Heavy Metal Removal and Neutralization of Acid Mine Waste Water ‐ Kinetic Study

The influence of the apatite on the efficiency of neutralization and on heavy metal removal of acid mine waste water has been studied. The analysis of the treated waste water samples with apatite has shown an advanced purification, the concentration of the heavy metals after the treatment of the waste water with apatite being 25 to 1000 times less than the Maximum Concentration Limits admitted by European Norms (NTPA 001/2005). In order to establish the macro‐kinetic mechanism in the neutralization process, the activation energy, Ea, and the kinetic parameters, rate coefficient of reaction, k_r, and k_t were determined from the experimental results obtained in “ceramic ball‐mill” reactor. The obtained values of the activation energy Ea >> 42 kJ mol^?1 (e.g. Ea = 115.50 ± 7.50 kJ mol^?1 for a conversion of sulphuric acid η_H2SO4 = 0.05, Ea = 60.90 ± 9.50 kJ mol^?1 for η ^H2SO4 = 0.10 and Ea = 55.75 ± 10.45 kJ mol^‐1 for η ^H2SO4 = 0.15) suggest that up to a conversion of H2SO4 equal 0.15 the global process is controlled by the transformation process, adsorption followed by reaction, which means surface‐controlled reactions. At a conversion of sulphuric acid η ^H2SO4 > 0.15, the obtained values of activation energy Ea < 42 kJ mol^‐1 (e.g. Ea = 37.55 ± 4.05 kJ mol^‐1 for η ^H2SO4 = 0.2, Ea = 37.54 ± 2.54 kJ mol^‐1 for η ^H2SO4 = 0.3 and Ea = 37.44 ± 2.90 kJ mol^‐1 for η ^H2SO4 = 0.4) indicate diffusion‐controlled processes. This means a combined process model, which involves the transfer in the liquid phase followed by the chemical reaction at the surface of the solid. Kinetic parameters as rate coefficient of reaction, kr with values ranging from (5.02 ± 1.62) 10‐4 to (8.00 ± 1.55) 10‐4 (s^‐1) and transfer coefficient, kt, ranging from (8.40 ± 0.50) 10‐5 to (10.42 ± 0.65) 10‐5 (m s^‐1) were determined.     

Superparamagnetic polyvinylpyrrolidone/chitosan/Fe3O4 electrospun nanofibers as effective U(VI) adsorbents

Magnetoactive electrospun fibrous membranes consisting of polyvinylpyrrolidone (PVP), chitosan (CS) and pre-fabricated, double-layer oleic acid-coated magnetite nanoparticles (OA.OA.Fe₃O₄) were fabricated and evaluated as new adsorbent materials for the removal and recovery of uranium (U(VI)) from aqueous solutions. The adsorption has been investigated by batch-type experiments and the solid material has been characterized by X-ray diffraction spectroscopy (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy/energy dispersive X-ray analysis (TEM/EDX) and vibration sample magnetometry (VSM) measurements prior and after uranium adsorption. The experimental adsorption data were found to be well fitted with the Langmuir isotherm and the pseudo-second order kinetic model. The results indicate that PVP/CS/OA.OA.Fe₃O₄ fibrous adsorbents exhibit good adsorption properties towards U(VI) in aqueous solutions, achieving a q_max value of 0.77 mol kg⁻¹ (183.3 mg g⁻¹) at pH 6.0. The experiments regarding the regeneration and reuse of the magnetoactive adsorbents were carried out using Na₂CO₃, at pH ~11. After four cycles, the percentage relative adsorption remained stable (~100%) whereas the desorption percentage decreased from 31.9% to 21.0%. Generally, the presented results demonstrate that the incorporation of the Fe₃O₄ NPs has a positive effect on the adsorption efficiency of U(VI) from aquatic environments.     

Subquadratic Algorithms for 3SUM

We obtain subquadratic algorithms for 3SUM on integers and rationals in several models. On a standard word RAM with w-bit words, we obtain a running time of . In the circuit RAM with one nonstandard AC ⁰ operation, we obtain . In external memory, we achieve O(n ²/(MB)), even under the standard assumption of data indivisibility. Cache-obliviously, we obtain a running time of . In all cases, our speedup is almost quadratic in the “parallelism” the model can afford, which may be the best possible. Our algorithms are Las Vegas randomized; time bounds hold in expectation, and in most cases, with high probability.     

纳米孔传感技术应用于肿瘤早期诊断的研究进展

近几十年来,尽管研究人员一直在努力开发新的诊断和治疗技术,癌症仍然是世界上发病率和死亡率最高的疾病之一。其中关键点是在肿瘤发生的早期进行诊断。现有的肿瘤早期诊断方法有很多缺点,比如对病患肿瘤组织的侵入。因此,与肿瘤相关的无创诊断的研究已经越来越多并已经取得进展。研究发现,蛋白、DNA或者RNA等生物大分子都有可能成为潜在的肿瘤标志物,已有的检测方法也存在许多缺点。纳米孔因具有独特的物理和电学性质,对生物分子的检测有快速、无需标记和扩增等优点,已被广泛使用和证明。在不远的将来,应用纳米孔对肿瘤标志物进行检测,进行肿瘤诊断并监控治疗过程值得期待。主要介绍了纳米孔传感技术应用于肿瘤早期诊断中肿瘤标志物检测的研究进展。     

生物医用材料的3D打印技术与发展

近年来,由于3D打印技术的迅猛发展,有关3D打印技术的应用受到科学界广泛关注,特别是生物医学领域。3D打印材料的瓶颈制约着3D打印技术的发展,特别是用于生物医学领域的打印材料,只有非常局限的几种,但是研究可打印生物医用材料意义重大,经济效益显著。简述了3D打印技术在生物医学工程上的应用。重点综述了用于3D打印的生物医用材料,主要涉及金属、陶瓷、高聚物、复合材料以及生物墨水等,并且阐述了3D打印材料的发展前景。     

单纯手法复位与手法复位加敏使朗口服治疗良性阵发性位置性眩晕疗效分析

目的 比较单纯手法复 位 和 手 法 复 位 加 口 服 抗 眩 晕 药 治 疗 后 半 规 管 良 性 阵 发 性 位 置 性 眩 晕（PC ？BPP V ） 的疗效。方法 将2004 年1 月～2011 年6 月期间收治的236 例 BPP V 患 者 随 机 分 为 两 组, 对 照 组 112 例采用单纯手法复位, 治疗组124 例在手法复位基础上加敏使朗口服, 两组均于治疗后1 周和3 个月时复查, 比较其疗效。结果 治疗后1 周时, 对照组和治疗组的有效率分别为86 .61 % 和89 .52 % , 治疗后3 个月时对照组有效率92 .86 % （104／112 ） , 治疗组有效率为93 .54 % （116／124 ） , 两者比较差异均无统计学意义（P ＞0 .05 ） 。结论 单纯手法复位法和手法复位加口服抗眩晕药物治疗 BPP V 疗效相当。     

A versatile access to new halogenated 7-azidocoumarins for photoaffinity labeling: Synthesis and photophysical properties

A versatile methodology for the synthesis of 6/8-halogenated 7-aminocoumarins from the corresponding 7-hydroxy analogs using Pd-catalyzed amination reaction as the key step is presented. Further readily conversion into 7-azidocoumarins was performed and the resulting aryl azides proved higher stability and reactivity than the corresponding non-halogenated parent compound. These new compounds may thus constitute attractive scaffolds for designing novel photoaffinity reagents for various challenging bio-labeling applications.     

“傲视”——基于P2P技术的实时流媒体系统

在本篇论文中介绍了一个开发成功的，基于P2P技术的实时流媒体系统——“傲视”。该系统在数据传输方式上利用了P2P的原理．即每一个用户在接收服务器数据的同时，相互之间进行一定数据交换，这一原理类似于著名的软件BitTorrent（BT）。由于在数据传榆过程中。用户之间可以相互交换数据，而并不需要一定从服务器获取数据，因此使得该系统具有两个明显的技术优势：1．降低媒体源的硬件要求。2．降低信号源的输出带宽要求。经过校内测试，利用该系统只需要普通的个人电脑（P4 1．6G，256M内存）利用学生宿舍的100M带宽的网口．就可以在校园网中对全校上百用户进行多媒体网络广播（548Kbps）。实现学生个人电台、个人电视台功能。     

Multilevel optimization algorithms in computer aided production control in process industry

The use of optimization techniques in production control is discussed. Two optimization problems in relation to typical process industry complexes are formulated. A modified version of Tamura's algorithm is reviewed. The promising performance of the computerised algorithms is illustrated by numerical results. DISPATCHER, a practical operative decision support system, is described.