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1.
Nature ; 626(7997): 105-110, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38297175

RESUMO

Silicon solar cells are a mainstay of commercialized photovoltaics, and further improving the power conversion efficiency of large-area and flexible cells remains an important research objective1,2. Here we report a combined approach to improving the power conversion efficiency of silicon heterojunction solar cells, while at the same time rendering them flexible. We use low-damage continuous-plasma chemical vapour deposition to prevent epitaxy, self-restoring nanocrystalline sowing and vertical growth to develop doped contacts, and contact-free laser transfer printing to deposit low-shading grid lines. High-performance cells of various thicknesses (55-130 µm) are fabricated, with certified efficiencies of 26.06% (57 µm), 26.19% (74 µm), 26.50% (84 µm), 26.56% (106 µm) and 26.81% (125 µm). The wafer thinning not only lowers the weight and cost, but also facilitates the charge migration and separation. It is found that the 57-µm flexible and thin solar cell shows the highest power-to-weight ratio (1.9 W g-1) and open-circuit voltage (761 mV) compared to the thick ones. All of the solar cells characterized have an area of 274.4 cm2, and the cell components ensure reliability in potential-induced degradation and light-induced degradation ageing tests. This technological progress provides a practical basis for the commercialization of flexible, lightweight, low-cost and highly efficient solar cells, and the ability to bend or roll up crystalline silicon solar cells for travel is anticipated.

2.
Nature ; 2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39236747

RESUMO

Two-terminal monolithic perovskite-silicon tandem solar cells demonstrate huge advantages in power conversion efficiency (PCE) compared to their respective single-junction counterparts1,2. However, suppressing interfacial recombination at the wide-bandgap perovskite/electron transport layer interface, without compromising its superior charge transport performance, remains a significant challenge for perovskite-silicon tandem cells3,4. By exploiting the nanoscale discretely distributed LiF ultrathin layer followed by an additional deposition of diammonium diiodide molecule, we have devised a bilayer intertwined passivation strategy that combines efficient electron extraction with further suppression of nonradiative recombination. We constructed perovskite-silicon tandem devices on double-side textured Czochralski (CZ)-based silicon heterojunction cell, which featured a mildly-textured front surface and a heavily-textured rear surface, leading to simultaneously enhanced photocurrent and uncompromised rear passivation. The resulting perovskite-silicon tandem achieved an independently certified stabilized PCE of 33.89%, accompanied by an impressive fill factor (FF) of 83.0% and an open-circuit voltage (Voc) of nearly 1.97 volts. To our knowledge, this represents the first reported certified efficiency of a two-junction tandem solar cell exceeding the single-junction Shockley-Queisser limit of 33.7%.

3.
Small ; : e2403098, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39162110

RESUMO

To meet the ever-increasing demand of proton exchange membrane fuel cell (PEMFC), it is necessary to carry out structure optimization for low-cost and high-stability oxygen reduction reaction (ORR) catalysts. Herein, a zeolitic imidazolate framework (ZIF)-derived carbon material with a mass of heteroatoms and defects is developed and serves as advanced support for nano-Pt-based ORR catalysts. This unique structure enhances the interaction between nano-Pt and support, leading to higher ORR intrinsic activity. During fuel cell applications, it demonstrates impressive water-retaining capacity and electrochemical stability. Under H2-O2 supply without cathode humidification, this catalyst achieves high mass activity of 0.475 A mgPt -1, with only 7.4% attenuation in maximum power density after 20 000 cycles of accelerated durability test, highlighting its remarkable potential for fuel cell applications. Physicochemical characterization and theoretical simulation reveal the crucial anchoring effect of heteroatom-doped defects to nano-Pt, providing valuable insights for further ORR catalyst design and PEMFC applications.

4.
Environ Sci Technol ; 58(23): 10388-10397, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38828512

RESUMO

Selective catalytic reduction of nitrogen oxides (NOx) with ammonia (NH3-SCR) is an efficient NOx reduction strategy, while the denitrification (deNOx) catalysts suffer from serious deactivation due to the coexistence of multiple poisoning substances, such as alkali metal (e.g., K), SO2, etc., in industrial flue gases. It is essential to understand the interaction among various poisons and their effects on the deNOx process. Herein, the ZSM-5 zeolite-confined MnSmOx mixed (MnSmOx@ZSM-5) catalyst exhibited better deNOx performance after the poisoning of K, SO2, and/or K&SO2 than the MnSmOx and MnSmOx/ZSM-5 catalysts, the deNOx activity of which at high temperature (H-T) increased significantly (>90% NOx conversion in the range of 220-480 °C). It has been demonstrated that K would occupy both redox and acidic sites, which severely reduced the reactivity of MnSmOx/ZSM-5 catalysts. The most important, K element is preferentially deposited at -OH on the surface of ZSM-5 carrier due to the electrostatic attraction (-O-K). As for the K&SO2 poisoning catalyst, SO2 preferred to be combined with the surface-deposited K (-O-K-SO2ads) according to XPS and density functional theory (DFT) results, the poisoned active sites by K would be released. The K migration behavior was induced by SO2 over K-poisoned MnSmOx@ZSM-5 catalysts, and the balance of surface redox and acidic site was regulated, like a synergistic promoter, which led to K-poisoning buffering and activity recovery. This work contributes to the understanding of the self-detoxification interaction between alkali metals (e.g., K) and SO2 on deNOx catalysts and provides a novel strategy for the adaptive use of one poisoning substance to counter another for practical NOx reduction.


Assuntos
Zeolitas , Zeolitas/química , Catálise , Oxirredução , Óxidos de Nitrogênio/química , Óxidos/química , Amônia/química , Desnitrificação , Metais/química
5.
Biomed Chromatogr ; 36(6): e5366, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35274340

RESUMO

Schizophrenia is a debilitating psychiatric disorder affecting approximately 1% of the population worldwide. Disturbances in the homocysteine metabolism are an important factor in the pathophysiology of schizophrenia. In this research, a novel validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) quantification procedure was developed to investigate three significant compounds of homocysteine metabolism: homocysteine, cysteine, and methionine in patients with schizophrenia and healthy controls. Sample preparation involved a reduction with dithiothreitol followed by protein precipitation, and the chromatographic runtime was 2 min. The LC-MS/MS method was validated according to CLSI C62-A and the Chinese Guidance for Liquid Chromatography and Mass Spectrometry Clinical Application. The performance of the method was excellent with a coefficient of variation for precision in the range of 0.5-6.9%, an accuracy of 90.4-101.6%. In addition, the practical applicability of the method was demonstrated by applying it in the routine sample analysis for a schizophrenic patient. Increased homocysteine levels and decreased cysteine levels were observed in the patient with schizophrenia. These results indicate that the activity of the transsulfuration pathway may play a key role in the pathogenesis of schizophrenia.


Assuntos
Esquizofrenia , Espectrometria de Massas em Tandem , Cromatografia Líquida/métodos , Cisteína/química , Homocisteína , Humanos , Metionina , Espectrometria de Massas em Tandem/métodos
6.
J Environ Sci (China) ; 103: 157-171, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33743898

RESUMO

Selective catalytic reduction is the most efficient and reliable equipment for NOx control in current diesel engines. However, the issue of urea crystallization becomes increasingly serious with the implement of the new emissions standards. In this paper, urea deposit samples collected from engine test bed and tube furnace were characterized by thermogravimetric analysis and Fourier transform-infrared analysis to aid the comprehension of urea deposit formation. Moreover, thermogravimetric tests were conducted to disclose the effects of catalyst on the thermal decomposition processes of urea deposit. The results indicated that less temperature resistant species are formed in the engine test bed than in the tube furnace at conditions with the same temperatures. The main compositions in the World Harmonized Transient Cycle (WHTC) urea deposits are urea, cyanuric acid (CYA) and ammelide, implying that accelerating the decomposition of these species could prevent the accumulation of urea deposit. CuWTi, Cuß and CuZSM catalysts could lead to increased yield of CYA during pure urea thermolysis. Cuß, CuWTi and VWTi catalysts tend to promote the thermolysis of CYA while VWTi has the most significant catalytic effects on the thermal decomposition of ammelide and ammeline.


Assuntos
Poluentes Atmosféricos , Emissões de Veículos , Poluentes Atmosféricos/análise , Catálise , Gasolina , Ureia , Emissões de Veículos/análise
7.
Zhongguo Zhong Yao Za Zhi ; 46(17): 4417-4423, 2021 Sep.
Artigo em Zh | MEDLINE | ID: mdl-34581045

RESUMO

In view of the current inadequate standards for Gleditsiae Spina in the Chinese Pharmacopoeia, this study put forward some new items of the quality standards of Gleditsiae Spina. Thin-layer chromatography(TLC) was performed for identification with the reference substance of taxifolin and the reference material of Gleditsiae Spina as the control. According to the general principles of the Chinese Pharmacopoeia(2020 edition, Vol. 4), the moisture, total ash content, and alcohol-soluble extract of medicinal materials and decoction pieces of Gleditsiae Spina were determined. The content determination method for medicinal materials and decoction pieces of Gleditsiae Spina was established using high-performance liquid chromatography(HPLC), with taxifolin as the quality control index. Based on the determination results of 30 batches of samples of Gleditsiae Spina from different habitats, the draft quality standards of Gleditsiae Spina were developed, which provided suggestions for the revision of the quality standards of Gleditsiae Spina in the Chinese Pharmacopoeia.


Assuntos
Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão , Controle de Qualidade , Padrões de Referência
8.
Environ Sci Technol ; 54(23): 15476-15488, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33156618

RESUMO

Industrialization has resulted in the rapid increase of volatile organic compound (VOC) emissions, which have caused serious issues to human health and the environment. In this study, an extensive Cu incorporating TiO2 induced nucleophilic oxygen structure was constructed in the CuTiOx catalyst, which exhibited superior low-temperature catalytic activity for C3H6 combustion. Thorough structural, surface characterization and density functional theory (DFT) calculations revealed that the Cu-O-Ti hybridization induced nucleophilic oxygen initiates C3H6 combustion by abstracting the C-H bond. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results indicated that incorporated copper species acted as the major adsorbent site for the propene molecule. In combination of the DRIFTS and DFT results, the promotion effect of the nucleophilic O on the C-H bond abstraction and CO2 formation pathway was proposed. The surface doping induced nucleophilic oxygen as strong Brønsted basic sites for low-temperature propene combustion exemplified an efficient strategy for rational design of next-generation environmental catalysts.


Assuntos
Espécies Reativas de Oxigênio , Alcenos , Catálise , Humanos , Oxirredução , Temperatura
9.
Pharmacology ; 104(1-2): 7-20, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30947229

RESUMO

BACKGROUND: Ocotillol, RT5 and F11, the main active components of ocotillol type ginsenosides, have attracted a lot of attention due to their beneficial effects on neurodegenerative disease models of Alzheimer's disease. Pharmacokinetic (PK) is a bridge linking the herbal medicines and their pharmacological responses. However, few data are available regarding PK behaviors of ocotillol type ginsenosides. METHODS: The liquid chromatography-tandem mass spectrometry methods were developed and validated to calculate the concentrations of 3 ginsenosides in different biological matrices. Rat and beagle dog plasma samples were deproteinized with methanol and separated on Shim-pack GIST C18 column. All of the analytes were detected in positive ion mode using multiple reaction monitoring. RESULTS: The methods showed good linearity (r > 0.996) in the established concentration range. All validated data, such as specificity, intra- and inter-day precision, accuracy, extraction recovery, matrix effect, and stability were within required limits. The values of Cmax and AUC(0-t) indicated ocotillol type ginsenosides had low systemic exposure and poor absorption into blood. T1/2 and MRT(0-t) demonstrated the elimination process of ocotillol type ginsenosides might be slow. Double peaks were observed in the mean plasma concentration versus time profiles of ocotillol, RT5, and F11 after oral intake. CONCLUSIONS: This was the first PK investigation of the ocotillol type ginsenosides in rats and beagle dogs. The results we found here were helpful to our understanding of the absorption mechanism of ocotillol type ginsenosides and provided the scientific basis for further pre-clinical research.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Ginsenosídeos/farmacocinética , Fármacos Neuroprotetores/farmacocinética , Panax/química , Espectrometria de Massas em Tandem/métodos , Administração Oral , Animais , Cromatografia Líquida de Alta Pressão/métodos , Cães , Avaliação Pré-Clínica de Medicamentos , Feminino , Ginsenosídeos/administração & dosagem , Masculino , Fármacos Neuroprotetores/administração & dosagem , Ratos , Padrões de Referência , Reprodutibilidade dos Testes , Distribuição Tecidual
10.
Molecules ; 23(6)2018 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-29843370

RESUMO

We designed a series of novel phenothiazine-1,2,3-triazole hybrids by the molecular hybridization strategy and evaluated their antiproliferative activity against three cancer cell lines (MDA-MB-231, MDA-MB-468 and MCF-7). For the structure-activity relationships, the importance of 1,2,3-triazole and substituents on phenyl ring was explored. Among these phenothiazine-1,2,3-triazole hybrids, compound 9f showed the most potent inhibitory effect against MCF-7 cells, with an IC50 value of 0.8 µM. Importantly, compound 9f could induce apoptosis against MCF-7 cells by regulating apoptosis-related proteins (Bcl-2, Bax, Bad, Parp, and DR5). These potent phenothiazine-1,2,3-triazole hybrids as novel apoptosis inducers might be used as antitumor agents in the future.


Assuntos
Antineoplásicos/síntese química , Proteínas Reguladoras de Apoptose/genética , Neoplasias da Mama/genética , Fenotiazinas/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Estrutura Molecular , Fenotiazinas/química , Fenotiazinas/farmacologia , Relação Estrutura-Atividade
11.
Fungal Genet Biol ; 101: 7-19, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28212851

RESUMO

Cyclic AMP signaling controls a range of physiological processes in response to extracellular stimuli in organisms. Among the signaling cascades, cAMP, as a second messenger, is orchestrated by adenylate cyclase (biosynthesis) and cAMP phosphodiesterases (PDEs) (hydrolysis). In this study, we investigated the function of the high-affinity (PdeH) and low-affinity (PdeL) cAMP phosphodiesterase from the carcinogenic aflatoxin producing fungus Aspergillus flavus, and found that instead of PdeL, inactivation of PdeH exhibited a reduction in conidiation and sclerotia formation. However, the ΔpdeL/ΔpdeH mutant exhibited an enhanced phenotype defects, a similar phenotype defects to wild-type strain treated with exogenous cAMP. The activation of PKA activity was inhibited in the ΔpdeH or ΔpdeL/ΔpdeH mutant, both of whom exhibited increasing AF production. Further analysis by qRT-PCR revealed that pdeH had a high transcriptional level compared to pdeL in wild-type strain, and affected pdeL transcription. Green fluorescent protein tagging at the C-terminus of PDEs showed that PdeH-GFP is broadly compartmentalized in the cytosol, while PdeL-GFP localized mainly to the nucleus. Overall, our results indicated that PdeH plays a major role, but has overlapping function with PdeL, in vegetative growth, development and AF biosynthesis in A. flavus.


Assuntos
Aflatoxinas/biossíntese , Aspergillus flavus/genética , Diester Fosfórico Hidrolases/genética , Esporos Fúngicos/genética , Aflatoxinas/genética , Núcleo Celular/genética , AMP Cíclico , Regulação Fúngica da Expressão Gênica , Transdução de Sinais , Esporos Fúngicos/crescimento & desenvolvimento
12.
Zhongguo Zhong Yao Za Zhi ; 42(11): 2102-2109, 2017 Jun.
Artigo em Zh | MEDLINE | ID: mdl-28822155

RESUMO

The chemical constituents from lipophilic parts in the roots of Angelica dahurica cv. Yubaizhi were studied in this paper. The compounds were separated and purified by repeated column chromatographic methods on silica gel and HPLC, and the chemical structures of compounds were determined by spectral data analyses. Thirty-three compounds were obtained and identified as isoimperatorin (1), imperatorin (2), stigmasterol (3), isooxypeucedanin (4), pabulenol (5), psoralen (6), bergapten (7), isodemethylfuropinarine (8), phellopterin (9), osthenol (10), alloimperatorin (11), xanthotoxin (12), xanthotoxol (13), isopimpinellin (14), alloisoimperatorin (15), ß-sitosterol (16), oxyalloimperatorin (17), pabularinone (18), 5-hydroxy-8-methoxypsoralen (19), columbianetin (20), heracol (21), isogosferol (22), 2″R-neobyakangelicol (23), byakangelicin ethoxide (24), byakangelicin (25), oxypeucedanin hydrate (26), uracil (27), umbelliferone (28), bergaptol (29), demethylfuropinarine (30), isobyakangelicol (31), oxypeucedanin ethanolate (32), heraclenol (33). Among them, compounds 8, 10, 17, 21, and 30 were obtained from the roots of title plant for the first time.


Assuntos
Angelica/química , Cumarínicos/isolamento & purificação , Furocumarinas/isolamento & purificação , Raízes de Plantas/química , Sitosteroides/isolamento & purificação
13.
Fungal Genet Biol ; 81: 113-9, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25813270

RESUMO

Small non-coding RNA (sRNA) in various organisms remains a mysterious subject. Although microRNAs (miRNAs) have been intensively investigated in plants and animals, the study of miRNAs in fungi has been limited. Only microRNA-like RNAs (milRNAs) have been reported in several filamentous fungi. In this study, Illumina deep sequencing was performed to characterize the sRNA in Aspergillus flavus and to evaluate their responses to water activity and temperature. Global expression analysis showed an extensively differential expression of sRNA loci in A. flavus under different temperature or water activities. In addition, a total of 135 milRNAs were identified in A. flavus. The milRNA profiles obtained in deep sequencing were further validated by RT-qPCR assay. The presence and differential expression of milRNAs under different temperature or water activities in A. flavus imply that milRNAs might play important roles in the mycotoxin biosynthesis and mycelium growth in fungi A. flavus.


Assuntos
Aspergillus flavus/efeitos dos fármacos , Aspergillus flavus/efeitos da radiação , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica/efeitos da radiação , MicroRNAs/biossíntese , Temperatura , Água/metabolismo , Aspergillus flavus/genética , Perfilação da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , MicroRNAs/genética , Reação em Cadeia da Polimerase em Tempo Real
14.
Phys Chem Chem Phys ; 17(43): 29142-9, 2015 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-26462874

RESUMO

The relative framework stability of Cu/CHA zeolites (SAPO-34 and SSZ-13) was studied during hydrothermal aging at 800 °C, and the fundamental mechanism for the framework change was investigated. Additionally, the relationship between the variation in the framework and active SCR reaction sites was established. SAPO-34 showed stronger stability during hydrothermal aging than SSZ-13. The results showed that dealumination occurred in the SSZ-13 zeolite, leading to the loss of crystallinity and a severe decrease of the Brönsted acid sites. Simultaneously, the detached Al(OH)3 species deactivated the Cu species by the transformation of isolated Cu(2+) ions to CuAlOx species. While the vacancy in the SAPO-34 framework caused by desilication could be healed with the migration of extra-framework Al and P atoms to the defects. And the Cu species showed a certain degree of aggregation with the improved redox ability of the aged Cu/SAPO-34 zeolite and the acidic properties were well maintained.

15.
Front Oncol ; 14: 1385695, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39188678

RESUMO

Gastric calcifying fibrous tumor (CFT) is a rare benign mesenchymal tumor. Several previous studies have reported surgical resection for gastric CFT larger than 20mm for the difficulty in preoperative diagnosis. Here, we report a rare case of large gastric CFT treated with endoscopic submucosal excavation (ESE). A 70-year-old woman presented with recurrent epigastric pain and underwent endoscopy, which revealed a 35mm-sized submucosal tumor in the gastric body. ESE was performed after imaging examination and endoscopic ultrasonography. En bloc resection was achieved, but due to the specimen's substantial size and difficulty in mincing, it posed challenges for removal through the mouth. Finally, the specimen was temporarily placed in the stomach and was completely removed two days later. The diagnosis was confirmed based on pathological and immunohistochemical findings. There was no recurrence during the patient's 11-month follow-up. We provided a case report related to the diagnosis and endoscopic treatment for large gastric CFT. In addition, our experience of temporarily leaving a large postoperative specimen, considered a benign lesion, in the stomach for later removal was successful but requires appropriate timing to avoid blockage of the gastrointestinal tract.

16.
J Hazard Mater ; 479: 135716, 2024 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-39236543

RESUMO

Condensable particulate matter (CPM) and filterable particulate matter (FPM) emitted from industrial sources have been well studied, but their emissions from vehicles have not yet been covered. This study explores the emission characteristics of CPM and FPM from typical diesel vehicles under various driving conditions. The emission factors (EFs) of CPMs under driving conditions were 5.4-10.4 times higher than those of FPMs, while CPMs EFs under transient driving conditions were about 2.5 times higher than those under steady driving conditions. CPM and FPM are mainly composed of organic matter accounting for 53.3 %-92.9 %, while the intermediate and semi-volatile organic compounds dominate the organic matter accounting for 86.3 %-98.6 %. Similar to industrial sources, alkanes are the predominant organic species emitted by diesel vehicles, comprising 42.0 %-64.0 % of the detected organic components. Inorganic CPM is primarily composed of NH4+ , representing 84.9 %-87.6 % of the total, in contrast to industrial sources where SO42- and Cl- dominate. Interestingly, the air pollution control devices installed on diesel vehicles under steady driving conditions perform better in removing organic CPM and producing higher inorganic CPM emissions than those under transient driving conditions. These findings will enhance the comprehensive understanding of particulate matter emitted from diesel vehicles and provide a scientific foundation for the development of related control technologies.

17.
ACS Omega ; 9(1): 97-116, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38222571

RESUMO

With increasing concerns about carbon emissions and the resulting climate impacts, Li-ion batteries have become one of the most attractive energy sources, especially in the transportation sector. For Li-ion batteries, an effective thermal management system is essential to ensure high-efficiency operation, avoid capacity degradation, and eliminate safety issues. Thermal management systems based on heat pipes can achieve excellent cooling performance in limited space and thus have been widely used for the temperature control of Li-ion batteries. In this paper, the thermal management systems of Li-ion batteries based on four types of heat pipes, i.e., flat single-channel heat pipes, oscillating heat pipes, flexible heat pipes, and microchannel heat pipes, are comprehensively reviewed based on the studies in the past 20 years. The effects of different influencing factors on the cooling performance and thermal runaway behavior of Li-ion batteries are thoroughly discussed in order to provide an in-depth understanding for researchers and engineers. It is concluded that for all types of thermal management systems based on heat pipes, water spray cooling could achieve better cooling performance than forced air cooling and water bath cooling, while its energy consumption is obviously smaller than forced air cooling. For thermal management systems based on oscillating heat pipes, improved heat transfer characteristics could be achieved by increasing the number of turns, using a relatively larger inner hydraulic diameter and using a length ratio between the evaporator and condenser higher than 1.0. Heat pipes fabricated by flexible materials suffer from permeation of noncondensable gases from ambient and leakage of working fluid. These issues could be partly resolved by adding thermal vias filled with metallic materials and covering the sealing part with indium coating or designing a multilayered structure with metallic materials in it. Moreover, the limitations and future trends of Li-ion battery thermal management systems based on heat pipes are presented. It is pointed out that the thermal runaway behavior and heating performance of battery thermal management systems based on heat pipes should be further elaborated. The analysis of this paper could provide valuable support for future investigations on Li-ion battery thermal management systems based on heat pipes; it could also guide the choice and design of Li-ion battery thermal management systems based on heat pipes in commercial use.

18.
Polymers (Basel) ; 16(8)2024 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-38675085

RESUMO

A three-dimensional helix geometry unit cell is established to simulate the complex spatial configuration of 3D braided composites. Initially, different types of yarn factors, such as yarn path, cross-sectional shape, properties, and braid direction, are explained. Then, the multiphase finite element method is used to develop a new theoretical calculation procedure based on the unit cell for predicting the impacts of environmental temperature on the thermophysical properties of 3D four-direction carbon/epoxy braided composites. The changing rule and distribution characteristics of the thermophysical properties for 3D four-direction carbon/epoxy braided composites are obtained at temperatures ranging from room temperature to 200 °C. The influences of environmental temperature on the coefficients of thermal expansion (CTE) and the coefficients of thermal conduction (CTC) are evaluated, by which some important conclusions are drawn. A comparison is conducted between theoretical and experimental results, revealing that variations in temperature exert a notable influence on the thermophysical characteristics of 3D four-directional carbon/epoxy braided composites. The theoretical calculation procedure is an effective tool for the mechanical property analysis of composite materials with complex geometries.

19.
J Colloid Interface Sci ; 657: 334-343, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38043235

RESUMO

Reconstruction universally occurs over non-layered transition metal sulfides (TMSs) during oxygen evolution reaction (OER), leading to the formation of active species metal (oxy)hydroxide and thus significantly influences the OER performance. However, the reconstruction process and underlying mechanism quantitatively remain largely unexplored. Herein, we proposed an electrochemical reaction mechanism, namely sulfide oxidation reaction (SOR), to elucidate the reconstruction process of pyrite-type TMSs. Based on this mechanism, we evaluated the reconstruction capability of NiS2 doped with transition metals V, Cr, Mn, Fe, Co, Cu, Mo, Ru, Rh, and Ir within different doped systems. Two key descriptors were thus proposed to describe the reconstruction abilities of TMSs: USOR (the theoretical electric potential of SOR) and ΔU (the difference between the theoretical electric potential of SOR and OER), representing the initiation electric potential of reconstruction and the intrinsic reconstruction abilities of TMSs, respectively. Our finding shows that a lower USOR readily initiate reconstruction at a lower potential and a larger ΔU indicating a poorer reconstruction ability of the catalyst during OER. Furthermore, Fe-doped CoS2 was used to validate the rationality of our proposed descriptors, being consistent with the experiment findings. Our work provides a new perspective on understanding the reconstruction mechanism and quantifying the reconstruction of TMSs.

20.
Sci China Life Sci ; 67(6): 1133-1154, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38568343

RESUMO

Detecting genes that affect specific traits (such as human diseases and crop yields) is important for treating complex diseases and improving crop quality. A genome-wide association study (GWAS) provides new insights and directions for understanding complex traits by identifying important single nucleotide polymorphisms. Many GWAS summary statistics data related to various complex traits have been gathered recently. Studies have shown that GWAS risk loci and expression quantitative trait loci (eQTLs) often have a lot of overlaps, which makes gene expression gradually become an important intermediary to reveal the regulatory role of GWAS. In this review, we review three types of gene-trait association detection methods of integrating GWAS summary statistics and eQTLs data, namely colocalization methods, transcriptome-wide association study-oriented approaches, and Mendelian randomization-related methods. At the theoretical level, we discussed the differences, relationships, advantages, and disadvantages of various algorithms in the three kinds of gene-trait association detection methods. To further discuss the performance of various methods, we summarize the significant gene sets that influence high-density lipoprotein, low-density lipoprotein, total cholesterol, and triglyceride reported in 16 studies. We discuss the performance of various algorithms using the datasets of the four lipid traits. The advantages and limitations of various algorithms are analyzed based on experimental results, and we suggest directions for follow-up studies on detecting gene-trait associations.


Assuntos
Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Estudo de Associação Genômica Ampla/métodos , Humanos , Algoritmos , Análise da Randomização Mendeliana , Transcriptoma/genética
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