预期的效果。     

LDPC码在OFDM通信系统中的应用与仿真

介绍了正交频分复用(OFDM)基带传输系统及其模型,概述了LDPC的编译码方法,研究了其在OFDM系统中的性能,并与卷积码进行了比较.仿真表明,LDPC码在OFDM基带传输系统中具有更好的纠错能力.     

High efficiency D-A structured luminogen with aggregation-induced emission and mechanochromic characteristics

A novel luminogen, CZ2TPAN, with typical D-A architecture was obtained. It shows intramolecular charge transfer and aggregation-induced emission characteristics with high solid-state efficiency of 65.3%. Moreover, it exhibits reversible mechanochromic behavior between crystalline and amorphous states with remarkable emission color change from green (504 nm) to yellow (545nm).     

鱼类饲料配方及制作

在约300种养殖鱼类中,仅50种有营养学数据,不到10 种有完全的营养学数据.在饲料蛋白源中,鱼粉是鲑鳟鱼类饲料的主要蛋白源,蛋白质含量为60%～80 %.肉骨粉一般蛋白质含量为50 %左右,赖氨酸含量较鱼粉低.肉骨粉灰分含量可到30 %,限制了其在鱼类饲料中的应用.一般在鲑鳟鱼类饲料中用量不超过10 %,温水性鱼类饲料中用量不超过15 %.血粉蛋白质含量为80 %～86 %,是很好的赖氨酸来源,但缺乏蛋氨酸.血粉的适口性较差,在鲑鳟饲料中用量不超过10 %,温水性鱼类饲料中不超过5 %.肉骨-血粉混合物的营养成分与鱼粉接近,可完全替代沟鲶饲料中的鱼粉.鸡肉粉蛋白质含量为60 %～70 %,可替代鲑鳟饲料中10 %的鱼粉及温水性鱼类饲料中50 %的蛋白质.水解羽毛粉蛋白质含量约为85 %,但消化率较低.可替代鲑鳟及温水性鱼类饲料中10 %的蛋白质.鸡肉粉-羽毛粉混合物可替代虹鳟饲料中50 %的鱼粉.豆粕可替代虹鳟饲料中50 %的鱼粉蛋白,是温水性鱼类饲料的主要蛋白源.豆粕中存在一些抗营养因子.一般豆油提取过程可以分解大部分抗营养因子.一些报道表明进一步热处理可以提高豆粕的营养价值.经过热处理的全脂豆粉,如果添加蛋氨酸及赖氨酸,可以替代虹鳟及鲤鱼饲料中50 %～75 %的鱼粉.棉粕对鱼的适口性好,但缺少赖氨酸.除非添加赖氨酸,棉粕在温水性鱼类饲料中用量不应超过30 %.花生粕适口性好,但缺少赖氨酸.添加量超过20 %时,需添加赖氨酸.葵花子粕赖氨酸含量较低,可替代虹鳟饲料中40%的鱼粉及温水性鱼类饲料中20 %的鱼粉.低毒菜粕可替代虹鳟饲料中66 %的鱼粉.添加增味剂后,去植酸菜籽蛋白浓缩物可完全替代虹鳟饲料中的鱼粉.玉米面筋含42 %～60 %的蛋白质,添加水平在虹鳟饲料可达20 %,鲤鱼饲料可达10 %.酒精业副产物含27 %蛋白质,适口性好但赖氨酸含量低,添加水平在虹鳟饲料可达10 %,温水性鱼类饲料可达30 %.非营养因子也会影响到饲料制作.如制作膨化饲料需至少25 %的谷类原料.棉粕含量过高会减缓挤压速度.非营养性添加剂包括黏合剂、类胡萝卜素、鱼药、激素、抗微生物及真菌制剂、抗氧化剂、增味剂,但不应在饲料中添加纤维素,其含量应尽量降低.饲料制作工艺包括蒸汽制粒及挤压.挤压可制作浮性、沉性及缓沉性饲料,并能提高消化率,但会分解一些维生素.     

青海省唐古特铁线莲指纹图谱的构建

[目的]建立青海省唐古特铁线莲中齐墩果酸成分HPLC指纹图谱,为其质量控制提供方法学依据.[方法]采用HPLC法建立唐古特铁线莲中齐墩果酸指纹图谱,标示其共有峰与特征峰,进行相似度评价.[结果]通过对10批唐古特铁线莲药材的测定,标定15个共有峰和12个非共有峰,建立了测试样品的HPLC指纹图谱.[结论]该方法准确、稳定、可靠,可用于唐古特铁线莲的质量研究和评价.     

Hypervariable 'minisatellite' regions in human DNA

The human genome contains many dispersed tandem-repetitive 'minisatellite' regions detected via a shared 10-15-base pair 'core' sequence similar to the generalized recombination signal (chi) of Escherichia coli. Many minisatellites are highly polymorphic due to allelic variation in repeat copy number in the minisatellite. A probe based on a tandem-repeat of the core sequence can detect many highly variable loci simultaneously and can provide an individual-specific DNA 'fingerprint' of general use in human genetic analysis.     

Substrate specificity and affinity of a protein modulated by bound water molecules

Water molecules influence molecular interactions in all biological systems, yet it is extremely difficult to understand their effects in precise atomic detail. Here we present evidence, based on highly refined atomic structures of the complexes of the L-arabinose-binding protein with L-arabinose, D-fucose and D-galactose, that bound water molecules, coupled with localized conformational changes, can govern substrate specificity and affinity. The atoms common to the three sugars are identically positioned in the binding site and the same nine strong hydrogen bonds are formed in all three complexes. Two hydrogen-bonded water molecules in the site contribute further to tight binding of L-arabinose but create an unfavourable interaction with the methyl group of D-fucose. Equally tight binding of D-galactose is attained by the replacement of one of the hydrogen-bonded water molecules by its--CH2OH group, coordinated with localized structural changes which include a shift and redirection of the hydrogen-bonding interactions of the other water molecule. These observations illustrate how ordered water molecules can contribute directly to the properties of proteins by influencing their interaction with ligands.     

单管半导体激光器快轴准直轴向误差分析

分别采用ZEM AX光学设计软件和高斯光束传输变换理论算法对单管半导体激光器快轴准直透镜轴向误差进行模拟计算分析。基于微透镜准直设备的单管快轴准直实验结果与两种方法得到的结果进行对比,分析得出高斯光束传输变换理论计算的曲线图更加接近实验结果。