预热处理对褐煤热解过程氧元素迁移的影响

以中国呼伦贝尔褐煤为原料,基于工业分析、元素分析、傅里叶变换红外光谱、气相色谱-质谱联用分析,考察140-230℃预热处理对褐煤650℃等温热解氧迁移的影响。结果表明,与未经预热处理的干煤热解相比,褐煤经200℃预热处理后热解,迁移至热解水和半焦中的氧分别下降7.55%和1.43%,迁移至焦油和气体中的氧分别增加6.66%和1.61%,焦油中酚类氧增加一倍。褐煤预热过程中氢键的减少与热解焦油中正己烷可溶物所含酚类化合物的增加,经原位红外漫反射光谱分析,发现源自OH…π、OH…N和羟基自缔合氢键在预热过程中断裂形成自由OH·,导致酚类化合物中苯酚和甲酚含量增加。     

Reprint of: Recent advances in the functionalization of allenes via radical process

This review is focused on the recent advances in the functionalization of allenes via radical process. Different radical partners including carbon radicals and heteroatom radicals are discussed in the reactions of allenes. Generally, the radical formed in situ would attack the allene at the central carbon leading to allyl radical intermediate. However, the formation of alkenyl radical intermediate from allene could be observed as well in some cases with high regioselectivity and stereoselectivity.     

Tofu-inspired microcarriers from droplet microfluidics for drug delivery

Microcarriers have attracted increasing interests in drug delivery. In order to develop this technique, it is prone to focus on the generation of functional particles through using simple approaches and novel but accessible materials. Here, inspired by the formation mechanism of tofu that through the mixing of soymilk and brine for cross-linking soybean proteins, we present novel soybean protein microcarriers by using microfluidic generation approach for drug delivery. Since the soybean protein droplets are generated by microfluidic emulsification method, the tofu microparticles present highly monodisperse and homogeneous morphologies. Because of the excellent biocompatibility of the soybean protein and the interconnected porous structures throughout the whole microparticles after freeze-drying, various kinds of drugs and active molecules could be absorbed and loaded in the microcarriers, which makes them versatile for drug delivery. It can be anticipated that the microfluidic-generated tofu microcarriers will have great potential in the biomedical field.     

Facile cyclic ammonium salt with the smallest size for high performance electric double layer capacitors

A novel cyclic ammonium salt, N,N-dimethylpyrrolidinium tetrafluoroborate (P₁₁-BF₄), was successfully synthesized for the first time. The smallest cyclic structure of P₁₁-BF₄ induced high solubility and conductivity in PC, which can easier enter the micropores of activated carbon and occupy more surface area during charge/discharge process.     

在紫外和可见光下具有高催化活性的珊瑚状金红石型二氧化钛的制备

采用溶剂热法在二乙二醇溶液中制备了珊瑚状的金红石二氧化钛(Rut-dg)。扫描电子显微镜(SEM)和X射线衍射(XRD)表明样品呈均匀分散的球形颗粒,直径约为1μm,表面具有珊瑚状的突起结构,半径约10 nm。氮气吸附-脱附结果表明样品比表面达到228 m2·g-1,是商品金红石的7倍多。由于其特殊的形貌,Rut-dg在紫外光下的催化产氢量达到25 000μmol·g-1·h-1,比P25高出50%,是商品金红石活性的13倍。在可见光下的产氢量为270μmol·g-1·h-1,而P25和商品金红石则没有明显活性。进一步实验表明,Rut-dg样品表面检测不到可能引起活性增加的有机杂质存在,因此,珊瑚状的形貌是影响活性的重要因素。样品在300℃焙烧后,珊瑚状表面结构明显烧结,比表面下降了50%,导致产氢量下降了15%～25%,这也说明珊瑚状结构大大促进了光催化产氢活性的提高。     

新型6-氟-4(3H)-喹唑啉酮类Schiff碱的合成及其抑菌活性

以2-氨基-5-氟苯甲酸为起始原料，与醋酐酰化关环制得6-氟-2-甲基噁嗪-4-酮(1)； 1在80%水合肼中回流反应制得6-氟-2-甲基-3-氨基-4(3H)-喹唑啉酮(2)； 2分别与羟基芳醛和杂环芳醛反应合成了6个6-氟-4(3H)-喹唑啉酮类Schiff碱（3a~3f），其中3b~3f为新化合物，其结构经¹H NMR， ¹³C NMR， IR和元素分析表征。采用琼脂扩散法研究了3a~3f对大肠杆菌、金黄色葡萄球菌和枯草杆菌的抑制活性。结果表明：用药浓度为400 μg·mL^-1时，3a~3f对受试菌种均有一定的抑制活性，其中6-氟-2-甲基-3-(4-吡咯苯亚甲氨基)-4(3H)-喹唑啉酮(3c)抑菌活性最强，对大肠杆菌和枯草杆菌的抑菌圈直径分别为9.38 mm和9.00 mm。     

聚电解质型正渗透汲取液

聚电解质作为正渗透汲取液具有渗透压高、溶质反向渗透、易于回收等特点,符合理想正渗透汲取液的要求。此外,多种分离方法诸如纳滤、超滤和热处理可用于其回收,使得聚电解质型汲取液成为诸如氯化钠等的传统无机汲取液的理想代替物。近年来关于聚电解质型汲取液的研究日益增加,而聚电解质型汲取液较无机型汲取液有许多独特的性质,应对相关研究进展予以总结。本文以聚电解质的化学结构分类对其研究进展进行了概述。重点总结了不同种类聚电解质的分子量、渗透压、黏度等性质,以及正渗透过程的水通量及溶质反向渗透情况,同时还介绍了相应的正渗透机理。最后,探讨和总结了各类汲取液的特点,并展望了未来的研究方向。     

理工科专业基础核心课程思政教学实践——以化工原理课程为例

The principles of chemical engineering is the foundation of chemical engineering professional core courses. This article introduces the goal and content of course Ideology and politics for principles of chemical engineering course. Ideological education has been carried out on the teachers' quality, knowledge, cases, historical personages, and teaching practice to provide reference for education in science and engineering course.     

New Type of Columnar Liquid Crystal Superlattice in Double-Taper Ionic Minidendrons

Wedge-shaped molecules, such as dendrons, are among the most important building blocks for directed supramolecular self-assembly. Here we present a new approach aimed at widening the range and complexity of potential mesophases by introducing double-tapered mesogens. Two series of compounds are presented, both alkali metal salts (Li, Na, Cs) of 3,4,5-tris-alkoxybenzoic acid with a second tapered tris-alkoxyaryl group attached at the end of an alkoxy chain. The double-tapered compounds all display an unusual hexagonal columnar phase consisting of one ionic and three non-ionic columns per unit cell. The cation size has an unexpectedly drastic effect on unit cell size. Unlike most columnar phases, the current phases show unusually high dimensional stability on heating, and high stiffness in spite of being 80–85 % aliphatic, attributed to their molecular topology. The described approach may lead to co-assemblies of multifunctional materials, for example, parallel p- and n-semiconducting nanowires or parallel ionic and electronic conductors.     

Targeted Construction of Amorphous MoSx with an Inherent Chain Molecular Structure for Improved Pseudocapacitive Lithium-Ion Response

Owing to low ion/electron conductivity and large volume change, transitional metal dichalcogenides (TMDs) suffer from inferior cycle stability and rate capability when used as the anode of lithium-ion batteries (LIBs). To overcome these disadvantages, amorphous molybdenum sulfide (MoS_x) nanospheres were prepared and coated with an ultrathin carbon layer through a simple one-pot reaction. Combining X-ray photoelectron spectroscopy (XPS) with theoretical calculations, MoS_x was confirmed as having a special chain molecular structure with two forms of S bonding (S²⁻ and S₂²⁻), the optimal adsorption sites of Li⁺ were located at S₂²⁻. As a result, the MoS_x electrode exhibits superior cycle and rate capacities compared with crystalline 2H-MoS₂ (e.g., delivering a high capacity of 612.4 mAh g⁻¹ after 500 cycles at 1 A g⁻¹). This is mainly attributed to more exposed active S₂²⁻ sites for Li storage, more Li⁺ transfer pathways for improved ion conductivity, and suppressed electrode structure pulverization of MoS_x derived from the inherent chain-like molecular structure. Quantitative charge storage analysis further demonstrates the improved pseudocapacitive contribution of amorphous MoS_x induced by fast reaction kinetics. Moreover, the morphology contrast after cycling demonstrates the dispersion of active materials is more uniform for MoS_x than 2H-MoS₂, suggesting the MoS_x can well accommodate the volume stress of the electrode during discharging. Through regulating the molecular structure, this work provides an effective targeted strategy to overcome the intrinsic issues of TMDs for high-performance LIBs.