指向数学素养生长的三维结构化加工

指向数学素养生长的三维结构化加工是指通过基于数学的原本加工,追溯数学知识的本原,理解核心概念的意义,建构以核心概念为中心的知识结构;通过基于心理学的认知加工,以多元表征为载体,将数学学科知识结构内化于心,逐步转化为学生的认知结构;通过基于教育学的学程加工,序列转换系统设计,将学生认知结构外化于行,逐步转化为学生素养结构。

基于数学素养生长的课堂教学实践初探

数学素养是数学课堂教学的理想目标和不断的追求,如何在每一节数学课堂教学中,有效关注数学素养,让每位学生的数学素养得以生长,需要教师不断地探索和追寻。

开展实验教学,促进小学素养生长

在学习小学数学的过程中,学生在思维上与认知上已经出现了两极分化的现象。数学中有关抽象的认知较多,学生在理解上有一定的困难,久而久之,就形成了一定的差异。要想在课堂上减少两极分化,教师就要改变教学方式,让学生对抽象的认知有直观的体验。做实验能给学生以最直观的认知,能让他们将做与学结合起来,能让他们在课堂"活"起来,进而使大多数学生能在实验中理解认知、应用认知,生成能力。

指向素养生长的小学数学作业设计

核心素养是一种动力系统、一种综合品质。数学课堂强调“教-学-评”一致,其中的“评”更多地体现在作业设计上。指向素养生长的小学数学作业设计一般具备如下六种思路:重视知识整合,“一例带一串”;融入生活现实,数学身边化;积累活动经验,操作促思考;改变思维定式,变式促灵活;注重现实应用,悟数学内涵;强化易错训练,提学习质量。如果小学数学作业设计是指向素养生长的,那么学生核心素养的达成也就能成为现实。

数学实验:赋予儿童数学素养自然生长的力量

＂数学实验＂是儿童数学学习的一种重要方式。在数学教学中,教师要捕捉数学教材中的＂实验基因＂,充分发掘数学实验素材。＂数学实验＂拓展了学生的学习时空,教学中教师要让数学实验从封闭走向开放,从感性走向理性,从抽象走向直观,让数学实验的过程成为学生经历数学化的过程。

有效提问,促进小学语文素养生长

提问是实施课堂教学的一种方式,是师生之间互动的桥梁,也是促进认知生长、能力生成的重要途经。有效的课堂提问,能在吸引学生兴趣的同时,让学生积极参与到教师设置的活动中去,进而让更多语用的体验成为可能。基于此,教师要有效提问,进而在提升课堂质量的同时,让生长真实地发生。

教师专业成长和学生素养“生长”例谈

本文通过对一节高中地理课研究,从对这节课的打磨和修改方面,阐释了课例研究对教师专业成长的促进作用。从学生活动方面,让学生动手实验,观察实验过程、描述实验现象、解释产生原因,阐释了在学生活动中培养地理实践力,让学生的素养在真实情境中“生长”。

Biotransformation of Gastrodin by Cell Suspension Cultures of Catharanthus roseus

应用长春花 (Catharanthusroseus (L .)G .Don)悬浮细胞培养体系对天麻素进行了生物转化反应研究。经过8d培养形成一个转化产物 ,应用光谱方法鉴定转化产物的结构为对羟基苯甲醇 ,为天麻素水解后形成的甙元。

数学阅读:全学科阅读的重要一环

迈向核心素养时代,高品质的全学科阅读成为学生素养生长的基石。调查发现,数学阅读的推进存在一定程度的“瓶颈”,如远景与现实的矛盾、方向与视角的偏狭、方法与困难的挑战、选材与框架的局限。数学阅读的推进需要课内外协同发力:得法于课内,分阶段阅读数学课本,让学生会读;得益于课外,全方位补充数学读物,让学生爱读。

活动体验:实现语文课堂创享的根本途径

在小学语文课堂教学中,开展创享课堂体验活动,不仅能有效激发学生语文知识的探究欲望,也能在知识生成过程中发展思维与语言能力,获得丰富深刻的思想与情感体验,并在体验知识生成的过程中发展语文核心素养。本文以认知性活动体验、探究性认知体验、分享性活动体验为例,通过情境感知、问题驱动、自主探究、合作分享的具体过程,探讨真实、有效、深刻的活动体验,让语文课堂从个体智慧走向"创享"的集体智慧。

聚焦实验,给初中化学教学增添一丝灵动

化学是一门跟实验密切相关的科学,在实验过程中学生能探究化学的原理、知晓化学的变化、走进化学的奇幻世界。可以说,没有实验就没有化学,因此在教学过程中,教师要尽可能地将实验与训练、探究、讲解对接起来,使学生的素养能得到真正的生长。为使实验能更好地对接学生的认知水平,教师也要不断改变实验教学,使他们获得最适切的化学教育。

Study on Rooting of Strawberry Bechika

[Objective] The aim was to study rooting environment of strawberry ＂Bechi- ka＂ seedlings, and the somaclone domesticated transplanting was carded on. [Method] With the stem tip of stolon as material, the influence factom of rooting and the effects of different transplanting substrata on survival rate was investigated. [Result] The results showed that： 1/2MS was the best concentration for rooting and the rooting rate could reach 100%. IBA was better than IAA for rooting on growth regu- lator levdls, and it had the best effect on rooting with 0.3 mg/L, which produced the thickest and most-fibrous roots. Activated carbon had positive influences on the growth of roots, and the suitable concentration of activated carbon was 0.5 mg/l_ for rooting. The study found that survival rate of tissue culture seedlings was obviously higher in the combination of perlite and vermiculite than that in the combination of humus and sand, and the survival rate could reach 98.1% （perlite：vermiculite=l：l）. Seedlings in various transplanting substrata could normally bloom, fruit and form stolons. [Conclusion] The study provided technical support for achieving large-scale production of virus-free strawberry and quickly cultivating good seedlings.

Effects of nutrients and light intensity on the growth and biochemical composition of a marine microalga Odontella aurita

Algal biotechnology has advanced greatly in the past three decades. Many microalgae are now cultivated to produce bioactive substances. Odontella aurita is a marine diatom industrially cultured in outdoor open ponds and used for human nutrition. For the first time, we have systematically investigated the effects of culture conditions in cylindrical glass columns and fiat-plate photobioreactors, including nutrients （nitrogen, phosphorus, silicon, and sulfur）, light intensity and light path, on O. aurita cell growth and biochemical composition （protein, carbohydrate, β-1,3-glucan, lipids, and ash）. The optimal medium for photoautotrophic cultivation of O. aurita contained 17.65 mmol/L nitrogen, 1.09 mmol/L phosphorus, 0.42 mmol/L silicon, and 24.51 mmol/L sulfur, yielding a maximum biomass production of 6.1-6.8 g/L and 6.7-7.8 g/L under low and high light, respectively. Scale-up experiments were conducted with fiat-plate photobioreactors using different light-paths, indicating that a short light path was more suitable for biomass production of O. aurita. Analyses of biochemical composition showed that protein content decreased while carbohydrate （mainly composed of 15-1,3-glucan） increased remarkably to about 50% of dry weight during the entire culture period. The highest lipid content （19.7% of dry weight） was obtained under 0.11 mmol/L silicon and high light conditions at harvest time. Fatty acid profiles revealed that 80% were Cx4, C^6, and C20, while arachidonic acid and eicosapentaenoic acid （EPA） accounted for 1.6%-5.6% and 9%-20% of total fatty acids, respectively. High biomass production and characteristic biochemical composition profiles make O. aurita a promising microalga for the production ofbioactive components, such as EPA and D-1,3-glucan.

Effects of Nutritional Factors on the Growth and Heterotrophic Eicosapentaenoic Acid Production of Diatom Nitzschia laevis

The effects of several nutritional factors on the growth and eicosapentaenoic acid （EPA） production of diatom Nitzschia laevis were studied. 4LDM （quadrupled concentration of the nutrient salt） was the optimal concentration of nutrient salt for the growth and EPA production ofN. laevis. The growth ofN. laevis was inhibited when the glucose concentration was either lower than 10gL^-1 or higher than 15 gL^-1. Both sodium nitrate and urea were good nitrogen sources for the growth and EPA production, while ammonium chloride seriously decreased the dry cell weight （DW） and the EPA content. Silicate seriously influenced the growth of N. laevis. The maximum DW of 2.34 gL^-1 was obtained in the presence of 150 mgL^-1 Na2SiO3· 9H2O. The EPA content remained almost the same when the silicate concentration was lower than 150mgL^-1; however, higher silicate concentrations resulted in a steady decrease of EPA content. Low medium salinity （≤29） did not seem to influence the DW of N. laevis, and high salinity resulted in a decrease of DW. The highest EPA content （4.08%） and yield （110mgL^-1） were observed at the salinity of 36 and 29, respectively. Key words polyunsaturated fatty acid; eicosapentaenoic acid; microalga; Nitzschia laevis; heterotrophy

Phosphorus fertilizer induced changes in the soil available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory

A study was carried out to investigate changes in the soil plant-available P,the P nutrition and the growth of Pinus radiata seedlings grown in association with understory,broom（Cytisus scoparius L.） or ryegrass（Lolium multiflorum） on Orthic Allophanic Soil,following the application of three rates of triple superphosphate（TSP）（0,50,and 100 mg·kg^-1P） under a glasshouse condition.The application of P fertilizer enhanced P availability in the rhizospheric of radiata seedlings and the bulk soils in a P-deficient site.P availability in the rhizospheric soils of ryegrass and broom,grown in association with radiata,were also increased by the presence of radiata roots.P concentrations in new shoot needles,old shoot needles,stem and roots of radiata pine increased with increase rates of TSP application,but the effects of ryegrass and broom on P nutrition of radiata seedlings depended on the soil P status.In the absence of P fertilizer addition（control treatment）,P concentrations in new shoot needles,old shoot needles,stem,and roots of radiata grown in association with broom were higher than those with ryegrass,whereas,when P fertilizer was added（50 and 100 mg·kg^-1） the P concentration was lower.This is probably related to the growth of broom that may have removed much of the plant-available P in the soil as indicated by the consistently lower Bray-2 P concentration in the rhizosphere soil of radiata in association with broom than that in the rhizosphere soil of radiata in association with grass at the two high P rates.Furthermore,in the high P fertile soil（application rate of 100 mg·kg^-1）,the dry matter yield of radiata was lower when it was grown with broom than with ryegrass.This result suggests that in moderate to high P fertile soils,P.radiata seedlings grow better with ryegrass than with broom,because broom grows vigorously in high P fertile soil and competes with P.radiata for P and perhaps for other nutrients as well.

Effects of different phosphorus concentrations and N/P ratios on the growth and photosynthetic characteristics of Skeletonema costatum and Prorocentrum donghaiense

The effects of different phosphorus(P) concentrations(0.36, 3.6, and 36 μmol/L corresponding to low-, middle-, and high-P concentration groups, respectively) and nitrogen(N)/P ratios on the growth and photosynthetic characteristics of S keletonema costatum and Prorocentrum donghaiense were studied. For both species, the high-P(HP) concentration group showed the greatest algal density and highest specifi c growth rate. Changes in the maximum effi ciency of photosystem Ⅱ(F _v/F_m) were monitored under the various P and N/P conditions. The largest decrease in F _v/F_m was in the low-P(LP) group in S. costatum and in the HP group in P. donghaiense. There were high rapid light curves and photochemical quantum yields(Φ _(PSⅡ)) for S. costatum in the HP group, while the actual photosynthetic capacity was higher in P. donghaiense than in S. costatum in the MP group. Under eutrophic but relatively P-restricted conditions, P. donghaiense had higher photosynthetic activity and potential, which could cause this dinofl agellate to increasingly dominate the phytoplankton community in these conditions. Under the same P concentration and N/P ratio, P. donghaiense had a larger relative maximum rate of electron transport and higher Φ _(PSⅡ) values than those of S. costatum. These differences between P. donghaiense and S. costatum may explain the interaction and succession patterns of these two species in the Changjiang(Yangtze) River estuary from a photosynthesis perspective.

Plant Enzymes, Root Exudates, Cluster Roots and Mycorrhizal Symbiosis are the Drivers of P Nutrition in Native Legumes Growing in P Deficient Soil of the Cape Fynbos in South Africa

The Cape fynbos is characterised by highly leached, sandy, acidic soils with very low nutrient concentrations. Plant-available P levels range from 0.4 μg P g-1 to 3.7 μg P g-I soil, and 1-2 mg N gl soil. Despite these low nutrient concentrations, the fynbos is home to 9,030 vascular plant species with 68.7% endemicity. How native plant species survive such low levels of available P is intriguing, and indeed the subject of this review. In the fynbos soils, P is easily precipitated with cations such as Fe and Al, forming AI-P and Fe-P in acidic soils, or Ca-P in neutral-to-alkaline soils. The mechanisms for promoting P availability and enhancing P nutrition include the development of mycorrhizal symbiosis （with 80%-90% of higher plants, e.g., Cyclopia, Aspalathus, Psoralea and Leucadendron etc.） which exhibits 3-5 times much greater P acquisition than non-mycorrhizal roots. Formation of cluster roots by the Leguminosae （Fabaceae） and their exudation of Kreb cycle intermediates （organic acids） for solubilizing P, secretion of root exudate compounds （organic acids, phenolics, amino acids, etc.） that mobilize P. The synthesis and release of acid and alkaline phosphatase enzyme that catalyze the cleavage of mineral P from organic phosphate esters in acidic and alkaline soils, and the development of deep tap roots as well as massive secondary roots within the uppermost 15 cm of soil for capturing water and nutrients. Some fynbos legumes employ all these adaptive mechanisms for enhancing P nutrition and plant growth. Aspalathus and Cyclopia species typically form mycorrhizal and rhizobial symbiosis for improving P and N nutrition, produce cluster roots and acid phosphatases for increasing P supply, and release root exudates that enhance P solubilisation and uptake.

Effects of salinity and nutrients on the growth and chlorophyll fluorescence of Caulerpa lentillifera

Caulerpa lentillifera is a green algae that distributes worldwide and is cultivated for food. We assessed vegetative propagation of C. lentillifera by measuring the specific growth rate （SGR） and chlorophyll fluorescence of the green algae cultured at different salinities and nutrient levels. The results indicated that C. lentillifera can survive in salinities ranging from 20 to 50, and can develop at salinities of 30 to 40. The maximum SGR for C. lentillifera occurred at a salinity of 35. Both chlorophyll content and the ratio of variable to maximum fluorescence （F_v/F_m） were also at a maximum at a salinity of 35. Photosynthesis was inhibited in salinities greater than 45 and less than 25. Both the maximum SGR and maximum chlorophyll content were found in algae treated with a concentration of 0.5 mmol/L of NO3-N and 0.1 mmol/L of PO_4-P. The photosynthetic capacity of photosystem Ⅱ （PSⅡ） was inhibited in cultures of C. lentillifera at high nutrient levels. This occurred when NO_3-N concentrations were greater than 1.0 mmol/L and when PO4-P concentrations were at 0.4 mmol/L. As there is strong need for large-scale cultivation of C. lentillifera, these data contribute important information to ensure optimal results.

Soil Micronutrients and Citrus Growth

By using nutritional diagnosis of citrus leaves and determining soil micronutrients,the relationship between soil micronutrients and citrus growth in southern China has been studied.Studies showed that there was a significant positive correlation between available micronutrients (such as Zn,Mo,Cu)in the soil and the corresponding nutrients in citrus leaves.Thus,one can roughly learn of the sufficiency or deficiency of certain nutrients in soils by analyzing citrus leaves.Rational spray of Zn B or Mo fertilizer not only improved citrus yields but also increased the total sugar of Satsuma mandarin and of Xinhui orange by 2.9 and 17.2% respectively compared with the control.Spraying Mo fertilizer increased the vitamin C content of Satsuma mandarin juice by 4.7%-8.4%,maturated fruits 7-10 days earlier and gave the peel a brighter color.The ultramicroscopic characteristics of Zn-deficient citrus leaves were investigated under an electron microscope.Results showed that the Zn-deficient leaf cell was characterized mainly by poor cytoplasm,endoplasmic reticula and ribosomes and by big starch grains in the chloroplast.As a result of spraying Zn fertilizer the structure of the cell returned to normal,the cytoplasm became rich and the amount of chloroplast increased.There also appeared a great deal of multiform endoplasmic reticula,thus promoting the photosynthesis of Zn-deficient plants.This provides a cytologico-theoretical basis for fertilization of high-yielding citrus trees.

Growth Responses of Trees to Micronutrients and Their Feedback Effect in Various Soil-Forest Ecosystems of Taihu Lake Region

Vector analysis technique and ecological sequential comparison methods were adopted to study tree growth response to the micronutrients, B, Mo, Cu, Zn, Fe, and Mn, in soils derived from various parent materials in the forest area of Taihu Lake region in southeast China. The results showed that the dry weight of individual current-year needle of Chinese fir (Cunninghamia lanceolata) grown on the soi1 derived from granite parent rock was increased by 8% and 13% in comparison with that grown on the soils derived from sandstone and ash-tuff parent rock, respectively. And such dry weight of loblolly pine (Pinus taeda) grown on the soil derived from sandstone parent rock was increased by 21% in comparison with that on the soil derived from ash-tuff parent rock. One of the reasons for those results was that micronutrients content in the soil derived from ash-tuff parent rock were not sufficient to meet the requirement of the growth of Chinese fir and loblolly pine, i.e., micronutrients in soil were deficient and/or induced deficient. The amounts of Cu, Zn, Fe, and Mn uptake by Chinese fir and loblolly pine were in agreement with the contents of available micronutrients in soil respectively, except for B and Mo. Meanwhile, there might exist an "antagonism" between the uptake of B versus Mo by trees, although more studies are needed to confirm it. Regression analysis indicated that amount of a soil available micronutrient was correlated to the type of parent material and its total amount in the forest floor, except for B. The F test identified that the correlation of each equation reached the significant level to different extents, respectively. The t test confirmed that amount of available forms was mainly depended on the type of parent material for Mo, Cu, Zn and Mn but on the forest floor for Fe. There was a feedback effect of forest stand on the amount of soil available micronutrients. The ability of accumulating available micronutrients in soil was better by the sawtooth oak (Quercus acutissima) stand than by the Chinese fir stand (except for B). The ability of accumulating available Zn, Fe, Mn and Mo in soil was better by the Chinese fir stand than by the loblolly pine stand, while as for available B and Cu, by the latter was better than by the former. When discussing the effect of forest stand on the amount of soil available micronutrients, not only the amount of micronutrient in the forest floor and the parent materials but also the amount of micronutrient taken up by current-year needles have to be considered.