Optimal Fermentation Conditions for Melanin Production by Streptomyces G-HD-4

为提高链霉菌g-Hd-4的黑色素产生量,以l-酪氨酸为底物,对该菌种产黑色素的工艺条件进行研究,通过单因素试验和均匀设计试验,得到最佳产黑色素的发酵条件为:马铃薯15g/100Ml、乳糖2.5g/100Ml、干酪素2.07g/100Ml、MgSO40.11g/100Ml、kH2PO40.25g/100Ml、l-酪氨酸0.25g/100Ml、以接种量为6%(体积分数),培养基起始PH值为6.0,装液量为25Ml,28℃,150r/MIn振荡培养5d,黑色素产量可达(13.4±0.05)g/l,比在基础培养基中的黑色素产量(5.78g/l)提高约2.3倍。In order to improve melanin production by Streptomyces G-HD-4 fermentation, the optimal conditions for fermenting L-tyrosine by this strain were investigate by single factor and uniform design methods.The optimal medium compositions (on the basis of 100 mL medium) were 15 g potato, 2.5 g lactose, 2.07 g casein, 0.25 g KH2PO4, 0.11 g MgSO4, and 0.25 g L-tyrosine.The optimal fermentation process was that 25 mL of medium was contained in a 250 mL flask for 5-day fermentation at initial pH 6.0, 28 ℃ and 150 r/min shaking speed.As a result, the maximum melanin yield reached up to (13.4 ± 0.05) g/L, approximately 2.3 times higher than that obtained using preoptimization fermentation medium

The Research Report on Construction Mechanism and Operation Mode of Cross-Strait Chinese Education and Collaborative Innovation of Cultural Transmission (Ⅰ)

壹、引言华文教育是海外华人社会的重要特色和支撑,也是中华文化在海外传承传播的重要载体。当今的中国和中华文化正加快步伐走向世界、融入世界,大力发展华文教育,进一步增强华侨华人的民族文化认同,促进华语华文和中华文化在世界各国的传播推广,已成为广大华侨华人越来越迫切的需求,也使得华文教育日益被视为海外华侨华人的“留根工程“和提高民族素质、参与时代竞争的“希望工程“和“民生工程“。随着大陆经济的发展和两岸关系的良性互动,加强海峡两岸华文教育的交流合作,共同襄助

The Development and Innovation of International Chinese Language Education --Based on demand orientation

伴随着汉语教学的国际化进程，国际汉语教学的多样化趋势愈加凸显，需要我们着力开拓国际汉语教学的思路，实现不同教学目标、满足教学对象的不同“需求”。“亚太地区国际汉语教学学会第八届年会”紧密结合世界各地的汉语学习“需求”，发表了许多有价值的观点，挖掘了国际汉语教学与研究的多元特征，展示了汉语国际教育的发展与创新态势。With the globalization of Chinese language teaching, the diversity becomes increasingly obvious in teaching Chinese as an international language. It is necessary to open new mind in order to achieve different teaching objectives and satisfy the different demands of teaching object. The 8th annual conference of Asia-Pacific Consortium of Teaching Chinese as an International Language publishes many valuable opinions which combined with the demands of Chinese language learners around the world. It explores the multi-characteristics and shows the development and innovation of international Chinese language education.国家社会科学基金项目“19世纪稀见英文期刊与汉语域外传播研究”（15BYY052）、教育部人文社会科学规划项目“17-19世纪欧洲汉学视野中的汉语类型特征研究”（13YJAZH021）、厦门大学社科繁荣计划科研启动项目“欧洲的汉语传播与华文跨境教育研究”（2013HGF04）、两岸关系和平发展协同创新中心专项课题的阶段性成果

The Research Report on Construction Mechanism and Operation Mode of Cross-Strait Chinese Education and Collaborative Innovation of Cultural Transmission( Ⅱ)

《海外华文教育》2015第1期刊发了本研究报告之一,主要是对台湾华文教育的历史、现状及发展趋势进行了梳理与述评,分析研究台湾华文教育体系的构成及其特点。本文拟在分析对比两岸华文教育理念与措施之共性与差异的基础上,从历史机遇、现实基础、民族文化认同以及两岸关系发展等方面,阐述两岸华文教育与文化传播协同创新的必要性、可行性及其前景,预测分析可

Automatic Gain Control Design in Software Radio Receiver

This paper primarily elaborates automatic gain control design method in software radio receiver. It mainly uses in-phase and quadrature components quadratic sum to subtract the expectation of the output power to get the error statistic of the plus. The error statistic of the plus is smoothed by first order digital filter, and then is used to gain the output signals of controller. Thereby, it can make the system work well in certain dynamic region area of signals. It is designed for the Cooling Storage Ring ...中文文摘：本文主要阐述了软件无线电接收机中的相干AGC设计,主要利用了同相和正交支路的平方和与所期望的信号输出功率值相减,得到增益的误差统计量。该误差统计量经过一阶数字滤波器平滑,然后用于控制器输出信号的增益,从而使系统在一定的信号动态范围内都能工作。该设计主要用于兰州重离子加速器冷却存贮环的主环(CSRm)的重离子束团踢轨(Kicker System)的精确控制

新型软件无线电正交同步采样方法

本文主要阐述了新型的软件无线电I、Q两路同步采样方法,主要利用了平方律部件、一阶环路滤波器和NCO来对I、Q两路采样时间差的进行闭环控制,实现了实时同步采样,降低了对AD芯片采样速率要求,同时也为后续的基带信号处理提供了方便。该设计主要用于兰州重离子加速器冷却存贮环的主环(CSRm)的重离子束团踢轨(Kicker System)的精确控制

The realization of the fast adder-subtracter for the 23 bit’s floating point numbers by VHDL

With the development of LSI, FPGA/CPLD has been used more and more in the fields of digital signal processing and au-tocontrol and so on. And with the development of the techniques of digital processing, for fitting the system’s function, it should be a higher requirement to speed and used-resource to compute the floating point numbers. The author introduces a high speed adder-subtracter of the 23 bit’s floating point numbers, which is carried out with the parallel arithmetic and the computational speed cou...中文文摘：随着大规模集成电路的不断发展,FPGA/CPLD在数字信号处理、自动控制等方面得到了越来越多的应用。并且伴随着数字化处理技术的不断发展,为满足系统功能的要求,对浮点数运算的速度以及相应占用的资源也就提出了更高的要求。笔者即介绍了以VHDL语言为基础,采用并行算法且计算速度达到33MHz的,对23位标准浮点数实现的高速浮点加减法运算器,并以Cyclone II芯片EP2C20F484为硬件环境,最终进行时序模拟仿真,从而验证该浮点加减法器的正确性和快速特性

Prosodic boundaries in speech: A window to spoken language comprehension

韵律边界加工与言语理解紧密相关,最近十几年来逐渐成为心理学和语言学的研究焦点。韵律系统包含若干由小到大的韵律单位,不同单位的韵律成分其边界强度不同,表现在音高、延宕和停顿三个声学线索上的参数也不同。句子的听力理解过程中,听话人运用声学线索感知权重策略对韵律边界的声学线索进行加工。从神经层面上来看,对于韵律边界的加工,大脑显示出独立且特异性的神经机制。韵律边界的加工能力在婴儿出生后随年龄的增长而发展,到了老年阶段则逐渐退化,而且似乎能够对二语迁移。未来,需要扩大对韵律边界声学表现的考查范围,进一步明确韵律边界的加工过程,进一步厘清韵律边界加工和句法加工之间的关系,进一步关注二语者韵律边界加工能力的发展。</p

聚二乙烯基苯微球介质制备及其在奥曲肽层析分离中的应用

以二乙烯基苯为单体,采用微孔膜乳化法制备了尺寸均一的水包油乳液,在75℃下悬浮聚合20 h,制得均一的聚二乙烯基苯微球填料,粒径为14.2 μm,粒径分布系数R_(span)=0.71,孔径为65 nm,比表面积为160 m~2/g. 通过高压匀浆法将合成的微球介质高效装填不锈钢液相色谱柱(φ4.6 mm×250 mm),使柱效达11000塔板数. 利用装填的色谱柱进行多肽药物奥曲肽的分离纯化,奥曲肽从固相合成粗品中快速有效分离,纯度由42.89%提高到99.99%