The High Mountain Asia(HMA)is a prominent global mountain system characterized by an average altitude exceeding 4,000 m,intricate topography,and significant spatial variability in climatic conditions.Despite its impor...The High Mountain Asia(HMA)is a prominent global mountain system characterized by an average altitude exceeding 4,000 m,intricate topography,and significant spatial variability in climatic conditions.Despite its importance,there has been a relative paucity of research focusing on the spatiotemporal variations of snow cover,key controlling factors,and variability within HMA sub-basins.This study aims to address this gap by extracting snow cover percentage(SCP)and snow cover days(SCD)data from MOD10A2 snow products,integrating these with precipitation(P)and temperature(T)data from ERA5.Our objective is to analyze the spatiotemporal distribution characteristics of snow cover and to use path analysis to elucidate the key climatic factors and spatial differences influencing snow cover changes.The findings indicate that,on a temporal scale,the overall SCP in HMA exhibited a declining trend from 2001 to 2021.Interannual variations in SCP across HMA sub-basins revealed a decreasing trend in the Pamir(PAM),Western Tibetan Plateau(WTS),Eastern Tibetan Plateau(ETS),Western Kunlun(WKL),Qilian Shan(QLS),and Himalaya(HDS)regions,while an increasing trend was observed in other areas.Spatially,22.97%of the HMA regions experienced an increase in SCD,primarily in the Western Himalaya(WHL),Central Himalaya(CHL),and Southeastern Xizang(SET)regions.Conversely,28.08%of the HMA regions showed a decrease in SCD,predominantly in the Eastern Himalaya(EHL),HDS,and WTS regions.Temperature(T)emerged as the primary influencing factor of SCD change in most HMA sub-basins.However,in the Eastern Kunlun(EKL)and WHL sub-basins,precipitation(P)was identified as the main driver of SCD change,affecting all elevation zones in these regions.Additionally,other climatic conditions can also impact snow cover beyond the primary controlling factor.展开更多
Rapid hole extraction from photoanodes to cocatalysts is a crucial prerequisite for the realization of highly efficient photoelectrochemical(PEC)water splitting.Herein,Mn-doped nickel-iron layered double hydroxides(Mn...Rapid hole extraction from photoanodes to cocatalysts is a crucial prerequisite for the realization of highly efficient photoelectrochemical(PEC)water splitting.Herein,Mn-doped nickel-iron layered double hydroxides(Mn:NiFe-LDHs),as a co-catalyst,were grafted on bismuth vanadate(BVO)for significantly improved charge transfer and stability simultaneously,in addition to the accelerated water oxidation kinetics.The detailed experimental and theoretical analysis collectively verify that Mn doping increases charge density around Ni and Fe sites.The electron-rich Ni sites boost the kinetics of oxygen evolution reaction and promote the hole extraction simultaneously.Moreover,the electrons are transferred from electron-rich Fe sites to V sites,which effectively restrains the dissolution of V^(5+)ions and enhances the stability of BVO photoanodes.Consequently,the resulting Mn:NiFe-LDH/BVO photoanode achieves a remarkable photocurrent density of 5.5 mA cm^(-2)at 1.23 V versus reversible hydrogen electrode(RHE)with excellent stability.The construction of electron-rich oxygen evolution cocatalysts provides a promising strategy to promote the hole extraction and increase the stability for improved PEC performance.展开更多
Zhengzhou is one of the most haze-polluted cities in Central China with high organic carbon emission,which accounts for 15%-20%of particulate matter(PM_(2.5))in winter and causes significantly adverse health effects.V...Zhengzhou is one of the most haze-polluted cities in Central China with high organic carbon emission,which accounts for 15%-20%of particulate matter(PM_(2.5))in winter and causes significantly adverse health effects.Volatile organic compounds(VOCs)are the precursors of secondary PM_(2.5)and O_(3)formation.An investigation of characteristics,sources and health risks assessment of VOCs was carried out at the urban area of Zhengzhou from 1^(st) to 31^(st) December,2019.The mean concentrations of total detected VOCs were 48.8±23.0 ppbv.Alkanes(22.0±10.4 ppbv),halocarbons(8.1±3.9 ppbv)and aromatics(6.5±3.9 ppbv)were the predominant VOC species,followed by alkenes(5.1±3.3 ppbv),oxygenated VOCs(3.6±1.8 ppbv),alkyne(3.5±1.9,ppbv)and sulfide(0.5±0.9 ppbv).The Positive Matrix Factorization model was used to identify and apportion VOCs sources.Five major sources of VOCs were identified as vehicular exhaust,industrial processes,combustion,fuel evaporation,and solvent use.The carcinogenic and non-carcinogenic risk values of species were calculated.The carcinogenic and non-carcinogenic risks of almost all air toxics increased during haze days.The total non-carcinogenic risks exceeded the acceptable ranges.Most VOC species posed no non-carcinogenic risk during three haze events.The carcinogenic risks of chloroform,1,2-dichloroethane,1,2-dibromoethane,benzyl chloride,hexachloro-1,3-butadiene,benzene and naphthalene were above the acceptable level(1.0×10^(-6))but below the tolerable risk level(1.0×10^(-4)).Industrial emission was the major contributor to non-carcinogenic,and solvent use was the major contributor to carcinogenic risks.展开更多
AIM： To observe the curative effect of galactosylated chitosan （GC）/5-fluorouracil （5-FU） nanoparticles in liver caner mice and its side effects. METHODS： The GC/5-FU nanoparticle is a nanomate- rial made by cou...AIM： To observe the curative effect of galactosylated chitosan （GC）/5-fluorouracil （5-FU） nanoparticles in liver caner mice and its side effects. METHODS： The GC/5-FU nanoparticle is a nanomate- rial made by coupling GC and 5-FU. The release experiment was performed in vitro. The orthotropic liver cancer mouse models were established and divided into control, GC, 5-FU and GC/5-FU groups. Mice in the control and GC group received an intravenous injection of 200 μL saline and GC, respectively. Mice in the 5-FU and GC/5-FU groups received 200 μL （containing 0.371 mg 5-FU） 5-FU and GC/5-FU, respectively. The tumor weight and survival time were observed. The cell cycle and apoptosis in tumor tissues were monitored by flow cytometry. The expression of p53, Bax, Bcl-2, caspase-3 and poly adenosine 50-diphosphate-ribose polymerase 1 （PARP-1） was detected by immunohistochemistry, reverse transcription-polymerase chain reaction and Western blot. The serum blood biochemical parameters and cytotoxic activity of natural killer （NK） cell and cy- totoxicity T lymphocyte （CTL） were measured. RESULTS： The GC/5-FU nanoparticle is a sustained release system. The drug loading was 6.12% ± 1.36%, the encapsulation efficiency was 81.82% ± 5.32%, and the Zeta potential was 10.34 ± 1.43 mV. The tu- mor weight in the GC/5-FU group （0.4361±0.1153 g vs 1.5801 ± 0.2821 g, P 〈 0.001） and the 5-FU （0.7932±0.1283 g vs 1.5801 ±0.2821 g, P 〈 0.001） was sig- nificantly lower than that in the control group; GC/5- FU treatment can significantly lower the tumor weight （0.4361± 0.1153 g vs 0.7932±0.1283 g, P 〈 0.001）, and the longest median survival time was seen in the GC/5-FU group, compared with the control （12 d vs 30 d, P 〈 0.001）, GC （13 d vs 30 d, P 〈 0.001） and 5-FU groups （17 d vs 30 d, P 〈 0.001）. Flow cytom- etry revealed that compared with the control, GC/5- FU caused a higher rate of G0-G1 arrest （52.79% ± 13.42% vs 23.92%±9.09%, P = 0.014 ） and apopto- sis （2.55% ±1.10% vs 11.13% ±11.73%, P 〈 0.001） in hepatic cancer cells. Analysis of the apoptosis path- ways showed that GC/5-FU upregulated the expression of p53 at both the protein and the mRNA levels, which in turn lowered the ratio of Bcl-2lBax expression; this led to the release of cytochrome C into the cytosol from the mitochondria and the subsequent activation of caspase-3. Upregulation of caspase-3 expression de- creased the PARP-1 at both the mRNA and the protein levels, which contributed to apoptosis. 5-FU increased the levels of aspartate aminotransferase and alanine aminotransferase, and decreased the numbers of platelet, white blood cell and lymphocyte and cytotoxic activities of CTL and NK cells, however, there were no such side effects in the GC/5-FU group. CONCLUSION： GC/5-FU nanoparticles can significant- ly inhibit the growth of liver cancer in mice via the p53 apoptosis pathway, and relieve the side effects and im- munosuppression of 5-FU.展开更多
Dear Editor, As a complex disease, the development and progression of hepatocellular carcinoma （HCC） involves the interactions of multiple proteins, genes and miRNAs in various biological pathways, and it has been ...Dear Editor, As a complex disease, the development and progression of hepatocellular carcinoma （HCC） involves the interactions of multiple proteins, genes and miRNAs in various biological pathways, and it has been extensively studied with different high-throughput techniques. However, efforts to integrate multiple data sources at different levels, especially with regard to biological pathways and interaction networks, are still negligible in the HCC research field.展开更多
There is a global movement calling for the integration of Western medicine（WM）and traditional Chinese medicine（TCM）[1].The World Health Organization suggests that health care would be improved by integrating tradi...There is a global movement calling for the integration of Western medicine（WM）and traditional Chinese medicine（TCM）[1].The World Health Organization suggests that health care would be improved by integrating traditional and complementary medicines into the practices of health care service delivery and self-health care[1].The WM and TCM are commonly integrated in the contemporary practice of medicine in China.展开更多
Aurum nanomaterials(ANM), combining the features of nanotechnology and metal elements, have demonstrated enormous potential and aroused great attention on biomedical applications over the past few decades. Particularl...Aurum nanomaterials(ANM), combining the features of nanotechnology and metal elements, have demonstrated enormous potential and aroused great attention on biomedical applications over the past few decades. Particularly, their advantages, such as controllable particle size, flexible surface modification, higher drug loading, good stability and biocompatibility, especially unique optical properties, promote the development of ANM in biomedical field. In this review, we will discuss the advanced preparation process of ANM and summarize their recent applications as well as their prospects in diagnosis and therapy. Besides, multi-functional ANM-based theranostic nanosystems will be introduced in details, including radiotherapy(RT), photothermal therapy(PTT), photodynamic therapy(PDT), immunotherapy(IT), and so on.展开更多
Inorganic photocatalysts have been regarded as a promising candidate in the domain of tumor photodynamic therapy(PDT)due to their inspirational photocatalytic activity.In this study,a Bi_(4)O_(5)Br_(2)photocatalyst wa...Inorganic photocatalysts have been regarded as a promising candidate in the domain of tumor photodynamic therapy(PDT)due to their inspirational photocatalytic activity.In this study,a Bi_(4)O_(5)Br_(2)photocatalyst was synthesized and it exhibited effective photo-killing activity of A549 cells(a human lung carcinoma epithelial cell line)in vitro.On this basis,we modified Bi_(4)O_(5)Br_(2)with carbon quantum dots(CQDs)via a hydrolysis method at room temperature,which resulted in an improved photo-killing effect of Bi_(4)O_(5)Br_(2)to A549 cells.The samples and the interaction between samples and cells were fully characterized.It has been found that the loading of CQDs on Bi_(4)O_(5)Br_(2)can reduce the hydration ratio,increase the cellular uptake and improve the photogenerated reactive oxygen species(ROS)as compared with pristine Bi_(4)O_(5)Br_(2).Electron spin resonance(ESR)analysis and radical-trapping experiments manifested that the ROS contributed to PDT may be·O^(2-)and ·OH.This study may provide a useful strategy to ameliorate the penetrability,cell compatibility and PDT effect upon cancer cells of other inorganic photocatalysts.展开更多
Introduction of the photothermal effect into transition-metal oxide photoanodes has been proven to be an effective method to improve the photoelectrochemical(PEC)water-splitting performance.However,the precise role of...Introduction of the photothermal effect into transition-metal oxide photoanodes has been proven to be an effective method to improve the photoelectrochemical(PEC)water-splitting performance.However,the precise role of the photothermal effect on the PEC performance of photoanodes is still not well understood.Herein,spinel-structured ZnFe_(2)O_(4)nanoparticles are deposited on the surface of hematite(Fe_(2)O_(3)),and the ZnFe_(2)O_(4)/Fe_(2)O_(3)photoanode achieves a high photocurrent density of 3.17 mA cm^(-2)at 1.23 V versus a reversible hydrogen electrode(VRHE)due to the photothermal effect of ZnFe_(2)O_(4).Considering that the hopping of electron small polarons induced by oxygen vacancies is thermally activated,we clarify that the main reason for the enhanced PEC performance via the photothermal effect is the promoted mobility of electron small polarons that are bound to positively charged oxygen vacancies.Under the synergistic effect of oxygen vacancies and the photothermal effect,the electron conductivity and PEC performance are significantly improved,which provide fundamental insights into the impact of the photothermal effect on the PEC performance of small polaron-type semiconductor photoanodes.展开更多
The combination regimen of trastuzumab(Tras)plus Nab-paclitaxel(Nab)is recommended to treat HER2-positive(HER2+)cancers.However,they exert effects in different mechanisms:Tras need to stay on cell membranes,while Nab ...The combination regimen of trastuzumab(Tras)plus Nab-paclitaxel(Nab)is recommended to treat HER2-positive(HER2+)cancers.However,they exert effects in different mechanisms:Tras need to stay on cell membranes,while Nab need to be endocytosed,therefore the concurrent combination regimen may not be the best one in HER2+tumors treatment.Caveolin-1(Cav-1)is a key player in mediating their endocytosis and is associated with their efficacy,but few researches noticed the opposite effect of Cav-1 expression on the combination efficacy.Herein,we systematically studied the Cav-1 expression level on the combination efficacy and proposed an optimized and clinically feasible combination regimen for HER2+Cav-1 High tumor treatment.In the regimen,lovastatin(Lova)was introduced to modulate the Cav-1 expression and the results indicated that Lova could downregulate Cav-1 expression,increase Tras retention on cell membrane and enhance the in vitro cytotoxicity of Tras in HER2+Cav-1 High cells but not in HER2+Cav-1 Low cells.Therefore,by exchanging the dosing sequence of Nab and Tras,and by adding Lova at appropriate time points,the precise three-drug-sequential regimen(PTDS,Nab(D1)-Lova(D2)-Lova&Tras(D2+12 h))was established.Compared with the concurrent regimen,the PTDS regimen exhibited a higher in vitro cytotoxicity and a stronger tumor growth inhibition in HER2+Cav-1 High tumors,which might be a promising combination regimen for these patients in clinics.展开更多
The application of nanomedicines in oral drug delivery effectively promotes the drug absorption and transportation through enterocytes.Nevertheless,the absence of mechanism studies on efficacy and safety limits their ...The application of nanomedicines in oral drug delivery effectively promotes the drug absorption and transportation through enterocytes.Nevertheless,the absence of mechanism studies on efficacy and safety limits their final translation in humans.Although the vesicular trafficking has been verified as the general character for transport of nanomedicines,the deeper mechanism in molecular mechanism is still unclear.Moreover,the cellular transport of nanomedicines is a dynamic process involved by different organelles and components.However,most of existing studies just pay attention to the static location of nanomedicines,but neglect the dynamic biological effects on cells caused by them.Here,we prepared gold nanoparticles(Au NPs)as the model and cultured epithelial cell monolayer to explore the nano-bio interactions at the molecular level.The traditional pharmacological inhibition strategy and subcellular imaging technology elucidated the macropinocytosis/endosome/MVB/lysosome pathway during the transportation of Au NPs.Proteomics strategy based on mass spectrometry(MS)was utilized to identify and quantify proteins involved in the cellular transport of nanomedicines.Multiple proteins related to subcellular structure,signal transduction,energy transformation and metabolism regulation were demonstrated to be regulated by nanoparticle transport.These alterations of protein expression clarified the effects of intracellular proteins and verified the conventional findings.More importantly,it revealed a feedback mechanism of cells to the nano-trafficking.We believed that these new regulatory mechanisms provided new insights into the efficient transport of nanomedicines through epithelial barriers.展开更多
The interplay among diverse cell populations in the tumor microenvironment contributes to tumor progression.Targeting to different cell populations might result in improved therapeutic effects on malignant tumors.Inte...The interplay among diverse cell populations in the tumor microenvironment contributes to tumor progression.Targeting to different cell populations might result in improved therapeutic effects on malignant tumors.Integrins high express on many kinds of tumor cells,and VEGF has a strong effect on tumor angiogenesis.Therefore,based on tumor cells and angiogenesis,we fabricated integrin-targeting cRGD-DOX nanoparticles and combined them with the anti-VEGF antibody bevacizumab.We evaluated the antitumor effect of this combination therapy in an integrin-overexpressing MDA-MB-231 tumor model.The cRGD-DOX nanoparticles were effectively uptake by MDA-MB-231 cells and the uptake was related to the expression of integrinin;cRGD-DOX nanoparticles showed less cytotoxic than free DOX;Bevacizumab did not show significant cytotoxicity against MDA-MB-231 cells at concentrations less than 1 mg/mL.The in vivo results showed that bevacizumab could reduce tumor interstitial fluid pressure;the combination of bevacizumab and cRGD-DOX nanoparticles showed enhanced antitumor effects compared with the corresponding single-agent treatments.These findings suggested the combination of angiogenesis antibody and integrin-targeting nanoparticle loaded with a cytotoxic drug was a promising cancer treatment regimen.展开更多
Photothermal(PTT) and photodynamic(PDT) combined therapy has been hindered to clinical translation, due to the lack of available biomaterials, difficult designs of functions,and complex chemical synthetic or preparati...Photothermal(PTT) and photodynamic(PDT) combined therapy has been hindered to clinical translation, due to the lack of available biomaterials, difficult designs of functions,and complex chemical synthetic or preparation procedures. To actualize a high-efficiency combination therapy for cancer via a feasible approach, three readily available materials are simply associated together in one-pot, namely the single-walled carbon nanohorns(SWCNH), zinc phthalocyanine(ZnPc), and surfactant TPGS. The established nanodispersion is recorded as PCT. The association of SWCNH/ZnPc/TPGS was confirmed by energy dispersive spectrum, Raman spectrum and thermogravimetric analysis. Under lighting, PCT induced a temperature rising up to about 60 ℃ due to the presence of SWCNH, production a 7-folds of singlet oxygen level elevation because of ZnPc, which destroyed almost all4T1 tumor cells in vitro. The photothermal effect of PCT depended on both laser intensity and nanodispersion concentration in a linear and nonlinear manner, respectively. After a single peritumoral injection in mice and laser treatment, PCT exhibited the highest tumor temperature rise(to 65 ℃) among all test groups, completely destroyed primary tumor without obvious toxicity, and inhibited distant site tumor. Generally, this study demonstrated the high potential of PCT nanodispersion in tumor combined therapy.展开更多
[Objectives]This study was conducted to investigate the effects of artificially cultured Eisenia foetida and wild earthworms ( Pheretima sp.) on the changes of microbial populations in forest soil in different seasons...[Objectives]This study was conducted to investigate the effects of artificially cultured Eisenia foetida and wild earthworms ( Pheretima sp.) on the changes of microbial populations in forest soil in different seasons.[Methods]Artificially cultured E.foetida and wild earthworms were introduced to forest soil,and changes in the number of microbial populations under earthworm-microbe interaction were investigated in different seasons by tracking observation.The effects of earthworm activities on the number of different microbial populations were discussed also.[Results]Different microbial populations all increased in the soil to different degrees after the introduction of earthworms.The effects of the wild earthworms on the changes in bacteria,actinomycetes and fungi in the soil were different from those of artificially cultivated earthworms to certain degrees.[Conclusions]This study provides a theoretical basis for organic agriculture that relies on the decomposition of organic matter to release nutrients.展开更多
Nanotechnology has been widely used in the field of medicine, and it can significantly improve the bioavailability and the target efficiency of medicines. However, after administration, nanomedicines can adsorb biomol...Nanotechnology has been widely used in the field of medicine, and it can significantly improve the bioavailability and the target efficiency of medicines. However, after administration, nanomedicines can adsorb biomolecules that can influence their effects. It was reported that the adsorption of plasma proteins can change the surface properties of nanoparticles. When nanoparticles pass through cells, they may carry some cellular proteins out of cells. Currently, it is unclear whether the adsorbed proteins affect the uptake of nanoparticles in the next cell layer. To simplify this complex biological process, BSA-capped gold nanoparticles were prepared and incubated with Caco-2 cell lysate to simulate conditions of transcytosis through epithelial cells. The surface morphology of nanoparticles was examined by TEM. SRB was used to evaluate the cytotoxicity of the nanoparticles. The uptake and cellular distribution of the nanoparticles were detected by ICP-MS and CLSM. The results suggested that the adsorption of cell proteins could enhance the adhesion and uptake of gold nanoparticles. The gold nanoparticles were mainly located in lysosomes, and there were some Lysate-capped AuNPs in the mitochondria whereas no BSA-capped AuNPs appeared there.展开更多
The secondary flow driven by the primary vortex in a cylinder,generating the so called"tea leaf paradox",is fundamental for understanding many natural phenomena,industrial applications and scientific researc...The secondary flow driven by the primary vortex in a cylinder,generating the so called"tea leaf paradox",is fundamental for understanding many natural phenomena,industrial applications and scientific researches.In this work,the effect of wettability on the primary vortex and secondary flow is investigated by the three-dimensional multiphase lattice Boltzmann method based on a chemical potential.We find that the surface wettability strongly affects the shape of the primary vortex.With the increase of the contact angle of the cylinder,the sectional plane of the primary vortex gradually changes from a steep valley into a saddle with two raised parts.Because the surface friction is reduced correspondingly,the core of the secondary vortex moves to the centerline of the cylinder and the vortex intensity also increases.The stirring force has stronger effects to enhance the secondary flow and push the vortex up than the surface wettability.Interestingly,a small secondary vortex is discovered near the three-phase contact line when the surface has a moderate wettability,owing to the interaction between the secondary flow and the curved gas/liquid interface.展开更多
A calculation method for heats of formation (HOF, referred to as △Hf) based on the density functional theory (DFT) is presented in this work. Similar to Gaussian-3 theory, the atomic scheme is applied to calculate th...A calculation method for heats of formation (HOF, referred to as △Hf) based on the density functional theory (DFT) is presented in this work. Similar to Gaussian-3 theory, the atomic scheme is applied to calculate the heats of formation of the molecules. In this method, we have modified the formula for calculation of Gaussian-3 theory in several ways, including the correction for diffuse functions and the correction for higher polarization functions. These corrections are found to be significant. The average absolute deviation from experiment for the 164 calculated heats of formation is about 1.9 kcal·mol?1, while average absolute deviation from G3MP2 for the 149 (among the 164 molecules, 15 large-sized molecules can not be calculated at the G3MP2 level) calculated heats of formation is only about 1.9 kcal·mol?1. It indicates that the present method can be applied to predict the heats of formation of medium-sized and large-sized molecules, while the heats of formation of these molecules using Gaussian-3 theory are much difficult, even impossible, to calculate. That is, this method provides a choice in the calculation of △Hf for medium-sized and large-sized molecules.展开更多
Due to complex geological structures and a narrow safe mud density window,offshore fractured formations frequently encounter severe lost circulation(LC)during drilling,significantly hindering oil and gas exploration a...Due to complex geological structures and a narrow safe mud density window,offshore fractured formations frequently encounter severe lost circulation(LC)during drilling,significantly hindering oil and gas exploration and development.Predicting LC risks enables the targeted implementation of mitigation strategies,thereby reducing the frequency of such incidents.To address the limitations of existing 3D geomechanical modeling in predicting LC,such as arbitrary factor selection,subjective weight assignment,and the inability to achieve pre-drilling prediction along the entire well section,an improved prediction method is proposed.This method integrates multi-source data and incorporates three LC-related sensitivity factors:fracture characteristics,rock brittleness,and in-situ stress conditions.A quantitative risk assessment model for LC is developed by combining the subjective analytic hierarchy process with the objective entropy weight method(EWM)to assign weights.Subsequently,3D geomechanical modeling is applied to identify regional risk zones,enabling digital visualization for pre-drilling risk prediction.The developed 3D LC risk prediction model was validated using actual LC incidents from drilled wells.Results were generally consistent with field-identified LC zones,with an average relative error of 19.08%,confirming its reliability.This method provides practical guidance for mitigating potential LC risks and optimizing drilling program designs in fractured formations.展开更多
In this research,a high ductility Mg-Gd-Mn magnesium alloy was designed and developed,with an elongation capability surpassing 50%.To gain insights into the underlying mechanism behind the high ductility of the Mg-2Gd...In this research,a high ductility Mg-Gd-Mn magnesium alloy was designed and developed,with an elongation capability surpassing 50%.To gain insights into the underlying mechanism behind the high ductility of the Mg-2Gd-0.5Mn alloy,quasi-in-situ electron backscattered diffraction and two-beam diffraction were conducted.The results reveal that the Mg-Gd-Mn alloy exhibits a distinct rare-earth texture,and the activation of non-basal slip systems is evident from the clear observation of non-basal slip traces during the later stages of deformation.However,the primary deformation mechanisms in Mg-Gd-Mn alloy remain basalslip and{10–12}tensile twinning,and the remarkable ductility observed in Mg-Gd-Mn alloys can be attributed to the softening of non-basal slip modes,which leads to a coordinated deformation between various modes of deformation.To further validate this conclusion,an analysis was conducted using a visco-plastic self-consistent(VPSC)model to investigate the relative activity of basal and non-basal slip in Mg-Gd-Mn alloys.The obtained results align well with experimental observations,providing additional support for the hypothesis.展开更多
Photoelectrochemical(PEC)water splitting using bismuth vanadate(BiVO_(4))as a photoanode shows promise for renewable hydrogen production.Depositing cobalt phosphate(CoPi)on the BiVO_(4)photoanode as an oxygen evolutio...Photoelectrochemical(PEC)water splitting using bismuth vanadate(BiVO_(4))as a photoanode shows promise for renewable hydrogen production.Depositing cobalt phosphate(CoPi)on the BiVO_(4)photoanode as an oxygen evolution cocatalyst(OEC)is an effective method to improve the PEC performance.However,the CoPi/BiVO_(4)photoanode still faces challenges in terms of slow interface photogenerated carrier transport.Herein,we utilize the advantage of the classical strong metal-support interaction(SMSI)between Au and BiVO_(4)to prepare a CoPi/Au/BiVO_(4)(SMSI-CoPi/Au/BiVO_(4))photoanode.Due to the formation of SMSI,the accumulated electrons at the interface of CoPi/Au induce the accelerated extraction of photogenerated holes.Meanwhile,the active electron density of CoPi is increased,leading to improved water oxidation kinetic.As a result,the SMSI-CoPi/Au/BiVO_(4)photoanode exhibits a high photocurrent density of 5.01 m A cm^(-2)at 1.23 V versus the reversible hydrogen electrode and an applied bias photon-to-current efficiency of 1.78%.This work highlights a novel approach to enhance hole transfer and water oxidation kinetics of OEC/BiVO_(4)composite photoanodes,offering the great potential of using SMSI for PEC water splitting.展开更多
基金supported by Tianchi talent project(Granted No.51052401507)。
文摘The High Mountain Asia(HMA)is a prominent global mountain system characterized by an average altitude exceeding 4,000 m,intricate topography,and significant spatial variability in climatic conditions.Despite its importance,there has been a relative paucity of research focusing on the spatiotemporal variations of snow cover,key controlling factors,and variability within HMA sub-basins.This study aims to address this gap by extracting snow cover percentage(SCP)and snow cover days(SCD)data from MOD10A2 snow products,integrating these with precipitation(P)and temperature(T)data from ERA5.Our objective is to analyze the spatiotemporal distribution characteristics of snow cover and to use path analysis to elucidate the key climatic factors and spatial differences influencing snow cover changes.The findings indicate that,on a temporal scale,the overall SCP in HMA exhibited a declining trend from 2001 to 2021.Interannual variations in SCP across HMA sub-basins revealed a decreasing trend in the Pamir(PAM),Western Tibetan Plateau(WTS),Eastern Tibetan Plateau(ETS),Western Kunlun(WKL),Qilian Shan(QLS),and Himalaya(HDS)regions,while an increasing trend was observed in other areas.Spatially,22.97%of the HMA regions experienced an increase in SCD,primarily in the Western Himalaya(WHL),Central Himalaya(CHL),and Southeastern Xizang(SET)regions.Conversely,28.08%of the HMA regions showed a decrease in SCD,predominantly in the Eastern Himalaya(EHL),HDS,and WTS regions.Temperature(T)emerged as the primary influencing factor of SCD change in most HMA sub-basins.However,in the Eastern Kunlun(EKL)and WHL sub-basins,precipitation(P)was identified as the main driver of SCD change,affecting all elevation zones in these regions.Additionally,other climatic conditions can also impact snow cover beyond the primary controlling factor.
基金financially supported by the National Natural Science Foundation of China(Nos.52472241,52403108 and 52301285)the Department of Science and Technology of Hubei Province(Nos.2025AFA114 and 2024CSA076)+1 种基金Wuhan Science and Technology Bureau(Nos.2023020201010116 and 2024040801020319)Hubei Provincial Department of Education(No.Q20231703)
文摘Rapid hole extraction from photoanodes to cocatalysts is a crucial prerequisite for the realization of highly efficient photoelectrochemical(PEC)water splitting.Herein,Mn-doped nickel-iron layered double hydroxides(Mn:NiFe-LDHs),as a co-catalyst,were grafted on bismuth vanadate(BVO)for significantly improved charge transfer and stability simultaneously,in addition to the accelerated water oxidation kinetics.The detailed experimental and theoretical analysis collectively verify that Mn doping increases charge density around Ni and Fe sites.The electron-rich Ni sites boost the kinetics of oxygen evolution reaction and promote the hole extraction simultaneously.Moreover,the electrons are transferred from electron-rich Fe sites to V sites,which effectively restrains the dissolution of V^(5+)ions and enhances the stability of BVO photoanodes.Consequently,the resulting Mn:NiFe-LDH/BVO photoanode achieves a remarkable photocurrent density of 5.5 mA cm^(-2)at 1.23 V versus reversible hydrogen electrode(RHE)with excellent stability.The construction of electron-rich oxygen evolution cocatalysts provides a promising strategy to promote the hole extraction and increase the stability for improved PEC performance.
基金supported by the Study of Collaborative Control of PM_(2.5)and O_(3)Pollution in Zhengzhou City(No.20200321A)。
文摘Zhengzhou is one of the most haze-polluted cities in Central China with high organic carbon emission,which accounts for 15%-20%of particulate matter(PM_(2.5))in winter and causes significantly adverse health effects.Volatile organic compounds(VOCs)are the precursors of secondary PM_(2.5)and O_(3)formation.An investigation of characteristics,sources and health risks assessment of VOCs was carried out at the urban area of Zhengzhou from 1^(st) to 31^(st) December,2019.The mean concentrations of total detected VOCs were 48.8±23.0 ppbv.Alkanes(22.0±10.4 ppbv),halocarbons(8.1±3.9 ppbv)and aromatics(6.5±3.9 ppbv)were the predominant VOC species,followed by alkenes(5.1±3.3 ppbv),oxygenated VOCs(3.6±1.8 ppbv),alkyne(3.5±1.9,ppbv)and sulfide(0.5±0.9 ppbv).The Positive Matrix Factorization model was used to identify and apportion VOCs sources.Five major sources of VOCs were identified as vehicular exhaust,industrial processes,combustion,fuel evaporation,and solvent use.The carcinogenic and non-carcinogenic risk values of species were calculated.The carcinogenic and non-carcinogenic risks of almost all air toxics increased during haze days.The total non-carcinogenic risks exceeded the acceptable ranges.Most VOC species posed no non-carcinogenic risk during three haze events.The carcinogenic risks of chloroform,1,2-dichloroethane,1,2-dibromoethane,benzyl chloride,hexachloro-1,3-butadiene,benzene and naphthalene were above the acceptable level(1.0×10^(-6))but below the tolerable risk level(1.0×10^(-4)).Industrial emission was the major contributor to non-carcinogenic,and solvent use was the major contributor to carcinogenic risks.
基金Supported by Natural Science Foundation of Shanghai,No.09ZR1424700 and 114119a4700Minhang District Natural Science Foundation of Shanghai,No. 2009MHZ085grants from Minhang District Public Health Bureau of Shanghai,No.2009MW28
文摘AIM： To observe the curative effect of galactosylated chitosan （GC）/5-fluorouracil （5-FU） nanoparticles in liver caner mice and its side effects. METHODS： The GC/5-FU nanoparticle is a nanomate- rial made by coupling GC and 5-FU. The release experiment was performed in vitro. The orthotropic liver cancer mouse models were established and divided into control, GC, 5-FU and GC/5-FU groups. Mice in the control and GC group received an intravenous injection of 200 μL saline and GC, respectively. Mice in the 5-FU and GC/5-FU groups received 200 μL （containing 0.371 mg 5-FU） 5-FU and GC/5-FU, respectively. The tumor weight and survival time were observed. The cell cycle and apoptosis in tumor tissues were monitored by flow cytometry. The expression of p53, Bax, Bcl-2, caspase-3 and poly adenosine 50-diphosphate-ribose polymerase 1 （PARP-1） was detected by immunohistochemistry, reverse transcription-polymerase chain reaction and Western blot. The serum blood biochemical parameters and cytotoxic activity of natural killer （NK） cell and cy- totoxicity T lymphocyte （CTL） were measured. RESULTS： The GC/5-FU nanoparticle is a sustained release system. The drug loading was 6.12% ± 1.36%, the encapsulation efficiency was 81.82% ± 5.32%, and the Zeta potential was 10.34 ± 1.43 mV. The tu- mor weight in the GC/5-FU group （0.4361±0.1153 g vs 1.5801 ± 0.2821 g, P 〈 0.001） and the 5-FU （0.7932±0.1283 g vs 1.5801 ±0.2821 g, P 〈 0.001） was sig- nificantly lower than that in the control group; GC/5- FU treatment can significantly lower the tumor weight （0.4361± 0.1153 g vs 0.7932±0.1283 g, P 〈 0.001）, and the longest median survival time was seen in the GC/5-FU group, compared with the control （12 d vs 30 d, P 〈 0.001）, GC （13 d vs 30 d, P 〈 0.001） and 5-FU groups （17 d vs 30 d, P 〈 0.001）. Flow cytom- etry revealed that compared with the control, GC/5- FU caused a higher rate of G0-G1 arrest （52.79% ± 13.42% vs 23.92%±9.09%, P = 0.014 ） and apopto- sis （2.55% ±1.10% vs 11.13% ±11.73%, P 〈 0.001） in hepatic cancer cells. Analysis of the apoptosis path- ways showed that GC/5-FU upregulated the expression of p53 at both the protein and the mRNA levels, which in turn lowered the ratio of Bcl-2lBax expression; this led to the release of cytochrome C into the cytosol from the mitochondria and the subsequent activation of caspase-3. Upregulation of caspase-3 expression de- creased the PARP-1 at both the mRNA and the protein levels, which contributed to apoptosis. 5-FU increased the levels of aspartate aminotransferase and alanine aminotransferase, and decreased the numbers of platelet, white blood cell and lymphocyte and cytotoxic activities of CTL and NK cells, however, there were no such side effects in the GC/5-FU group. CONCLUSION： GC/5-FU nanoparticles can significant- ly inhibit the growth of liver cancer in mice via the p53 apoptosis pathway, and relieve the side effects and im- munosuppression of 5-FU.
基金Supplementary information is linked to the online version of the paper on the Cell Research website. Acknowledgments We are very thankful to Dr Dusan M Jeftinija （Department of Neurosience ＆ Anatomy, University of Louisville, Kentucky, USA） for his help during the manuscript preparation. This work was supported by grants from the State Key Program of Basic Research of China （2007CB108800, 2009CB918400, 2010CB912102）, the Hi-Tech Research and Development Program of China （2006AA02Z313）, National Natural Science Foundation of China （30870575） and Science and Technology Commission of Shanghai Municipality （06DZ22923）.
文摘Dear Editor, As a complex disease, the development and progression of hepatocellular carcinoma （HCC） involves the interactions of multiple proteins, genes and miRNAs in various biological pathways, and it has been extensively studied with different high-throughput techniques. However, efforts to integrate multiple data sources at different levels, especially with regard to biological pathways and interaction networks, are still negligible in the HCC research field.
文摘There is a global movement calling for the integration of Western medicine（WM）and traditional Chinese medicine（TCM）[1].The World Health Organization suggests that health care would be improved by integrating traditional and complementary medicines into the practices of health care service delivery and self-health care[1].The WM and TCM are commonly integrated in the contemporary practice of medicine in China.
基金Supported by the National Basic Research Program of China(2015CB932100)
文摘Aurum nanomaterials(ANM), combining the features of nanotechnology and metal elements, have demonstrated enormous potential and aroused great attention on biomedical applications over the past few decades. Particularly, their advantages, such as controllable particle size, flexible surface modification, higher drug loading, good stability and biocompatibility, especially unique optical properties, promote the development of ANM in biomedical field. In this review, we will discuss the advanced preparation process of ANM and summarize their recent applications as well as their prospects in diagnosis and therapy. Besides, multi-functional ANM-based theranostic nanosystems will be introduced in details, including radiotherapy(RT), photothermal therapy(PTT), photodynamic therapy(PDT), immunotherapy(IT), and so on.
基金This research was financially supported by the National Natural Science Foundation of China(Nos.21303116,21676178 and 21706179).
文摘Inorganic photocatalysts have been regarded as a promising candidate in the domain of tumor photodynamic therapy(PDT)due to their inspirational photocatalytic activity.In this study,a Bi_(4)O_(5)Br_(2)photocatalyst was synthesized and it exhibited effective photo-killing activity of A549 cells(a human lung carcinoma epithelial cell line)in vitro.On this basis,we modified Bi_(4)O_(5)Br_(2)with carbon quantum dots(CQDs)via a hydrolysis method at room temperature,which resulted in an improved photo-killing effect of Bi_(4)O_(5)Br_(2)to A549 cells.The samples and the interaction between samples and cells were fully characterized.It has been found that the loading of CQDs on Bi_(4)O_(5)Br_(2)can reduce the hydration ratio,increase the cellular uptake and improve the photogenerated reactive oxygen species(ROS)as compared with pristine Bi_(4)O_(5)Br_(2).Electron spin resonance(ESR)analysis and radical-trapping experiments manifested that the ROS contributed to PDT may be·O^(2-)and ·OH.This study may provide a useful strategy to ameliorate the penetrability,cell compatibility and PDT effect upon cancer cells of other inorganic photocatalysts.
基金This work was supported by the National Natural Science Foundation of China(51902297,52002361,52003300,and 22109120)the Zhejiang Provincial Natural Science Foundation of China(LQ21B030002)the fund of the Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education,and Hubei Key Laboratory of Catalysis and Materials Science.
文摘Introduction of the photothermal effect into transition-metal oxide photoanodes has been proven to be an effective method to improve the photoelectrochemical(PEC)water-splitting performance.However,the precise role of the photothermal effect on the PEC performance of photoanodes is still not well understood.Herein,spinel-structured ZnFe_(2)O_(4)nanoparticles are deposited on the surface of hematite(Fe_(2)O_(3)),and the ZnFe_(2)O_(4)/Fe_(2)O_(3)photoanode achieves a high photocurrent density of 3.17 mA cm^(-2)at 1.23 V versus a reversible hydrogen electrode(VRHE)due to the photothermal effect of ZnFe_(2)O_(4).Considering that the hopping of electron small polarons induced by oxygen vacancies is thermally activated,we clarify that the main reason for the enhanced PEC performance via the photothermal effect is the promoted mobility of electron small polarons that are bound to positively charged oxygen vacancies.Under the synergistic effect of oxygen vacancies and the photothermal effect,the electron conductivity and PEC performance are significantly improved,which provide fundamental insights into the impact of the photothermal effect on the PEC performance of small polaron-type semiconductor photoanodes.
基金by the National Natural Science Foundation of China(Nos.81872809,82073786)the Beijing Natural Science Foundation(L212013).
文摘The combination regimen of trastuzumab(Tras)plus Nab-paclitaxel(Nab)is recommended to treat HER2-positive(HER2+)cancers.However,they exert effects in different mechanisms:Tras need to stay on cell membranes,while Nab need to be endocytosed,therefore the concurrent combination regimen may not be the best one in HER2+tumors treatment.Caveolin-1(Cav-1)is a key player in mediating their endocytosis and is associated with their efficacy,but few researches noticed the opposite effect of Cav-1 expression on the combination efficacy.Herein,we systematically studied the Cav-1 expression level on the combination efficacy and proposed an optimized and clinically feasible combination regimen for HER2+Cav-1 High tumor treatment.In the regimen,lovastatin(Lova)was introduced to modulate the Cav-1 expression and the results indicated that Lova could downregulate Cav-1 expression,increase Tras retention on cell membrane and enhance the in vitro cytotoxicity of Tras in HER2+Cav-1 High cells but not in HER2+Cav-1 Low cells.Therefore,by exchanging the dosing sequence of Nab and Tras,and by adding Lova at appropriate time points,the precise three-drug-sequential regimen(PTDS,Nab(D1)-Lova(D2)-Lova&Tras(D2+12 h))was established.Compared with the concurrent regimen,the PTDS regimen exhibited a higher in vitro cytotoxicity and a stronger tumor growth inhibition in HER2+Cav-1 High tumors,which might be a promising combination regimen for these patients in clinics.
基金The National Key R&D Program of China(Grant No.2017YFA0205600)the National Natural Science Foundation of China(Grant No.81690264,81573359 and 81703441)。
文摘The application of nanomedicines in oral drug delivery effectively promotes the drug absorption and transportation through enterocytes.Nevertheless,the absence of mechanism studies on efficacy and safety limits their final translation in humans.Although the vesicular trafficking has been verified as the general character for transport of nanomedicines,the deeper mechanism in molecular mechanism is still unclear.Moreover,the cellular transport of nanomedicines is a dynamic process involved by different organelles and components.However,most of existing studies just pay attention to the static location of nanomedicines,but neglect the dynamic biological effects on cells caused by them.Here,we prepared gold nanoparticles(Au NPs)as the model and cultured epithelial cell monolayer to explore the nano-bio interactions at the molecular level.The traditional pharmacological inhibition strategy and subcellular imaging technology elucidated the macropinocytosis/endosome/MVB/lysosome pathway during the transportation of Au NPs.Proteomics strategy based on mass spectrometry(MS)was utilized to identify and quantify proteins involved in the cellular transport of nanomedicines.Multiple proteins related to subcellular structure,signal transduction,energy transformation and metabolism regulation were demonstrated to be regulated by nanoparticle transport.These alterations of protein expression clarified the effects of intracellular proteins and verified the conventional findings.More importantly,it revealed a feedback mechanism of cells to the nano-trafficking.We believed that these new regulatory mechanisms provided new insights into the efficient transport of nanomedicines through epithelial barriers.
基金National Natural Science Foundation of China(Grant No.81690264)the National Key Research and Development Program of China(Grant No.2017YFA0205600)Beijing Natural Science Foundation(Grant No.7162108)
文摘The interplay among diverse cell populations in the tumor microenvironment contributes to tumor progression.Targeting to different cell populations might result in improved therapeutic effects on malignant tumors.Integrins high express on many kinds of tumor cells,and VEGF has a strong effect on tumor angiogenesis.Therefore,based on tumor cells and angiogenesis,we fabricated integrin-targeting cRGD-DOX nanoparticles and combined them with the anti-VEGF antibody bevacizumab.We evaluated the antitumor effect of this combination therapy in an integrin-overexpressing MDA-MB-231 tumor model.The cRGD-DOX nanoparticles were effectively uptake by MDA-MB-231 cells and the uptake was related to the expression of integrinin;cRGD-DOX nanoparticles showed less cytotoxic than free DOX;Bevacizumab did not show significant cytotoxicity against MDA-MB-231 cells at concentrations less than 1 mg/mL.The in vivo results showed that bevacizumab could reduce tumor interstitial fluid pressure;the combination of bevacizumab and cRGD-DOX nanoparticles showed enhanced antitumor effects compared with the corresponding single-agent treatments.These findings suggested the combination of angiogenesis antibody and integrin-targeting nanoparticle loaded with a cytotoxic drug was a promising cancer treatment regimen.
基金supported by the National Natural Science Foundation of China (81690264)the National Basic Research Program of China (2015CB932100)the Innovation Team of the Ministry of Education (BMU20110263)。
文摘Photothermal(PTT) and photodynamic(PDT) combined therapy has been hindered to clinical translation, due to the lack of available biomaterials, difficult designs of functions,and complex chemical synthetic or preparation procedures. To actualize a high-efficiency combination therapy for cancer via a feasible approach, three readily available materials are simply associated together in one-pot, namely the single-walled carbon nanohorns(SWCNH), zinc phthalocyanine(ZnPc), and surfactant TPGS. The established nanodispersion is recorded as PCT. The association of SWCNH/ZnPc/TPGS was confirmed by energy dispersive spectrum, Raman spectrum and thermogravimetric analysis. Under lighting, PCT induced a temperature rising up to about 60 ℃ due to the presence of SWCNH, production a 7-folds of singlet oxygen level elevation because of ZnPc, which destroyed almost all4T1 tumor cells in vitro. The photothermal effect of PCT depended on both laser intensity and nanodispersion concentration in a linear and nonlinear manner, respectively. After a single peritumoral injection in mice and laser treatment, PCT exhibited the highest tumor temperature rise(to 65 ℃) among all test groups, completely destroyed primary tumor without obvious toxicity, and inhibited distant site tumor. Generally, this study demonstrated the high potential of PCT nanodispersion in tumor combined therapy.
基金Supported by Scientific Reserch Fund of Sichuan Provincial Education Department in 2015(15ZA0335)
文摘[Objectives]This study was conducted to investigate the effects of artificially cultured Eisenia foetida and wild earthworms ( Pheretima sp.) on the changes of microbial populations in forest soil in different seasons.[Methods]Artificially cultured E.foetida and wild earthworms were introduced to forest soil,and changes in the number of microbial populations under earthworm-microbe interaction were investigated in different seasons by tracking observation.The effects of earthworm activities on the number of different microbial populations were discussed also.[Results]Different microbial populations all increased in the soil to different degrees after the introduction of earthworms.The effects of the wild earthworms on the changes in bacteria,actinomycetes and fungi in the soil were different from those of artificially cultivated earthworms to certain degrees.[Conclusions]This study provides a theoretical basis for organic agriculture that relies on the decomposition of organic matter to release nutrients.
基金The National Basic Research Program of China(973 program,Grant No.2015CB932100)National Natural Science Foundation of China(Grant No.81130059)
文摘Nanotechnology has been widely used in the field of medicine, and it can significantly improve the bioavailability and the target efficiency of medicines. However, after administration, nanomedicines can adsorb biomolecules that can influence their effects. It was reported that the adsorption of plasma proteins can change the surface properties of nanoparticles. When nanoparticles pass through cells, they may carry some cellular proteins out of cells. Currently, it is unclear whether the adsorbed proteins affect the uptake of nanoparticles in the next cell layer. To simplify this complex biological process, BSA-capped gold nanoparticles were prepared and incubated with Caco-2 cell lysate to simulate conditions of transcytosis through epithelial cells. The surface morphology of nanoparticles was examined by TEM. SRB was used to evaluate the cytotoxicity of the nanoparticles. The uptake and cellular distribution of the nanoparticles were detected by ICP-MS and CLSM. The results suggested that the adsorption of cell proteins could enhance the adhesion and uptake of gold nanoparticles. The gold nanoparticles were mainly located in lysosomes, and there were some Lysate-capped AuNPs in the mitochondria whereas no BSA-capped AuNPs appeared there.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11862003,81860635,11462003the Key Project of Guangxi Natural Science Foundation under Grant No.2017GXNSF DA198038Guangxi “Bagui Scholar” Teams for Innovation and Research Project
文摘The secondary flow driven by the primary vortex in a cylinder,generating the so called"tea leaf paradox",is fundamental for understanding many natural phenomena,industrial applications and scientific researches.In this work,the effect of wettability on the primary vortex and secondary flow is investigated by the three-dimensional multiphase lattice Boltzmann method based on a chemical potential.We find that the surface wettability strongly affects the shape of the primary vortex.With the increase of the contact angle of the cylinder,the sectional plane of the primary vortex gradually changes from a steep valley into a saddle with two raised parts.Because the surface friction is reduced correspondingly,the core of the secondary vortex moves to the centerline of the cylinder and the vortex intensity also increases.The stirring force has stronger effects to enhance the secondary flow and push the vortex up than the surface wettability.Interestingly,a small secondary vortex is discovered near the three-phase contact line when the surface has a moderate wettability,owing to the interaction between the secondary flow and the curved gas/liquid interface.
文摘A calculation method for heats of formation (HOF, referred to as △Hf) based on the density functional theory (DFT) is presented in this work. Similar to Gaussian-3 theory, the atomic scheme is applied to calculate the heats of formation of the molecules. In this method, we have modified the formula for calculation of Gaussian-3 theory in several ways, including the correction for diffuse functions and the correction for higher polarization functions. These corrections are found to be significant. The average absolute deviation from experiment for the 164 calculated heats of formation is about 1.9 kcal·mol?1, while average absolute deviation from G3MP2 for the 149 (among the 164 molecules, 15 large-sized molecules can not be calculated at the G3MP2 level) calculated heats of formation is only about 1.9 kcal·mol?1. It indicates that the present method can be applied to predict the heats of formation of medium-sized and large-sized molecules, while the heats of formation of these molecules using Gaussian-3 theory are much difficult, even impossible, to calculate. That is, this method provides a choice in the calculation of △Hf for medium-sized and large-sized molecules.
基金supported by the National Natural Science Foundation of China(No.52074312)the CNPC Science and Technology Innovation Foundation(No.2021DQ02-0505)+1 种基金the Open Fund Project of the National Key Laboratory for the Enrichment Mechanism and Efficient Development of Shale Oil and Gas(No.36650000-24-ZC0609-0006)the Major Science and Technology Project of Karamay City(No.20232023zdzx0003).
文摘Due to complex geological structures and a narrow safe mud density window,offshore fractured formations frequently encounter severe lost circulation(LC)during drilling,significantly hindering oil and gas exploration and development.Predicting LC risks enables the targeted implementation of mitigation strategies,thereby reducing the frequency of such incidents.To address the limitations of existing 3D geomechanical modeling in predicting LC,such as arbitrary factor selection,subjective weight assignment,and the inability to achieve pre-drilling prediction along the entire well section,an improved prediction method is proposed.This method integrates multi-source data and incorporates three LC-related sensitivity factors:fracture characteristics,rock brittleness,and in-situ stress conditions.A quantitative risk assessment model for LC is developed by combining the subjective analytic hierarchy process with the objective entropy weight method(EWM)to assign weights.Subsequently,3D geomechanical modeling is applied to identify regional risk zones,enabling digital visualization for pre-drilling risk prediction.The developed 3D LC risk prediction model was validated using actual LC incidents from drilled wells.Results were generally consistent with field-identified LC zones,with an average relative error of 19.08%,confirming its reliability.This method provides practical guidance for mitigating potential LC risks and optimizing drilling program designs in fractured formations.
基金support from the National Science Foundation of China(No.52071037)Zhejiang province science and technology planning project(No.2022C01008).
文摘In this research,a high ductility Mg-Gd-Mn magnesium alloy was designed and developed,with an elongation capability surpassing 50%.To gain insights into the underlying mechanism behind the high ductility of the Mg-2Gd-0.5Mn alloy,quasi-in-situ electron backscattered diffraction and two-beam diffraction were conducted.The results reveal that the Mg-Gd-Mn alloy exhibits a distinct rare-earth texture,and the activation of non-basal slip systems is evident from the clear observation of non-basal slip traces during the later stages of deformation.However,the primary deformation mechanisms in Mg-Gd-Mn alloy remain basalslip and{10–12}tensile twinning,and the remarkable ductility observed in Mg-Gd-Mn alloys can be attributed to the softening of non-basal slip modes,which leads to a coordinated deformation between various modes of deformation.To further validate this conclusion,an analysis was conducted using a visco-plastic self-consistent(VPSC)model to investigate the relative activity of basal and non-basal slip in Mg-Gd-Mn alloys.The obtained results align well with experimental observations,providing additional support for the hypothesis.
基金supported by the National Natural Science Foundation of China(Nos.52472241,52403108 and 52301285)Department of Science and Technology of Hubei Province(Nos.2025AFA114 and 2024CSA076)+1 种基金Wuhan Science and Technology Bureau(Nos.2023020201010116 and 2024040801020319)Hubei Provincial Department of Education(No.Q20231703)。
文摘Photoelectrochemical(PEC)water splitting using bismuth vanadate(BiVO_(4))as a photoanode shows promise for renewable hydrogen production.Depositing cobalt phosphate(CoPi)on the BiVO_(4)photoanode as an oxygen evolution cocatalyst(OEC)is an effective method to improve the PEC performance.However,the CoPi/BiVO_(4)photoanode still faces challenges in terms of slow interface photogenerated carrier transport.Herein,we utilize the advantage of the classical strong metal-support interaction(SMSI)between Au and BiVO_(4)to prepare a CoPi/Au/BiVO_(4)(SMSI-CoPi/Au/BiVO_(4))photoanode.Due to the formation of SMSI,the accumulated electrons at the interface of CoPi/Au induce the accelerated extraction of photogenerated holes.Meanwhile,the active electron density of CoPi is increased,leading to improved water oxidation kinetic.As a result,the SMSI-CoPi/Au/BiVO_(4)photoanode exhibits a high photocurrent density of 5.01 m A cm^(-2)at 1.23 V versus the reversible hydrogen electrode and an applied bias photon-to-current efficiency of 1.78%.This work highlights a novel approach to enhance hole transfer and water oxidation kinetics of OEC/BiVO_(4)composite photoanodes,offering the great potential of using SMSI for PEC water splitting.
