增效过磷酸钙的增效机制及其对玉米生长的影响

利用猪毛、风化煤和腐植酸钠的水解液为增效剂制备了一种增效过磷酸钙,探讨了增效过磷酸钙的增效机制及其对玉米生长的影响。结果表明,蒸馏水浸提条件下,增效过磷酸钙能减缓水溶磷的释放,具备较高的pH值缓冲性。与普通过磷酸钙相比,增效过磷酸钙处理的玉米生物量平均增加了41.9%,吸磷量和吸钙量分别增加了61.7%和27.8%,根系活力增加了24.3%。该研究结果对过磷酸钙生产的技术改进具有指导意义。     

Crystal violet dye sorption and transport in/through biobased PVA cryogel membranes

Cryogels based on poly(vinyl alcohol) [PVA] and three types of bioinsertions such as scleroglucan, cellulose microfibers, and zein, respectively, have been prepared using capacity of PVA to crosslink by repeated freezing–thawing cycles. The effect of the incorporation of biopolymers on the properties of PVA cryogel has been studied by using several techniques such as: scanning electron microscopy, differential scanning calorimetry, and Fourier transform infrared studies. The obtained biobased cryogel membranes were subjected to sorption and to diffusion experiments using Crystal Violet (CV), a dye commonly used in the textile industry and in medicine. Image analysis with CIELAB system was used both to monitor the cryogels loading with CV and to gain insight in the dye state into the gel, in correlation with the bioinsertion type and gels morphology. Dye diffusion but also sorption capacity of the cryogels was found to be closely related to the type of biopolymer. In this article the equilibrium (sorption isotherms) and transport properties (diffusion and permeability coefficients) of CV, in/through physical cross‐linked PVA hydrogel membranes with bioinsertions has been reported. The highest efficiency for the CV removal from aqueous solutions was obtained for the PVA/Scl cryogels. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41838.     

A new ternary phase in the system CaO–Al2O3–Cr2O3: Crystal structure and thermal expansion of CaAl2Cr2O7

Polycrystalline material of a novel phase in the system CaO–Al₂O₃–Cr₂O₃ has been obtained by solid-state reactions. Chemical analysis indicated the composition CaAl₂Cr₂O₇. Single-crystal growth of the new compound using borax as a mineralizer was successful. Diffraction experiments at ambient conditions on a crystal with composition CaAl_2.13Cr_1.87O₇ yielded the following basic crystallographic data: space group P 3, a = 7.7690(5) Å, c = 7.6463(5) Å, V = 399.68(6) ų, Z = 3. Structure determination and subsequent least-squares refinements resulted in a residual of R(|F|) = 2.3% for 1440 independent observed reflections and 113 parameters. To the best of our knowledge, the structure of CaAl_2.13Cr_1.87O₇ or CaAl₂Cr₂O₇ represents a new structure type. It belongs to the group of double layer structures where individual double layers contain octahedrally and tetrahedrally coordinated cation positions. Linkage between neighboring sheet packages is provided by additional calcium cations. Furthermore, thermal expansion has been studied in the interval between 29 and 790°C using in situ high-temperature single-crystal diffraction. No indications for a structural phase transition were observed. From the evolution of the lattice parameters the thermal expansion tensor has been obtained. A pronounced anisotropy is evident. The response of structural building units to variable temperature has been discussed.     

多晶硅锭中硬质点分析及控制研究

以多晶硅锭中硬质点为研究对象,通过实验研究和数值模拟的方法,对多晶硅锭中硬质点进行形貌和成分分析,并提出改善控制方法。研究结果表明硅锭中部的硬质点较细小,主要由SiC组成;硅锭头部的硬质点较粗大,主要由SiC和Si3N4组成,还有少量O的存在。进一步研究发现多晶硅定向凝固铸锭炉的热场结构对于多晶硅锭硬质点形成有直接影响,通过改进热场结构,优化晶体生长界面,显著减少了铸锭中硬质点的数量。     

Characteristics of pigments,modification, and their functionalities

Novel treatments of pigments with inorganic materials have tremendous industrial and commercial prospects. Specific treatment of pigment has a marked effect on its behavior during application. The treatment allows a broad modification of the surface characteristics of pigment particles which leads to improved functionalities. Surface modification of pigments is achieved via coating, polymerization with modifying reagent, treatment with derivatives or polymers, which alter either the optical, conductivity or dispersibility during processing and application. These and many other distinguishing factors that affect the characteristics of pigments such as the class, crystal structure, particle morphology, particle size, hiding power, pigment volume concentration, surface character, and surface treatment have been reviewed. Various organic pigments such as those from fungus and bacteria, and the various families of pigment types such as metallic pigment, light interference, and diffractive pigments which presents decorative quality such as leafing, nonleafing, pearlscent, and Fabry‐Perot effects on substrates have also been reviewed in addition to those from inorganic sources with emphasis on the structure and physiochemical modifications using metal and nonmetal Ions.     

PLC与单片机之间的串行通信及应用

在工业自动化控制领域,较为重要的内容就是PLC和单元机之间的远距离控制,并且在自控系统设计过程中,经常遇到的难题就是PLC和单片机之间远距离通信,基于PLC和单片机两者优势充分发挥的基础上,能够确保PLC和单片机之间串行通信的良好实现。本文基于实际情况的基础上,通过对现阶段较为常见且应用较为广泛的单片机进行分析探讨。     

惯性导航设备升沉数据测试系统研究

研制了一套基于STM32单片机与单轴摇摆台的测试系统,利用固定圆心、固定半径条件下的圆内三角形关系,通过拉线传感器采集单轴摇摆台复合运动中的升沉数据;同时,对惯性导航设备输出的升沉数据进行采集与处理。对测试系统输出的升沉数据进行了验证,实验结果表明:该测试系统的测试数据准确合理,可实现对惯性导航设备升沉参数的动态测试,弥补了现有同类测试系统的结构复杂、量程小等不足。     

A series of Er~(3+)-activated SrLaGa_3O_7 single crystal fibers for mid-infrared laser application

A multidisciplinary approach for the production and characterization of a series of high concentration Er~(3+)activated SrLaGa_3 O_7(abbreviated as Er:SLGO) crystal fibers is shown to have a great promise for implementation in mid-infrared laser applications.The current approach includes the design and formation of unique layered tetrahedral network structures with several kinds of rare earth(RE) ions including Er ions distributing statistically between layers,such as Er:SLGO,Er,Nd:SLGO,Er,Yb,Ho:SLGO,Er,Eu:SLGO and Er,Ho:SLGO.Five kinds of Er:SLGO crystal fibers were designed to grow via a micropulling down method.Spectroscopic analyses show that Er,Yb,Ho:SLGO and Nd,Er:SLGO crystal fibers were superiorly endowed with inhomogeneous broadening absorption and strong emission.The unique structural components design enables the generation of improved absorption and emission recombination,and the inhibition of self-termination as well.Generally,the use of structural components design may warrant high-efficiency emissions in RE-doped crystal fibers.     

极端电场环境激励下的VO2相变性能研究与应用

为揭示VXOY薄膜场致相变规律,推广钒氧化物应用于卫星控制系统,指导氧化钒规模制备,将磁控溅射法和真空退火工艺相结合,在Al2O3陶瓷基片上制备出VXOY薄膜,降低了实验对仪器精度的要求,提高了实验的成功率。对基片进行磁控溅射镀膜,在管式炉中进一步氧化处理生成表面均匀的V2O5,然后进行高温退火处理,对不同退火条件下的生成的薄膜进行了XRD表征。测得了电场激励下VXOY薄膜的相变现象,验证了电场激励下焦耳热并非薄膜相变的主导因素;总结了不同组分下VXOY薄膜的相变规律,研究了不同V6O13含量对VO2薄膜临界相变电压的影响规律,可指导VXOY薄膜应用于微纳卫星等极端环境下的设备控制系统。     

含La2O3奥氏体不锈钢堆焊合金层晶粒细化机制及对其耐腐蚀、磨损性能的影响

目的 通过在超低碳Cr19Ni10不锈钢堆焊合金中加入稀土氧化物La2O3，细化其微观组织，获得力学性能、耐腐蚀性能和耐磨性能等综合性能优良的堆焊合金层。方法 采用添加La2O3的超低碳Cr19Ni10不锈钢焊条制备了四种不锈钢堆焊合金。采用X射线荧光光谱、红外碳硫分析仪和X射线衍射分析仪，对堆焊合金层的元素组成和相组成进行了测定。采用金相显微镜和晶粒度统计软件，对堆焊合金层的微观组织形貌进行观察，并对晶粒度进行了统计分析。采用显微维氏硬度计和纳米压痕仪对堆焊合金层的硬度和杨氏模量进行了测定。采用电化学工作站和CSM摩擦磨损试验机对堆焊合金层的耐腐蚀性能和耐磨性能进行了评价，并且采用白光共聚焦显微镜对磨损后的磨痕形貌和尺寸进行了观察和测定。采用二维晶格错配度理论，对La2O3/γ-Fe界面间的晶格错配关系进行了计算。结果 在堆焊合金层中加入La2O3，随着La2O3加入量的增加，堆焊合金层奥氏体晶粒细化越明显。当La2O3的添加量由0%增加至1.5%时，奥氏体晶粒平均面积由400 μm²减少为210 μm²。堆焊合金层加入La2O3，可以明显提高其力学性能、耐腐蚀性能和耐磨损性能。当La2O3的添加量由0%增加至1.0%时，堆焊合金层的微观硬度由180HV增加到225HV，宏观硬度由125HBS增加到150HBS，杨氏模量由186 GPa左右增加到217 GPa，腐蚀电位由?0.4 V增加到?0.25 V，磨痕深度由50 μm减小到10 μm。La2O3(001)面和γ-Fe(110)面的二维晶格错配度为8.7%(<12%)，说明La2O3可以作为γ-Fe的中等有效异质形核基底，从而细化了堆焊合金层中的奥氏体晶粒。结论 La2O3可以有效地细化奥氏体晶粒，改善堆焊合金层的力学性能，提高其耐腐蚀和耐磨损性能。但是，La2O3加入量存在一个最佳值，当La2O3的加入量为1.0%时，堆焊合金层的综合性能最好。