以“活用”贯穿数学教学活动

学生是学习的主人,数学教学应是学生获得人生体验、激发生命活力的殿堂。教师要活用教材、教法、评价和应用,让数学课堂充满生机和活力。

作文出新有妙法

文章出新有什么窍门吗? 一、逆向思维法.顺着命题人的意图去写,这是求同思维,比较难以出新.可以换用逆向思维方式,反着命题人的意图去写,只要言之成理也会被肯定,容易出新.

新闻写作中术语的锤炼与活用

术语属于行业语的范畴,它是指某门学科中的专门用语。如:正数、负数(数学);胚根、基因(生物);电荷、电磁场(物理);化合、分解(化学);血型、会诊(医学);突袭、战术(军事)。这些术语除了用于专门学科和领域外,还经常被活用于社会用语,而在新闻写作中已成为一种常见的修辞手段。经过巧妙地锤炼活用,

特殊二次根式的简捷解法

1 约分法抓住题目的数学特点巧妙地将分子或分母作类似分解因式的变形,这样可以约去分子和分母的公因式,从而达到化简的目的。

Fenlong Cultivation-the Fourth Set of Farming Methods Invented in China

The basic theory and effect of the new farming method of ＂Fenlong＂ cultivation which has been included in the main extension technology of Ministry of Agriculture of the People＇s Republic of China is fully illustrated for the first time, and it is the fourth set （generation） of farming modes and methods following manpower, animal and mechanical （tractor） farming. It follows the natural law to achieve soil activation, water saving, oxygen increase, warming and desalination through the active use of natural resources like soil, rainfall and solar energy, thereby promoting a new round of natural agricultural production and quality improvement and water con- servation, which has crop yield increase by 10%-30%, quality improvement of 5%, natural precipitation retaining increase by100%. The characteristics and mechanism are the use of spiral drill for one-time completion of the land preparation by drilling vertically to 30-50 cm of soil layer through high speed peeling. After instant high temperature and many fierce impacts, mechanical frictions, it could achieve the multiplication of the number of loose soil, soil physical modification and expansion of the soil nutrients, reservoirs, oxygen, microorganisms （＂Four pools＂）. Fenlong cultivation can give birth to new farming culture and civilization, and it can achieve the physical ＂desalinized＂ transformation and utilization of saline soil. The formation of Fenlong green farming technology system makes it possible to invent the farming tools of ＂serf-propelled Fenlong machinery＂ that has got the patent, and it is the method for farmland （dry land, paddy field） Fenlong cultivation, saline-alkali soil smash-ridging cultivation and for the abundance of grass ecology on degraded grassland. The application of Fenlong ＂4＋1＂ （arable, saline-alkali soil, grasslands, Sponge City＋rivers） green development in China can achieve the ＂double safety＂ of food and living space.

Tannins from Canarium album with potent antioxidant activity

The contents of total phenolics and extractable condensed tannins in the leaves, twigs and stem bark of Canarium album were determined. The structural heterogeneity of condensed tannins from stem bark was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS） and nuclear magnetic resonance （NMR） analyses The results show the predominance of signals representative of procyanidins and prodelphinidins. In addition, epicatechin and epigallocatechin polymers with galloylated procyanidin or prodelphinidin were also observed. The tannins were screened for their potential antioxidant activities using l,l-diphenyl-2-picrylhydrazyl （DPPH） and ferric reducing/antioxidant power （FRAP） model systems. Tannins extracted from leaves, twigs and stem bark all showed a very good DPPH radical scavenging activity and ferric reducing power.

“唱”新语文教学 享受课堂快乐

新理念下的语文教学要活用教材,活用学法,巧用资源,让学生体验学习语文的快乐,使学生真正树立终身教育观,让教育成为唤醒心灵的音乐,让学生享受教育,享受生活,享受人生。

Rational construction of thermally stable single atom catalysts:From atomic structure to practical applications

As a new frontier in catalysis field,single-atom catalysts(SACs)hold unique electronic structure and high atom utilization,which have displayed unprecedented activity and selectivity toward a wide range of catalytic reactions.However,many reported SACs are susceptible to Ostwald ripening process in high temperature environment or long-term catalytic application,which will cause sintering and deactivation.This is due to the weak interaction between the metal atom and supports.The regeneration and recycling of deactivated catalysts will greatly increase the time and economic cost of industrial production.Therefore,it is necessary to develop SACs with excellent thermal stability to meet the industrial demands.Here,we discuss the fundamental comprehension of the stability of thermally stable SACs obtained from different synthesis methods.The influences of the speciation of metal centers and coordination environments on thermal stability are summarized.The importance of using novel in situ and operando characterizations to reveal dynamic structural evolution under synthesis and reaction conditions and to identify active sites of thermally stable SACs is highlighted.The mechanistic understanding of the unique role of thermally stable SACs in thermocatalytic application is also discussed.At last,a brief perspective on the remaining challenges and future directions of thermally stable SACs is presented.

Polyphenol Oxidase Activity and Inhibition in White Yam （Dioscorea Rotundata. Var. Laasirin） Chips as African Fries for Human Consumption

Polyphenol oxidase, a bi-functional enzyme, has been implicated in enzymatic browning of yam and other tubers in a negative way. The objective of this present study was to examine the activity of polyphenol oxidase in Dioscorea rotundata. Var. laasirin and the efficiency of heat and chemical treatments in inhibiting this enzyme. Crude Polyphenol Oxidase （PPO） of Dioscorea rotundata.Var. Laasirin was isolated and the kinetics studied using the lineweaver-burk plot. The activity of the enzyme was evaluated using spectrophotomeric method. Yam PPO catalyzes oxidation of various substrates with catechol being the most readily oxidized substrate. The Michaelis-Menten constant （Km） and maximum reaction velocity （Vmax） for yam PPO were 0.00037 and 0.3125 respectively. Inhibition data showed that the enzyme had least activity （71.70） when blanched at 95℃ for 7 mins with chemical treatment involving a combination of 0.5% Sodium metabisulphite （Food grade） and 0.5% Ascorbic acid （Food grade）. The activity was highest （83.02） when it was blanched at 95 ℃ for 7 rains. This study has shown that it is possible to inhibit polyphenol oxidase activity in white yam using the chemical pretreatments and processing conditions described in this study for possible adoption in the production of packaged frozen yam chips by food industries.

A new ketosteroid from red alga Acanthophora spicifera

A new ketosteroid, along with six known steroids, was isolated from the ethanolic extracts of red alga Acanthophora spicifera （Vahl.） Boergesen. The structures, identified using chemical and spectroscopic methods including 2D NMR, were： （1） 22-hydroxy-5α-eholest-3,6-dione, （2） 6-hydroxycholest-4-ene-3-one, （3） cholest-4-ene-3,6-dione, （4） cholest-5-ene-3β-ol, （5） 5u-cholestane-3,6-dione, （6） β-Sitosterol and （7） Saringosterol. The MTT method was used to test the cytotoxicity of the compounds against the human cancer cell lines, HCT-8, Bel-7402, BGC-823, A549 and HELA. Compounds 1, 2, 3 and 5 showed moderate cytotoxic activity against human cancer cell lines.

A study on the Application of the Activity Theory to Leaming Activity Design of MOOC in English Grammar Teaching

MOOC has become the topic of the education reform in recent years. From activity theory point of view, meaningful learning is an active, conscious, constructive, and socially medicated practice that includes reciprocal intention-action-reflection activities. This paper aims to try to give a MOOC learning activity design model in grammar teaching which tries to offer a reference for the MOOC teaching in grammar lesson.

Using Multiple Intelligences Approach in Designing Classroom Activities

In 1983, Horward Gardner, a professor of education at Harvard Universiy introduced the theory of Multiple Intelligence. This theory states that people have a unique blend of capabilities and skills （intelligences）. In the classroom context, it implies that students possess different kinds of minds and therefore learn, remember, perform, and understand in different ways. Based on the theory, Gardner challenged the previous practices that gauged intelligence using IQ test which focused more on the ability to use language and/or logic. According to him, the measurement of people＇s intelligence should not be limited to linguistic and logical-mathematical abilities only, but should also cover other abilities. In addition to language and logic, Gardner proposed six other intelligences, which in the past were known as aptitudes or interests, namely： Visual-Spatial Intelligence, Musical Intelligence, Bodily-Kinesthetic Intelligence, Intrapersonal Intelligence, Interpersonal Intelligence, and Naturalist Intelligence. As an English teacher, we often have to deal with the fact that our classes consist of students who posses different intelligences. To help the students reach their maximum learning potential, teacher needs to respect students＇ uniqueness and accommodate the variety of intelligences. This can be done by applying multiple intelligences approach in designing classroom activities.

An Evaluation Method for the Potential of Old Apartment Buildings＇ Rehabilitation in Brazil

The rehabilitation of older buildings for residential use that started in the last few decades of the 20th century has become recurrent in some Brazilian cities. In Sao Paulo, for instance, this subject is within the context of the revitalization of its downtown area with the reintroduction of residential occupancy in the region as a consequence of actions taken by public and private groups. However, older buildings were designed based on the technologies and regulations available in the past and applied to meet the lifestyles of the time of their construction. This paper presents a method for the analysis of older apartment buildings, diagnosing their strengths and limitations in adapting to both the new Brazilian regulatory and legislative requirements, and the contemporary domestic demands. Requirements, criteria and methods for evaluation were studied, and defined as well as procedures for the application of a method which allows for a physical and systematic analysis of old apartment buildings. It was found that the proposed method can be an important support tool at the moment of studying the feasibility of rehabilitation processes, guiding and providing grounds for the design and building decisions of the professionals involved in these processes.

Research on Symbolic Design of Product in the Symbolic Consumption Era

With the advent of the era of symbolic consumption, products＇ value of his ＂symbol＂ is getting more and more important. By discussing the meaning of the symbolic design of product, it puts forward the design method of realizing symbolic design from the inspects of products＇ shape, material, color, and using ways, and constructs the symbolic value of commodity, and manifests the target users＇ emotion, identity, way of life, differences in value orientation, etc, to meet the high-level needs of people.

Application of Planar Seismogenic Structure to the Seismotectonic Method——A Case Study in the Dayao-Yao'an Area

In seismic hazard analysis of nuclear power plant of China there is a need to identify both seismogenic structures and seismotectonic zones. In past practice,the identification of the seismogenic structures was often based on the surface active faults and characterization of linear seismic source. In a situation which shows quite strong non-random seismic activity and lacks surface active faults,it is difficult to evaluate the seismic hazard reasonably. Taking seismogenic structures in the Dayao-Yao'an area as a case study in this paper,we discuss the need and the possibility to apply the planar seismogenic structure to the seismotectonic method. We suggest that the planar seismogenic structure should be considered when applying the seismotectonic method to the seismic risk assessment of nuclear engineering in future.

A Mew Technique to Rapidly Test Agrochemicai Residues In Fruits and Vegetables

Extraction of AchE, relationship between substrate and enzyme concentration, and inhibition effects of the agrochemicals to AchE are discussed in this paper. Through the re-search, the proper AchE concentration for hydrolysis of 1 ml 1mmol/L substrate and I50 val-ues of the agrochemicals to AchE are decided. It is proved that Asch-DTNB method is a rapid test tool for agrochemical residues in fruits and vegetables.A rapid test card has been developed with sensitivity of 0.05mg/L.