查找使用阿拉丁产品的科研文献

An Evaluation of Acute Hydrogen Sulfide Poisoning in Rats through Serum Metabolomics Based on Gas Chromatography-Mass Spectrometry

Meiling Zhang,Mingjie Deng,Jianshe Ma,Xianqin Wang

Hydrogen sulfide (H2S) is the second leading cause of toxin-related deaths in the operational site. Its main target organs of toxic effects are the central nervous system and respiratory system. In this study, we developed a serum metabonomic method, based on gas chromatography-mass spectrometry (GC/MS), to evaluate the effect of acute poisoning by hydrogen sulfide on rats. Pattern recognition analysis, including both principal component analysis (PCA) and partial least squares-discriminate analysis (PLS-DA), revealed that acute hydrogen sulfide poisoning induced metabolic perturbations. Compared to the control group, the level of urea, glucose, glyceryl stearate in rat serum of the poisoning group increased after two hours, and the level of glucose, docosahexaenoic acid, glyceryl stearate and arachidonic acid in rat serum of the poisoning group increased after 48 h, while the l-valine, galactose, l-tyrosine levels decreased. Our results indicate that metabonomic methods based on GC/MS may be useful to elucidate acute hydrogen sulfide poisoning through the exploration of biomarkers.

Lead-Free CsCu2I3 Perovskite Nanostructured Networks Gas Sensor for Selective Detection of Trace Nitrogen Dioxide at Room Temperature

Xia Sun,Jie Yang,Zhilin Wu,Gang Meng,Xuezheng Guo,Delin Kuang,Lian Xiong,Weijie Qu,Xiaodong Fang,Xi Yang,Xiaosheng Tang,Yong He

A Facile Method for the Synthesis of Porous ZnO Hollow Microspheres and Their Gas Sensing Properties for Acetone

Xiang Di,Lin Huiming,Ma Jie,Chen Xiang,Jiang Jingjie,Qu Fengyu

In order to enrich the variety of zinc oxide (ZnO), well-defined porous ZnO hollow microspheres (PZHM) by a mass of nanoparticles were successfully synthesized through a simple solvothermal method. Zinc acetate and 1,2-propylene glycol was used as zinc source and solvent respectively to fabricate PZHM without the assistance of any surfactant. Upon changing the amount of zinc acetate and 1,2-propylene glycol, the morphology of the samples could be adjusted. PZHM, with 1–2 μm in diameter and 200–300 nm in wall thickness, were found to be composed of nanoparticles that assembles to form the large surface area and highly porous samples. Gas sensing performances of the ZnO hollow spheres have been investigated, showing high sensitivity (S = 180 at 1000 ppm), low detection limit (1 ppm), fast response/recovery (8/9 s), and very good selectivity.

Gas–solid two-phase flow (GSF) mechanochemical synthesis of dual-metal–organic frameworks and research on electrochemical properties

Jun Zhao,Bo Jin,Rufang Peng

As an alternative approach for conventional mechanochemical synthesis, a novel gas–solid two-phase flow (GSF) synthetic technique for the mechanochemical synthesis of dual metal–organic frameworks (DMOFs) was reported for the first time. The prepared CoMn2(BTC)2 was characterized by FT-IR, DTA, TG/DTG, and XRD studies. The results indicated that CoMn2(BTC)2 (BTC = 1,3,5-benzenetricarboxylate) was successfully synthesized after 10 min at a rate of 60 kg h−1. CoMn2O4 microspheres were also prepared via the CoMn2(BTC)2 precursor method and characterized using FT-IR, XPS, XRD, SEM, EDS, and BET methods. The electrochemical properties of the as-prepared CoMn2O4 were investigated, and the GSF results showed that the microsphere electrodes of CoMn2O4 had a high specific capacitance (969 F g−1) at a current density of 1 A g−1 in 3 M aqueous KOH solution.

Engineering α-MoC1–x through Gradient Si/Al Ratios of Zeolite Supports for Efficient Water–Gas Shift Reaction

Wenting Zhou,Yongkang Huang,Xiaofeng Gao,Zixuan Ma,Ziyu Song,Lili Lin,Ding Ma,Siyu Yao

Pt/α-MoC catalysts, synthesized by supporting platinum on α-phase molybdenum carbide (α-MoC), have emerged as promising candidates for the low-temperature water–gas shift reaction (WGSR) due to their high catalytic activity. However, their performance is often limited by insufficient density of active Pt–Mo interfacial sites and inadequate stability under reaction conditions. In this study, a ternary Pt/α-MoC/MFI catalyst was constructed by incorporating MFI-type zeolites with varying Si/Al ratios as a support component. Comprehensive characterization revealed that modulating the Si/Al ratio of the zeolite support alters the carburization process, with silica-rich supports promoting the formation of a more optimal molybdenum carbide structure and effectively suppressing carbon deposition during reaction. In addition, the use of high-silica supports increased the number of active Pt–Mo interfacial sites and enhanced key steps such as water dissociation and –OH group conversion. Consequently, the Pt/α-MoC/S-1 catalyst─synthesized using purely siliceous S-1 zeolite as the support─exhibited the highest intrinsic activity of 7.4 molCO/molPt/s at 523 K, outperforming all other zeolite-supported Pt/α-MoC catalysts as well as the bulk Pt/α-MoC catalyst.

Getting insights into gas-phase sulfation effect on catalytic performance of praseodymium oxides in NH3-SCR of NO

Yandi Cai,Peng Yang,Qinglong Liu,Kaili Ma,Wenxin Ma,Wang Song,Qiuhui Qian,Fei Gao,Wei Tan,Lin Dong

Sulfation treatment has been widely used to promote the catalytic performance of ceria (CeO 2 ) based catalysts for the selective catalytic reduction of NO by NH 3 (NH 3 -SCR of NO). Praseodymium oxide (PrO x ), another commonly used rare earth material with similar structural properties as CeO 2 , also shows satisfactory redox properties due to the facile redox cycle of Pr 3+ ↔ Pr 4+ . In this work, gas phase sulfation treatment with varied duration was performed on PrO x at 200 °C, and the NH 3 -SCR activity of sulfated PrO x was evaluated. Based on the results of systematic characterizations (e.g., N 2 -physisorption, NH 3 oxidation , NO oxidation, in situ diffuse Fourier transform infrared spectroscopy), it is revealed that the catalytic performance of sulfated PrO x is highly dependent on the sulfation time (or the amount of sulfate species deposited on PrO x ), which has a significant impact on the competitive reaction between NH 3 oxidation and NH 3 -SCR of NO, thus determining the NH 3 -SCR activity of PrO x . This work provides new insight into tuning the interaction between PrO x surface and reactants (NO, NH 3 ) via sulfation treatment, which cam guide the design and application of PrO x based catalysts for NH 3 -SCR of NO in the future.

Monodisperse ZnFe2O4 nanospheres synthesized by a nonaqueous route for a highly slective low-ppm-level toluene gas sensor

Chengjun Dong,Xu Liu,Xuechun Xiao,Shangfeng Du,Yude Wang

Monodisperse ZnFe 2 O 4 nanospheres were succesuffully synthesized via a nonaqueous route in benzyl alcohol at low temperaure of 200   °C. It was found that the ZnFe 2 O 4 is 7–16   nm in diameter with a large surface area of 87.40   m 2 /g. The gas sensor based on ZnFe 2 O 4 nanospheres shows a high pontential for detecting low-ppm-level toluene, exhibiting a good linearity ranging from 1 to 100   ppm with a high response (100   ppm:9.98) and excellent selectivity.

Tannic Acid/Polyvinyl Alcohol as a Wellbore Strengthener for Water-Based Drilling Fluid in Natural Gas Hydrate Reservoir

Xing Xing Wang,Guan Cheng Jiang,Guo Shuai Wang,Li Li Yang,Yin Bo He,Xiao Ya Wu

In South China Sea, the natural gas hydrates are usually reserved in argillaceous siltstones. These argillaceous siltstones are weakly cemented and incorporated with the solid hydrates. During the drilling process, the natural gas hydrates may decompose unexpectedly, resulting in the wellbore collapse. To improve the stability of the wellbore, this study develops a wellbore strengthener for water-based drilling fluids used in argillaceous siltstones. Tannic acid/polyvinyl (TA/PVA) alcohol has been adopted for preparing the wellbore stabilizer. A series of experiments have been conducted to investigate the effects of newly developed wellbore strengthener on the mechanical properties of the argillaceous siltstones as well as its mechanisms on the wellbore stability. The experimental results show that the wellbore strengthener developed in this study can significantly improve the compressive strengths of the argillaceous siltstone cores. The AFM characterizations indicate that the adhesion force between the silica (the major compound in argillaceous siltstones) microspheres and the wellbore strengthener can reach up to 2138 nN. Moreover, the SEM images visually show good cementation of the argillaceous siltstones after being treated by the wellbore strengthener. In addition, the wellbore strengthener can also assist in reducing the fluid losses of water-based drilling fluids. It is hopeful that the wellbore strengthener provided in this study help the development of underwater natural gas hydrates.

Gas Chromaotography-Mass Spectrometry Analysis of Insecticidal Essential Oil Derived from Chinese Ainsliaea fragrans Champ ex Benth (Compositae)

MP Zhao,XC Liu,QZ Liu,ZL Liu

Heterogeneous electro-Fenton catalysis with self-supporting CFP@MnO2-Fe3O4/C cathode for shale gas fracturing flowback wastewater

Pei Dong,Xi Chen,Meiting Guo,Zhiyuan Wu,Haolong Wang,Feifei Lin,Jinqiang Zhang,Shuaijun Wang,Chaocheng Zhao,Hongqi Sun

Self-supporting electrodes have triggered great interests in improving electro-Fenton (EF) system for degradation of refractory organic pollutants . In this work, a novel self-supporting carbon fiber paper (CFP) electrode modified by transition metals, e.g. Fe and Mn, was fabricated and employed as a heterogeneous EF cathode. The prepared electrode exhibited excellent degradation for a number of typical organic pollutants along with superior stability. Remarkably, a high removal efficiency was achieved in the EF treatment of shale gas fracturing flowback wastewater. Results indicated that 65.2% TOC and 74.8% COD were eliminated after 4 h degradation. The residual COD value of the real wastewater was 80 mg L −1 , meeting the emission requirement of the integrated wastewater discharge standard (COD   ＜   100 mg L −1 ) with a low specific energy consumption of 6.9   kWh   kg −1   COD −1 . This work demonstrates a competing alternative for efficient decontamination of real wastewater using an electro-Fenton strategy with a low-cost electrode.

Molecularly imprinted solid-phase extraction coupled with gas chromatography for the determination of four chloroacetamide herbicides in soil

Yan Wang,Xiaoyang Jin,Dan Zhao,Xiaohong Guo,Ranhong Li

A molecularly imprinted solid phase extraction (MISPE) coupled with gas chromatography (GC) for the simultaneous separation and determination of four chloroacetamide herbicides, alachlor, acetochlor, pretilachlor and metolachlor, in soil was developed. Molecularly imprinted polymers (MIPs) with butachlor as the dummy template were synthesized via precipitation polymerization, where methacrylic acid (MAA) was used as the functional monomer, ethylene glycol dimethacrylate (EDMA) as the crosslinker and acetonitrile as the porogen. Fourier-transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM) were used to characterize the polymers. Under the optimum SPE conditions, the polymer sorbents can selectively extract and enrich alachlor, acetochlor, pretilachlor and metolachlor. A comparison experiment also showed that the MISPE cartridges were better than the nonimprinted and C18 cartridges in terms of recovery. The mean recoveries of the four chloroacetamide herbicides from blank soil spiked at 0.1, 0.5, and 1 μg mL−1 ranged between 80.6 and 90.2% with relative standard deviations (RSD) of less than 8% (n = 5). The limit of detection (LOD) and the limit of quantification (LOQ) of the four analytes were in the range of 1.0 × 10−12 to 5 × 10−11 g and 0.0005–0.025 mg kg−1, respectively. The presented MISPE-GC method exhibited highly selective separation and enrichment of trace chloroacetamide herbicides and could be potentially applied to the determination of chloroacetamide herbicides in soil.

Fabrication and property evaluation of calcium-oxide-loaded microcapsules during supplemental heat-based exploitation of natural gas hydrates

Jintang Wang,Zihua Shao,Yujing Bai,Guolei He,Xudong Wang,Lei Liu,Bo Liao,Xiaohui Sun,Kaihe Lv,Jinsheng Sun

The exploitation of natural gas hydrates (NGHs) by traditional methods is far lower than the commercial target. Calcium oxide (CaO)-based in situ supplemental heat combined with depressurization is a novel method for effectively exploiting NGHs. In this study, we propose an in situ supplemental heat method with the sustained-release CaO-loaded microcapsules coated with polysaccharide film. The modified CaO-loaded microcapsules were coated with polysaccharide films using covalent layer-by-layer self-assembly and wet modification process, with (3-aminopropyl) trimethoxysilane as the coupling agent and modified cellulose and chitosan as the shell materials. Microstructural characterization and elemental analysis of the microcapsules verified the change in the surface composition during the fabrication process. We found that the overall particle size distribution was within the range of 1–100 μm, corresponding to the particle size distribution in the reservoir. Furthermore, the sustained-release microcapsules exhibit controllable exothermic behavior. The decomposition rates of the NGHs under the effect of CaO and CaO-loaded microcapsules coated with one and three layers of polysaccharide films were 36.2, 17.7, and 11.1 mmol h−1, respectively, while the exothermic time values were 0.16, 1.18, and 6.68 h, respectively. Finally, we propose an application method based on sustained-release CaO-loaded microcapsules used for the supplemental heat-based exploitation of NGHs.