The Tower of Babel

<正>At first, the people of the whole world had only one language and used the same words. As they wandered about in the East, they came to a plain in Babylonia and settled there. They said to one another,“Come on! Let's make bricks and bake them hard.” So they had bricks to build with and tar to hold them together. They said,“Now, let's build a city with a tower that reaches the sky, so that we can make a name for ourselves and not be scattered all over the earth.”     

THE APPLICATION OF HUBBARD TEACHING METHOD TO IMPROVING CHINESE STUDENTS'''' LISTENING AND SPEAKING

<正> 1 The problems Chinese students often have: Chinese students often have such a problem that after having learned English for several years, they can not express their ideas in English and can not understand what a native English speaker is speaking to them, either. They have get enough vocabulary, knowledge about grammar and sentence structures. They can read and understand English well. But they can not communicate with a native English speaker. Another problem is when they speak,especially to a foreigner, they feel shy. They are afraid of making mistakes.     

Money Is Not Everything

Today more and more people want to get more money. Many people think if they have a lot of money, they can buy whatever they want to and even do whatever they want to. They also think only money can make people happy. Some people even do something wrong i…     

Language and Brain

Man has a big brain (脑). He can think, learn and speak. Scientists once thought that men are different from animals because they can think and learn. Now they know that dogs, cats and birds can learn, too. They are beginning to understand that men are different from animals be-     

The Use of Smartphones in Primary Education： Improving Arithmetic Calculations in Pre-service Primary Teacher Training

It is difficult for teachers to track student learning on a daily basis. However, the Intemet and new technologies that students use every day can make this much easier and more accessible. This article intends to make evident that using student response systems, such as Socrative and a smartphone, teachers can get more control of their students＇ pace of learning and their progress. Socrative is a very useful tool that helps teachers track student learning in real time. Socrative software can be downloaded on students＇ smartphones, tablets, or laptops and can facilitate online testing with immediate feedback and access to test results. Students receive immediate feedback as soon as they finish answering test questions. It can also promote cooperative learning when students work in groups discussing coursework. Use of the software can increase motivation, self-esteem, and understanding of concepts discussed in class.     

Two Friends and Tow Apples

Tom and Mike were good friends. Sometimes they were kind to each other, but sometimes they were not.One day they went out for a walk together. At noon they were very hungry and they went into a restaurant to have lunch. The waiter came up to them and asked: "What can I do for you?"Please bring us two apples first, " said Tom.     

博客(英文)

A "blogger" is a person who writes on an Internet computer Web site called a "blog". The word "blog" is a short way of saying web log, or personal Web site. Anyone can start a blog, and they can write about anything they like. There are millions of blogs on the Internet today. They provide news, information and ideas to many people who read them. They contain links to other Web sites. And they provide a place for people to write their ideas and react to the ideas of others.A research com p…     

The non-antibacterial effects and possible clinical applications of macrolide antibiotics

As a kind of fast bacteriostatic drugs, macrolides can block both the protein synthesis and the mRNA movement of bacteria via binding to 50S ribosome. Since erythromycin (EM), the 14-membered-ring macrolide was first used clinically as an antibiotic in 19…     

教你正确用(二十三) A Cup of English(英文)

Dos and Don'ts in America-美国文化点滴 Living in a different culture sometimes can be stressful. The term "Culture Shock" is often used to describe a person's excitement, confusion, frustration, and eventual adaptation when getting into a new culture from his home culture. "Culture" includes many aspects, which can range from things as small as the way people drink coffee in the morning, to how they design their houses, and to things as big as their perceptions on the world-their philosophies. Today, let's chat a bit about     

The ABC of ELT... TBL ——In this Issue,Jane and Dave Willis look at Task-Based Learning

TBL, also known as TBLT (task-based learning and teaching) and, in the USA, as TBL (task-based instruction) is an approach which uses communication tasks as the central focus for language teaching and learning. Basically the term task in TBL, refers to a meaning -focused activity. There are a number of definitions in the literature, but they can be characterized also follows: the learner s principle focus is on exchanging and understanding meanings, rather than on practice of pre-specified forms or patterns there is some kind of communicative purpose or goal set for the task, so learners know what they are expected to achieve by the end tasks can involve any or all four skills, e. g. a     

Optimization of acidic extraction of astaxanthin from Phaffia rhodozyma

Optimization of a process for extracting astaxanthin from Phaffia rhodozyma by acidic method was investigated,regarding several extraction factors such as acids, organic solvents, temperature and time. Fractional factorial design, central composite design and response surface methodology were used to derive a statistically optimal model, which corresponded to the following optimal condition concentration of lactic acid at 5.55 mol/L, ratio of ethanol to yeast dry weight at 20.25 ml/g, temperature for cell-disruption at 30 ℃, and extraction time for 3 min. Under this condition, astaxanthin and the total carotenoids could be extracted in amounts of 1294.7 μg/g and 1516.0 μg/g, respectively. This acidic method has advantages such as high extraction efficiency, low chemical toxicity and no special requirement of instruments. Therefore, it might be a more feasible and practical method for industrial practice.     

Studies on optimization of nitrogen sources for astaxanthin production by <Emphasis Type="Italic">Phaffia rhodozyma</Emphasis>

Fermentation ofPhaffia rhodozyma is a major method for producing astaxanthin, an important pigment with industrial and pharmaceutical application. To improve astaxanthin productivity, single factor and mixture design experiments were used to investigate the effects of nitrogen source on Phaffia rhodozyma cultivation and astaxanthin production. Results of single factor experiments showed nitrogen source could significantly affect P. rhodozyma cultivation with respect to carbon source utilization, yeast growth and astaxanthin accumulation. Further studies of mixture design experiments using （NH4）2SO4, KNO3 and beef extract as nitrogen sources indicated that the proportion of three nitrogen sources was very important to astaxanthin production. Validation experiments showed that the optimal nitrogen source was composed of 0.28 g/L （NH4）2SO4, 0.49 g/L KNO3 and 1.19 g/L beef extract. The kinetic characteristics of batch cultivation were investigated in a 5-L pH-stat fermentor. The maximum amount of biomass and highest astaxanthin yield in terms of volume and in terms of biomass were 7.71 mg/L and 1.00 mg/g, respectively.     

生物活性剂对红发夫酵母生长及虾青素形成的影响

本文研究了多种生物激活剂对红发夫酵母生长及虾青素形成的影响,实验结果表明适量添加肌苷、鸟苷和CMP促进作用明显.     

消炎药2-羟基-4-甲氧基苯乙酮的高效液相色谱分析方法

对2-羟基-4-甲氧基苯乙图的高效液相色谱分析方法进行了研究。结果表明,在Spherisorb－ODS柱上,以甲醇-水（80：20,v／v）为流动相,在268mm波长下能很好地分离和检测题示物质。在药物浓度5～80mg／L范围内具有良好的线性关系,Y=8．345X—0．018,r=0．9998,检测限为0．3mg／L,平均回收率为99．7％,精密度RSD=1．3％。     

红外光谱内标法测定红霉素肠溶片中红霉素的含量

用红外光谱内标法(K3[Fe(CN)6)]·6H2O为内标物)测定了红霉素肠溶片中红霉素的含量.实验表明:混合物红外光谱中红霉素的测量峰(1714.6cm-1)和K3[Fe(CN)6)]·6H2O的内标峰(2119.0cm-1)的峰高比(y=h i/h s)与两者质量比(x=m i/m s)有良好的线性关系,其线性回归方程为y=0.2642x-0.0579,相关系数R2=0.9973.据此测得红霉素肠溶片中红霉素的含量为标示量的101%,相对标准偏差为0.51%,加标回收率分别为96.8%¹01.9%.该方法无需分离提取,简便,快速,成本低,测定结果准确,特别适合批量检测和药品质量的快筛,有应用价值.     

中性红电离平衡体系吸收光谱的高斯多峰拟合

中性红水溶液电离平衡体系的紫外可见吸收光谱特征是酸式HNR+最大吸收峰542 nm与碱式NR最大吸收峰 457～ 470 nm叠合在一起.当pH值升高时,碱式吸收峰强度逐渐增大,酸式吸收峰强度逐渐减小.首次将高斯多峰拟合技术用于中性红水溶液电离平衡体系紫外可见吸收光谱分析,实现了酸式和碱式叠合峰的分峰拟合计算,得到两个吸收峰的积分面积,即峰强度S1和S2.S1和S,之比与NR-和HNR+浓度之比成正比,进而计算中性红水溶液酸离解常数pKa.26.4℃时,用本方法测量的pKa值为7.20,拟合优度精度高,R2、Chi2分别达到0.999和10-5 ～10-6.拟合计算结果还表明:随着体系pH值增加,中性红碱式吸收峰发生显著蓝移.这种波长位移引起由固定波长建立起来的浓度与吸光度的线性关系发生偏离,引起约3％系统误差高斯多峰拟合技术改进的pKa分光光度测量方法可广泛用于此类多组分体系紫外可见吸收光谱研究.     

色谱重叠峰的分辨与酚类定性定量分析

本文探讨了HELP法在水中酚类色谱重叠峰的分辨与定性定量分析中的应用．实验结果表明：各组分浓度比为1：50的范围内分辨光谱与真实光谱十分吻合．在104-10－6g/ml的浓度范围内分辨色谱的定量结果线性关系良好．分辨下限3．0×10－7g/ml,相对标准偏差5．0％．     

偏最小二乘紫外分光光度法同时测定邻、间、对甲酚

本文在乙醇／水（体积比１：８）混合溶剂中，用偏最小、二乘紫外分光光度法同时测定了甲酚的三个同分异构体。在２５０－２８５ｎｍ波长范围内，浓度为０—７０ｕｇ／ｍＬ的三种甲酚均遵守比耳定律。邻、间、对甲酚的最大吸收波长分别为２７０．５，２７１．５和２７７ｎｍ，相应的摩尔吸光系数为１．５６×１０￣３、１．３８×１０￣３和１．６５×１０￣３。测定合成样和工业甲酚的结果相对标准偏差均小３．５％，１／ｍｏｌ·ｃｍ。这个结果符合微量分析要求。     

Simultaneous detection of seven phenolic acids in Danshen injection using HPLC with ultraviolet detector

A high-performance liquid chromatographic (HPLC) method with ultraviolet (UV) detector had been developed for simultaneous quantification of danshensu, protocatechuie aldehyde, caffeic acid, salvianolic acid D, rosmarinic acid, salvianolic acid B and salvianolic acid A in Danshen injection. According to the UV spectra of these components, three detection wavelengths have been selected as follows: 280 nm for danshensu and protocatechuic aldehyde, 326 nm for caffeic acid, salvianolic acid D and rosmarinic acid, 286 nm for salvianolic acid B and salvianolic acid A. The limit of detection (LOD) was improved to be in the range of 0.008～0.160 μg/ml. Moreover, excellent linear behavior over the investigated concentration range was observed, with R>0.999 for all the analytes.     

高效液相色谱法测定水发食品中的甲醛

采用二硝基苯肼衍生-高效液相色谱法测定水发物食品中甲醛的含量.选择diamonsirC18柱（5 μm,250 mm×4.6 mm）色谱柱,流动相为V（甲醇）∶V（水）=（5.5∶4.5）,流速为1.0 mL·min^-1,检测波长为357 nm,进样量为10μL,对水发物中甲醛的含量进行检测.结果表明：甲醛在0.0063 ～0.1260 μg范围内呈良好的线性关系,r =0.9991;平均回收率为105％;该方法简便、准确、重现性好.