海蛎壳粉废弃物负载CuCl_2作为高效、廉价以及可回收催化剂合成炔胺类化合物(英文)

发展了一种经济、简单的海蛎壳粉负载的CuCl2异相催化剂OSP-CuCl2,用来催化醛-炔-胺之间的A3偶联反应.OSP-CuCl2容易通过简单的方法从海蛎壳粉以及CuCl2制备,且显示出高的催化活性以及良好的可循环回收性.在微波辅助以及无溶剂条件下,以OSP-CuCl2为催化剂,能够以高产物收率制备出一系列炔胺类化合物.OSP-CuCl2可通过简单的过滤方式进行回收,并至少可循环使用6次.初步放大实验表明,炔胺类化合物能够以150 mmol的规模制备(87%收率).     

Two-Step Structure Phase Transition,Dielectric Anomalies,and Thermochromic Luminescence Behavior in a Direct Band Gap 2D Corrugated Layer Lead Chloride Hybrid of [(CH3)4N]4Pb3Cl10

A direct band gap 2D corrugated layer lead chloride hybrid, [(CH₃)₄N]₄Pb₃Cl₁₀ ( 1 ), shows analogous topology to the {Mg₃F₁₀⁴⁻}_∞ layer in Cs₄Mg₃F₁₀, and with the (CH₃)₄N⁺ cations locating in the inorganic layer voids and between the interlayers. Two reversible structural phase transitions occur in 1 at 225/210 K and 328/325 K upon heating/cooling, respectively. On going from the low- to intermediate-temperature phase, the space group changes from P2₁/c to Cmca, and the crystallographic axis perpendicular to the layers is doubled with the order–disorder transformation of (CH₃)₄N ⁺ cations between the interlayers. The intermediate- and high-temperature phases are isomorphic with similar cell parameters and packing structure; their main difference concerns the disorder degree of the (CH₃)₄N ⁺ cations between the interlayers. The two-step structural phase transitions lead to dielectric anomalies around the corresponding T_c. Interestingly, 1 shows multiband emission, originating from the recombination of exciton and emission of defects. Moreover, 1 exhibits divergent thermochromic luminescent features around the T_c on the intermediate to low temperature transition.     

False Detection of Cyanide Ion in Photographic Processing Waste Solutions Using Standardized Reference Methods

Abstract

Although cyanide compounds are not incorporated in photographic processing solutions, false detection of cyanide ion is often encountered during the determination of total cyanide by various standardized methods such as ISO, ANSI and JIS. Various organic compounds and nitrogen compounds in the processing solutions were examined because of this false detection. The results suggest that hydrogen cyanide is formed by a reaction between these compounds during the distillation process for the separation of total cyanide, even though ISO, ANSI and JIS were used. The results support the following three mechanisms of cyanide formation involved in the process: (1) Hydroxylammonium salts reacts with another ingredient, formaldehyde, to form formaldoxime, which then decomposes to HCN. (2) Hydroxylammonium is oxidized by air to form nitrite ion, which subsequently reacts with organic compounds such as aminocarboxylic acids and aromatic amines (the colour-developing agent) to form HCN. (3) Potassium permanganate oxidizes aromatic amines to form HCN.     

Chemists around the World,Take Your Part in the Circular Economy!

Based on recent examples and initiatives reported in the literature, this concept article discusses how chemistry can contribute to the circular economy approach in order to improve our current and future economical, societal, and environmental system. Through five proposed levels of contribution, chemists can take a significant part in this global approach via the consideration of green chemistry principles, the simplification of syntheses, the limitation of complex products preparation, the efficient utilization of resources but also the novel ways of waste valorization. A more systematic and generalized environmental and economic assessment from the lab-scale is also recommended. At last, chemists have to work even more collaboratively and in a multidisciplinary way, within chemistry and beyond.     

陶瓷细骨料替代方式对混凝土抗压强度的影响

为了提高废弃陶瓷在混凝土中的利用率，将废弃陶瓷破碎、筛分加工成人工细骨料，按不同比例(10%，20%，30%，40%及50%)，且分别采用“C”替代法(即传统替代方式，要求陶瓷细骨料细度模数与天然河砂细度模数相近即可，等质量取代)、“P”替代法(陶瓷细骨料一对一平均替代对应的不同粒径的天然河砂)、“D”替代法(陶瓷细骨料一对一且仅替代粒径为1.18，2.36和4.75mm粒径相对较大的天然河砂)及“X”替代法(陶瓷细骨料一对一且仅替代粒径为0.15，0.3和0.6mm粒径相对较小的天然河砂)取代天然河砂，制备陶瓷细骨料混凝土.共设计21组混凝土，包括基准混凝土1组，“C”，“P”，“D”及“X”替代法各5组.水胶比均为0.49，进行混凝土28d的抗压强度试验.结果表明:在水胶比为0.49的条件下，陶瓷细骨料掺量不大于50%时，陶瓷细骨料混凝土抗压强度和基准混凝土为同一强度等级，均到达C30强度等级要求；不同的替代方式，对应的陶瓷细骨料最佳掺量不同；不同的陶瓷细骨料掺量，对应的最优替代方式不同.     

铜基载氧体与可燃固体废弃物化学链燃烧特性研究

采用机械混合法制备了铜基载氧体,利用两段式管式炉反应平台和磁悬浮热重分析仪分别研究了铜基载氧体与石墨、可燃固体废弃物典型组分及可燃固体废弃物热解气模型物CH₄的化学链燃烧特性。结果表明,机械混合法制备的Cu80Si950载氧体强度高,具有良好的转化率和循环稳定性,是实现可燃固体废弃物化学链燃烧的一种比较理想的载氧体。利用扫描电镜(SEM)、X射线衍射仪(XRD)和颗粒强度测定仪对各个反应阶段载氧体进行分析。结果表明,Cu80Si950载氧体参与反应后表面结构发生巨大改变,机械强度骤降。多次循环之后载氧体结构趋于规则均匀化,形成类似球棒形状的大孔隙率结构,强度保持不变,使得载氧体在长时间使用过程中反应性能得以维持。     

Highly Efficient Diglycolamide‐Based Task‐Specific Ionic Liquids: Synthesis,Unusual Extraction Behaviour,Irradiation, and Fluorescence Studies

Two new diglycolamide‐based task‐specific ionic liquids (DGA? TSILs) were evaluated for the extraction of actinides and lanthanides from acidic feed solutions. These DGA? TSILs were capable of exceptionally high extraction of trivalent actinide ions, such as Am³⁺, and even higher extraction of the lanthanide ion, Eu³⁺ (about 5–10 fold). Dilution of the DGA? TSILs in an ionic liquid, C₄mim⁺ ? NTf₂^?, afforded reasonably high extraction ability, faster mass transfer, and more efficient stripping of the metal ion. The nature of the extracted species was studied by slope analysis, which showed that the extracted species contained one NO₃^? anion, along with the participation of two DGA? TSIL molecules. Time‐resolved laser fluorescence spectroscopy (TRLFS) analysis showed a strong complexation with no inner‐sphere water molecule in the Eu^III? DGA? TSIL complexes in the presence and absence of C₄mim⁺ ? NTf₂^? as the diluent. The very high radiolytic stability of DGA? TSIL 6 makes it one of the most‐efficient solvent systems for the extraction of actinides under acidic feed conditions.     

Ce4+替代Pu4+的模拟固化体(Gd1-xCex)2Zr2O7+x的合成及结构演变

Gd₂Zr₂O₇中Gd具有很大的中子吸收截面, 其烧绿石结构-缺陷萤石结构的转变能较低, 使其成为理想的核废料固化基材. 使用硝酸盐为原料, 添加少量NaF作助熔剂, 在较低温度下(和传统高温固相反应相比), 合成了烧绿石型Gd₂Zr₂O₇. 以Ce⁴⁺模拟Pu⁴⁺, 研究了Gd₂Zr₂O₇对锕系核素的固化, 并合成了系列模拟固化体(Gd_1-xCe_x)₂Zr₂O_7+x (0≤x≤0.6). 采用粉末X射线衍射(XRD)对系列样品进行了表征. 结果表明: 随着x值的增大,样品从烧绿石结构向缺陷萤石结构转变, 且晶胞大小基本保持恒定, 但当x=0.6时, 衍射峰明显宽化, 晶格畸变比较严重, 晶格稳定性降低. 当x=1时, 即用Ce⁴⁺完全取代Gd³⁺进行合成, 不能得到Ce₂Zr₂O₈, 产物发生了相分离, 为四方结构的(Zr_0.88Ce_0.12)O₂和萤石结构的(Ce_0.75Zr_0.25)O₂的混合物. 模拟固化体的浸出率测试表明: 当x≤0.2时, 各元素浸出率均很低, 但当x≥0.4时, 各元素的浸出率明显升高, 说明以Gd₂Zr₂O₇作为固化Pu⁴⁺的基材, Pu⁴⁺掺入量不宜高于40%.     

Ash and Slag Waste as a Secondary Raw Material

In the process of industrial corporation activities a lot of waste, which pollutes the atmosphere, is generated, for example ash and slag. In Tomsk region, by estimates, ash stores occupy about 600 hectares, which contain about 25 million tons by weight. In Russian thermal power-stations ash disposal areas there are about 1.3 billion tons of ash, and only 10% of it is used. That is why this problem is topical enough. In this paper the scheme of producing ash ceramic bricks and complex ash and slag waste processing is shown. Besides, profitability of the project is presented.