A note on “A mixed integer programming model for advanced planning and scheduling (APS)”

In a recent paper, Chen and Ji [Chen, K., Ji, P., 2007. A mixed integer programming model for advanced planning and scheduling (APS). European Journal of Operational Research 181, 515–522] develop a mixed integer programming model for advanced planning and scheduling problem that considers capacity constraints and precedence relations between the operations. The orders require processing of several operations on eligible machines. The model presented in the above paper works for the case where each operation can be processed on only one machine. However, machine eligibility means that only a subset of machines are capable of processing a job and this subset may include more than one machine. We provide a general model for advanced planning and scheduling problems with machine eligibility. Our model can be used for problems where there are alternative machines that an operation can be assigned to.     

Near-infrared dyes,nanomaterials and proteins

Taking the advantage of reduced scattering and low autofluorescence background, the NIR fluorescence probes, such as fluorescence proteins, organic molecules and nanoparticles, not only hold the promise of in vivo imaging of biological processes in physiology and pathology with high signal-to-noise ratio, but also for clinical diagnosis. In this review, we provide an overview of the recent progress on NIR probes, focusing on fundamental mechanisms of NIR dyes and nanoparticles, and protein engineering strategies for NIR proteins.     

Nanodiamonds for advanced optical bioimaging and beyond

Nanodiamond (ND) has emerged as an intriguing material in recent years both industrially and in research. During the last decade, ND has furthered its way into the biomedical field, mainly due to its inherent photoluminescent properties. In parallel, the development of advanced biomedical imaging methods and techniques has faced a steep upswing, making these two a ‘perfect match’. The optical and physical properties of ND can be tuned, rendering them highly interesting as versatile biomedical imaging probes. In this short review, we will cover a few of the most recently emerged applications of NDs in biomedical imaging and contemplate on current challenges and future directions.     

Engineering nanostructures of CuO-based photocatalysts for water treatment: Current progress and future challenges

Nowadays, increasing extortions regarding environmental problems and energy scarcity have stuck the development and endurance of human society. The issue of inorganic and organic pollutants that exist in water from agricultural, domestic, and industrial activities has directed the development of advanced technologies to address the challenges of water scarcity efficiently. To solve this major issue, various scientists and researchers are looking for novel and effective technologies that can efficiently remove pollutants from wastewater. Nanoscale metal oxide materials have been proposed due to their distinctive size, physical and chemical properties along with promising applications. Cupric Oxide (CuO) is one of the most commonly used benchmark photocatalysts in photodegradation owing to the fact that they are cost-effective, non-toxic, and more efficient in absorption across a significant fraction of solar spectrum. In this review, we have summarized synthetic strategies of CuO fabrication, modification methods with applications for water treatment purposes. Moreover, an elaborative discussion on feasible strategies includes; binary and ternary heterojunction formation, Z-scheme based photocatalytic system, incorporation of rare earth/transition metal ions as dopants, and carbonaceous materials serving as a support system. The mechanistic insight inferring photo-induced charge separation and transfer, the functional reactive radical species involved in a photocatalytic reaction, have been successfully featured and examined. Finally, a conclusive remark regarding current studies and unresolved challenges related to CuO are put forth for future perspectives.     

Degradation of methylparaben by sonocatalysis using a Co–Fe magnetic carbon xerogel

The degradation of methylparaben (MP) through 20 kHz ultrasound coupled with a bimetallic Co-Fe carbon xerogel (CX/CoFe) was investigated in this work. Experiments were performed at actual power densities of 25 and 52 W/L, catalyst loadings of 12.5 and 25 mg/L, MP concentrations between 1 and 4.2 mg/L and initial pH values between 3 and 10 in ultrapure water (UPW). Matrix effects were studied in bottled water (BW) and secondary treated wastewater (WW), as well as in UPW spiked with bicarbonate, chloride or humic acid. The pseudo–first order kinetics of MP degradation increase with power and catalyst loading and decrease with MP concentration and matrix complexity; moreover, the reaction is also favored at near–neutral conditions and in the presence of dissolved oxygen. The contribution of the catalyst is synergistic to the sonochemical degradation of MP and the extent of synergy is quantified to be >45%. This effect was ascribed to the ability of CX/CoFe to catalyze the dissociation of hydrogen peroxide, formed through water sonolysis, to hydroxyl radicals. Experiments in UPW spiked with an excess of tert-butanol (radical scavenger), sodium dodecyl sulfate or sodium acetate (surfactants) led to substantially decreased rates (i.e. by about 8 times), thus implying that the liquid bulk and the gas-liquid interface are major reaction sites. The stability of CX/CoFe was shown by performing reusability cycles employing magnetic separation of the catalyst after the treatment stage. It was found that the CX/CoFe catalyst can be reused in up to four successive cycles without noteworthy variation of the overall performance of the sonocatalytic process.     

CoFe2O4/CuO活化过氧乙酸高效降解磺胺甲恶唑(英文)

利用化学沉淀法和溶胶凝胶法,通过两步法成功制备出含有尖晶石钴铁氧体和氧化铜的复合催化剂CoFe₂O₄/CuO,通过扫描电子显微镜(SEM)、X射线光电子能谱(XPS)和X射线衍射(XRD)对制备出的CoFe₂O₄/CuO进行表征,探究不同高级氧化体系对磺胺甲恶唑(SMX)去除能力,考察过氧乙酸(PAA)浓度、催化剂投加量、水体中常见干扰物质(Cl^-,HCO-3,SO₄^2-,HA)和不同自由基捕获剂对SMX去除的影响。分析结果表明CoFe₂O₄/CuO同时具有CoFe₂O₄与CuO的特征,对比单独CoFe₂O₄与CuO,CoFe₂O₄/CuO对PAA展现出极高的活化性能,在最佳反应条件下(催化剂投加量=20mg·L^-1,c(PAA)=200μ...     

Metal-Organic Frameworks for Photocatalytic Water Splitting and CO2 Reduction

Photocatalytic water splitting and carbon dioxide (CO₂) reduction provide promising solutions to global energy and environmental issues. In recent years, metal-organic frameworks (MOFs), a class of crystalline porous solids featuring well-defined and tailorable structures as well as high surface areas, have captured great interest toward photocatalytic water splitting and CO₂ reduction. In this review, the semiconductor-like behavior of MOFs is first discussed. We then summarize the recent advances in photocatalytic water splitting and CO₂ reduction over MOF-based materials and focus on the unique advantage of MOFs for clarifying the structure-property relationship in photocatalysis. In addition, some representative characterization techniques have been presented to unveil the photocatalytic kinetics and reaction intermediates in MOF-based systems. Finally, the challenges, and perspectives for future directions are proposed.     

Vacuum-UV-photolysis of aqueous solutions of citric and gallic acids

The vacuum-UV- (VUV-) photolysis of water is one of the advanced oxidation processes (AOP) based on the production of hydroxyl radicals (HO) that can be applied to the degradation of organic pollutants in aqueous systems. The kinetics of the VUV-photolyses of aqueous solutions of citric acid (1) or gallic acid (2) were investigated in the presence or absence of dissolved molecular oxygen (O₂) and under different pH conditions. In the case of 1, the rate of consumption of the substrate was faster at pH 3.4 than in alkaline solution (pH 11), whereas, in the case of 2, the variation of pH (2.5–7.5) did not affect the course of the reaction. Unexpectedly, the rates of depletion of both 1 and 2 decreased in the absence of O₂, this effect being much more pronounced in the case of 2. In order to explain these results, possible reaction pathways for the degradation of 1 and 2 are proposed, and the roles of the oxidizing (HO) and reducing (H and e_aq⁻) species produced by the VUV-photolysis of water are discussed.     

大学化学先修课程的实践与思考

中国大学先修课程是国内在基础教育阶段探索人才培养的一种新模式,同时也是高校探索通过综合评价选拔人才的途径之一。在连续3个轮次教学实践的基础上,北京师范大学第二附属中学对大学化学课程的目标定位、课程内容、实施方式以及资源建设等方面进行了系统的总结,讨论了目前大学先修课程实施过程中所面临的若干问题。