TETRAHEDRON
·
2019
·Vol. 75
·期 31
·4174-4179
·
IF 2.379
Yingying Zuo,Feng Xiong,Jing Zhao
Organic sulfur compounds have broad applications in biology, medicine and material sciences and intensive efforts have been devoted to developing mild and general C–S bond-forming methods. However, a mild, transition-metal-free, direct C–H bond functionalization method remains elusive. Here, we report the use of an internal oxidant-directing strategy to achieve this goal. The cascade reactions described here show excellent chemoselectivity and a wide substrate scope for both oxyamines and sulfenylation reagents. This study enlarges the synthesis toolbox for preparing structurally diverse sulfilimines under mild conditions.
研究领域:
有机化学
·
合成化学
·
药物化学
·
生物医学材料
·
分子生物学
✓ 已验证
DOI
高影响因子
COMBUSTION AND FLAME
·
2021
·
IF 4.185
Jizhen Zhu,Sixu Wang,Mohsin Raza,Yuan Feng,Jing Li,Yebing Mao,Liang Yu,Yong Qian,Xingcai Lu
Methanol is an attractive oxygenate increasingly used as primary fuel for dual-fuel combustion technology yielding beneficial thermal-efficiency and emissions in modern engines. As such, it is significant to fundamentally understand the autoignition behavior of methanol/diesel mixtures. This study measured the ignition delay times (IDTs) of methanol/diesel blends with different mixing ratios (30%, 50%, 70% methanol by mol.) on a heated shock tube and a heated rapid compression machine at temperatures of 650−1450 K, pressures of 6−20 bar, and equivalence ratios of 0.5, 1.0 and 2.0. The typical two-stage ignition characteristics with the negative temperature coefficient response were observed for dual-fuel mixtures. In general, both the total and first-stage IDTs decrease with the increment of pressure and equivalence ratio as well as diesel proportion in mixtures. The simulation results performed with a published detailed mechanism in conjunction with a tri-component diesel surrogate demonstrate generally good agreement with the experimental data at all test conditions. Moreover, a crossover of IDTs occurs at a higher temperature (~1500 K) for varying equivalence ratios, and experiment and simulation both exhibit a non-linear mixing effect of methanol addition on diesel ignition. Interestingly, simulation results clearly suggest a crossover (~940 K) for mixtures with varying methanol content at an intermediate-temperature, where the IDT of the mixture with a lower methanol ratio becomes longer as the temperature is higher than that of the crossover. Furthermore, brute-force sensitivity analyses assisted with reaction path analysis were conducted to gain deeper insights into the autoignition chemistry of dual-fuel mixtures, especially for the chemical interaction between both fuels during the low-temperature oxidation process . It is found that methanol hardly generates •OH, whereas •OH is mainly produced by the low-temperature reaction pathways of diesel. Thus, •OH is the bridge for both fuels during the ignition process. At the high methanol ratio, the H-abstraction of diesel is mainly via •HO 2 while CH 3 OH consumes a large percentage of •OH. Consequently, the competition between methanol and diesel for •OH radicals inhibits the overall reactivity of reaction network. In addition, the original data reported here lay a foundation for the development and validation of more accurate and robust dual-fuel kinetic schemes.
研究领域:
燃烧化学
·
燃料科学
·
化学动力学
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内燃机工程
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替代燃料技术
✓ 已验证
DOI
高影响因子
Journal of Chemistry
·
2021
·Vol. 2021
·期 1
·5685596
·
IF 2.506
Jia Ma,Jianer Wang,Yuping He,Yiwei Huang,Yejun Chen
Solvothermal reaction of 4,4’,4’-nitrilotribenzoic acid (H 3 TCA) with Ca(NO 3 ) 2 ·4H 2 O and Cd(NO 3 ) 2 ·4H 2 O successfully afforded a heterometallic compound, that is, [Cd 2 Ca(TCA) 2 (DMA) 2 (H 2 O) 3 ] n ·2n(DMA) ( 1 , DMA = N,N’-dimethylacetamide). The structure of 1 was further characterized through EA, diffraction of single crystal X-ray, and thermogravimetric analysis (TGA) together with powder X-ray diffraction (PXRD). Moreover, complex 1 ’s luminescent performance in solid state was also discussed at environmental temperature. The applications on the ischemic cerebral infarction therapy were evaluated, and the specific mechanism was investigated at the same time. Firstly, the hypersensitivity C-reactive protein (hs-CRP) content in human brain microvascular endothelial cell (HBMEC) was measured with real-time reverse transcription-polymerase chain reaction (RT-PCR). Then, interleukin-18 and interleukin-1 β content released through the HBMEC was detected with enzyme-linked immunosorbent assay (ELISA).
研究领域:
生物无机化学
·
神经药理学
·
炎症生物学
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转化医学
·
分子影像学
✓ 已验证
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Qingquan Tang,Weiyi Zhang,Jiayin Yuan,Qiang Zhao
Charged cyclic polymers, e.g. cyclic DNAs and polypeptides , play enabling roles in organisms, but their synthesis was challenging due to the well-known “polyelectrolyte effect”. To tackle the challenge, we developed a templated method to synthesize a library of imidazolium and pyridinium based cyclic poly(ionic liquid)s. Cyclic templates, cyclic polyimidazole and poly(2-pyridine), were synthesized first through ring-closure method by light-induced Diels−Alder click reaction. Through quaternization of cyclic templates followed by anion metathesis, the cyclic poly(ionic liquid)s were synthesized, which paired with varied counter anions.
研究领域:
高分子化学
·
有机合成
·
功能材料
·
离子液体
·
生物医用材料
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2020
·Vol. 45
·期 4
·5841-5851
·
IF 3.741
Zhi Ming Wang,Peng Liu,Yan Peng Cao,Feng Ye,Chao Xu,Xiao Ze Du
Summary In this study, novel Pt-IrO 2 nanofiber catalysts for oxygen evolution reaction (OER) were successfully prepared using the electrospinning method with a high-concentration precursor solution. The composition and structure of catalysts were characterized, and the electrocatalytic performance of the nanofiber catalysts in water electrolysis was investigated from various aspects such as overpotential, charge transfer resistance, and exchange current density. Special attention was paid on the effect of Pt/Ir ratio on the electrocatalytic activity of the electrospun nanofibers. The results showed that the Pt-IrO 2 nanofiber catalysts with average fiber diameters ranging from 10 to 100 nm can be successfully obtained by the electrospinning method, and the average diameter decreased with the increase of Pt content. Since a bigger amount of IrO 2 content and a thinner fiber structure are all beneficial to the electrocatalytic performance, the Pt-IrO 2 catalysts with Pt:Ir = 1:9 and Pt:Ir = 9:1 both showed better catalytic performance for OER than the commercial IrO 2 , which was also demonstrated by the lower charge transfer resistance and higher exchange current density. As a result, the overpotentials of Pt-IrO 2 catalysts with Pt:Ir = 1:9 and Pt:Ir = 9:1 are 50 mV and 32 mV lower than the overpotential of the commercial IrO 2 at 30 mA cm −2 in 0.5 M H 2 SO 4 , respectively. The electrospun Pt-IrO 2 nanofiber catalyst with proper Pt content seems to be very promising since it can not only improve the catalytic performance and the safety of PEM electrolysis cells, but also reduce the amount of more expensive Ir in catalysts.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源化学
·
催化化学
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Chunyu Xu,Yajuan Jiang,Shijie Ren,Tao Huang,Xiuyun Zhang,Guisheng Zhu,Kunpeng Jiang,Yunyun Zhao,Huarui Xu
In this paper, a facile bio-templating method is proposed to prepare NiCoP coated on amorphous carbon (NiCoP@AC) composite electrode materials with using bagasse as template and carbon source. NiCoP nanowire network arrays precursors coating on bagasse substrate with high yield were prepared via a novel synthesis strategy utilizing the toluene-water interface reaction process, which subsequently formed as NiCoP@AC composite electrode materials after phosphating process. The assembled core-shell structure attenuated the volume expansion during charging and discharging, additionally, the overall electrical conductivity of the composite was also improved owing to the characteristic of bagasse biochar. The NiCoP@AC electrode exhibited high specific capacitance (1706 F g −1 at 1 A g −1 ), outstanding rate capability (82.1 % capacity retention from 1 to 20 A g −1 ) and good cycling stability (retaining 80.0 % capacitance over 5000 cycles). In addition, bagasse biomass activated carbon (BAC) was prepared via a typical alkaline activation process for the use as negative electrode. The as-fabricated NiCoP@AC//BAC supercapacitor displayed a high energy density of 46.2 Wh kg −1 at a power density of 807.3 W kg −1 , and an excellent capacitance retention rate (88.5 % after 5000 cycles), suggesting that the as-prepared NiCoP@AC electrode materials have wide application prospects in high-performance supercapacitors.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
生物基材料
·
功能复合材料
✓ 已验证
DOI
高影响因子
Small
·
2024
·Vol. 21
·期 4
·2410657
·
IF 13
Jia Wang,De Wang,Zelin Zhao,Ganggang Chang,Wei Guo,Jun Xu,Yinyu Xiang,Junrui Li,Junsheng Li
Developing cost-effective ruthenium (Ru)-based HER electrocatalysts as alternatives to commercial Pt/C is crucial for the advancement of proton exchange membrane water electrolysis (PEMWE). However, the strong hydrogen adsorption of Ru-based catalysts restricts its activity. Herein, a strategy is reported to tune the electronic structure and improve mass transfer by implanting Ru atoms onto the (002) facet of two-dimensional zeolitic imidazolate framework-67 (Ru@ L ZIF (002) ) to optimize the d -band center ( ε d ) of Ru and the hydrogen spillover behavior. Benefiting from the ultrathin nanosheet structure and optimized ε d of Ru, the over-strong H adsorption energy is weakened and the electron/mass transfer is facilitated. Ru@ L ZIF (002) exhibits an overpotential of 9.2 mV at 10 mA cm −2 and a long-lasting stability of 35 days at 100 mA cm −2 . The mass activity and price activity of Ru@ L ZIF (002) is 2.9 and 14.7 times higher than Pt/C, respectively. More impressively, Ru@ L ZIF (002) delivers a cell voltage of 2.01 V at a high current density of 4 A cm −2 in PEMWE. The excellent long-term durability of 1200 hours operating at 4 A cm −2 with an ultralow decay rate of 7.5 × 10 −3 mV h −1 has been achieved, making it promising as a cost-effective alternative to Pt/C catalyst for PEMWE applications.
研究领域:
电催化
·
材料科学
·
能源化学
·
纳米材料
·
电化学工程
·
可持续能源技术
✓ 已验证
DOI
高影响因子
TETRAHEDRON-ASYMMETRY
·
2010
·
IF 2.625
Zhen-Wei Zhang,Gui Lu,Miao-Miao Chen,Ning Lin,Yong-Bo Li,Tamio Hayashi,Albert S.C. Chan
The first asymmetric Mannich-type reaction of methyl isocyanoacetate with N -sulfonylimines catalyzed by cinchona alkaloid derivatives yielded 2-imidazolines with high diastereoselectivities and good enantioselectivities (up to >99:1 dr and 70% ee). This reaction provided a convenient route to access various substituted 2-imidazoline-4-carboxylates and related α,β-diamino acids in high enantiomeric purities.
研究领域:
有机化学
·
药物化学
·
不对称合成
·
催化化学
·
生物有机化学
✓ 已验证
DOI
高影响因子
Journal of CO2 Utilization
·
2017
·
IF 4.292
Lijun Zhao,Haiyang Cheng,Tong Liu,Yan Li,Zhong Ying,Wenjing Yang,Weiwei Lin,Xiangchun Meng,Chengxue Wang,Fengyu Zhao
An efficient green process was developed for production of p -aminophenol (PAP) from hydrogenation of nitrobenzene (NB) over a traditional Pt/Al 2 O 3 catalyst in a reaction medium of supercritical CO 2 (scCO 2 ) and H 2 O without any additional acid catalyst involved. The combination of scCO 2 and H 2 O was confirmed to be effective for the production of PAP. The acidity, aroused by the in situ formed carbonic acid, increased with CO 2 pressure, which acted as acid catalysis during the reaction, and it can easily self-neutralize by depressurization of CO 2 , resulting in a green and a intensive process for it removed the final neutralization and salts disposal of the traditional liquid acids. Under the optimal reaction conditions, a high yield to PAP (68.9%) was achieved at the high conversion of NB (98.5%). Moreover, the results of in situ diffuse reflectance FTIR spectra revealed that CO was generated by the reverse water-gas shift reaction (CO 2 + H 2 → CO + H 2 O), it can adsorbed on the surface of Pt/Al 2 O 3 to suppress the undesired deep hydrogenation of N -phenylhydroxylamine (PHA) to aniline (AN), which also contributed to the obtained high selectivity of PAP. Therefore, the present green and efficient catalysis process will arouse the interest of researchers in the fields of the green and sustainable organic synthesis.
研究领域:
绿色化学
·
有机合成
·
催化化学
·
环境友好工艺
·
工业化学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2017
·
IF 5.401
Huiqiang Wang,Zhanfang Ma
A new strategy for signal amplification was introduced in a label-free amperometric immunoassay platform. Improvements in the signal occurred following the oxidation of glucose by glucose oxidase and catalysis by polythionine of the produced H 2 O 2 from the previous oxidation reaction. In addition, a multifunctional conductive hydrogel, polypyrrole-polythionine-gold with glucose oxidase , was synthesised with a one-pot method using pyrrole and thionine as monomers, ammonium persulfate and HAuCl 4 as co-oxidant agents, and glucose oxidase as the doping agent. Combined with the hydrogel, a label-free amperometric immunoassay for the tumour marker neuron-specific enolase (NSE) was obtained. If operated at 0 V (vs. Ag/AgCl), the sensor exhibited a wide liner range from 100 ng mL −1 to 1 pg mL −1 and ultralow detection limit of 0.65 pg mL −1 (S/N = 3). The presented method was further used for the analysis of human serum samples and showed good consistency with detection results from an electrochemiluminescence immunoassay.
研究领域:
肿瘤学
·
免疫学
·
生物传感器
·
分子诊断
·
转化医学
·
临床检验医学
·
纳米生物技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Ying Jiang,Kai Chen,Jinping He,Yuxue Sun,Xiaorong Zhang,Xiaoxing Yang,Haiming Xie,Jun Liu
Composite solid electrolytes (CSEs), which combine the advantages of solid polymer electrolytes and inorganic solid electrolytes, are considered to be promising electrolytes for all-solid-state lithium metal batteries. However, the current CSEs suffer from defects such as poor inorganic/organic interface compatibility, lithium dendrite growth, and easy damage of electrolyte membrane, which hinder the practical application of CSEs. Herein, a CSE (PBHL@LLZTO@DDB) with polyurethane (PBHL) as the polymer matrix and Li 6.4 La 3 Zr 1.4 Ta 0.6 O 12 (LLZTO) modified by silane coupling agent (DDB) as inorganic fillers (LLZTO@DDB) has been prepared. Disulfide bond exchange reactions between PBHL and LLZTO@DDB enable PBHL@LLZTO@DDB to form a dynamic three-dimensional (3D) inorganic/organic hybrid network, which promotes the uniform dispersion of LLZTO in PBHL@LLZTO@DDB, improves the Li + conductivity (1.24 ± 0.08 × 10 −4 S cm −1 at 30 ℃), and broadens the electrochemical stability window (5.16 V vs. Li + /Li). Moreover, a combination of hydrogen bonds and disulfide bonds endows PBHL@LLZTO@DDB with excellent self-healing properties. As such, both all-solid-state symmetric and full cells exhibit excellent cycle performance at ambient temperature. More importantly, the healed PBHL@LLZTO@DDB can almost completely restore its original electrochemical properties, indicating its application potential in flexible electronic products.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
固态离子学
✓ 已验证
DOI
高影响因子
Biomed Research International
·
2015
·Vol. 2015
·期 1
·139179
·
IF 1.579
Jingjing Sun,Yiling Chen,Jun Sheng,Mi Sun
To improve the reusability and organic solvent tolerance of microbial lipase and expand the application of lipase (hydrolysis, esterification, and transesterification), we immobilized marine microbial lipase using different methods and determined the properties of immobilized lipases. Considering the activity and cost of immobilized lipase, the concentration of lipase was fixed at 2 mg/mL. The optimal temperature of immobilized lipases was 40°C and 5°C higher than free lipase. The activities of immobilized lipases were much higher than free lipase at alkaline pH (more than 50% at pH 12). The free lipase lost most activity (35.3%) and immobilized lipases retained more than 46.4% of their initial activity after 3 h heat treatment at 70°C. At alkaline pH, immobilized lipases were more stable than free lipase (more than 60% residue activity at pH 11 for 3 h). Immobilized lipases retained 80% of their activity after 5 cycles and increased enzyme activity (more than 108.7%) after 3 h treatment in tert-butanol. Immobilization of lipase which improved reusability of lipase and provided a chance to expand the application of marine microbial lipase in organic system expanded the application range of lipase to catalyze hydrolysis and esterification in harsh condition.
研究领域:
酶工程
·
分子生物学
·
生物催化
·
工业微生物学
·
蛋白质化学
·
应用酶学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）