Polymer hydrogel cross-linked by inorganic nanoparticles for removing trace metal ions

Hydrogels for absorbing metal ions in wastewater have attracted more attentions in the environmental field especially for recent years. The removal efficiency of hydrogel adsorbents for eliminating metal ions is highly related with the effective contact between adsorbents and adsorbates. However, poor water absorption capacity of the hydrogel adsorbents would restrict on the expose of adsorption sites to the targeted subjects, causing undesirable removal ratio (RR) especially for metal ions at trace level. Thereby, the reported hydrogel adsorbents mainly focus on the removal of high content but not the trace level of metal ions so far. In this work, poly(acrylamide) (PAM)/poly(acrylic acid) (PAA)/Ca(OH)₂ composite hydrogel is applied to adsorb trace metal ions. Swelling ratio of such PAM/PAA/Ca(OH)₂ gel reaches 2,530 g/g, resulting in effective exposure of active sites and further expected RR for trace metal ions. The RRs of such adsorbent for Cu²⁺ (initial concentration C₀ = 0.064 mg/L), Al³⁺ (C₀ = 0.27 mg/L), Co²⁺ (C₀ = 0.59 mg/L), Cr⁶⁺ (C₀ = 0.52 mg/L), Mn²⁺ (C₀ = 0.55 mg/L), Ni²⁺ (C₀ = 0.59 mg/L), Zn²⁺ (C₀ = 0.65 mg/L), Ag⁺ (C₀ = 1.08 mg/L), and La³⁺ (C₀ = 1.39 mg/L) are 56.6, 80.8, 41.3, 29.3, 34.6, 44.6, 55.9, 45.8, and 35.5%, respectively. This work broadens the application of hydrogel adsorbent for eliminating trace metal ions from polluted water.     

Unveiling the role of Fe3O4in polymer spin valve near Verwey transition

The spinterface formed between ferromagnetic(FM)electrode and organic materials is vital for performance optimization in organic spin valve(OSV).Half-metallic Fe₃O₄with drastic change in structure,conductivity and magnetic property near Verwey transition can serve as an intrinsic spinterface regulator.However,such modulating effect of Fe₃O₄in OSV has not been comprehensively investigated,especially below the Verwey transition temperature(Tv).Here,we highlight the important role of Fe₃O₄electrode in reliable-working and controllable Fe₃O₄/P3HT/Co polymer spin valves by investigating the magnetoresistance(MR)above and below 7V.In order to distinguish between different contributions to charge transport and related MR responses,the systematic electronic and magnetic characterizations were carried out in full temperature range.Particularly,the first-order metal-insulator transition in Fe₃O₄has a dramatic effect on the MR enhancement of polymer spin valves at 7V.Moreover,both the conducting mode transformation and MR line shape modulation could be accomplished across 7V.This research renders unique scenario to multimodal storage by external thermodynamic parameters,and further reveals the importance of spin-dependent interfacial modification in polymer spin valves.     

空间红外大口径折射式低温镜头设计与验证

针对目标探测类空间红外相机大范围成像、高灵敏度探测、高精度定位等应用需求,文中提出采用像方远心光路和低温光学技术结合的解决方案,设计了物方视场角8°×8°、入瞳口径265 mm、工作温度200 K的像方远心折射式光学系统。镜头最大口径280 mm,采用多级分散的弹性支撑设计,解决大口径低温透镜装框、透镜组件支撑和镜头整体安装各环节的热应力卸载问题。在保证高刚度和低漏热的情况下,使低温下透镜的热应力对镜头能量集中度的影响降低到可接受范围内。镜头完成装调及室温下像质确认后,进行了力学振动试验,并将其制冷到200 K水平测试像质,测试结果表明,镜头能量集中度达到轴上75%,边缘视场72%。     

The Marginal Density of a TMA(1) Process

This note reconsiders the marginal density of a threshold moving average process and proposes a simple yet effective numerical algorithm to implement that by solving an associated integral equation. This algorithm can also be applied to calculate stationary probability density or distribution functions of a few other types of nonlinear stationary stochastic processes numerically.     

Synthesis of highly efficient,structurally improved Li4SiO4 sorbents for high-temperature CO2 capture

Li₄SiO₄ sorbents for high-temperature CO₂ removal have drawn extensive attention owing to their potential application in carbon capture and storage (CCS). The major challenge in the application lies in the poor CO₂ capture performance under realistic conditions of low CO₂ concentrations, owing to the dense structure and poor porosity. In this work, Li₄SiO₄ sorbents were prepared with porous micromorphologies and large contact areas using a variety of organometallic Li-precursors, achieving fast CO₂ sorption kinetics, high capacity and excellent cyclic stability at a low CO₂ concentration (15?vol%). It was found that a high conversion of ~?74% was maintained for pure Li₄SiO₄ even after 100 sorption/desorption cycles. Moreover, by doping with Na₂CO₃ to reduce the CO₂ diffusion resistance, the conversion of the sorbent was further enhanced to 93.2%. The enhancement mechanism of alkali carbonate have been proven here to be ascribed to the formation of the eutectic melt of Li/Na carbonates, the existence and function of which has been confirmed in this study.     

IDS告警融合与关联模型的研究

入侵检测是保障网络安全的重要手段,针对现有入侵检测系统中告警数量多、协调性差等问题,论文提出了一种具有告警融合与关联功能的告警处理系统模型,该模型冗余告警量少、整体检测能力强,并能进行攻击企图的预测,能有效提高入侵检测的效率,有助于进一步增强网络的健壮性。     

Growth Defects in Langasite Crystals Observed with White Beam Synchrotron Radiation Topography

Langasite single crystal was grown by the Czochralski method and its perfection was assessed by white beam synchrotron radiation topography. It is found that the growth core and the growth striations are the primary growth defects and they show strong X-ray kinematical contrast in the topographs. Another typical defect in LGS crystal is dislocation. The formation mechanisms of these growth defects in LGS crystals were discussed.     

人工颅骨用复合材料中微量甲基丙烯酸甲酯的气相色谱法测定

采用氢气焰离子化检测器(FID),以正丁醇为外标物,PEG-20M为固定相,甲醇作为溶剂,气相色谱法测定复合材料人工颅骨中微量MMA的含量。其相对标准偏差<0.022,平均回收率(n=4)为98.0％～99.1％。此方法操作简便,用于实际样品分析可得到满意的结果。     

DS90C363/DS90CF364 LVDS发送/接收器在数字RGB液晶屏上的应用

通过在FPD铁路上使用LVDS技术可使具有数字RGB接口的液晶显示屏的工作距离大大增加。文章通过一个具体应用环境介绍了21位LVDS发送器/接收器DS90C363/DS90CF364传输套片的主要特性、引脚功能、工作原理，同时指出了在具体设计使用时的注意事项。     

3-N-丙酰基-2-芳基-5-(3-碘苯基)-1,3,4-(噁)唑啉类化合物的合成及表征

以3-碘苯甲酸为原料，在浓硫酸作用下与乙醇反应制得3-碘苯甲酸乙酯（1），再以无水乙醇为溶剂，在105℃化合物1与80％的水合肼反应8h，制得3-碘苯甲酰肼（2）。在无水乙醇中，在90～95℃化合物2分别与4-甲基苯甲醛、2-氯苯甲醛、4-氯苯甲醛、4-羟基苯甲醛、2，4-二氯苯甲醛、4-甲氧基苯甲醛、3-硝基苯甲醛、4-硝基苯甲醛和4-二甲氨基苯甲醛反应得到相应的酰腙E3（a～i）]。最后化合物3（a～i）分别与丙酸酐脱水环化成了3-M丙酰基-2-芳基-5-（3-碘苯基）-1，3，4-噁唑啉类化合物E4（a～i）]，收率分别为86．2％，70．5％，80．1％，68．2％，62．4％，75．2％，73．2％，70．5％和63．2％。并通过元素分析，IR，^1H NMR和MS对化合物4（a～i）的结构进行了表征。