Plasma-aided manufacturing

The present and potential applications of plasma-aided manufacturing are discussed and described. Plasma-aided manufacturing is used for producing new materials with unusual and superior properties, for developing new chemical compounds and processes, for machining, and for altering and refining materials and surfaces. Plasma-aided manufacturing has direct applications to semiconductor fabrication, materials synthesis, welding, lighting, polymers, anticorrosion coatings, machine tools, metallurgy, electrical and electronics devices, hazardous waste removal, high-performance ceramics, and many other items in both the high-technology and the more traditional industries in the United States     

ICP-MS在城市道路尘土中非常规监测微量元素污染评价中的应用

采集了石河子城区32个站点的道路尘土样本,测定了样品中10种非常规监测微量元素(B,Be,Bi,Co,Ga,Li,Sb,Sn,Tl,V)的含量。并采用地积累指数法、元素相关性分析和主成分分析法对尘土中的微量元素污染程度和来源进行了分析。结果表明：道路尘土中微量B,Be,Bi,Co,Ga,Li,Sb,Sn,Tl和V的平均含量分别为41.11,1.68,0.52,13.58,36.26,24.91,3.37,3.64,0.42,72.66 mg·kg-1。其中,Co,Li和Tl的平均含量均低于新疆土壤元素背景值,B,Be和V的平均含量和新疆土壤元素背景值相似,Bi,Ga,Sb和Sn的平均含量高于新疆和世界土壤元素背景值。地积累指数计算结果表明：B,Be,Co,Ga,Li,Tl和V污染级数为0,说明无污染,而Sb,Bi和Sn污染较为严重(污染等级分别为2,1,1)。元素相关性分析和主成分分析多元统计方法计算结果表明,Bi,Co,Sb和Tl主要是人为来源,B,Be,Li和V主要是自然来源,而Ga和Sn可能受自然因素和人为因素的共同影响。     

ICP-MS/ICP-AES测定小麦穗离体培养籽粒营养元素及重金属含量

环境中重金属污染会导致谷物营养缺乏、代谢紊乱.借助ICP-MS/ICP-AES系统和离体穗培养方法,准确测定灌浆期不同浓度铜、镉(0,5,15,45 mg·L-1)处理对籽粒营养元素及重金属元素含量的影响.结果显示,不司浓度铜、镉处理显著降低小麦粒重;外源铜促进了籽粒P,K,Mg,Ca,Na,Mn和Zn含量的增加,抑制了 Fe和B的吸收.镉的加入对小麦籽粒P,K,Ca,Mg和Mn的吸收起促进作用,然而对Na,Fe,Zn和B的吸收起拮抗作用.外源铜、镉抑制小麦籽粒对Hg的积累,但籽粒Cu和Cd含量最高分别超过国家食品卫生标准的55和62倍,存在极大安全隐患.     

Physical Manipulation of Lanthanide‐Activated Photoluminescence

Versatile manipulation of lanthanide photoluminescence not only enables a more thorough understanding of the luminescent mechanism, but also promotes their widespread applications including advanced display and security, bioimaging and biotherapy, and sensors. The traditional chemical methods, engineering of composition, concentration, size, morphology, and surface defects, can easily tune the excitation, energy transfer and emission processes and have been frequently used. Despite the powerful ability to control luminescence intensity and selectivity, these chemical approaches suffer from cumbersome synthesis processes and are usually time consuming and irreversible. Recently, there have been numerous examples of physical approaches realizing in situ, real time, and reversible luminescence manipulation for certain materials under a given excitation. Herein, the existing physical strategies comprising temperature, magnetic field, electric field, and mechanical stress are summarized. For each approach, the action mechanism, material design, applications, as well as current challenges are discussed, and possible development directions and broadening of the potential application areas are considered.     

Recent Advances in the Study of Phosphorene and its Nanostructures

Phosphorene, a single layer of black phosphorus, has attracted considerable attention recently due to its intriguing structures and fascinating electronic properties. In particular, its remarkable properties, such as high charge carrier mobility, direct band-gap semiconducting characteristics, and strong anisotropies in electro-optical and thermo-mechanical properties, etc., are opening up brand-new opportunities for its applications in nanoelectronics, optoelectronics, sensors, energy conversion, and advanced engineering materials, etc. In this article, we present recent advances in the study of phosphorene and its derivatives (nanoribbons, nanotubes, fullerenes, and heterostructures) with special emphasis on structures, morphologies, properties (electronic, optical, magnetic, thermal, mechanical), and applications (transistors, phonon detectors, digital circuits, sensors, thermoelectric materials, Li-ion batteries). In addition, routes for modifying these properties by physical and chemical functionalization, defect engineering, strain engineering, and electric fields are discussed. Our intent is to present a state-of-the-art view in this fast-evolving field, with a balanced theoretical and experimental perspective.     

Thermal plasmas

Although many thermal plasma processes have been developed for industrial applications, the wide acceptance as a manufacturing technology is prevented due to economical and competitive reasons, and/or reproducibility and reliability aspects. This paper is devoted to an assessment of the present knowledge in the following topics: (1) plasma torch and performance of blown arc (dc or ac), transferred arc and radio frequency torches; (2) established industrial applications with special emphasis on cutting, welding, spraying, transferred arc reclamation, reheating and purification, reheating metal melts, smelting reduction, chemical operations, and waste destruction; (3) recent developments in the knowledge of fundamental processes in plasma torches with power sources, cathodes (hot and cold), anodes (static and dynamic behavior), and torch components; (4) modeling-thermodynamic and transport properties, plasma flow with and without the Maxwell's equations; (5) measurement techniques including emission and absorption spectroscopy, laser scattering, enthalpy probes, video cameras, spectral analysis, shadowgraphy, and particle diagnostics either in flight with statistical measurements and those giving characteristics of a single particle upon flattening on a substrate; and (6) plasma-processing development in the presently used industrial processes and also in prospective processes with surface hardening, ultrafine powder production, plasma-assisted CVD, and plasma-fluidized or spouted bed reactors     

高速重轨平直度在线检测研究

重轨的平直度检测是重轨生产过程中重要的一个环节,该项检测的速度、准确性、稳定性等因素直接影响重轨总体质量。 本文以中国某大型钢铁集团轨梁厂的重轨平直度检测现状为背景,利用激光传感、数据采集、计算技术等现代技术,设计了一套基于并行计算的重轨平直度在线检测系统。系统采用14个激光位移传感器和2个旋转编码器分别对于重轨的7个水平方向位移测点、7个竖直方向位移测点、和重轨传输方向的位移进行实时测量,得到的信号转换为数字信号后,在PC机内通过GPU并行计算进行同步配准、块内数据分析、块间数据分析、帧间数据分析等处理,除去粗糙度、氧化铁皮、高频振动、低频振动等干扰,最后得到并输出平直度信息。实验及现场应用表明,该方法检测速度可达到3m/s、精确度可达到0.1mm.     

INAA for determination of trace elements in bottom sediments of the Selenga river basin in Mongolia

Instrumental neutron activation analysis (INAA) was used for the determination of major, minor and trace elements in samples of bottom sediments of the inflows of the Selenga river basin to assess the impact of the contamination from the industrial complex Erdenet and other industrial enterprises in Mongolia. A total of 42 elements (Na, Mg, Cl, K, Ca, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Sr, Rb, Sr, Zr, Nb, Sb, Cs, Ba, La, Ce, Nd, Sm, Eu, Tb, Dy, Tm, Hf, Ta, W, Au, Hg, Th, and U) was determined by combination of conventional and epithermal neutron activation analysis at the IBR-2 reactor, FLNP JINR, Dubna. For the first time such a large set of elements was used for characterization of the bottom sediments as accumulating media which may reflect industrial contamination of the water basin. The concentrations of heavy metals and other trace elements in the samples from three inflows of the Selenga river basin were compared with data from the previous studies. It was shown that the industrial zone of the Erdenet Mining Corporation (EMC) and gold mining zone Zaamar are the sources of strong environmental contamination. The concentrations of Cu and Sb determined in sediment samples of the River Khangal and Govil near the EMC exceed average crustal rock and soil values by factors of 50 and 15, respectively. In the area of the gold mining zone Zaamar concentrations of Au, As, and Sb exceed crustal rock and soil values by factors of 4, 25, and 6, respectively. The relatively high levels of As, V, Zn, V, and Sr in the sediments of the studied rivers are obviously due to the discharges of untreated wastewater of desalination plant, electrical power station, textile industry and mining activities as well as domestic wastewater.     

ICP-AES测定肉苁蓉及其提取物中矿质元素含量

采用ICP-AES法测定两种肉苁蓉及其提取物中11种矿质元素,结果表明：肉苁蓉中Mn,K,Ca,Mg,Na含量（μg·g-1）显著高于管花肉苁蓉,分别为17.70,16 278.03,1 947.25,1 662.76,106.79;肉苁蓉50%甲醇提取物中Fe,Cu,P含量为水提物的1.5倍、2.4倍、1.1倍,Mn,Zn,K,P,Mg,Na含量为100%甲醇提取物的3.8倍、1.2倍、1.6倍、2.3倍、2.2倍、1.1倍;管花肉苁蓉50%甲醇提取物中Cu和P含量为水提物的1.6倍和1.2倍,Mn,Zn,K,P,Mg,Na,Al含量为100%甲醇提取物的2.0倍、1.6倍、1.6倍、1.4倍、1.8倍、1.2倍、1.2倍;肉苁蓉和管花肉苁蓉内矿质元素在50%甲醇中的溶出率分别是60.79%～83.10%和44.58%～83.84%,且Mn, Zn, K, P, Ca, Na, Al的溶出率显著高于水和100%甲醇提取。此研究为高效利用肉苁蓉药材中的矿质元素提供了科学依据。     

Spectroscopic ellipsometry and polarimetry for materials and systems analysis at the nanometer scale: state-of-the-art, potential, and perspectives

This paper discusses the fundamentals, applications, potential, limitations, and future perspectives of polarized light reflection techniques for the characterization of materials and related systems and devices at the nanoscale. These techniques include spectroscopic ellipsometry, polarimetry, and reflectance anisotropy. We give an overview of the various ellipsometry strategies for the measurement and analysis of nanometric films, metal nanoparticles and nanowires, semiconductor nanocrystals, and submicron periodic structures. We show that ellipsometry is capable of more than the determination of thickness and optical properties, and it can be exploited to gain information about process control, geometry factors, anisotropy, defects, and quantum confinement effects of nanostructures.     

Magnetic properties of (Ga,Mn)N ternaries and structural,electronic, and magnetic properties of cation-mixed (Ga,Mn)(As,N) and (In,Mn)(As,N) quaternaries

ABINIT simulation package with built in local density, generalized gradient, and spin local density approximations was used to investigate the structural, electronic, and magnetic properties of cation mixed (Ga,Mn)(As,N) and (In,Mn)(As,N) quaternaries with equal and fixed compositions of Ga, In, and Mn atoms. In particular, total energy minimization approach was used to compute the equilibrium structural parameters of zinc-blende (GaAs, InAs, and MnAs), wurtzite (GaN, InN, and MnN) binary parent compounds, as well as, the corresponding equilibrium parameters of (Ga,Mn)(As,N) and (In,Mn)(As,N) quaternary systems. The band structures of zinc-blende GaAs, InAs, and MnAs binary parent compounds were computed and analyzed. Spin polarized band structures of the cation mixed (Ga,Mn)(As,N) and (In,Mn)(As,N) quaternaries with equal compositions of Ga, In, and Mn cations were computed and analyzed using spin local density approximation based calculations. Moreover, the magnetic properties of (Ga,Mn)(As,N) and (In,Mn)(As,N) quaternaries with equal concentration of Ga, In, and Mn cations were investigated. Our results suggest that the two quaternary systems are nonmagnetic. An interpretation of our results is presented. In addition, the magnetic properties of (Ga,Mn)N nanocrystal ternaries constructed from doping GaN with one or two Mn atoms were investigated using Vienna Ab-initio Simulation Package (VASP) and compared with those of (Ga,Mn)(As,N) quaternaries.     

基于高光谱分析的淫羊藿药用成分快速检测研究

中药材淫羊藿富含朝霍定和淫羊藿苷等黄酮类化合物,具有滋阴补肾、提高免疫力等功效,有较大的药用价值。当前,面对生产及育种过程中批量样品快速、无损检测需求的增加,传统的化学分析方法难以满足需要,而高效、廉价的现代高光谱分析技术备受青睐。但受制于光谱数据谱峰重叠及噪声的干扰,全波段光谱分析建模存在模型精度不高和运行效率低的问题。利用便携式地物光谱仪器获取淫羊藿可见-近红外光谱数据,借助遗传算法（GA）特征波段选择方法剔除无关波段,并与偏最小二乘回归（PLSR）分析建模技术结合,构建淫羊藿药用组分（朝霍定A、朝霍定B、朝霍定C和淫羊藿苷）高光谱GA-PLSR校正模型,探讨淫羊藿药用组分含量高效分析预测的可行性,并挖掘获取淫羊藿品质鉴定的重要光谱响应波段。结果表明：高光谱分析结合化学计量学在淫羊藿有效药用组分的快速无损检测方面具有相当大的潜力。与全波段PLSR校正模型相比,通过GA迭代优化,参与建模的有效光谱数据得到简化,GA-PLSR模型的测量精度和稳定性得到明显提升。主要表现在交叉验证的决定系数（R2_CV）得到明显提高,交叉验证的均方根误差（RMSE_CV）普遍降低。其中,四种药用组分校正模型的R2_CV分别从0.645,0.720,0.718和0.642提升为0.671,0.835,0.782和0.796;同时,其对应的RMSE_CV值分别由2.102,2.896,21.069和1.221降为2.071,2.230,18.656和0.912。此外,明确了红边波段690～740 nm以及420 nm附近波段为淫羊藿药用组分朝霍定A、朝霍定B、朝霍定C和淫羊藿苷光谱鉴别分析的重要响应波段。该研究为高光谱技术淫羊藿品质准确高效鉴定和光谱传感器的波段设计提供一定的理论依据。     

NMR-based metabonomic analysis of MnO-embedded iron oxide nanoparticles as potential dual-modal contrast agents

MnO-embedded iron oxide nanoparticles (MnIO-NPs) can be treated as potential dual-modal contrast agents. However, their overall bio-effects and potential toxicity remain unknown. In this study, the metabolic effects of MnIO-NPs (dosed at 1 and 5 mg Fe/kg) on Sprague–Dawley rats were investigated using metabonomic analysis, histopathological examination, and conventional biochemical analysis. The histological changes included a focal inflammation in the liver at high-dose and a slightly enlarged area of splenic white pulp after 48 h post-dose. Blood biochemical analysis showed that albumin, globulins, aspartate aminotransferase, lactate dehydrogenase, blood urea nitrogen, and glucose changed distinctly compared to the control. The metabonomic analysis of body fluids (serum and urine) and tissues (liver, kidney, and spleen) indicated that MnIO-NPs induced metabolic perturbation in rats including energy, nucleotides, amino acids and phospholipid metabolisms. Besides, the variations of supportive nutrients: valine, leucine, isoleucine, nicotinamide adenine dinucleotide (phosphate), and nicotinamide, and the conjugation substrates: glycine, taurine, glutamine, glutathione, and methyl donors (formate, sarcosine, dimethylglycine, choline, and betaine) were involved in detoxification reaction of MnIO-NPs. The obtained information would provide identifiable ground for the candidate selection and optimization.

     

发射光谱法同时测定钛基复合材料中的镍铁钼锰和硼的研究

研究了用碳粉、碳酸钙、氧化铜和氧化铍作缓冲剂同时测定钛基复合材料中的镍、铁、钼、锰和硼的发射光谱法,选择铍作内标线,不需分离、不需化学处理,直接压样于杯形的石墨电极中,具有简便、快速、准确。对测定条件、干扰因素进行了研究,从而建立测定镍、铁、钼、锰和硼的新方法。镍、铁、钼、锰和硼的分析线分别为300.36,248.33,315.82,260.57和249.68 nm,内标线选择为铍的298.61 nm,镍、铁、钼、锰和硼的线性范围分别为0.003%～0.30%;0.001%～0.20%;0.003%～0.30%;0.001%～0.20%;0.001%～0.20%。镍、铁、钼、锰和硼的检测限分别0.003%,0.001%,0.003%,0.001%,0.001%,其回收率在95.80%～104.8%范围内,当n=9时,相对标准偏差RSD均小于5%。用于样品的测定取得了满意的结果。     

Optically and non-optically excited thermography for composites: A review

Composites, such as glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP), and adhesive bonding are being increasingly used in fields of aerospace, renewable energy, civil and architecture, and other industries. Flaws and damages are inevitable during either fabrication or lifetime of composites structures or components. Thus, nondestructive testing (NDT) are extremely required to prevent failures and to increase reliability of composite structures or components in both manufacture and in-service inspection. Infrared thermography techniques including pulsed thermography, pulsed phase thermography, and lock-in thermography have shown the great potential and advantages. Besides conventional optical thermography, other sources such as laser, eddy current, microwave, and ultrasound excited thermography are drawing increasingly attentions for composites. In this work, a fully, in-depth and comprehensive review of thermography NDT techniques for composites inspection was conducted based on an orderly and concise literature survey and detailed analysis. Firstly, basic concepts for thermography NDT were defined and introduced, such as volume heating thermography. Next, the developments of conventional optic, laser, eddy current, microwave, and ultrasound thermography for composite inspection were reviewed. Then, some case studies for scanning thermography were also reviewed. After that, the strengths and limitations of thermography techniques were concluded through comparison studies. At last, some research trends were predicted. This work containing critical overview, detailed comparison and extensive list of references will disseminates knowledge between users, manufacturers, designers and researchers involved in composite structures or components inspection by means of thermography NDT techniques.     

蒜氨酸和甲基蒜氨酸的红外及拉曼光谱研究

利用傅里叶红外光谱和共聚焦显微拉曼光谱技术,比较分析了大蒜主要功能活性成分前体蒜氨酸和甲基蒜氨酸粉末纯品的红外和拉曼谱。在3 200～2 800 cm-1和1 700～200 cm-1波段检测到显著的红外和拉曼吸收峰,其中蒜氨酸在3 080,1 617,1 582,1 496,1 418,1 342,1 301,919 cm-1处有8个较强的红外吸收峰,以及在3 088,1 636,1 404,1 290,1 051,790,745,693,588 cm-1处有9个较强的拉曼振动峰,可作为蒜氨酸的特征峰;甲基蒜氨酸在1 644,1 481,1 395,1 370,1 233,1 068,1 004,892 cm-1处有8个较强的红外吸收峰,以及在1 644,1 310,1 073,1 011,998,893,846,702,676 cm-1处有9个较强的拉曼振动峰,可作为甲基蒜氨酸的特征峰。蒜氨酸和同系物甲基蒜氨酸的红外及拉曼光谱具有明显差异,红外及拉曼光谱技术为蒜氨酸及其同系物的快速、 简便的分析提供了方法。     

Near-infrared spectroscopy combined with equidistant combination partial least squares applied to multi-index analysis of corn

Development of small, dedicated, reagentless, and low-cost spectrometer has broad application prospects in large-scale agriculture. An appropriate wavelength selection method is a key, albeit difficult, technical aspect. A novel wavelength selection method, named equidistant combination partial least squares (EC-PLS), was applied for wavenumber selection for near-infrared analysis of crude protein, moisture, and crude fat in corn. Based on the EC-PLS, a model set that includes various models equivalent to the optimal model was proposed to select independent and joint-analyses models. The independent analysis models for crude protein, moisture, and crude fat contained only 16, 12, and 22 wavenumbers, whereas the joint-analyses model for the three indicators contained only 27 wavenumbers.Random validation samples excluded from the modeling process were used to validate the four selected models. For the independent analysis models, the validation root mean square errors (V_SEP), validation correlation coefficients (V_R_P), and relative validation root mean square errors (V_RSEP) of prediction were 0.271%, 0.946, and 2.8% for crude protein, 0.275%, 0.936, and 2.6% for moisture, and 0.183%, 0.924, and 4.5% for crude fat, respectively. For the joint-analyses model, the V_SEP, V_R_P, and V_RSEP were 0.302%, 0.934, and 3.2% for crude protein, 0.280%, 0.935, and 2.7% for moisture, and 0.228%, 0.910, and 5.6% for crude fat, respectively. The results indicated good validation effects and low complexity. Thus, the established models were simple and efficient.The proposed wavenumber selection method provided also valuable reference for designing small dedicated spectrometer for corn. Moreover, the methodological framework and optimization algorithm are universal, such that they can be applied to other fields.     

近红外光谱技术(NIRS)在检测牧草霉菌毒素中的应用

具有快速、高效、无损、在线等优势的近红外光谱技术(near infrared reflectance spectroscopy technique,NIRS)已经在农业、食品、化工、医学等领域获得广泛应用。牧草在加工贮藏过程中,受多种真菌的侵染,引起霉菌毒素在牧草中积累。霉菌毒素会通过动植物产品进入人畜的食物链,引起人畜中毒。牧草中霉菌毒素的常规检测不但需要粉碎、浸提、层析等繁琐的样品前处理过程,还需要酶联免疫吸附法、高效液相色谱法、溥层色谱法等后续检测过程。通过发展高精度、低检出限的光谱仪器,建立相应霉菌毒素检测的软件技术与校正模型,能够在牧草利用中达到快速准确检测霉菌毒素的含量和性质,从而为牧草的合理加工与利用提供依据,促进NIRS技术在健康畜产品生产领域的应用。     

Recent progress in perpendicularly magnetized Mn-based binary alloy films

In this article, we review the recent progress in growth, structural characterizations, magnetic properties, and related spintronic devices of tetragonal MnxGa and MnxA1 thin films with perpendicular magnetic anisotropy. First, we present a brief introduction to the demands for perpendicularly magnetized materials in spintronics, magnetic recording, and perma- nent magnets applications, and the most promising candidates of tetragonal MnxGa and MnxA1 with strong perpendicular magnetic anisotropy. Then, we focus on the recent progress of perpendicularly magnetized MnxGa and MnxA1 respec- tively, including their lattice structures, bulk synthesis, epitaxial growth, structural characterizations, magnetic and other spin-dependent properties, and spintronic devices like magnetic tunneling junctions, spin valves, and spin injectors into semiconductors. Finally, we give a summary and a perspective of these perpendicularly magnetized Mn-based binary alloy films for future applications.     

Ultrasound assisted extraction of food and natural products. Mechanisms,techniques, combinations,protocols and applications. A review

This review presents a complete picture of current knowledge on ultrasound-assisted extraction (UAE) in food ingredients and products, nutraceutics, cosmetic, pharmaceutical and bioenergy applications. It provides the necessary theoretical background and some details about extraction by ultrasound, the techniques and their combinations, the mechanisms (fragmentation, erosion, capillarity, detexturation, and sonoporation), applications from laboratory to industry, security, and environmental impacts. In addition, the ultrasound extraction procedures and the important parameters influencing its performance are also included, together with the advantages and the drawbacks of each UAE techniques. Ultrasound-assisted extraction is a research topic, which affects several fields of modern plant-based chemistry. All the reported applications have shown that ultrasound-assisted extraction is a green and economically viable alternative to conventional techniques for food and natural products. The main benefits are decrease of extraction and processing time, the amount of energy and solvents used, unit operations, and CO₂ emissions.