Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 61
Filtrar
1.
Angew Chem Int Ed Engl ; : e202417130, 2024 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-39344002

RESUMO

Glycine as one of the most abundant amino acids in human proteins, with extensive applications in both life and industry, is conventionally synthesized through complex procedures or toxic feedstocks. In this study, we present a facile and benign electrochemical pathway for synthesis of glycine through reductive coupling of glyoxylic acid and nitrate over a copper-bismuth bimetal catalyst derived from a metal-organic framework (MOF) array on copper foam (Cu/Bi-C@CF). Remarkably, Cu/Bi-C@CF achieves a fantastic selectivity of 89%, corresponding a high Faraday efficiency of 65.9%. From control experiments, introduction of Bi caused the binding energy of Cu shift to lower state, which leads to a high selectivity towards the formation of key hydroxylamine intermediate rather than ammonia product, facilitating the formation of oxime and providing additional sites for subsequent hydrogenation reaction on the way to glycine. Moreover, the MOF array derivation ensures the effective dispersion of Bi and enhances the stability of Cu/Bi-C@CF. This innovative approach not only presents sustainable pathways for the production of value-added organonitrogen compounds utilizing readily available carbon and nitrogen sources, but also provides novel insights into the design of multistage structural catalysts for sequential reactions.

2.
Small ; : e2403991, 2024 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-39136429

RESUMO

Acquiring a highly efficient electrocatalyst capable of sustaining prolonged operation under high current density is of paramount importance for the process of electrocatalytic water splitting. Herein, Fe-doped phosphide (Fe-Ni5P4) derived from the NiFc metal-organic framework (NiFc-MOF) (Fc: 1,1'-ferrocene dicarboxylate) shows high catalytic activity for overall water splitting (OWS). Fe-Ni5P4||Fe-Ni5P4 exhibits a low voltage of 1.72 V for OWS at 0.5 A cm-2 and permits stable operation for 2700 h in 1.0 m KOH. Remarkably, Fe-Ni5P4||Fe-Ni5P4 can sustain robust water splitting at an extra-large current density of 1 A cm-2 for 1170 h even in alkaline seawater. Theoretical calculations confirm that Fe doping simultaneously reduces the reaction barriers of coupling and desorption (O*→OOH*, OOH*→O2 *) in the oxygen evolution reaction (OER) and regulates the adsorption strength of the intermediates (H2O*, H*) in the hydrogen evolution reaction (HER), enabling Fe-Ni5P4 to possess excellent dual functional activity. This study offers a valuable reference for the advancement of highly durable electrocatalysts through the regulation derived from coordination frameworks, with significant implications for industrial applications and energy conversion technologies.

3.
Angew Chem Int Ed Engl ; 63(31): e202406564, 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-38766872

RESUMO

How to achieve CO2 electroreduction in high efficiency is a current challenge with the mechanism not well understood yet. The metal-organic cages with multiple metal sites, tunable active centers, and well-defined microenvironments may provide a promising catalyst model. Here, we report self-assembly of Ag4L4 type cuboctahedral cages from coordination dynamic Ag+ ion and triangular imidazolyl ligand 1,3,5-tris(1-benzylbenzimidazol-2-yl) benzene (Ag-MOC-X, X=NO3, ClO4, BF4) via anion template effect. Notably, Ag-MOC-NO3 achieves the highest CO faradaic efficiency in pH-universal electrolytes of 86.1 % (acidic), 94.1 % (neutral) and 95.3 % (alkaline), much higher than those of Ag-MOC-ClO4 and Ag-MOC-BF4 with just different counter anions. In situ attenuated total reflection Fourier transform infrared spectroscopy observes formation of vital intermediate *COOH for CO2-to-CO conversion. The density functional theory calculations suggest that the adsorption of CO2 on unsaturated Ag-site is stabilized by C-H⋅⋅⋅O hydrogen-bonding of CO2 in a microenvironment surrounded by three benzimidazole rings, and the activation of CO2 is dependent on the coordination dynamics of Ag-centers modulated by the hosted anions through Ag⋅⋅⋅X interactions. This work offers a supramolecular electrocatalytic strategy based on Ag-coordination geometry and host-guest interaction regulation of MOCs as high-efficient electrocatalysts for CO2 reduction to CO which is a key intermediate in chemical industry process.

4.
Angew Chem Int Ed Engl ; 63(26): e202405553, 2024 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-38594220

RESUMO

Oxime ethers are attractive compounds in medicinal scaffolds due to the biological and pharmaceutical properties, however, the crucial and widespread step of industrial oxime formation using explosive hydroxylamine (NH2OH) is insecure and troublesome. Herein, we present a convenient method of oxime ether synthesis in a one-pot tandem electrochemical system using magnesium based metal-organic framework-derived magnesium oxide anchoring in self-supporting carbon nanofiber membrane catalyst (MgO-SCM), the in situ produced NH2OH from nitrogen oxides electrocatalytic reduction coupled with aldehyde to produce 4-cyanobenzaldoxime with a selectivity of 93 % and Faraday efficiency up to 65.1 %, which further reacted with benzyl bromide to directly give oxime ether precipitate with a purity of 97 % by convenient filtering separation. The high efficiency was attributed to the ultrafine MgO nanoparticles in MgO-SCM, effectively inhibiting hydrogen evolution reaction and accelerating the production of NH2OH, which rapidly attacked carbonyl of aldehydes to form oximes, but hardly crossed the hydrogenation barrier of forming amines, thus leading to a high yield of oxime ether when coupling benzyl bromide nucleophilic reaction. This work highlights the importance of kinetic control in complex electrosynthetic organonitrogen system and demonstrates a green and safe alternative method for synthesis of organic nitrogen drug molecules.

5.
Clin Neurol Neurosurg ; 239: 108229, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38479036

RESUMO

OBJECTIVE: First, the efficacy and safety of aspirin-ticagrelor after cerebral artery stenting in ischemic stroke patients is controversial. Second, there is a gap in the research on guiding two antiplatelet therapy (DAPT) after stenting based on the CYP2C19 genotype. METHODS: This retrospective study included patients who underwent cerebral artery stenting at the First Affiliated Hospital of Chongqing Medical University from January 2019 to February 2023. We divided them into the aspirin-clopidogrel group and aspirin-ticagrelor group and carefully collected baseline information laboratory data and imaging results from the patients. The efficacy outcomes were 30 days recurrent stroke, 90 days recurrent stroke, and 180 days recurrent stroke, and the safety outcome was intracranial hemorrhage. T-tests or Fisher's tests were performed for study outcomes in both groups of patients. OUTCOME: A total of 372 patients were included. For efficacy outcomes, aspirin-ticagrelor was associated with a reduced risk of 180 days recurrent stroke, in patients with CYP2C19 LOF allele (OR = 0.426, CI = 0.184-0.986, P = 0.042) and CYP2C19 intermediate metabolic genotype (OR = 0.237, CI = 0.026-1.034, P = 0.044), compared with aspirin-clopidogrel. There was no significant difference in the rate of intracranial hemorrhage (ICH) between patients with aspirin-clopidogrel and aspirin-ticagrelor, regardless of overall (OR = 1.221, CI = 0.115-7.245, P = 0.683), CYP2C19 LOF allele carriers (OR = 1.226, CI = 0.411-3.658, P = 0.715), or CYP2C19 intermediate metabolizer (OR = 1.221, CI = 0.115-7.245, P = 0.683). No significant differences were found between the two DAPTs on other efficacy and safety outcomes. CONCLUSION: A cohort study found that aspirin-ticagrelor was significantly superior to aspirin-clopidogrel in reducing 180 days recurrent stroke in CYP2C19 LOF allele carriers and CYP2C19 intermediate metabolizers. There was no significant difference between aspirin-ticagrelor and aspirin-clopidogrel in the risk of intracranial hemorrhage in terms of ICH rates.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Humanos , Clopidogrel/uso terapêutico , Ticagrelor/efeitos adversos , Aspirina/efeitos adversos , Inibidores da Agregação Plaquetária/efeitos adversos , Citocromo P-450 CYP2C19/genética , Citocromo P-450 CYP2C19/metabolismo , Estudos de Coortes , Estudos Retrospectivos , Hemorragias Intracranianas/induzido quimicamente , Artérias Cerebrais , Acidente Vascular Cerebral/genética , Resultado do Tratamento
6.
Sci Bull (Beijing) ; 69(6): 763-771, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38246797

RESUMO

The development of cost-effective electrocatalysts with high efficiency and long durability for hydrogen evolution reaction (HER) remains a great challenge in the field of water splitting. Herein, we design an ultrafine and highly dispersed Ru nanoparticles stabilized on porous V8C7/C matrix via pyrolysis of the metal-organic frameworks V-BDC (BDC: 1,4-benzenedicarboxylate). The obtained Ru-V8C7/C composite exhibits excellent HER performance in all pH ranges. At the overpotential of 40 mV, its mass activity is about 1.9, 4.1 and 9.4 times higher than that of commercial Pt/C in acidic, neutral and alkaline media, respectively. Meanwhile, Ru-V8C7/C shows the remarkably high stability in all pH ranges which, in particular, can maintain the current density of 10 mA cm-2 for over 150 h in 1.0 mol L-1 phosphate buffer saline (PBS). This outstanding HER performance can be attributed to the high intrinsic activity of Ru species and their strong interface interactions to the V8C7/C substrate. The synergistic effect of abundant active sites on the surface and the formed Ru-C-V units at the interface promotes the adsorption of reaction intermediates and the release of active sites, contributing the fast HER kinetics. This work provides a reference for developing versatile and robust HER catalysts by surface and interface regulation for pH tolerance.

7.
Angew Chem Int Ed Engl ; 63(3): e202311752, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37830922

RESUMO

Inorganic nitrogen oxide (NOx ) species, such as NO, NO2 , NO3 - , NO2 - generated from the decomposition of organic matters, volcanic eruptions and lightning activated nitrogen, play important roles in the nitrogen cycle system and exploring the origin of life. Meanwhile, excessive emission of NOx gases and residues from industry and transportation causes troubling problems to the environment and human health. How to efficiently handle these wastes is a global problem. In response to the growing demand for sustainability, scientists are actively pursuing sustainable electrochemical technologies powered by renewable energy sources and efficient utilization of hydrogen energy to convert NOx species into high-value organonitrogen chemicals. In this minireview, recent advances of electrocatalytic systems for NOx species valorization in organonitrogen synthesis are classified and described, such as amino acids, amide, urea, oximes, nitrile etc., that have been widely applied in medicine, life science and agriculture. Additionally, the current challenges including multiple side reactions and complicated paths, viable solutions along with future directions ahead in this field are also proposed. The coupling electrocatalytic systems provide a green mode for fixing nitrogen cycle bacteria and bring enlightenment to human sustainable development.

8.
Clin Neurol Neurosurg ; 234: 108005, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37837908

RESUMO

BACKGROUND: Current studies have concluded that MT (Mechanical Thrombectomy) is safe and effective for tandem lesions (TL). However, The benefit of bridging therapy for TL is controversial. OBJECTIVE: To compare efficacy and safety between bridging therapy and direct thrombectomy of tandem lesions. METHOD: We conducted a systematic review and meta-analysis of studies comparing bridging therapy versus direct thrombectomy among TL patients with regards to symptomatic intracerebral hemorrhage(sICH), Parenchymal hemorrhage (PH), 3-month mortality, modified Rankin Scale (mRS) score within 3 months, successful reperfusion, and excellent reperfusion. The meta-analysis of proportions was conducted with a common effects model. RESULT: Five studies (n = 1198 patients) were identified for the systematic review. For safety outcomes, the bridging group had no significant difference in the rate of symptomatic intracranial hemorrhage (OR = 0.78, 95% CI = 0.49-1.25, P = 0.31) and the rate of PH (OR = 0.67, 95% CI = 0.39-1.13, P = 0.13) but significantly lower rate of 3-month mortality (OR = 0.53, 95% CI = 0.37-0.75, P = 0.0004) compared to the direct thrombectomy group. In terms of efficacy outcomes, the bridging therapy group had a significantly higher rate of 3- month good functional outcome (mRS 0-2) (OR = 1.76, 95% CI = 1.38-2.24, P < 0.00001) and successful recanalization (OR = 1.69, 95% CI = 1.27-2.25, P = 0.0003) but no significant difference in the rate of excellent recanalization(OR = 1.21, 95% CI = 0.91-1.59, P = 0.19) in patients with TL compared to direct thrombectomy group. CONCLUSION: Bridging therapy is effective in improving the 3-month functional prognosis and increasing the rate of arterial recanalization without increasing the risk of intracranial hemorrhage in patients with TL compared to direct thrombectomy. A large multicentre clinical RCT is expected, as are advanced intravenous thrombolysis and endovascular thrombectomy techniques.


Assuntos
Isquemia Encefálica , Acidente Vascular Cerebral , Humanos , Resultado do Tratamento , Acidente Vascular Cerebral/cirurgia , Acidente Vascular Cerebral/tratamento farmacológico , Trombectomia/efeitos adversos , Trombectomia/métodos , Hemorragias Intracranianas/etiologia , Hemorragias Intracranianas/tratamento farmacológico , Terapia Trombolítica/métodos , Isquemia Encefálica/terapia , Fibrinolíticos/uso terapêutico
9.
Angew Chem Int Ed Engl ; 62(45): e202312239, 2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37728507

RESUMO

Pyridine oximes produced from aldehyde or ketone with hydroxylamine (NH2 OH) have been widely applied in pharmaceutics, enzymatic and sterilization. However, the important raw material NH2 OH exhibits corrosive and unstable properties, leading to substantial energy consumption during storage and transportation. Herein, this work presents a novel method for directly synthesizing highly valuable pyridine oximes using in situ generated NH2 OH from electrocatalytic NO reduction with well-design nanofiber membranes (Al-NFM) derived from NH2 -MIL-53(Al). Particularly, 2-pyridinealdoxime, the precursor of antidote pralidoxime (2-PAM) for nerve agents suffering from scarcity and high cost, was achieved with a Faraday efficiency up to 49.8 % and a yield of 92.1 %, attributing to the high selectivity of NH2 OH production on Al-NFM, further easily reacted with iodomethane to produce 2-PAM. This study proposes a creative approach, having wide universality for synthesizing pyridine and other oximes with a range of functional groups, which not only facilitates the conversion of exhaust gas (NO) and waste water (NO2 - ) into valuable chemicals especially NH2 OH production and in situ utilization through electrochemistry, but also holds significant potential for synthesis of neuro detoxifying drugs to humanity security.

10.
Angew Chem Int Ed Engl ; 62(30): e202306726, 2023 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-37254227

RESUMO

The conversion of industrial exhaust gases of nitrogen oxides into high-value products is significantly meaningful for global environment and human health. And green synthesis of amino acids is vital for biomedical research and sustainable development of mankind. Herein, we demonstrate an innovative approach for converting nitric oxide (NO) to a series of α-amino acids (over 13 kinds) through electrosynthesis with α-keto acids over self-standing carbon fiber membrane with CoFe alloy. The essential leucine exhibits a high yield of 115.4 µmol h-1 corresponding a Faradaic efficiency of 32.4 %, and gram yield of products can be obtained within 24 hours in lab as well as an ultra-long stability (>240 h) of the membrane catalyst, which could convert NO into NH2 OH rapidly attacking α-keto acid and subsequent hydrogenation to form amino acid. In addition, this method is also suitable for other nitrogen sources including gaseous NO2 or liquidus NO3 - and NO2 - . Therefore, this work not only presents promising prospects for converting nitrogen oxides from exhaust gas and nitrate-laden waste water into high-value products, but also has significant implications for synthetizing amino acids in biomedical and catalytic science.

11.
Environ Sci Technol ; 57(17): 7041-7050, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37078822

RESUMO

Ozone catalytic oxidation (OZCO) has gained great interest in environmental remediation while it still faces a big challenge during the deep degradation of refractory volatile organic compounds (VOCs) at room temperature. Hydroxylation of the catalytic surface provides a new strategy for regulating the catalytic activity to boost VOC degradation. Herein, OZCO of toluene at room temperature over hydroxyl-mediated MnOx/Al2O3 catalysts was originally demonstrated. Specifically, a novel hydroxyl-mediated MnOx/Al2O3 catalyst was developed via the in situ AlOOH reconstruction method and used for toluene OZCO. The toluene degradation performance of MnOx/Al2O3 was significantly superior to those of most of the state-of-the-art catalysts, and 100% toluene was removed with an excellent mineralization rate (82.3%) and catalytic stability during OZCO. ESR and in situ DRIFTs results demonstrated that surface hydroxyl groups (HGs) greatly improved the reactive oxygen species generation, thus dramatically accelerating the benzene ring breakage and deep mineralization. Furthermore, HGs provided anchoring sites for uniformly dispersing MnOx and greatly enhanced toluene adsorption and ozone activation. This work paves a way for deep decomposition of aromatic VOCs at room temperature.


Assuntos
Ozônio , Óxidos , Temperatura , Tolueno , Oxirredução , Radical Hidroxila , Catálise
12.
Angew Chem Int Ed Engl ; 62(26): e202304007, 2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37072344

RESUMO

How to transfer industrial exhaust gases of nitrogen oxides into high-values product is significantly important and challenging. Herein, we demonstrate an innovative method for artificial synthesis of essential α-amino acids from nitric oxide (NO) by reacting with α-keto acids through electrocatalytic process with atomically dispersed Fe supported on N-doped carbon matrix (AD-Fe/NC) as the catalyst. A yield of valine with 32.1 µmol mgcat -1 is delivered at -0.6 V vs. reversible hydrogen electrode, corresponding a selectivity of 11.3 %. In situ X-ray absorption fine structure and synchrotron radiation infrared spectroscopy analyses show that NO as nitrogen source converted to hydroxylamine that promptly nucleophilic attacked on the electrophilic carbon center of α-keto acid to form oxime and subsequent reductive hydrogenation occurred on the way to amino acid. Over 6 kinds of α-amino acids have been successfully synthesized and gaseous nitrogen source can be also replaced by liquid nitrogen source (NO3 - ). Our findings not only provide a creative method for converting nitrogen oxides into high-valued products, which is of epoch-making significance towards artificial synthesis of amino acids, but also benefit in deploying near-zero-emission technologies for global environmental and economic development.


Assuntos
Aminoácidos Essenciais , Óxido Nítrico , Aminoácidos , Hidrogenação , Carbono , Gases , Cetoácidos
13.
Front Neurol ; 14: 1103270, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36937530

RESUMO

Objective: The association between serum uric acid (UA) and spontaneous hemorrhagic transformation (HT) has been seldom studied, and the role of UA in spontaneous HT remains unclear. This study aims to investigate the sex-dependent association between UA and spontaneous HT in patients with ischemic stroke. Method: We retrospectively included patients with ischemic stroke in a tertiary academic hospital between December 2016 and May 2020. Patients were included if they presented within 24 h after the onset of symptoms and did not receive reperfusion therapy. Spontaneous HT was determined by an independent evaluation of neuroimaging by three trained neurologists who were blinded to clinical data. A univariate analysis was performed to identify factors related to spontaneous HT. Four logistic regression models were established to adjust each factor and assess the association between UA and spontaneous HT. Results: A total of 769 patients were enrolled (64.6% were male patients and 3.9% had HT). After adjusting the confounders with a P < 0.05 (model A) in the univariate analysis, the ratio of UA and its interquartile range (RUI) was independently associated with spontaneous HT in male patients (OR: 1.85; 95% CI: 1.07-3.19; P = 0.028), but not in female patients (OR: 1.39; 95% CI: 0.28-6.82; P = 0.685). In models B-D, the results remain consistent with model A after the adjustment for other potential confounders. Conclusions: Higher serum UA was independently associated with a higher occurrence of spontaneous HT in male patients who were admitted within 24 h after the stroke onset without receiving reperfusion therapy.

14.
Angew Chem Int Ed Engl ; 62(17): e202302220, 2023 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-36859751

RESUMO

The construction of high-activity and low-cost electrocatalysts is critical for efficient hydrogen production by water electrolysis. Herein, we developed an advanced electrocatalyst by anchoring well-dispersed Ir nanoparticles on nickel metal-organic framework (MOF) Ni-NDC (NDC: 2,6-naphthalenedicarboxylic) nanosheets. Benefiting from the strong synergy between Ir and MOF through interfacial Ni-O-Ir bonds, the synthesized Ir@Ni-NDC showed exceptional electrocatalytic performance for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and overall water splitting in a wide pH range, superior to commercial benchmarks and most reported electrocatalysts. Theoretical calculations revealed that the charge redistribution of Ni-O-Ir bridge induced the optimization of H2 O, OH* and H* adsorption, thus leading to the accelerated electrochemical kinetics for HER and OER. This work provides a new clue to exploit bifunctional electrocatalysts for pH-universal overall water splitting.

15.
J Am Chem Soc ; 145(8): 4659-4666, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36791392

RESUMO

Ultrasmall metal nanoparticles (NPs) show high catalytic activity in heterogeneous catalysis but are prone to reunion and loss during the catalytic process, resulting in low chemoselectivity and poor efficiency. Herein, a locking effect strategy is proposed to synthesize high-loading and ultrafine metal NPs in metal-organic frameworks (MOFs) for efficient chemoselective catalysis with high stability. Briefly, the MOF ZIF-90 with aldehyde groups cooperating with diamine chains via aldimine condensation was interlocked, which was employed to confine in situ formation of Au NPs, denoted as Au@L-ZIF-90. The optimized Au@La-ZIF-90 has highly dispersed Au NPs (2.60 ± 0.81 nm) with a loading amount around 22 wt % and shows a great performance toward 3-aminophenylacetylene (3-APA) from the selective hydrogenation of 3-nitrophenylacetylene (3-NPA) with a high yield (99%) and excellent durability (over 20 cycles), far superior to contrast catalysts without chains locking and other reported catalysts. In addition, experimental characterization and systematic density functional theory calculations further demonstrate that the locked MOF modulates the charge of Au nanoparticles, making them highly specific for nitro group hydrogenation to obtain 3-APA with high selectivity (99%). Furthermore, this locking effect strategy is also applicable to other metal nanoparticles confined in a variety of MOFs, and all of these catalysts locked with chains show great selectivity (≥90%) of 3-APA. The proposed strategy in this work provides a novel and universal method for precise control of the inherent activity of accessible metal nanoparticles with a programmable MOF microenvironment toward highly specific catalysis.

16.
Heliyon ; 9(1): e12875, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36711307

RESUMO

The digital economy is pushing more efficient and greener production and innovation processes, as well as quickening the mobility of production factors, which would have a critical impact on improving industrial green innovation efficiency. Based on the panel data of 30 Chinese provinces from 2005 to 2019, this study established a comprehensive index system to assess the level of provincial digital economy development, and adopted the SBM-DEA model including non-expected output to evaluate industrial green innovation efficiency, then adopted the Global Moran's I and Local Moran's I to test whether there is spatial autocorrelation, followed by the spatial Durbin model (SDM) and the mediating effect test model to investigate the direct impact, spatial spillover effect and indirect transmission mechanism of the digital economy on industrial green innovation efficiency. The results show that: both the development level of the digital economy and industrial green innovation efficiency show positive spatial autocorrelation; The digital economy not only has a significant direct role in promoting industrial green innovation efficiency but also has a spatial spillover effect; The digital economy can improve industrial green innovation efficiency by promoting manufacturing structure upgrading and stimulating enterprises' green technology innovation. The findings of this paper are helpful for policymakers to clarify the relationship between the digital economy and industrial green innovation efficiency and provide favorable policy directions for developing the digital economy to promote industrial green innovation efficiency.

17.
Environ Sci Pollut Res Int ; 30(8): 20415-20430, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36255571

RESUMO

Under the background of the deep convergence of China's digital services and manufacturing, it is of great significance to investigate the effects of the convergence of digital services and manufacturing on economic growth and carbon emissions reduction to the application of digital technology in the whole world. This paper constructs a simultaneous equation model and uses three-stage least squares to estimate the effect and mechanism of industrial convergence on economic growth and carbon emissions. The results show that (i) industrial convergence improves the change of total factor productivity (TFP) and the change of technical efficiency, and the reduction of carbon emissions is the main factor driving the growth of TFP and technical efficiency; (ii) industrial convergence and carbon emissions show a significant U-shaped relationship; (iii) the heterogeneity analysis shows that the convergence of capital-intensive, technology-intensive and labor-intensive manufacturing with digital services will help to improve the growth of TFP, it can inhibit carbon emissions first and then promote it. Therefore, the government should take targeted measures to promote industrial convergence of digital services and manufacturing according to the economic development and industry characteristics, so as to give full play to its positive role in economic growth and emissions reduction.


Assuntos
Carbono , Desenvolvimento Econômico , Carbono/análise , Dióxido de Carbono/análise , Comércio , China
18.
Sci Total Environ ; 857(Pt 2): 159295, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36228796

RESUMO

As a kind of emerging pollutant, volatile organic compounds (VOCs) are getting increasing attention due to their contribution to the formation of atmospheric haze and O3. Photocatalytic oxidation under vacuum ultraviolet photocatalytic oxidation (VUV-PCO) presents a promising method for VOCs degradation, but it is seldom studied for VOCs compound and the mechanism is still elusive. Herein, typical VOCs such as toluene and ethyl acetate were degraded separately or together in VUV system and in VUV-PCO system with the designed trifunctional catalyst Mn/TiO2/ZSM-5. Intermediates were recognized by PTR-TOF-MS. It is found that dual VOCs mixture outperformed single VOCs under both VUV process and VUV-PCO process. Possible degradation mechanisms were proposed. To explore the potential practicality of VUV-PCO technology, scale-up synthesis of Mn/TiO2/ZSM-5 on ceramic foams was successfully carried out and assembled into a homemade pilot-scale VUV-PCO equipment for the control of simulated VOCs complex (toluene, ethyl acetate, ethanol, and acetone). Pilot-scale catalytic testing with the monolithic catalysts achieved high removal efficiency (over 90 % efficiency after two cycles of regeneration) and confirmed the practical application possibility of VUV-PCO technology in multiple VOCs degradation. This work probes into the VUV-PCO technology applicability from lab scale to pilot scale and promotes the understanding of VUV and VUV-PCO in VOCs complex decomposition.


Assuntos
Compostos Orgânicos Voláteis , Vácuo , Raios Ultravioleta , Catálise , Oxirredução , Tolueno
19.
Anal Methods ; 14(45): 4690-4702, 2022 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-36353817

RESUMO

As economic globalization intensifies, the recent increase in agricultural products and travelers from abroad has led to an increase in the probability of invasive alien species. A major pathway for invasive alien species is agricultural quarantine materials (AQMs) in travelers' baggage. Thus, it is meaningful to develop efficient methods for early detection and prompt action against AQMs. In this study, a method based on the combination of odor detection of AQMs using ion mobility spectroscopy (IMS) and convolutional neural network (CNN) analysis for the identification of AQM species in luggage was developed. Two different ways were investigated to feed the IMS data of AQMs into the CNN, either as one-dimensional data (1D) (as a spectrum) or as two-dimensional data (2D) (as an IMS topographic map). The performances of CNN models were also compared to those of the commonly used classification algorithms: partial least squares discriminant analysis (PLS-DA) and soft independent modeling of class analogy (SIMCA). By doing gradient-weighted class activation mapping (Grad-CAM), the essential IMS feature regions from the CNN models to predict different AQM species were also identified. The results of this research demonstrated that the application of the CNN to the IMS data of AQMs yielded superior classification performance compared to PLS-DA and SIMCA. Especially, the CNN-2D model which utilized the IMS topographic map as input achieved the best classification accuracy both on the calibration and validation sets. In addition, the Grad-CAM method had an ability to detect critical discriminating spectral regions for different types of AQM samples, and could provide explanation for the CNNs' decision-making. Despite the inherent limitations of the present analytical protocol, the results showed that the method of IMS in combination with a CNN has great potential to be a complement for sniffer dogs and X-ray imaging techniques to detect AQMs.


Assuntos
Redes Neurais de Computação , Quarentena , Animais , Cães , Análise dos Mínimos Quadrados , Análise Discriminante , Análise Espectral
20.
Nanoscale ; 14(41): 15462-15467, 2022 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-36226441

RESUMO

Selective hydrogenation of α,ß-unsaturated aldehydes to obtain a high yield of unsaturated alcohols is important in industrial production. This is still a great challenge because it is thermally more favorable for the hydrogenation of CC than for the CO bond. Various strategies have been developed to optimize the catalysts for improving selectivity but are usually accompanied by the sacrifice of catalytic activity. Herein, we adopt the inert metal inducement strategy to synthesize a series of Ir-M alloy nanoparticle catalysts. The optimal catalyst IrCd5 exhibits impressive catalytic performance in the selective hydrogenation of cinnamaldehyde, achieving 96.7% conversion with 94.3% selectivity for cinnamal alcohol, which is far superior to that of the Ir counterpart. Furthermore, the H2 temperature-programmed desorption (H2-TPD) test, styrene-TPD test, surface valence band test and density functional theory calculations demonstrate that the adsorption mode of cinnamaldehyde shifted from parallel to vertical configurations after introducing an inert metal. Compared to Ir, the weaker adsorption of alkene and stronger adsorption of the substrate for IrCd5 lead to the prior adsorption and hydrogenation of the CO bond, thus elevating the selectivity of the cinnamal alcohol. This strategy disperses precious metal nanoparticles effectively, maximizes atomic utilization, and improves the selectivity, which provides a new avenue to design bimetal alloy catalysts for the selective hydrogenation of α,ß-unsaturated aldehydes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...