大学生学业分化的逻辑——源于布尔迪厄“实践理性”的分析

大学生的学业成就取决于学业行为。决定学业行为的因素来自两个方面:大学场域和学生的习性、继承的资本,这两种因素不会以一种单独的形式来影响学业行为。在现实中,大学场域和个体习性相遇后,学生会策略性地形成一种决定行为的认知系统,这个系统才是决定学业行为的最终因素。

论我国学生学业分化问题及其影响因素——基于中国教育长期追踪调查(CEPS)的数据分析

目前我国在校学生的学业分化问题,从某种意义上说,是一个人为的、继承的过程;它与社会阶层差异、城乡差异、父(母)亲受教育程度及职业差异、性别差异有着重要的关联性。研究数据表明,从整体上看,来自社会中上层、城市、父(母)亲受教育程度较高、其职业所需知识储备较多的家庭的学生,无疑在各类优质教育资源的占有和利用方面处于明显的优势地位,其学业表现也更为突出。而性别差异对学业分化的影响则还需要进一步的数据加以验证。

初中生学业成绩分化及干预的心理机制研究

初中生学业成绩分化既是一种普遍现象,也是一种必然现象。造成学业成绩分化的原因是复杂的,心理机制联结各种原因综合地影响着学业成绩及其分化。初中生的学习动机与学习能力的交互作用是最基本的学习心理机制,初中生的成就动机与迁移能力的合约作用是最内在的学习心理机制,初中生的学业自我概念是联结基本机制和内在机制的一统心理机制。干预学业成绩的分化可先从改变学生的学业自我概念着手,进而激活其成就动机与迁移能力的合约力,再继而扩大至学习动机与学习能力的交互力,最终形成学习动机与学习能力的各种因子相互激荡的一体心理机制活力。

初中生学业成绩分化的现状与对策研究——以武汉市某初中2016级学生为例

初中阶段是青少年学业和身心发展的重要时期,易形成品德修养、学业成绩、兴趣爱好等方面的分化局面。以初中生学业成绩分化为切入点,以武汉市某初中2016级学生为例,通过调查和相关数据分析,可窥见目前我国初中生学业成绩分化的状况,解释初中生出现学业成绩分化的原因,并据此提出相应的对策与建议。

关于对大学生学业两极分化外部成因的实证研究

大学生学习成绩的高低是对专业学习效果的呈现并影响着未来的职业发展。而环境因素对大学生学习成绩具有举足轻重的影响。为了解影响大学生学业分化的外部因素并提供相应的解决方案，本次研究采用问卷调查和访谈的研究方法对不同层次高校不同年级的大学生进行整群抽样调查，从学校和家庭两个方面来调查问题原因。

教育社会学视野中促进学生学业成绩合理分化的研究

促进教育公平发展的方式之一是提供均等的教育机会。如何促进教育质量的均衡发展,在教育研究中是一个难点。促进公平的基础就不能回避差异,而是客观分析学生学业成绩差异,通过对学生学业成绩分化的社会学研究,并给出策略建议以促进学生学业成绩的合理分化,使之实现教育的公平性与个性化的有效平衡。

以“业”观“学”——从作业中探寻三年级学生学业成绩分化的成因

三年级学生作业的多维变化,改变的不仅仅是书写,更多的是从所占学习时间、学习重心的转移而促使的态度、兴趣等分化的悄然产生,是伴随作业的分化现象而产生的整个学习过程的分化。导致这种分化的原因很多,主要因素有两点:一是学生不能很好地适应三年级的作业形式,没有形成与之相匹配的活动结构和方法,也就是学生知识与技能的掌握不足造成的成绩分化;二是教学要求与学生心理年龄特征的不匹配,造成了学生学习进步的停顿和对作业乃至整个学习体系的抵触、厌烦,也就是学习倦怠造成的成绩分化。

Sustainability Analysis of Cropland Use in Cropping-Pastoral Ecotone before and after the Grain-for-Green Policy:A Case Study from Yanchi County in Ningxia

[Objective] This study aimed to analyze the sustainability of cropland use in cropping-pastoral ecotone before and after the Grain-for-Green Policy. [Method] Using Yanchi County in Ningxia Hui Autonomous Region as a case study area, this investigation used the annual transfer rate of land use types, cropland suitability and emergy analysis to examine the major pressures affecting the sustainable use of cropland before and after the Grain-for-Green Policy. [Result] The expansion of con- struction land onto cropland was significant; the annual cropland area was still larger than the land area suitable for cropping after the policy; agrochemical inputs used for crop production gradually increased and unit crop outputs required more agro- chemical inputs. Cropland use sustainability showed a fluctuating downward trend. [Conclusion] The results imply that the protection of high quality cropland, further im- plementation of the policy and control of agrochemical inputs according to precipita- tion are the main measures needed for sustainable cropland use in cropping-pastoral ecotone.

Lead anthropogenic transfer and transformation in China

Information on lead redistribution and speciation changes in anthrosphere can help to analyze the whole lead cycle on the earth. Lead life cycle was traced based on the concepts of anthropogenic transfer and transformation. Lead transfer and the distribution of chemical species throughout the anthropogenic flow were identified in 2010 in China. The results show that 1.85 Mt lead ore was consumed(besides 1.287 Mt imported concentrated ore and 1.39 Mt lead scraps. After undergoing transformations, 3.53 Mt lead entered end services in chemical species of Pb, Pb O2 and PbSO4, altogether accounting for over 80% of the total lead products. Finally, 2.10 Mt ore was emitted into the environment in such species as PbSO4(26%), PbO(19%) and Pb(15%). Lead transfer begins in primary raw material sectors, and then transfers to manufacturing sectors. Lead provides services mainly in such industrial sectors as transportation, electrical power and buildings or construction.

Triboelectrostatic Separation-an Efficient Method of Producing Low Ash Clean Coal

At present, coal is mainly consumed as fuel. In fact, coal is also a kind of precious raw material in chemical industry on the premise that some harmful minerals should be removed from coal. The paper presents the results of the research on producing low ash (<2%) coal with triboelectrostatic separator used for producing high-grade active carbon. The test is conducted in bench-scale system, whose capacity is 30～100 kg/h. The results indicate that: 1) the ash content of clean coal increases with the increase of solid content of feedstock, on the contrary, the yield of clean coal is declining; 2) a high velocity may result in a good separation efficiency; 3) for the same solid content, the reunion caused by intermolecular force makes the separation efficiency drop down when the ultra-fine coal is separated; 4) the separation efficiency is improved with the increase of electric field intensity, but there is a good optimized match between the electric field intensity and yield of clean coal; 5) a low rank coal is easy-to-wash in triboelectrostatic separation process; 6) the yield of clean coal can be enhanced and the ash decreased through adapting optimized conditions according to various coals.

Distribution and degradation kinetics of cyhalodiamide in Chinese rice field environment

Cyhalodiamide is a novel agrochemical which is effective against Lepidoptera pests,including Cnaphalocrocis medinalis,Chilo suppressalis,Pieris rapae,Plutella xylostella,Helicoverpa armigera,etc.In the study,a fast and accurate analytical method was developed to detect cyhalodiamide in Chinese typical rice field environment by a modified Qu ECh ERS(Quick,Easy,Cheap,Effective,Rugged,Safe)method with UPLC-MS/MS(ultra-high performance chromatography-tandem mass spectrometry).The mean recoveries of cyhalodiamide varied from 73.5% to 107.5%,with the RSDs from 1.2% to 10.7%.The limits of determination(LODs)were 0.0005 mg·kg^(-1),and the limits of quantitation(LOQs)were from 0.002 to 0.01 mg·kg^(-1)in all five matrices.This method was used to determine cyhalodiamide residues for studies of the distribution and degradation kinetics in rice field environment.The field trials results showed that cyhalodiamide was easily degradable and the half-lives were4.2–13.6 d in rice straw,8.77 d in paddy soil and 5.37–8.45 d in paddy water,respectively.The final residues of cyhalodiamide in brown rice were below 0.35 mg·kg^(-1).The used dosage of 33.75 g·hm^(-2)with pre-harvest interval(PHI)of 21 d and the maximum residue limit(MRL)of cyhalodiamide in rice at 0.1 mg·kg^(-1)were recommended,which would be safe to human health and environment.The developed analytical method will be useful to monitor cyhalodiamide residues and safety evaluation in rice environment.

Membrane materials in the pervaporation separation of aromatic/aliphatic hydrocarbon mixtures—A review

The separation of aromatic/aliphatic hydrocarbon mixtures is a significant process in chemical industry, but challenged in some cases. Compared with conventional separation technologies, pervaporation is quite promising in terms of its economical, energy-saving, and eco-friendly advantages. However, this technique has not been used in industry for separating aromatic/aliphatic mixtures yet. One of the main reasons is that the separation performance of existed pervaporation membranes is unsatisfactory. Membrane material is an important factor that affects the separation performance. This review provides an overview on the advances in studying membrane materials for the pervaporation separation of aromatic/aliphatic mixtures over the past decade. Explored pristine polymers and their hybrid materials(as hybrid membranes) are summarized to highlight their nature and separation performance. We anticipate that this review could provide some guidance in the development of new materials for the aromatic/aliphatic pervaporation separation.

Commercial AM60 alloy for semisolid processing:Alloy optimization and thermodynamic analysis

Semisolid processing is now a commercially successful manufacturing route to produce net-shape parts in automotive industry. The conspicuous results of alloy optimization with thermodynamic simulations for semisolid processing of commercial AM60 alloy were present. The results indicate that the available processing temperature range of AM60 alloy is 170 ℃. The temperature sensitivity of solid fraction decreases with increasing solid fraction or with decreasing temperature above eutectic reaction temperature of AM60 alloy. When the solid fraction φs is 0.4, corresponding processing temperature is 603.8 ℃ and the sensitivity -dφs/dT is 0.0184. The effects of various alloying elements on the solidification behavior and SSM processability of AM60 alloy were calculated with Pandat software.

Indoor Particle Contamination in Airlaid Papermaking Workshop

An onsite testing based on eight-site air sampling was carried out in an airlaid papermaking workshop in Tianjin, China. By theoretical calculation, super absorbent polymer （SAP） size and its existent state in indoor static airflow were obtained. SAP content in the sampled air was tested through chemical analysis method and found to be 3.0-7.2 times that of the human health limit in production areas. The concentrations of total suspending particles （TSP） and respirable particles were achieved by weighing. Particles of the most concern differ for varied function areas. Particles smaller than 10μm are mostly produced in the main production process, and 73%-90% particles generated in packing areas are larger than 10μm. SAP raw material particles can easily changed to suspending form by inevitable extrusion and frication. Correlation between respirable particles and TSP agrees well with that in atmospheric environment.

Optimizing the Chemical Compositions of Protective Agents for Freeze-drying Bifidobacterium longum BIOMA 5920

Freeze drying has a deleterious effect on the viability of microorganisms. In front of this difficulty, the present study adopts response surface methodology to optimize the chemical compositions of protective agents to seek for maximum viability of Bifidobacterium longum BIOMA 5920 during freeze-drying. Through the compara- tive analysis of single protectant, the complex protective agents show better effect on the Bifidobacterium viability. Human-like collagen (HLC), trehalose and glycerol are confirmed as significant factors by Box-Behnken Design. The optimized formula for these three variables is tested as follows: HLC 1.23%, trehalose 11.50% and glycerol 4.65%. Under this formula, the viability is 88.23%, 39.67% higher in comparison to the control. The viable count is 1.07×10 9 cfu·g-1 , greatly exceeding the minimum viable count requirement (10 6 cfu·g-1 ).

The Relevance of Relationships in the Value Creation Process： Analysis of SCM in the Chemical-Pharmaceutical Sector

This work, through an empirical research （Jayaram, Kannan and Tan model）, aims at analysing, at the same time, the effect of ＂structural mechanisms＂ and ＂relationships building＂ factors on the value creation process in the Supply Chain. The two factors have been chosen among others, as they have been considered able to improve the internal and external processes of the firm and the Supply Chain, and in consequence, able to influence the value creation process of the Supply Chain Management. The research has been directed to the chemical and pharmaceutical sector of the Southern Lazio （Italy） and a factorial analysis, using the software SPSS （16.0） which has been performed in order to verify the influence of these factors in value creation process of the Supply Chain The outcomes confirm the positive contribute in the value creation process for companies that take care of the relationships among the stakeholders in the management process of the supply chain （the ＂relationships building＂ factor） and, in parallel with the analysis of the same process, the secondary role of the ＂structural mechanisms＂ factor has been highlighted.

Industry 5.0-The Relevance and Implications of Bionics and Synthetic Biology

Bionics （the imitation or abstraction of the ＂inventions＂ of nature） and, to an even greater extent, syn- thetic biology, will be as relevant to engineering development and industry as the silicon chip was over the last 50 years. Chemical industries already use so-called ＂white biotechnology＂ for new processes, new raw materials, and more sustainable use of resources. Synthetic biology is also used for the devel- opment of second-generation biofuels and for harvesting the sun＇s energy with the help of tailor-made microorganisms or biometrically designed catalysts. The market potential for bionics in medicine, en- gineering processes, and DNA storage is huge. ＂Moonshot＂ projects are already aggressively focusing on diseases and new materials, and a US-led competition is currently underway with the aim of creating a thousand new molecules. This article describes a timeline that starts with current projects and then moves on to code engineering projects and their implications, artificial DNA, signaling molecules, and biological circuitry. Beyond these projects, one of the next frontiers in bionics is the design of synthetic metabolisms that include artificial food chains and foods, and the bioengineering of raw materials; all of which will lead to new insights into biological principles. Bioengineering will be an innovation motor just as digitalization is today. This article discusses pertinent examples of bioengineering, particularly the use of alternative carbon-based biofuels and the techniques and perils of cell modification. Big data, analytics, and massive storage are important factors in this next frontier. Although synthetic biology will be as pervasive and transformative in the next 50 years as digitization and the Intemet are today, its ap- plications and impacts are still in nascent stages. This article provides a general taxonomy in which the development of bioengineering is classified in five stages （DNA analysis, bio-circuits, minimal genomes, protocells, xenobiology） from the familiar to the unknown, with implications for safety and security, in- dustrial development, and the development of bioengineering and biotechnology as an interdisciplinary field. Ethical issues and the importance of a public debate about the consequences of bionics and syn- thetic biology are discussed.

Effect of Three Different Growth Media on Yield and Oil Constituents of Rosemary （Rosmarinus officinalis L.） under Protected Agriculture Conditions

Medicinal plants provide an important source of cure since ancient time. Poor soil resources, scarce and saline water and the harsh environment limited the production of plants in the Arabian Gulf countries. This study aimed to investigate the production potential of rosemary （Rosmarinus officinalis L.） grown on different growth media under greenhouse conditions. Three growth media agricultural soil, compost and hydroponic system were used, whereas tuff （inert volcanic material） was used as substrate. The result indicated that the high salinity of the agricultural soil limited growth and oil yield in rosemary. Shoot height increased in 11 weeks, by 62%, 65% and 114% in plants grown in agricultural soil, hydroponic system and compost, respectively. Na content in plants grown in agricultural soil was significantly higher than in plants grown in the other treatment. Essential oil yield in plants grown in compost exceeded those in agricultural soil by 114%. Essential oil content （0.66%-1.5% w/w） and chemical constituents concentrations did not change significantly with growth media. The main constituents, more or less, are comparable to essential oils constituents reported from other countries. In comparison, better yields are obtained for individual components of the oils of plants grown under our green house conditions. This study demonstrated the great potential of commercial production of rosemary in the greenhouse without compromising the oil quality and oil yield.

Studies on Various Physico-Chemical Characteristics of Some Vegetable Oils

The industrial chemistry of oils and fats is a mature technology, with decades of experience and refinement behind current practices, therefore some physico-chemical characteristics of eleven vegetable oils sunflower oil （four different manufacturing companies）, olive oil （three different manufacturing companies）, corn oil, castor oil, coconut oil and canola oil in Iraqi Kurdistan region （Hawler city center） have been evaluated according to association of official analytical chemists （AOAC） （1995） official methods. The refractive index, viscosity, acid value, peroxide value, pH values, and values of specific gravity of the vegetable oil samples were measured at various different conditions. The results showed that some of the oil samples have unacceptable values in comparison with the standards.