在学校教学实驗园地上的工作过程对中学生唯物主义观点的培养

每一学年我們都要編訂中学生与少年自然科学家在学校教学实驗區地上进行实习作业的年度計划。每一班級的学生按小組为單位,分配予一定面积的土地,按教学大綱所規定的,进行植物栽培和实驗的具体作业。但少年自然科学家需完成超出大綱范圍較复杂的作业,除在园地上工作外,还規定要在集体农庄进行公益劳动。在上一学年中,五年級学生在园地上栽培:大田輪作方面——冬小麦、甜菜、黍、馬鈴薯;蔬菜輪作方面——番茄、食用甜菜、黄瓜、早熟馬鈴薯;飼料輪作方面——飼用粟、箭舌豆—燕麦、苜蓿,青料玉米。这些年級的少年自然科学家还增加以下的实驗;“追施矿質肥料对番茄产量的影响”,“播种方法对黍产量的影响”等。六年級学生栽培:大田輪作方面——春小麦、多黑麦、大麦、向日葵、玉米、亞麻、苜蓿;蔬菜輪作方面——早熟白菜、胡萝卜、小紅萝卜、蒔萝菜;飼料輪作方面——飼用甜菜、飼用南瓜,青料黑麦。此     

Stress analysis of anisotropic thick laminates in cylindrical bending using a semi-analytical approach

Semi-analytical elasticity solutions for bending of angle-ply laminates in cylindrical bending are presented using the state-space-based differential quadrature method (SSDQM). Partial differential state equation is derived from the basic equations of elasticity based on the state space concept. Then, the differential quadrature (DQ) technique is introduced to discretize the longitu- dinal domain of the plate so that a series of ordinary differential state equations are obtained at the discrete points. Meanwhile, the edge constrained conditions are handled directly using the stress and displacement components without the Saint-Venant principle. The thickness domain is solved analytically based on the state space formalism along with the continuity conditions at interfaces. The present method is validated by comparing the results to the exact solutions of Pagano’s problem. Numerical results for fully clamped thick laminates are presented, and the influences of ply angle on stress distributions are discussed.     

Pheromone synthesis in a biomicroreactor coated with anti-adsorption polyelectrolyte multilayer

To prepare a biosynthetic module in an infochemical communication project, we designed a silicon/glass microreactor with anti-adsorption polyelectrolyte multilayer coating and immobilized alcohol acetyl transferase (atf), one of the key biosynthetic enzymes of the pheromone of Spodoptera littoralis, on agarose beads inside. The system reproduces the last step of the biosynthesis in which the precursor diene alcohol (Z,E)-9,11-tetradecadienol is transformed into the major component (Z,E)-9,11-tetradecadienyl acetate. The scope of this study was to analyze and implement a multilayer, anti-adsorption coating based on layer-by-layer deposition of polyethylenimine/dextransulfate sodium salt (PEI/DSS). The multilayers were composed of two PEI with molecular weights 750 and 1.2 kDa at pH 9.2 or 6.0. Growth, morphology, and stability of the layers were analyzed by ellipsometry and atomic force microscopy (AFM). The anti-adsorption functionality of the multilayer inside the microreactor was validated. The activity of His(6)-(atf) was measured by gas chromatography coupled to mass spectrometer (GC-MS).     

恐龙的晚餐

一只饥饿的恐龙悄悄来到我的家。它已饿了一整天,大大的肚子饿扁扁！     

颜色变变变

让我们想像有5支竖管子排成环状[参见下图]，它们分别被记为A、B、C、D、E，这五个字母代表管中所灌入水的颜色，它们是：琥珀黄（amber）、蓝色（blue）、深红色（crimson）、钻石色（diamond）和翡翠绿（emerald）。由于这些管子排成环     

A declaration on the notion of science

While constantly revealing the laws of the objective world and of mankind itself, science, and technology, whose development is based on the former, have greatly advanced the productive forces of society and brought about changes to people's modes of production and life in general.     

Revisiting non-linear Thomson scattering with metamaterialsOA

<正>Non-linear optics is a branch of optics that studies the intriguing and sometimes unexpected ways in which light and matter interact at high intensities, when the polarization density does not respond linearly to the electric field of the light. The pursuit of the perfect non-linear optical material has been ongoing ever since the pioneering experiment on second harmonic generation carried out by Franken in 1961 [1]. Indeed,     

一个新的以人为中心的技术和职业教育与培训范式

两年前的9月25-28日,在德国波恩召开了名为“为了工作、公民素养和可持续性而学习”的联合国国际专家会议,会议讨论了国家应怎样应对1999年在韩国汉城会议上提出的挑战:     

论语言测试

一、何谓测试不管我们懂不懂,我们每天实际上在所有认识方面都在进行测试。当我们读一本书、听电视新闻或做饭时,我们都在检验设想、进行判断。不管何时我们尝试某事——一个新药方,一把新型网球拍,一双新式鞋——我们都在测试。我们都在根据行为样品形式对某事物做判断。外语学习者每次开口说话时都在测验他新学的语言形式。他们设计语言形式构建的方式,某些功能的表达形式。根据所接收的反馈,他们做出判断与决定。语言教