超微活化条件对磷矿粉磷素形态及肥效的影响

采用化学分析、红外光谱分析以及盆栽试验研究了活化剂添加量及研磨时间对超微活化磷矿粉磷素形态及生物有效性的影响。结果表明,与普通磷矿粉相比,磷矿粉经超微活化处理后有效磷提高了45.1%～58.7%,活性磷提高了169.4%～203.6%,水溶性磷含量随活化剂添加量的增加也明显提高;当活化剂添加量达到5%时,3次水溶性磷的累积释放量较相同条件下制得的超微细磷矿粉提高84倍以上。适当延长研磨时间有利于磷矿粉磷素的释放,但效果不显著。红外光谱分析结果表明:超微细活化磷矿粉中与PO34-、HPO24-相关的特征吸收峰强度较普通磷矿粉显著增强,且生成了与PO34-、HPO24-相关的新特征吸收峰,使磷矿粉中的磷向有效状态转变。盆栽试验结果进一步表明,超微活化磷矿粉处理的玉米生物量、磷素利用率均显著高于磷矿粉、普通超微细磷矿粉以及过磷酸钙和磷酸二铵等常规水溶性磷肥,可增强抗固定能力而显著提高土壤有效磷含量。超微活化磷矿粉较高的活性磷总量和水溶性磷持续适度的供磷强度是其生物有效性高的原因。

文化融合视域下村落公共空间的微活化有机更新——以大同市东沙窝村为例

在乡村振兴语境下,传统村落可传承历史文脉,保护文化遗产,建设具有公共性、生活性与文化性相结合的公共空间。文章以东沙窝村为例,提取村落公共空间的原型并将其进行分类,探求其分化逻辑,并根据现状分析村落公共空间发展的现实困境,从再现地域文化、原有空间适应性更新、提高整体协调性、民俗文化原真性、针灸式设计激活公共空间这五方面提出空间活化策略,以此为美丽乡村的公共空间建设提供参考。

基于温州山根村人居环境微活化改造的设计策略研究

改革开放以来,浙南地区城镇化经历了起点低、速度快的发展进程。快速城镇化带来了乡村土地利用无序杂乱,农民建房缺乏引导,整体村落格局凌乱,景观资源减少,乡村地域文化流失等诸多弊端。在此以山根村改造项目为例,阐述乡村人居环境微活化设计的理念和方法,通过对现有建筑景观资源的合理利用、有机更新,延续其乡村地域文化,同时注入新的活力,使得山根村的微活化设计能够成为温州周边乃至整个浙南地区经济文化持续发展的动力。

学问课堂背景下的生活化微写作探究

学问课堂中,当学生的学习自主性被充分激活之后,学生确实会有更多的问的动机,也确实能够提出更多有质量的问题。基于学生的生活去推行生活化微写作,则成为提高学生写作能力的重要抓手。生活化微写作最好的抓手之一,就是学生对生活的观照与提问。当学生认真研究生活并且能够用问题来驱动自己的思考时,学生的写作动机就容易被激活,也更容易寻找到写作对象。微写作的写作主题往往更加明确,切入口更小,更有利于学生利用短小精悍的文字来表达自己的所思所想。

活化石墨烯微片对聚β-羟基丁酸酯结晶性能和热性能的影响

采用溶液浇铸法制备了聚β-羟基丁酸酯(PHB)/活化石墨烯微片(GONPs)复合材料,并研究了GONPs对PHB晶体结构、非等温结晶性能、热分解温度和热加工稳定性的影响。结果表明:GONPs加快了PHB的非等温结晶,但不会改变PHB的晶体结构;PHB的结晶度和热分解温度均随GONPs用量的增加而提高;GONPs对PHB热加工稳定性的影响不显著,但PHB自热解发生后,PHB/GONPs复合材料的热降解程度较纯PHB变缓。

筒屋式村落的微活化有机更新——以浙江德清张陆湾村为例

以浙江德清张陆湾村为例,阐述筒屋式村落渐进式微活化改造的思路与方法;在乡村产业转型的语境下,通过筒屋的保护与改造、筒屋群体环境的品质提升等,实现乡村意象的恢复与重塑,助力乡村经济社会文化的持续发展。

高职劳动教育的育人逻辑:“微”生活化模式视角

新时期高职劳动教育是提升技术技能人才培养质量的重要途径。以碎片化和实时交互性为特征的“微媒体”逐渐重构高职劳动教育的育人模式,以劳动教育系统、科学、合理的育人逻辑为出发点,本研究结合“微”生活实践,从路径规划和策略选择两个方面构建高职院校劳动教育的“微”生活化模式,以期为创新高职劳动教育理念和教育内容提供思路。

电热冲击对场活化烧结微成型制备微型铜齿轮的影响

为研究场活化烧结微成型过程中电热冲击对粉末烧结致密化的影响,将装有铜粉末的模具在100 MPa压力下以50℃/s的预设升温速度加热至600℃,不保温,然后冷却至500℃,随后继续在500~600℃的温度范围内以同样的速度加热升温和冷却,如此循环1~5次,研究了快速加热时的电热冲击对制备微型铜齿轮的影响。研究发现,随着电热冲击循环次数的增加,所制备的分度圆直径为1.6 mm的8齿微型铜齿轮的致密性逐渐提高。当电热冲击循环次数为5次时,微型铜齿轮的相对密度为98.7%,整个制备过程仅为53 s。微观分析表明,微型铜齿轮的快速微成型过程由粉末颗粒的重新排列、粉末的弹塑性变形及碎化、颗粒间熔接及界面消失、电热冲击循环4个阶段组成。

利用微课有效提升中职学生数学核心素养

微课时代的中职数学教育要着眼于社会发展对人才类型的需求，致力于提升专业技能人才的综合素养，教学目的不再局限于让学生获得数学知识的技能，学生数学素养的培养成为核心。微课已经成为课堂教学的一个重要组成部分，更是学生课外自学的重要资源，数学教师应该充分利用微课在线上自学模式和课堂教学中的作用来提升学生的数学核心素养。

宁夏苏峪口磷矿绿色开发的技术思路探讨

宁夏苏峪口磷矿一般先浮选出精矿粉,再用硫酸加工生产过磷酸钙,该方法存在耗能过高及污染环境的问题。为了今后能继续绿色地开发贺兰山苏峪口磷矿资源,参考磷肥领域试验研究成果,对苏峪口磷矿绿色开发的技术思路进行了探讨研究。结果表明,可以在矿石利用过程中简化加工流程,直接制造硅钙磷肥或超微活化磷矿粉肥,从而实现绿色、节能、环保地开发利用贺兰山苏峪口磷矿资源。

小学写作教学中微创作的策略研究

中共中央办公厅、国务院办公厅印发《关于进一步减轻义务教育阶段学生作业负担和校外培训负担的意见》以来,给所有小学语文老师提出了新的要求,探索省时、高效的教学策略,成了所有小学语文老师的共同课题。课题组研究发现,巧妙设计写作情境,采用生活化微创作的策略,引导学生积累生活中的写作素材。生活成了写作的源头活水,有物可写,有情可抒,学生才能自由地表达真情实感,才能有效激发学生的写作兴趣。

无刻蚀镀铁电沉积机理及综合性能

无刻蚀镀铁变革了在硫酸液中电刻蚀与电镀铁分槽进行的镀铁工艺。无刻蚀镀铁是在同一电镀槽中完成对零件交流活化—交流起镀—交流过渡镀—小直流镀—直流过渡镀—全直流镀的全过程。由无刻蚀镀铁技术获得的镀铁层质量稳定、可靠。纯铁镀层的结合强度356MPa,含Ni、Co的合金镀铁层结合强度460MPa,旋转弯曲疲劳极限σ-1为363.85MPa,机车上的大型曲轴镀铁层保证期达30万公里,该技术再制造船舶、机车大型曲轴已实现规模化生产。文中综合了多年来对无刻蚀镀铁层的测试结果,探讨了无刻蚀镀铁层的电沉积机理和特点。研究认为,被镀零件表面经对称交流活化并使其处于微融活化态时,为Fe2+在基体中铁素体晶面上的择优放电沉积创造了条件;初始镀铁层的择优取向与基体相同,Fe2+在活化界面获得电子后先沿(110)晶面沉积,形成纳米等轴晶,随后转向沿(211)晶面沉积并形成纳米柱状晶,最终形成具有结合强度高、超细晶粒、硬度高、耐疲劳性和耐磨性好等特点的镀铁层。

热休克蛋白90α荧光免疫层析检测方法的建立

目的:建立人血清中热休克蛋白90α(HSP90α)的荧光免疫层析定量检测方法。方法:采用荧光免疫层析技术,对荧光微球制备、最佳反应时间、线性范围、精密性、回收率、临床检测等方面进行系统研究。结果:确定了各反应条件,最佳反应时间为5 min。线性范围0.39~100 ng/ml。精密性质控品高值(30 ng/ml)CV=8.14%;低值(10 ng/ml)CV=9.26%,高、中、低值血清的回收率为100.56%、99.76%、94.1%;与国外试剂盒(ELISA检测方法)平行检测40份临床血清,结果显示两者相关系数为0.968 5。结论:初步建立的方法具有良好的精密性和线性,临床符合率能满足临床检测技术要求,有望完善后报批用于临床。

Thermodynamics and kinetics of carbothermal reduction of zinc ferrite by microwave heating

The kinetics of carbon reduction of ZnFe2O4 in the temperature range of 550-950 °C was investigated in a microwave tank-type reactor. The mechanism of formation of ZnO and Fe3O4/FeO by the decomposition of ZnFe2O4 was detailed using the equilibrium calculations and thermodynamics analysis by HSC chemistry software 6.0. In addition, the effects of decomposition temperature, the C/ZnFe2O4 ratio, the particle size and the microwave power were assessed on the kinetics of decomposition. Zn recovery as high as 97.93%could be achieved at a decomposition temperature of 750 °C with C/ZnFe2O4 ratio of 1：3, particle size of 61-74 μm and microwave power of 1200 W. The kinetics of decomposition was tested with different kinetic models and carbon gasification control mechanism was identified to be the appropriate mechanism. The activation energy for the carbon gasification reaction was estimated to be 38.21 kJ/mol.

Fretting wear and friction oxidation behavior of 0Cr20Ni32AlTi alloy at high temperature

The fretting wear behavior of 0Cr20Ni32AlTi alloy was investigated with crossed cylinder contact under 80 N at 300 and 400 °C.Wear scar and debris were analyzed systematically by scanning electron microscopy and X-ray photoelectron spectroscopy.The results show that the friction logs are mixed fretting regime and gross slip regime with the magnitudes of displacement of 10 and 20 μm,respectively.Severe wear and friction oxidation occur on the material surface.A large number of granular debris produced in the fretting process can be easily congregated and adhered at the contact zone after repeated crushes.The resultant of friction oxidation is mainly composed of Fe3O4,Fe2O3,Cr2O3 and NiO.Temperature and friction are the major factors affecting the oxidation reaction rate.The fretting friction effect can enhance the oxidation reaction activity of surface atoms of 0Cr20Ni32AlTi alloy and reduce the oxidation activation energy.As result,the oxidation reaction rate is accelerated.

Electrodeposition of Ir on platinum in NaCl-KCl molten salt

The reduction mechanism of Ir in the NaCl-KCl-IrCl3 molten salt was investigated by cyclic voltammetry and chronopotentiometry, and Ir film was deposited effectively on platinum in potentiostatic mode. The morphology and constitution of Ir film were examined by scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD）. It is found that the reduction mechanism of Ir（III） is a three-electron step and electro reaction is a reversible diffusion controlled process; the diffusion coefficients of Ir（III） at 1083, 1113, 1143 and 1183 K are 1.56×10-4, 2.23×10-4, 2.77×10-4 and 4.40×10-4 cm2/s, respectively, while the activation energy of the electrode reaction is 102.95 kJ/mol. The compacted Ir film reveals that the applied potential greatly affects the deposition of Ir, the thickness of Ir film deposited at the potential of reduction peak is the highest, the temperature of the molten salt also exerts an influence on deposition, the film formed at a lower temperature is thinner, but more micropores would occur on film when the temperature went too high.

Effects of Hg and Ga on microstructures and electrochemical corrosion behaviors of Mg anode alloys

The effects of Hg and Ga on the electrochemical corrosion behaviors of the Mg-2%Hg, Mg-2%Ga and Mg-2%Hg-2%Ga (mass fraction) alloys were investigated by measurements of polarization curves, galvanostatic tests and measurements of electrochemical impedance spectroscopy. Scanning electron microscopy, X-ray diffractometry and energy dispersive spectrometry were employed to characterize the microstructures and the corroded surface of the above alloys. The results demonstrate that the microstructure of the Mg-2%Ga alloy is solid solution and the Mg-2%Hg and Mg-2%Hg-2%Ga alloys have white second-phases at the grain boundaries. The Mg-2%Ga alloy has the worst electrochemical activity and the best corrosion resistance, showing a mean potential of -1.48 V and a corrosion current density of 0.15 mA/cm2. The Mg-2%Hg-2%Ga alloy has the best electrochemical activity and the worst corrosion resistance, showing a mean potential of -1.848 V and a corrosion current density of 2.136 mA/cm2. The activation mechanism of the Mg-Hg-Ga alloy is dissolution-deposition of the Hg and Ga atoms.

Effect of Protective Cultivation Patterns of Rice in Cold Areas on Soil Physiological and Biochemical Status in Paddy Field

[Objective] The research aimed to explore how to use the soil reasonably,prevent the degradation of soil fertility,maintain soil fertility,improve the ecological environment of paddy field and improve the soil productivity of paddy field from the cultivation aspect.[Method] Taking kenjiandao 10 as the material,the variation laws of root weight,soil physical and chemical characteristics,soil enzyme,straw decomposition rate,soil temperature,microorganism of rice under the planting patterns of water-saving pro...

Microstructure and mechanical properties of Fe_3Al alloys prepared by MA-PAS and MA-HP

Fe3Al alloys with nearly full density were fabricated by plasma activated sintering（PAS） and hot pressing（HP） from mechanical alloyed Fe-28%Al（mole fraction） powders,respectively.It is found that A2-type Fe3Al alloys were obtained by PAS,and they had a heterogeneous grain size distribution,most areas had a grain size smaller than 500 nm,and other areas had a grain size of about 1 μm.Different to PAS,D03-type Fe3Al alloys with a grain size of of 1-2 μm were obtained by HP.The compression testing results show that yield strength values of Fe3Al alloys fabricated by PAS and HP are almost equal at an elevated temperature,and the compression yield strength was about 100 MPa for all at 800 ℃.The room temperature compression ductility of Fe3Al alloys by PAS was about 20%,which was superior to that of Fe3Al alloys prepared by HP and casting.

Development of a Multivalent Inactivated Vaccine against Pathogenic Escherichia coli Infection in Forest Musk Deer

A multivalent inactivated Escherichia coli vaccine for forest musk deer by using serotypes O4,O26,and O139 with Al（OH）3 adjuvant was prepared.The vaccine did not cause any adverse reactions in forest musk deer.The immunogenic effects of the vaccine were experimentally investigated in pregnant and young forest musk deer.The serum antibody titers of pregnant and young forest musk deer were determined by performing the micro-agglutination test.The serum antibody titers of pregnant forest musk deer were more stable from 35th to 68th d after the third vaccination,and the serum antibody titers of four pregnant forest musk deer were maintained 25,25,25,and 24 on 68th d after the third vaccination.Young forest musk deer showed serum antibody titers which were obtained due to nursing.Young forest musk deer were administered the first intramuscular vaccine injection at an age of approximately 60 days due to a fall in maternal antibody titers.The serum antibody titers of young forest musk deer were higher after the third vaccination and maintained at approximately the same level until they were 137 days old.The maternal antibodies and the antibodies produced by young forest musk deer could be helpful for protecting the young musk deer from the infections of pathogenic Escherichia coli strains（serotypes O4,O26,and O139）for 137 days after birth（during the nursing period and the period when the forest musk deer were susceptible to diseases）.