橡胶粒子和刚性纳米粒子对注塑级硬质聚氯乙烯复合材料断裂行为的影响

采用核壳型丙烯腈-苯乙烯-丁二烯共聚物(ABS)和纳米碳酸钙(CaCO3)协同改性聚氯乙烯(PVC),制备了注塑级硬质PVC纳米复合材料.通过透射电镜(TEM)、扫描电镜(SEM)、力学性能测试研究了其结构与性能,并采用有限元模拟方法研究了ABS与纳米CaCO3粒子对复合材料断裂行为的影响.当CaCO3含量低于12 p...     

Mg/Al型水滑石吸附硼的实验研究

采用共沉淀法制备了几种不同摩尔比的镁铝水滑石(LDHs),并对其进行了XRD、FT-IR表征.将其应用于吸附溶液中的硼,比较了它们对硼的吸附容量,最终选择了具有较高吸附容量的Mg4Al-LDH作为硼吸附荆.对Mg4Al-LDH吸附硼的实验条件进行了系统研究,得到了较高吸附容量下的实验条件.试验结果表明该等温吸附过程可用Langmuir吸附等温模型准确描述.     

The influence of temperature on crosshatching

The influence of temperature on crosshatching on ablating cone models made of wax and camphor is studied. Ablation experiments are carried out in supersonic tunnels. The relation between temperature and the wavelength of crosshatching is obtained. The effect of pressure on the wavelength of crosshatching is verified. The influence of temperature and pressure on the initial position of the appearance of crosshatching and on the time required for both the apperance of croosshatching and the formation of stable crosshatching are obtained and analyzed.     

Tuning the valence of the cerium center in (Na)phthalocyaninato and porphyrinato cerium double-deckers by changing the nature of the tetrapyrrole ligands

A series of 7 cerium double-decker complexes with various tetrapyrrole ligands including porphyrinates, phthalocyaninates, and 2,3-naphthalocyaninates have been prepared by previously described methodologies and characterized with elemental analysis and a range of spectroscopic methods. The molecular structures of two heteroleptic [(na)phthalocyaninato](porphyrinato) complexes have also been determined by X-ray diffraction analysis which exhibit a slightly distorted square antiprismatic geometry with two domed ligands. Having a range of tetrapyrrole ligands with very different electronic properties, these compounds have been systematically investigated for the effects of ligands on the valence of the cerium center. On the basis of the spectroscopic (UV-vis, near-IR, IR, and Raman), electrochemical, and structural data of these compounds and compared with those of the other rare earth(III) counterparts reported earlier, it has been found that the cerium center adopts an intermediate valence in these complexes. It assumes a virtually trivalent state in cerium bis(tetra-tert-butylnaphthalocyaninate) as a result of the two electron rich naphthalocyaninato ligands, which facilitate the delocalization of electron from the ligands to the metal center. For the rest of the cerium double-deckers, the cerium center is predominantly tetravalent. The valences (3.59-3.68) have been quantified according to their L(III)-edge X-ray absorption near-edge structure (XANES) profiles.     

Coordination and reduction in polyol-mediated solvothermal synthesis of nickel-based materials with controllable morphology and magnetic and electrochemical properties

Research on Chemical Intermediates - The coordination and reduction effects in polyol-mediated solvothermal synthesis were studied using nickel acetate as model precursor and ethylene glycol...     

锂离子电池电解质的新型锂盐——双乙二酸硼酸锂

介绍了一种新型锂盐--双乙二酸硼酸锂(LiBOB)的基本性质及制备进展,并重点综述了其在锂电中应用的有关研究,包括基于LiBOB电解液的导电性研究,对负极材料、正极材料的稳定性研究,与其他锂盐在锂离子电池中混合使用的性能研究等.     

Metabonomics analysis of semen euphorbiae and semen Euphorbiae Pulveratum using UPLC–Q-TOF/MS

Semen Euphorbiae (SE), the dry and mature seed of Euphorbia lathyris L., a common traditional Chinese medicine, has significant pharmacological activity. However, its toxicity limits its clinical application, and less toxic Semen Euphorbiae Pulveratum (SEP) is often used clinically. To explore the possible mechanism of SE frost-making and attenuation, this study used ultrahigh-performance liquid chromatography coupled with quadrupole time of flight mass spectrometry to perform a comprehensive metabolomics analysis of serum and urine samples from rats treated with SE and SEP, and performed histopathological evaluation of liver, kidney and colon tissues. Meanwhile, the different metabolites were visualized through multivariate statistical analysis and the HMDB and KEGG databases were used to distinguish the differential metabolites of SE and SEP to reveal related metabolic pathways and their significance. In total, 32 potential biomarkers, 14 in serum and 18 in urine, were identified. The metabolic pathway analysis revealed that arachidonic acid metabolism, sphingolipid metabolism, tyrosine and tryptophan biosynthesis, the tricarboxylic acid cycle and seven other metabolic pathways were significantly altered. Importantly, compared with SE, SEP reduced the metabolic disorder related to endogenous components. The mechanism may be related to the regulation of lipid metabolism, intestinal flora metabolites, amino acid metabolism and energy metabolism. This study provided new insights into the possible mechanism of SE freezing and attenuation.     

Determination of ginsenoside Rh3 in rat plasma by LC–MS/MS and its application to a pharmacokinetic study

Ginsenoside Rh3 (GRh3) is a bacterial metabolite of ginsenoside Rg5, which is the main component of hot-processed ginseng. A simple, efficient and sensitive method was developed and validated for the determination of GRh3 in rat plasma by LC–tandem mass spectrometry. After protein precipitation with methanol/acetonitrile (1:1, vol/vol) using propranolol as the internal standard, the target analytes were separated on an XDB C₁₈ column, with methanol containing 0.1% formic acid and water containing 0.1% formic acid used as mobile phases for gradient elution. Mass spectrometry was performed in electrospray ion source–positive ion mode and multiple reaction monitoring mode, monitoring the transitions m/z 622.5 → 425.5 and m/z 260.1 → 116.1 for GRh3 and internal standard, respectively. The concentration range of GRh3 was 20–20,000 ng/mL and the correlation coefficient (r²) was greater than 0.99. The accuracy error and relative standard deviation were below 15%. The extraction recovery and matrix effect were 74.2% to 78.7% and 96.9% to 108.4%, respectively. Under different conditions, GRh3 was stable in the range of 1.8%–8.7%. This method has been successfully applied to study the pharmacokinetics of GRh3 with an oral dose of 10.0 mg/kg and an intravenous dose of 2.0 mg/kg in rats, respectively. The absolute bioavailability of GRh3 was 37.6%.     

The first slipped pseudo-quadruple-decker complex of phthalocyanines

The first slipped pseudo-quadruple-decker complex of phthalocyanines was formed unexpectedly upon treatment of the protonated double-decker SmIIIH(Pc)[Pc(alpha-OC4H9)8] with NaOH. The supramolecular structure contains two double-decker units linked by two sodium ions by an extremely rare coordination mode of phthalocyanines in which an aza nitrogen atom and two oxygen atoms from neighboring alkoxy substituents form a tridentate ligand.