金刚石表面镀覆金属的性能研究

对人造金刚石表面进行盐浴镀Ti和化学镀Ni、Cu处理后 ,用SEM观测镀后金刚石的表面形貌及镀层界面 ,并测试分析了镀后金刚石的抗压强度和抗热蚀能力。结果表明 ,盐浴镀Ti的镀层与金刚石的结合界面比化学镀层更为致密 ;经化学镀后的金刚石抗压强度明显提高 ,镀Ti和镀Ni的金刚石抗热蚀能力较好。     

Natural polysaccharides platforms for oral controlled release of ketoprofen lysine salt

Context: Ketoprofen lysinate (KL) is one of the most widely used non-steroidal anti-inflammatory drugs in the symptomatic treatment of some chronic inflammatory diseases. Compared to ketoprofen, KL shows better pharmacokinetics and tolerability. However, due to its short half-life of 1–2?h, a multiple dose regimen is required for oral administration. Thus, the present work deals with its encapsulation in a hydrogel-based system by prilling in order to prolong its activity.

Objective: In this paper, we propose alginate and pectin as carriers and release tailoring agent for the development of hydrogel-based beads for KL retarded and sustained release.

Materials and methods: Beads were produced by a Nisco Encapsulator® using alginate or pectin. Operative variables were optimized to produce beads with desired morphology and size. Solid state properties were analyzed by SEM and DSC. Drug release performance was studied by Pharmacopeia pH-change assay to simulate gastrointestinal environment.

Results and discussion: Prilling technique was successfully used to encapsulate high soluble drugs as KL in polysaccharides-based hydrogels. Pectin proved to be a proper polymer able to encapsulate ketoprofen lysine salt. Formulation (F8) showed good morphological properties and size, high drug content (15.6%) and encapsulation efficiency (93.5%) and promising drug release profiles. Hosting F8 in an acid-resistant capsule (DR^®caps) a delivery platform has been developed to control KL release in a delayed (90?min lag time) and prolonged way (270?min complete release).

Conclusion: The platform may be proposed as potentially useful in the oral administration of NSAIDs in chronic inflammatory diseases affected by circadian rhythm.     

熔盐冷冻壁应用中关键工艺影响因素研究

在熔盐堆燃料干法处理流程中,处理设备面临着严重的材质腐蚀问题。熔盐冷冻壁技术被视为保护相关设备耐受化学腐蚀的有效方法,而冷冻壁厚度的稳定控制是干法处理流程应用冷冻壁技术实现处理工艺目的的关键。基于自行研制的冷冻壁实验装置,模拟了干法处理中熔盐冷冻壁的应用工况,考察了导热油进口温度、熔盐初始温度、加热器功率、冷冻壁初始厚度对冷冻壁厚度变化的影响,得到了各个因素的影响规律,并总结了最佳的应用工艺条件。利用热流量的变化分析了冷冻壁厚度变化的原因:热流量越大,冷冻壁厚度减小量越大,达到平衡时,热流量越大,冷冻壁平衡厚度越小。通过实验数据拟合得到了线热流密度与冷冻壁平衡厚度的关系式,平均相对误差11.2%。     

Influence of Coagulant Salt Addition on the Treatment of Oil‐in‐Water Emulsions by Centrifugation,Ultrafiltration, and Vacuum Evaporation

Abstract

Droplet size is a key factor in the treatment of oil‐in‐water (O/W) emulsions, because of its influence on emulsion properties. The addition of a coagulant salt generally causes emulsion destabilization, increasing the droplet size, and enhancing coalescence between oil droplets, which helps its further treatment. The influence of CaCl₂ addition on droplet size distribution of a commercial O/W emulsion used in machining processes was studied in order to facilitate oil removal and to improve its further treatment by centrifugation, ultrafiltration (UF) and vacuum evaporation. The critical coagulation concentration (CCC) was observed at a CaCl₂ concentration of 0.05 M. The quality of the final aqueous effluent, expressed as its chemical oxygen demand (COD) value, was compared for all treatments. The highest COD values were obtained for centrifugation, while the COD of the UF permeate was approximately constant for all UF trials. The best effluent quality was obtained by vacuum evaporation. A combination of these techniques should be appropriate for most industrial treatments of O/W emulsions, depending on the subsequent use of the resulting aqueous effluent.     

自贡盐商捐资办学述略

在中国教育近代化的历程中,商人起到了非常重要的作用。从19世纪50—70年代咸同年间到20世纪40年代抗日战争时期,两次“川盐济楚”造就了大批显赫一时、富甲一方的自贡盐商。这些发迹起家的盐商,捐献资本,创办义学和私学,开办新学,担任校董,引进新的教学内容和管理方式,推动地方教育的近代化,推进传统教育向新式教育的转变,有力地促进了地方教育事业的发展。     

Electrochemical Study on the Reduction Mechanism of Uranium Oxide in a LiCl-Li2O Molten Salt

By means of a linear sweep voltammetry, a cyclic voltammetry and a chronopotentiometry, the electrolytic reduction of uranium oxide has been studied to establish the reduction mechanisms, which are based on a simultaneous uranium oxide reduction and a Li₂O electrowinning, and the formation and electrolysis of lithium uranate. From the voltammograms, the reduction potentials of the uranium oxide and Li₂O were obtained. From the chronopotentiometries based on the results of the voltammograms, the uranium oxide was reduced to uranium metal through the reduction mechanisms showing a more than 99% conversion. For a verification of the reduction mechanisms feasibility, basic data on the electrolytic reduction of the uranium oxide was obtained from the experiments and the characteristics of the closed recycle of Li₂O were discussed.     

Investigation of the MSFR core physics and fuel cycle characteristics

The adoption of Th fuel in fast reactors is being reconsidered due to the potential favorable impact on actinide waste management and resource availability. A closed Th cycle leads to an actinide inventory with lower radiotoxicity and heat load for the first several thousands of years. Due to the typically low TRansUranic (TRU) Conversion Ratio (CR), Th can also be advantageous to expedite the consumption of legacy TRU. One of the main obstacles to the implementation of Th is the highly radioactive recycled fuel which requires remote handling under heavy shielding, inevitably penalizing economics and challenging conventional pin-based fuel manufacturing. From this perspective, the development of liquid-fuelled reactors, with Molten Salt Reactors regarded as the most promising, appears particularly attractive as fuel handling would be greatly simplified. The present paper investigates the fuel cycle performances of the reference GEN-IV Molten Salt Fast Reactor (MSFR) in terms of isotope evolution, radiotoxicity generation and safety-related parameters. Similarly to most MSR concepts proposed in the past, the MSFR is based on the fluoride molten salt technology, but it features the novelty of a fast neutron spectrum. Calculations are performed using state-of-the-art equilibrium-cycle methodologies, i.e., the ERANOS-based EQL3D procedure developed at the Paul Scherrer Institut and extended to the simulation of the MSFR. Selected results have been benchmarked with the Monte Carlo code PSG2/SERPENT. These results have also been used for the assessment of a diffusion module based on the COMSOL multi-physics toolkit, which is the subject of current studies aimed at efficiently simulating the peculiar MSFR transient behavior.     

浅谈食盐质量安全管理

为加强食盐产品质量管理,提升质量安全管理水平。通过分析食盐质量安全管理工作中存在问题和难点,提出相应的解决措施。     

Evaluation of the effects of sodium chloride,potassium sorbate,nisin and lysozyme on the probability of growth of Clostridium sporogenes

The aim of this study was to evaluate the combined effect of salt (sodium chloride, 0–8% w/v), sorbate (potassium sorbate, 0–4.5% w/v), nisin (0–500 ppm) and lysozyme (0–500 ppm) on the survival of Clostridium sporogenes as a non‐toxigenic surrogate of Clostridium botulinum in terms of the probability of growth by using a central composite rotatable design. The results indicated that salt and sorbate were the most effective factors in preventing the growth of Cl. sporogenes in high‐moisture (>95%) and low‐acid conditions. The probability of growth of Cl. sporogenes in broth was reduced by combinations of salt and sorbate. Nisin and lysozyme had insignificant effects on the probability of growth of Cl. sporogenes (P > 0.05). Lysozyme individually and in combination with nisin had no inhibitory effect on Cl. sporogenes. Overall, the addition of sorbate and lysozyme may allow the salt concentration to be reduced while preventing growth.     

Iron oxide nanoparticles synthesized by controlled bio-precipitation using leaf extract of Garlic Vine (Mansoa alliacea)

Iron (III) oxide nanoparticles were synthesized through green chemistry by the controlled reduction of hepta hydrous iron sulphate using the leaf extract of Garlic Vine. The crystalline phase of trivalent iron embedded in the primitive lattice of hexagonal β-Fe₂O₃ was obtained under the space group P3 (143). The scattered lines and considerably broadened peaks in the x-ray diffraction pattern indicate that the samples formed are crystallites of nano regime rather than bulk or amorphous in nature. Further, the size and the microstrain of the nanocrystallites were estimated through Hall Williamson analysis. The abundance of elemental iron present in the sample was estimated through Atomic Absorption Spectroscopy, whilst the UV visible analysis and FT-IR measurements, in accordance with XRD result, endorsed the formation of iron (III) oxide nanocrystals with iron predominantly occupying the octahedral sites. The band gap energy (2.84 eV) corresponds to the best fit is found to be for indirect allowed semiconducting transition between valance and conduction bands. Further, the TGA measurements were performed to identify the presence of capped polymer over the surface of nanoparticles, the organic decomposition temperature and phase transformation of meta-stable β-Fe₂O₃ to stable α-Fe₂O₃ at temperature above 500 °C.