JOURNAL OF RARE EARTHS
·
2024
·
IF 5.2
Haoyuan Zheng,Yuxiao Jia,Chen Jin,Hang Che,Chia-Tse Lee,Zhenke Chen,Guang Liu,Li Wang,Shixuan He,Xinhua Wang,Haizhen Liu,Mi Yan
The Mg(NH 2 ) 2 -2LiH composite system is a promising vehicle-mounted hydrogen storage material, but its application is limited due to serious thermodynamic and kinetic barriers. Adding additives can effectively optimize their hydrogen absorption and desorption kinetics and thermodynamic performance. In this work the comprehensive hydrogen storage performance of Mg(NH 2 ) 2 -2LiH with extremely small nano rare earth borides is improved, and a series of characterization methods and density functional theory (DFT) calculation systems was combined to study its hydrogen storage improvement mechanism. The research results show that the method of adding 5 wt% molten salt to prepare nano CeB 6 (24.5 nm) can significantly reduce the initial hydrogen absorption/release temperature of Mg(NH 2 ) 2 -2LiH from 110/130 to 45/90 °C, inhibit the generation of ammonia by-products, and improve hydrogen purity. Under low-temperature hydrogen absorption conditions at 120 °C, the improved sample can absorb 2.81 wt% hydrogen gas, with a hydrogen absorption capacity more than 3.5 times of the unmodified sample. The amount of hydrogen released at 150 °C reaches 3.35 wt%, which is more than twice that of the pristine sample, demonstrating excellent hydrogen absorption and release kinetics performance. After 10 consecutive hydrogen cycles, 4.64 wt% hydrogen can still be released, and the cycle retention rate can be increased from 85% before improvement to nearly 100%, demonstrating good reversibility. Mechanism studies show that nano CeB 6 can effectively weaken the Mg–N and N–H bonds of Mg(NH 2 ) 2 and inhibit the polycrystalline transformation of the hydrogen evolution product Li 2 MgN 2 H 2 at high temperatures. It can also provide nucleation active sites for hydrogen absorption and desorption in the material, making the system possess superior hydrogen absorption and desorption performance and cycling stability. This study provides new insights into the role of rare earth borides in Mg(NH 2 ) 2 -2LiH hydrogen storage materials, both experimentally and theoretically.
研究领域:
材料科学
·
化学工程
·
物理化学
·
理论化学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2019
·
IF 2.931
Zhong Wang,Si-Fu Tang,Xiaomin Hou
As a most abundant plasticizer , Di-(2-ethylhexyl) phthalate (DEHP) has been widely used in agriculture with an associated potential toxicity to many species including plants via the production of the excessive reactive oxygen species (ROS). However, the potential toxic mechanisms of the plasticizer DEHP-induced oxidative damage to plants remain unknown. The antioxidant enzyme glutathione peroxidase has been suggested as biomarkers to reflect over excessive oxidative stress . In this study, the effect of DEHP on AtGPX6 was evaluated by multi-spectroscopic techniques and molecular docking method. The fluorescence intensity of AtGPX6 was reduced by the static quenching mechanism upon the addition of DEHP. The predominant forces in complex formation was mainly impelled by hydrogen bonding and Van der Waals forces based on the negative Δ H and Δ S , which was in accordance with the molecular docking results. In addition, the secondary structural changes resulted from the complex formation were investigated in presence of different amounts of DEHP by the combination of fluorescence, UV–vis absorption and Circular dichroism spectra, which revealed the loosening and unfolding of the framework of AtGPX6 accompanied with the enhancement of the hydrophilicity around the tryptophan residues . The exploration of the interaction mechanism of DEHP with AtGPX6 at molecular level would help to evaluate the toxicity of the plasticizers and forecast the related adverse effects on plants.
研究领域:
植物学
·
环境毒理学
·
分子生物学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2022
·Vol. 47
·期 33
·14916-14929
·
IF 7.139
Hongzhi Wang,Chunxiao Wang,Weiguo Zhang,Suwei Yao
Developing non-noble metal catalysts with excellent electrocatalytic performance and stability is of great significance to hydrogen production by water electrolysis, but there are still problems of low activity, complex preparation and high cost. Herein, we fabricated a novel Ni 3 S 2 /Ni(OH) 2 dual-functional electrocatalyst by a one-step fast electrodeposition on nickel foam (NF). While maintaining the electrocatalytic performance of Ni 3 S 2 , the existence of heterostructure and Ni(OH) 2 co-catalyst function greatly improves the overall water splitting performance of Ni 3 S 2 /Ni(OH) 2 –NF. Hence, It shows a low overpotential of 66 mV at 10 mA cm −2 for HER and 249 mV at 20 mA cm −2 for OER. The dual-functional electrocatalyst needs only 1.58 V at 20 mA cm −2 when assembled two-electrode electrolytic cell. Impressively, the electrocatalyst also shows outstanding catalytic stability for about 800 h when 20 and 50 mA cm −2 constant current was applied, respectively which demonstrates a potential electrocatalyst for overall water splitting.
研究领域:
材料科学
·
电化学
·
能源催化
·
纳米材料
·
可持续能源
·
功能材料
·
界面化学
✓ 已验证
DOI
高影响因子
ACS Omega
·
2019
·
IF 2.584
Sherif M. Ibrahim,Yan Zhang,Yun Xue,Suliang Yang,Fuqiu Ma,Yang Gao,Yu Zhou,Guoxin Tian
The complexation and selectivity of N,N-di(2-ethylhexyl)-diglycolamic acid (HDEHDGA/kerosene, HA) toward the light lanthanides, La(III), Ce(III), Pr(III), and Nd(III), are presented for the extraction from chloride media. In the low pH region (pH 1.8–2.8), the obtained data reveal that the extraction of Ln(III) is governed by cation-exchange mechanism and is driven by the negative change in enthalpy. The results from the slope analysis method suggest the formation of LnA3·(HA)1or2 in the extraction process. As major extracted species with a core of LnA3 in the first coordination sphere, LnA3 might connect with one or two additional HA molecules in the second coordination sphere by hydrogen bonding. The LnA3 core might share similar coordination geometry to those of 1:3 Ln(III) complexes (LnA′3) with water-soluble N,N-dimethyl-diglycolamic acid (HDMDGA, HA′) formed in aqueous solutions or in solid-state compounds. The correlation between the extraction with HDEHDGA (HA) as an extractant and the complexation with HDMDGA (HA′) as a chelator has been explored by interpreting the separation factors for HA with the difference in the stability constants for HA′. Consequently, the ratios of the stability constants of the corresponding 1:3 complexes (LnA′3) with HDMDGA could be reasonably translated to the separation factors (SFs) with HDEHDGA, providing a valuable approach for understanding the origin of the extraction/separation mechanism. By comparing the extraction selectivity of HDEHDGA with that of the currently deployed extractants in the industry such as P204, P507, and Cyanex 272, HDEHDGA offers outstanding selectivity with considerable SFs (SFCe/La = 6.68, SFPr/Ce = 2.79, and SFNd/Pr = 2.65) for light Ln(III) pairs under conditions of low acid concentrations.
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
CRYSTAL RESEARCH AND TECHNOLOGY
·
2025
·
IF 1.9
Yansheng Jiang,Wei Wei,Hangwei Jia,Muhammad Arif,Zhihua Yang,Xiuling Yan,Xueling Hou
With the continuous development of optical science and technology, there are higher requirements for the versatility and multi-application scenarios of optical devices. Organic–inorganic hybrid birefringent crystals have attracted much attention due to their high flexibility in molecular design and assembly. In this work, an alkaline earth metal 2-hydroxybutanedioate Ba 3 (C 4 H 4 O 5 ) 2 (OH) 2 crystallizing in the C 2/ c space group is synthesized by the hydrothermal method. Its unit cell parameters are a = 20.0584(7) Å, b = 7.4499(3) Å, c = 9.5087(3) Å, and β = 96.808(2) °. Ba 3 (C 4 H 4 O 5 ) 2 (OH) 2 polycrystalline powder is characterized in detail by Fourier transform infrared (FTIR) absorption spectroscopy, UV–vis–NIR diffuse reflectance spectroscopy, and simultaneous thermal analysis. In addition, theoretical analyses are carried out using first-principles calculations and Hirshfeld surface analysis. The theoretical birefringence of Ba 3 (C 4 H 4 O 5 ) 2 (OH) 2 is calculated to be 0.1 @546 nm. At the same time, UV–vis–NIR diffuse reflectance and band structure calculations show that Ba 3 (C 4 H 4 O 5 ) 2 (OH) 2 has an indirect bandgap of 5.11 eV with a UV cutoff edge of 203 nm. By leveraging the complementary attributes of organic and inorganic materials, Ba 3 (C 4 H 4 O 5 ) 2 (OH) 2 stands out as a promising UV birefringent candidate.
✓ 已验证
产品关联
DOI
高影响因子
ENERGY AND BUILDINGS
·
2015
·
IF 2.884
Zhijian Liu,Wenlu Xu,Anni Lin,Tao He,Fan Lin
NaGd(WO 4 ) 2 :Eu 3+ /Bi 3+ films were deposited on SiO 2 glass substrates by spin-coating. The as-prepared films were heat treated at different temperatures. The properties of films were characterized by TG-DSC, XRD, SEM and fluorescence spectrophotometer. The TG-DSC curve indicated that films began to crystallize at about 600 °C. The XRD patterns and SEM images of films annealed at 600 °C, 700 °C and 800 °C showed that a higher temperature benefits to the higher crystallinity and induces the lower thickness. Meanwhile, it was found that the revolution of spin coating influenced the morphology of films obviously. Under the excitation at 396 nm, NaGd(WO 4 ) 2 :Eu 3+ /Bi 3+ films showed characteristic emission bands originating from 5 D 0 → 7 F j ( j = 1, 2, 3, and 4) transitions of Eu 3+ ions. It was also found that the excitation wavelength has great effect on the emission intensity.
研究领域:
材料科学
·
光电技术
·
光子学
✓ 已验证
DOI
高影响因子
International Journal of Nanomedicine
·
2012
·
IF 3.13
Xiaowei Ma,Huan Wang,Shubin Jin,Yan Wu,Xing-Jie Liang
Background There is an urgent need to develop drug-loaded biocompatible nanoscale packages with improved therapeutic efficacy for effective clinical treatment. To address this need, a novel poly (2-hydroxyethyl methacrylate)-poly (lactide)-1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine [PHEMA-g-(PLA-DPPE)] copolymer was designed and synthesized to enable these nanoparticles to be pH responsive under pathological conditions.Methods The structural properties and thermal stability of the copolymer was measured and confirmed by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and thermogravimetric analysis. In order to evaluate its feasibility as a drug carrier, paclitaxel-loaded PHEMA-g-(PLA-DPPE) nanoparticles were prepared using the emulsion-solvent evaporation method.Results The PHEMA-g-(PLA-DPPE) nanoparticles could be efficiently loaded with paclitaxel and controlled to release the drug gradually and effectively. In vitro release experiments demonstrated that drug release was faster at pH 5.0 than at pH 7.4. The anticancer activity of the PHEMA-g-(PLA-DPPE) nanoparticles was measured in breast cancer MCF-7 cells in vivo and in vitro. In comparison with the free drug, the paclitaxel-loaded PHEMA-g-(PLA-DPPE) nanoparticles could induce more significant tumor regression.Conclusion This study indicates that PHEMA-g-(PLA-DPPE) nanoparticles are promising carriers for hydrophobic drugs. This system can passively target cancer tissue and release drugs in a controllable manner, as determined by the pH value of the area in which the drug accumulates.
研究领域:
药剂学
·
肿瘤学
·
生物材料科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF POLYMER ENGINEERING
·
2022
·Vol. 42
·期 6
·507-519
·
IF 1.624
Xiaofei Yan,Zhikui Zhao,Jie Fang,Jiawei Li,Dongming Qi
A novel synergy flame retardant system of poly(ethylene terephthalate) (PET)/organic-Zn(H 2 PO 2 ) 2 /lithium containing polyhedral oligoheptyl silse-squioxane (Li-Ph-POSS) composites was prepared by the melt-blending method to improve the flame retardancy of PET. The synergistic effect of organic-Zn(H 2 PO 2 ) 2 and Li-Ph-POSS on the flame retardancy, thermal, and mechanical properties of the PET composites was investigated by the limiting oxygen index, vertical burning test, cone calorimeter, thermogravimetric analysis, differential scanning calorimeter, tensile tester, and dynamic mechanical analysis, respectively. The results show that the synergistic flame retardant effect between organic-Zn(H 2 PO 2 ) 2 and Li-Ph-POSS improves both the flame retardancy and the crystallization of PET. Moreover, the Li-Ph-POSS has a positive effect on the mechanical property of PET. This work provides a promising strategy for mitigating the fire hazard of PET using this synergy flame retardant system.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2018
·
IF 3.235
Yang Yuan,Jiaxin Wang,Xinjiong Ni,Yuhua Cao
A biosensor for determination of 3-chloro-1, 2-propandiol (3-MCPD) was developed based on the electrochemically catalytic reduction by hemoglobin (Hb). Hb was concentrated and immobilized with magnetic molecularly imprinted nanoparticles (MMIPs NPs). The MMIP NPs had a core-shell structure, with magnetic Fe 3 O 4 NPs as the core and SiO 2 as the shell. MMIPs NPs were modified on the surface of a magnetic electrode to constitute the Hb enzyme-like sensor. The biosensor could catalyze the electrochemical reduction of 3-MCPD, and a direct electrochemical determination of 3-MCPD could be achieved for the first time. The biosensor, where Hb immobilized with MMIPs NPs had high electrochemical response for 3-MCPD, increased by 37.5% compared with Hb immobilized with magnetic non-imprinted nanoparticle (MNIPs NPs). The biosensor increased the response by 19.56% again under an external magnetic field . The reduction peak current had a linear relationship with 3-MCPD concentration ranging from 1.0 mg·L −1 to 160 mg·L −1 with a detection limit (S/N = 3) of 0.25 mg·L −1 . The biosensor was applied to the determination of 3-MCPD in soy sauce samples successfully with recoveries between 97.4% and 99.6%.
研究领域:
生物传感器
·
分析化学
·
食品科学
·
电化学
·
分子生物学
·
纳米医学
✓ 已验证
DOI
高影响因子
Current Protocols
·
2023
·Vol. 3
·期 11
·e923
·
IF 0
Xuan Chen,Long Xie,Chenglong Zhang,Shen Tian,Zeyu Tang,Weiwei Tian,Patrick Lu,Xianbin Yang
Although small interfering RNA (siRNA) is a key player among gene inhibition therapeutics, there are many obstacles to the development of siRNA drugs due to inherent properties of oligonucleotides, including the unsatisfactory stability of unmodified siRNA, poor pharmacokinetic distribution, and the toxicity induced by off-target effects. To maximize treatment potency, chemical modification of siRNA has undoubtedly been the most successful strategy by far. Widely applied modifications include phosphorothioate linkages, 2′- O -methyl modifications, and 2′-fluoro modifications, among others. To extend the family of chemical modifications for oligonucleotides, 2′- O -cyanoethylated RNA analogs were developed through the replacement of the 2′-hydroxyl group with a 2′- O -cyanoethyl group (-OCH 2 CH 2 CN). This modification can provide several advantages over unmodified RNA, such as increased stability, improved binding affinity to complementary DNA or RNA strands, and resistance to degradation by cellular nucleases. The 2′- O -cyanoethyl-modified RNAs not only are applied in RNA silencing machinery but also act as research tools for studying RNA structure and function or for developing RNA-based diagnostics. Therefore, the efficient synthesis, deprotection, purification, and characterization of 2′- O -cyanoethylated RNAs deserves more attention. This protocol describes the chemical synthesis of 2′- O -cyanoethylated nucleotides and the solid-phase synthesis, deprotection, and purification of 2′- O -cyanoethylated RNAs. © 2023 Wiley Periodicals LLC. Basic Protocol 1 : Preparation of 6- N -dimethylformamidyl-5′- O -dimethoxytrityl-2′- O -cyanoethyl adenosine 3′-(2-cyanoethyl N , N -diisopropyl)phosphoramidite Basic Protocol 2 : Preparation of 4- N -acetyl-5′- O -dimethoxytrityl-2′- O -cyanoethyl cytidine 3′-(2-cyanoethyl N , N -diisopropyl)phosphoramidite Basic Protocol 3 : Preparation of 2- N -dimethylformamidyl-5′- O -dimethoxytrityl-2′- O -cyanoethyl guanine 3′-(2-cyanoethyl N , N -diisopropyl)phosphoramidite Basic Protocol 4 : Preparation of 5′- O -dimethoxytrityl-2′- O -2-cyanoethyl uridine 3′-(2-cyanoethyl N , N -diisopropyl)phosphoramidite Basic Protocol 5 : Solid-phase synthesis of 2′- O -cyanoethylated RNA analogs Basic Protocol 6 : Deprotection and purification of synthesized 2′- O -cyanoethyl-RNAs
研究领域:
分子生物学
·
生物化学
·
药物化学
·
RNA治疗学
·
有机合成
✓ 已验证
DOI
POLYMER
·
2012
·
IF 3.438
Hua Ye,Dongcheng Chen,Ming Liu,Xiao Zhou,Shi-Jian Su,Yong Cao
A series of light-emitting conjugated polymers (LEPs) based on building blocks of electron-donating trifluoren-2-ylamine (TFA), electrically neutral 1,3,5-trifluoren-2-ylbenzene (TFB), and electron-withdrawing 2,4,6-trifluoren-2-yltriazine (TFT) were successfully synthesized via palladium-catalyzed Suzuki cross-coupling polycondensation . Their structure–property relationships were thoroughly studied. For P1 containing electron-withdrawing backbone and electron-donating pendants, their photophysical properties in solution are strongly dependent on the solvent polarity due to the intense intramolecular charge-transfer (ICT) interaction. In addition, their emission colors and energy levels could be effectively tuned by changing the structure of the main chain as well as the substituent at the pendent fluorene of TFT, TFB, and TFA. To evaluate their electroluminescence properties, double-layer devices with a configuration of ITO/PEDOT:PSS (40 nm)/emitting layer (EML) (70–80 nm)/TPBI (30 nm)/CsF (1.5 nm)/Al were fabricated, where the developed polymers were used as an EML and TPBI (2,2′,2″-(1,3,5-benzenetriyl)-tris-(1-phenyl-1H-benzimidazole)) was used as an electron-transport and hole-block layer. Deep-blue light emission was achieved for the device based on P1d , a polymer based on TFT and the second generation (G2) of carbazole dendrimer pendant, that shows a maximum current efficiency (CE) of 1.26 cd A −1 , corresponding to external quantum efficiency (EQE) of 1.27%, with Commission Internationale de L'Eclairage (CIE) coordinates of (0.16, 0.14). In comparison, due to the intense ICT interaction between the main chain and the side chain, light-green emission was achieved for the device based on P1c , a polymer based on TFT and bis(9,9-dioctyl-9H-fluoren-2-yl)amine pendant, giving the highest maximum CE of 4.10 cd A −1 , corresponding to EQE of 2.45%, with CIE coordinates of (0.24,0.51), although either of the main chain and the side chain emits blue light.
研究领域:
材料科学
·
有机电子学
·
聚合物化学
·
光电子学
·
光物理
✓ 已验证
DOI
高影响因子
JOURNAL OF DAIRY SCIENCE
·
2023
·
IF 3.5
Yanmei Xi,Sana Ikram,Tong Zhao,Yiwei Shao,Ruirui Liu,Fuhang Song,Baoguo Sun,Nasi Ai
ABSTRACT Flavor sensation is one of the most prevalent characteristics of food industries and an important consumer preference regulator of dairy products. So far, many volatile compounds have been identified, and their molecular mechanisms conferring overall flavor formation have been reported extensively. However, little is known about the critical flavor compound of a specific sensory experience in terms of oxidized off-flavor perception. Therefore, the present study aimed to compare the variation in sensory qualities and volatile flavors in full-fat UHT milk (FFM) and low-fat UHT milk (LFM) samples under different natural storage conditions (0, 4, 18, 25, 30, or 37°C for 15 and 30 d) and determine the main component causing flavor deterioration in the FFM and LFM samples using sensory evaluation, electronic nose, and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). In addition, the Pearson correlation between the volatile flavor components and oxidative off-flavors was analyzed and validated by sensory reconstitution studies. Compared with the LFM samples, the FFM samples showed a higher degree of quality deterioration with increased storage temperature. Methyl ketones of odd carbon chains (i.e., 2-heptanone, 2-nonanone, 2-undecanone, 2-tridecanone, and 2-pentadecanone) reached a maximum content in the FFM37 samples over 30 d storage. The combined results of the Pearson correlation and sensory recombination study indicated that 2-heptanone, 2-nonanone, and 2-undecanone conferred off-flavor perception. Overall, the present study results provide potential target components for detecting and developing high-quality dairy products and lay a foundation for specific sensory flavor compound exploration in the food industry.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）