Developing efficient photocatalysts to address collaborative energy and environmental crises still faces significant challenges.In this report,we present a highly efficient MXene–based photocatalyst,which is combined...Developing efficient photocatalysts to address collaborative energy and environmental crises still faces significant challenges.In this report,we present a highly efficient MXene–based photocatalyst,which is combined with MoS_(2)nano patches and TiO_(2)/Ti_(3)C_(2)(TTC)nanowires through hydrothermal treatment.Of all the composites tested,the optimized photocatalyst gave a remarkable H_(2)and revolving polylactic acid(PLA)into pyruvic acid(PA).Achieving a remarkable H_(2)evolution rate of 637.1 and 243.2μmol g^(−1)h^(−1),in the presence of TEOA and PLA as a sacrificial reagent under UV-vis(λ≥365 nm)light irradiation.The improved photocatalytic activity is a result of the combination of dual cocatalyst on the surface of TTC photocatalyst,which create an ideal synergistic effect for the generation of PA and the production of H_(2)simultaneously.The MoS_(2)TiO_(2)/Ti_(3)C_(2)(MTT)composite can generate more photoexcited charge carriers,leading to the generation of more active radicals,which may enhance the system's photocatalytic activity.This work aims at demonstrating its future significance and guide the scientific community towards a more efficient approach to commercializing H_(2)through photocatalysis.展开更多
Both abiotic conditions and management influence the success of forest restoration.Despite growing interest and practical effort in restoring degraded forest landscapes,understanding of how disparate factors,such as t...Both abiotic conditions and management influence the success of forest restoration.Despite growing interest and practical effort in restoring degraded forest landscapes,understanding of how disparate factors,such as terrain,soil conditions,climate and silvicultural treatments,directly or collectively control species performance and shape community recovery remains limited.In this study,we assessed how topography and management intervention affect seedling survival and growth in the early stages of restoration.To do so,we established seven experimental plots,each measuring 20 m×20 m(400 m2)subdivided into 48 subplots,in coarse,anthropogenic grassland on a mid-elevation mountain slope in Hong Kong,and planted a total of 3975 native tree seedlings belonging to 12 tree species within them.To characterise topography,we modelled the elevation,slope,convexity and aspect of each subplot.Two types of tree guard(enclosed blue plastic sleeve and open yellow mesh),two types of fertiliser(organic and inorganic)and cardboard weeding mats were used to assess the impact of management interventions on the establishment of the seedlings.Survivorship,height and basal diameter were measured at 1,2 and 4 years after planting.We used generalised linear models to examine the effect of these factors and their interactions on seedling survival,and we applied linear models and hierarchical partitioning to explore their relative importance in determining the relative growth rate(RGR)of each species.The most parsimonious models were selected using the Akaike Information Criterion.Survivorship was 98.1%,95.2%and 86.4%across all plots in the first,second and fourth year,respectively.On average,topographic and management variables explained 1.48–3.34%of total variation in RGR,respectively,for all species.The models revealed that type of tree guard,aspect and elevation were the most important factors explaining RGR and survival.Results of hierarchical partitioning by species and growth period showed that the key determinants of performance vary by species and shift over the course of early seedling establishment,emphasising the importance of both spatial and temporal scales in the restoration of degraded tropical forests.Our findings support the use of enclosed tree guards and fertiliser to improve survivorship and growth across a range of broadleaved Asiatic species.All potential limiting factors pertaining to both site factors and management,as well as their interactions,should be considered in restoration planning to maximise restoration success.展开更多
Zr-4(Zr-1.5Sn-0.2Fe-0.1Cr,wt%), S5(Zr-0.8Sn-0.34Nb-0.39Fe-0.1Cr), T5(Zr-0.7Sn-1.07Nb-0.32Fe-0.08Cr) and Zr-1Nb were adopted to prepare Bi-containing zirconium alloys for systematically investigating the effect of Bi a...Zr-4(Zr-1.5Sn-0.2Fe-0.1Cr,wt%), S5(Zr-0.8Sn-0.34Nb-0.39Fe-0.1Cr), T5(Zr-0.7Sn-1.07Nb-0.32Fe-0.08Cr) and Zr-1Nb were adopted to prepare Bi-containing zirconium alloys for systematically investigating the effect of Bi addition on the corrosion resistance of zirconium alloys. The specimens were corroded in superheated steam at 400℃/10.3 MPa, and in lithiated water with 0.01 M LiOH or in deionized water at 360℃/18.6 MPa by autoclave testing. Results show that the corrosion resistance increases with the increasing of Bi content dissolved in α-Zr. But the presence of Bi-con- taining second phase particles (SPPs) is unfavorable for the enhancement of corrosion resistance. This indicates that the Bi dissolved in α-Zr matrix plays an important role in improving the corrosion resistance, while the precipitation of the Bi-containing SPPs does harm to the corrosion resistance.展开更多
There is a relatively low efficiency of Fe(Ⅲ)/Fe(Ⅱ) conversion cycle and H2 O2 decomposition(<30%) in conventional Fenton process,which further results in a low production efficiency of ·OH and seriously res...There is a relatively low efficiency of Fe(Ⅲ)/Fe(Ⅱ) conversion cycle and H2 O2 decomposition(<30%) in conventional Fenton process,which further results in a low production efficiency of ·OH and seriously restricts the application of Fenton.Herein,we report that the commercial MoO2 can be used as the cocatalyst in Fenton process to dramatically accelerate the oxidation of Lissamine rhodamine B(L-RhB),where the efficiency of Fe(Ⅲ)/Fe(Ⅱ) cycling is greatly enhanced in the Fenton reaction meanwhile.And the L-RhB solution could be degraded nearly 100% in 1 min in the MoO2 cocatalytic Fenton system under the optimal reaction condition,which is apparently better than that of the conventional Fenton system(~50%).Different from the conventional Fenton reaction where the ’OH plays an important role in the oxidation process,it shows that 1 O2 contributes most in the MoO2 cocatalytic Fenton reaction.However,it is found that the exposed Mo^4+ active sites on the surface of MoO2 powders can greatly promote the rate-limiting step of Fe^3+/Fe^2+ cycle conversion,thus minimizing the dosage of H2 O2(0.400 mmol/L) and Fe^2+(0.105 mmol/L).Interestingly,the MoO2 cocatalytic Fenton system also exhibits a good ability for reducing Cr(Ⅵ) ions,where the reduction ability for Cr(Ⅵ) reaches almost 100% within 2 h.In short,this work shows a new discovery for M002 cocatalytic advanced oxidation processes(AOPs),which devotes a lot to the practical water remediation application.展开更多
With the development of the human economy and green chemistry, people pay much more attention to environmental safety. Correspondingly, mesoporous TiO_2 and its correlated photocatalysts are able to help people seek f...With the development of the human economy and green chemistry, people pay much more attention to environmental safety. Correspondingly, mesoporous TiO_2 and its correlated photocatalysts are able to help people seek for better life. In this review, first of all, we briefly introduce the preparations and applications of mesoporous TiO_2-SiO_2 materials, which exhibit excellent performance in pollutants decomposition and H_2 evolution in photocatalysis. Then, we review the mesoporous composites of TiSiO_2 materials, which are ideal materials used in the photoreduction of air pollutants such as CO_2, NO and NO_2. It is powerfully evident from the literature surveys that these TiO_2 based mesoporous photocatalysts possess a large potential in environment and energy development.展开更多
Although MoS_(2) has been proved to be a very ideal cocatalyst in advanced oxidation process(AOPs),the activation process of peroxy mono sulfate(PMS)is still inseparable from metal ions which inevitably brings the ris...Although MoS_(2) has been proved to be a very ideal cocatalyst in advanced oxidation process(AOPs),the activation process of peroxy mono sulfate(PMS)is still inseparable from metal ions which inevitably brings the risk of secondary pollution and it is not conducive to large-scale industrial application.In this study,the commercial MoS_(2),as a durable and efficient catalyst,was used for directly activating PMS to degrade aromatic organic pollutant.The commercial MoS_(2)/PMS catalytic system demonstrated excellent removal efficiency of phenol and the total organic carbon(TOC)residual rate reach to 25%.The degradation rate was significantly reduced if the used MoS_(2) was directly carried out the next cycle experiment without any post-treatment.Interestingly,the commercial MoS_(2) after post-treated with H2 O_(2) can exhibit good stability and recyclability for cyclic degradation of phenol.Furthermore,the mechanism for the activation of PMS had been investigated by density functional theory(DFT)calculation.The renewable Mo4+exposed on the surface of MoS_(2) was deduced as the primary active site,which realized the direct activation of PMS and avoided secondary pollution.Taking into account the reaction cost and efficient activity,the development of commercial MoS_(2) catalytic system is expected to be applied in industrial wastewater.展开更多
This research was undertaken to clarify the characteristics of vegetation change and its main influencing factors on the Qinghai-Tibet Plateau. Using the greenness rate of change(GRC) and correlation factors, we analy...This research was undertaken to clarify the characteristics of vegetation change and its main influencing factors on the Qinghai-Tibet Plateau. Using the greenness rate of change(GRC) and correlation factors, we analyzed the trend of vegetation change and its dominant factors from 2000 to 2015. The results indicate that the vegetation tended to improve from 2000 to 2015 on the Qinghai-Tibet Plateau, with the improved area accounting for 39.93% of the total; and the degraded area accounting for 19.32%. The areas of degraded vegetation are mainly concentrated in the low-relief and intermediate-relief mountains of the high-altitude and extremely high-altitude areas on the Qinghai-Tibet Plateau, as the vegetation characteristics are impacted by the terrain. Temperature and precipitation have obvious response mechanisms to vegetation growth, but the effects of precipitation and temperature on vegetation degradation are not significant over a short time frame. Overgrazing and population growth are the dominant factors of vegetation degradation on the Qinghai-Tibet Plateau.展开更多
In this work we used CdS NWs(nanowires)with vanadium carbide(VC)attached via facile electrostatic self‐assembly and calcination method.The results showed that compared to pristine CdS NWs,the photocatalytic activity ...In this work we used CdS NWs(nanowires)with vanadium carbide(VC)attached via facile electrostatic self‐assembly and calcination method.The results showed that compared to pristine CdS NWs,the photocatalytic activity of CdS NWs loaded with the particular amount of VC was dramatically enhanced.Among them,the VC/CS‐15 indicated the highest enhancement for simultaneous production of H2 with selective oxidation of benzyl alcohol(BO)into benzaldehyde(BD).The highest hydrogen evolution rate of 20.5 mmol g^(-1)h^(-1)was obtained with more than 99%selectivity for BD production under visible light(λ˃420 nm)irradiation for 2 h,which was almost 661 times higher than the pristine CdS NWs.This enhancement of photocatalytic activity is due to the VC,which provides a favorable attraction for BO by lowering the zeta potential,along with the active site for hydrogen production,and retard the recombination of electron‐hole pairs by increasing the conductivity of the photocatalyst.Moreover,the apparent quantum efficiency(AQE)of VC/CS‐15 for BD and H_(2)production at monochromatic 420 nm is about 7.5%.At the end of the hydrogen evolution test,the selective oxidation with more than 99%selectivity was obtained.It hopes this work will prove its future significance and move scientific community toward a more economical way for achieving the commercialization of H_(2) by photocatalysis.展开更多
Heterogeneous Fenton has been widely used in the disposal of organic pollutants,however,slow regeneration of≡Fe(II)remains limitation for its practical application of long-term treatment.Herein,we come up with a nove...Heterogeneous Fenton has been widely used in the disposal of organic pollutants,however,slow regeneration of≡Fe(II)remains limitation for its practical application of long-term treatment.Herein,we come up with a novel Fe-based heterogeneous Fenton catalyst named as FeS_(x)O_(y)-X(X is the ratio of ethylene glycol to N,N-dimethylformamide).With the help of the abundant defect electrons in Sulfur vacancies,≡Fe(Ⅱ)regeneration on the surface of FeS_(x)O_(y)-1:1 was accelerated,resulting in a stable proportion of≡Fe(Ⅱ)on the surface,which maintained continuously stable generation of hydroxyl radical(·OH)and singlet oxygen(^(1)O_(2)).Thus,without any organic reagents or cocatalysts,FeS_(x)O_(y)-1:1 based Fenton system achieved effective long-term degradation of 560 mg/L quinoline within only 7 days,which was evidently better than reported Fe S and SV-Fe S_(2)(SV:Sulfur vacancy).The system had excellent adaptability to water quality and the COD removal rate of biochemical wastewater was as high as 79.8%.展开更多
The fabrication of S-scheme heterojunctions with fast charge transfer and good interface contacts,such as intermolecularπ–πinteractions,is a promising approach to improve photocatalytic performance.A unique two-dim...The fabrication of S-scheme heterojunctions with fast charge transfer and good interface contacts,such as intermolecularπ–πinteractions,is a promising approach to improve photocatalytic performance.A unique two-dimensional/two-dimensional(2D/2D)S-scheme heterojunction containing TpPa-1-COF/g-C_(3)N_(4) nanosheets(denoted as TPCNNS)was developed.The established maximum interfacial interaction between TpPa-1-COF NS and g-C_(3)N_(4) NS may result in aπ–πconjugated heterointerface.Furthermore,the difference in the work functions of TpPa-1-COF and g-C_(3)N_(4) results in a large Fermi level gap,leading to upward/downward band edge bending.The spontaneous interfacial charge transfer from g-C_(3)N_(4) to TpPa-1-COF at theπ–πconjugated interface area results in the presence of a built-in electric field,according to the charge density difference analysis based on density functional theory calculations.Such an enhanced built-in electric field can efficiently drive directional charge migration via the S-scheme mechanism,which enhances charge separation and utilization.Thus,an approximately 2.8 and 5.6 times increase in the photocatalytic hydrogen evolution rate was recorded in TPCNNS-2(1153μmol g^(-1) h^(-1))compared to pristine TpPa-1-COF and g-C_(3)N_(4) NS,respectively,under visible light irradiation.Overall,this work opens new avenues in the fabrication of 2D/2Dπ–πconjugated S-scheme heterojunction photocatalysts with highly efficient hydrogen evolution performance.展开更多
In recent years, MoS_(2) catalyzed/cocatalyzed Fenton/Fenton-like systems have attracted wide attention in the field of pollution control, but there are few studies on the effect of H_(2)O_(2) feeding way on the whole...In recent years, MoS_(2) catalyzed/cocatalyzed Fenton/Fenton-like systems have attracted wide attention in the field of pollution control, but there are few studies on the effect of H_(2)O_(2) feeding way on the whole Fenton process. Here, we report a new type of composite catalyst (MoS_(2)-Fe_(x)) prepared in a simple way with highly dispersed iron to provide more active sites. MoS_(2)-Fe_(x) was proved to possess selectivity for singlet oxygen (^(1)O_(2)) in effectively degrading sulfadiazine with a wide pH adaptability (4.0~10.0). Importantly, the mechanism of the interaction between H_(2)O_(2) and MoS_(2) on the Fenton reaction activity was revealed through the combination of experiment and density functional theory (DFT) calculations. Compared to the traditional “a large amount for one time” feeding way of H_(2)O_(2), the “small amount for multiple times” of H_(2)O_(2) feeding way can increase the degradation rate of sulfadiazine from 36.9% to 91.1% in the MoS_(2)-Fe_(x) heterogeneous Fenton system. It is demonstrated that the “small amount for multiple times” of H_(2)O_(2) feeding way can reduce the side reaction of decomposition of H_(2)O_(2) by MoS_(2) and effectively improve the utilization rate of H_(2)O_(2) and the stability of MoS_(2)-Fe_(x). Compared with Fe_(2)O_(3)^(-)based Fenton system, MoS_(2)-Fe_(x) can significantly save the amount of H_(2)O_(2). Compared with nano-iron powder, the formation of iron sludge in MoS_(2)-Fe_(x) system was significantly reduced. Furthermore, long-term degradation test showed that the MoS_(2)-Fe75/H_(2)O_(2) system could maintain the effectiveness of degrading organic pollutants for 10 days (or even longer). This study has a guiding significance for the large-scale treatment of industrial wastewater by improved Fenton technology in the future.展开更多
As a vital nutrient closely related to the cance r-cells proliferation,phosphate anions have been paid great attention as a promising anticancer agent.Generally,the transport of phosphate anions depends on a protein t...As a vital nutrient closely related to the cance r-cells proliferation,phosphate anions have been paid great attention as a promising anticancer agent.Generally,the transport of phosphate anions depends on a protein transport system which is regulated by ion homeostasis regulations.Herein,we designed a reactive anionic nanocarrier based on black phosphorus nanosheets(BPs)and artesunate(ART),which could enter cells through endocytosis to generate phosphate anions,avoiding the regulation of cell homeostasis.The ionic nanocarrier was coated by polydopamine to defend BPs and ART and functionalized by folate(FA)and hyaluronic acid(HA)for targeting factor.With the anchoring groups FA/HA targeted the carrier into cells,polydopamine coating decomposed to expose ART for further generating reactive oxygen species(ROS)in cancer cell microenvironment,providing oxidation conditions.Next,ROS generated by ART makes BPs decompose to phosphate anions with effectively speed,giving rise to the destruction of ion homeostasis to induce necro sis and inhibit the proliferation for cancer cells.In consequence,this research provides novel idea and direction for the ionic carriers and tumor therapeutics.展开更多
Prostate artery embolization is a well-known and promising treatment for benign prostatic hyperplasia, with the quantum leaps of research in medicine. We aim to provide an up-to-date review of the novel technique, inc...Prostate artery embolization is a well-known and promising treatment for benign prostatic hyperplasia, with the quantum leaps of research in medicine. We aim to provide an up-to-date review of the novel technique, including large retrospective studies and randomized control trials, ends with discussions of advantages and disadvantages of this minimally invasive technique.展开更多
The dynamical axion field is a new state of quantum matter where the magnetoelectric response couples strongly to its low-energy magnetic fluctuations.It is fundamentally different from an axion insulator with a stati...The dynamical axion field is a new state of quantum matter where the magnetoelectric response couples strongly to its low-energy magnetic fluctuations.It is fundamentally different from an axion insulator with a static quantized magnetoelectric response.The dynamical axion field exhibits many exotic phenomena such as axionic polariton and axion instability.However,these effects have not been experimentally confirmed due to the lack of proper topological magnetic materials.Combining analytic models and first-principles calculations,here we predict a series of van der Waals layered Mn2Bi2Te5-related topological antiferromagnetic materials that could host the long-sought dynamical axion field with a topological origin.We also show that a large dynamical axion field can be achieved in antiferromagnetic insulating states close to the topological phase transition.We further propose the optical and transport experiments to detect such a dynamical axion field.Our results could directly aid and facilitate the search for topological-origin large dynamical axion field in realistic materials.展开更多
Photocatalytic water oxidation is a crucial counter-electrode reaction in the process of photoelectrochemical energy conversion.Despite its importance,challenges remain in effectively and sustainably converting water ...Photocatalytic water oxidation is a crucial counter-electrode reaction in the process of photoelectrochemical energy conversion.Despite its importance,challenges remain in effectively and sustainably converting water to oxygen,particularly with readily available and inexpensive electrolyte solutions such as seawater.While metal oxide materials have demonstrated their advantages in promoting efficiency by reducing overpotential and improving light utilization,stability remains limited by corrosion in multicomponent seawater.In this paper,we reviewed the relationship between four basic concepts including photoelectrochemistry,metal oxide,water oxidation and seawater to better understand the challenges and opportunities in photoelectrochemical(PEC)seawater oxidation.To overcome these challenges,the advances in material design,interfacial modification,local environment control and reactor design have been further reviewed to benefit the industrial PEC seawater oxidation.Noticeably,we demonstrate engineered layered metal oxide electrodes and cell structures that enable powerful and stable seawater oxidation.We also outline and advise on the future direction in this area.展开更多
Background:SCNT(somatic cell nuclear transfer)is of great significance to biological research and also to the livestock breeding.However,the survival rate of the SCNT cloned animals is relatively low compared to other...Background:SCNT(somatic cell nuclear transfer)is of great significance to biological research and also to the livestock breeding.However,the survival rate of the SCNT cloned animals is relatively low compared to other transgenic methods.This indicates the potential epigenetic variations between them.DNA methylation is a key marker of mammalian epigenetics and its alterations will lead to phenotypic differences.In this study,ASMT(acetylserotonin-Omethyltransferase)ovarian overexpression transgenic goat was produced by using SCNT.To investigate whether there are epigenetic differences between cloned and WT(wild type)goats,WGBS(whole-genome bisulfite sequencing)was used to measure the whole-genome methylation of these animals.Results:It is observed that the different m Cp G sites are mainly present in the intergenic and intronic regions between cloned and WT animals,and their CG-type methylation sites are strongly correlated.DMR(differentially methylated region)lengths are located around 1000 bp,mainly distributed in the exonic,intergenic and intronic functional domains.A total of 56 and 36 DMGs(differentially methylated genes)were identified by GO and KEGG databases,respectively.Functional annotation showed that DMGs were enriched in biological-process,cellularcomponent,molecular-function and other signaling pathways.A total of 10 identical genes related to growth and development were identified in GO and KEGG databases.Conclusion:The differences in methylation genes among the tested animals have been identified.A total of 10 DMGs associated with growth and development were identified between cloned and WT animals.The results indicate that the differential patterns of DNA methylation between the cloned and WT goats are probably caused by the SCNT.These novel observations will help us to further identify the unveiled mechanisms of somatic cell cloning technology,particularly in goats.展开更多
Background:Gram-negative bacterial infections have a major economic impact on both the livestock industry and public health.Toll-like receptor 4(TLR4)plays a crucial role in host defence against Gram-negative bacteria...Background:Gram-negative bacterial infections have a major economic impact on both the livestock industry and public health.Toll-like receptor 4(TLR4)plays a crucial role in host defence against Gram-negative bacteria.Exploring the defence mechanism regulated by TLR4 may provide new targets for treatment of inflammation and control of bacterial infections.In a previous study,we generated transgenic sheep overexpressing TLR4 by microinjection to improve disease resistance.The defence mechanism through which TLR4 overexpression protected these sheep against pathogens is still not fully understood.Results:In the present study,we used Escherichia coli to infect monocytes isolated from peripheral blood of the animal model.The overexpression of TLR4 strongly enhanced the percentage of endocytosis and capacity of elimination in monocytes during the early stages of infection.This phenomenon was mainly due to overexpression of TLR4 promoting caveolae-mediated endocytosis.Pretreatment of the transgenic sheep monocytes with inhibitors of TLR4,Src signalling,or the caveolae-mediated endocytosis pathway reduced the internalization of bacteria,weakened the ability of the monocytes to eliminate the bacteria,and increased the pH of the endosomes.Conclusion:Together,our results reveal the effects of TLR4 on the control of E.coli infection in the innate immunity of sheep and provide crucial evidence of the caveolae-mediated endocytosis pathway required for host resistance to invading bacteria in a large animal model,providing theoretical support for breeding disease resistance in the future.Furthermore,Src and caveolin 1(CAV1)could be potentially valuable targets for the control of infectious diseases.展开更多
文摘Developing efficient photocatalysts to address collaborative energy and environmental crises still faces significant challenges.In this report,we present a highly efficient MXene–based photocatalyst,which is combined with MoS_(2)nano patches and TiO_(2)/Ti_(3)C_(2)(TTC)nanowires through hydrothermal treatment.Of all the composites tested,the optimized photocatalyst gave a remarkable H_(2)and revolving polylactic acid(PLA)into pyruvic acid(PA).Achieving a remarkable H_(2)evolution rate of 637.1 and 243.2μmol g^(−1)h^(−1),in the presence of TEOA and PLA as a sacrificial reagent under UV-vis(λ≥365 nm)light irradiation.The improved photocatalytic activity is a result of the combination of dual cocatalyst on the surface of TTC photocatalyst,which create an ideal synergistic effect for the generation of PA and the production of H_(2)simultaneously.The MoS_(2)TiO_(2)/Ti_(3)C_(2)(MTT)composite can generate more photoexcited charge carriers,leading to the generation of more active radicals,which may enhance the system's photocatalytic activity.This work aims at demonstrating its future significance and guide the scientific community towards a more efficient approach to commercializing H_(2)through photocatalysis.
基金The financial support of CLP Holdings Limited is acknowledged for supporting KFBG's ongoing applied forest restoration research.
文摘Both abiotic conditions and management influence the success of forest restoration.Despite growing interest and practical effort in restoring degraded forest landscapes,understanding of how disparate factors,such as terrain,soil conditions,climate and silvicultural treatments,directly or collectively control species performance and shape community recovery remains limited.In this study,we assessed how topography and management intervention affect seedling survival and growth in the early stages of restoration.To do so,we established seven experimental plots,each measuring 20 m×20 m(400 m2)subdivided into 48 subplots,in coarse,anthropogenic grassland on a mid-elevation mountain slope in Hong Kong,and planted a total of 3975 native tree seedlings belonging to 12 tree species within them.To characterise topography,we modelled the elevation,slope,convexity and aspect of each subplot.Two types of tree guard(enclosed blue plastic sleeve and open yellow mesh),two types of fertiliser(organic and inorganic)and cardboard weeding mats were used to assess the impact of management interventions on the establishment of the seedlings.Survivorship,height and basal diameter were measured at 1,2 and 4 years after planting.We used generalised linear models to examine the effect of these factors and their interactions on seedling survival,and we applied linear models and hierarchical partitioning to explore their relative importance in determining the relative growth rate(RGR)of each species.The most parsimonious models were selected using the Akaike Information Criterion.Survivorship was 98.1%,95.2%and 86.4%across all plots in the first,second and fourth year,respectively.On average,topographic and management variables explained 1.48–3.34%of total variation in RGR,respectively,for all species.The models revealed that type of tree guard,aspect and elevation were the most important factors explaining RGR and survival.Results of hierarchical partitioning by species and growth period showed that the key determinants of performance vary by species and shift over the course of early seedling establishment,emphasising the importance of both spatial and temporal scales in the restoration of degraded tropical forests.Our findings support the use of enclosed tree guards and fertiliser to improve survivorship and growth across a range of broadleaved Asiatic species.All potential limiting factors pertaining to both site factors and management,as well as their interactions,should be considered in restoration planning to maximise restoration success.
文摘Zr-4(Zr-1.5Sn-0.2Fe-0.1Cr,wt%), S5(Zr-0.8Sn-0.34Nb-0.39Fe-0.1Cr), T5(Zr-0.7Sn-1.07Nb-0.32Fe-0.08Cr) and Zr-1Nb were adopted to prepare Bi-containing zirconium alloys for systematically investigating the effect of Bi addition on the corrosion resistance of zirconium alloys. The specimens were corroded in superheated steam at 400℃/10.3 MPa, and in lithiated water with 0.01 M LiOH or in deionized water at 360℃/18.6 MPa by autoclave testing. Results show that the corrosion resistance increases with the increasing of Bi content dissolved in α-Zr. But the presence of Bi-con- taining second phase particles (SPPs) is unfavorable for the enhancement of corrosion resistance. This indicates that the Bi dissolved in α-Zr matrix plays an important role in improving the corrosion resistance, while the precipitation of the Bi-containing SPPs does harm to the corrosion resistance.
基金supported by the State Key Research Development Program of China (No.2016YFA0204200)National Natural Science Foundation of China (Nos.21822603,21811540394,5171101651,21677048,21773062,21577036)+3 种基金Shanghai Pujiang Program (No.17PJD011)the Fundamental Research Funds for the Central Universities (No.22A201514021)Project supported by Shanghai Municipal Science and Technology Major Project (No. 2018SHZDZX03)the Program of Introducing Talents of Discipline to Universities (No.B16017)
文摘There is a relatively low efficiency of Fe(Ⅲ)/Fe(Ⅱ) conversion cycle and H2 O2 decomposition(<30%) in conventional Fenton process,which further results in a low production efficiency of ·OH and seriously restricts the application of Fenton.Herein,we report that the commercial MoO2 can be used as the cocatalyst in Fenton process to dramatically accelerate the oxidation of Lissamine rhodamine B(L-RhB),where the efficiency of Fe(Ⅲ)/Fe(Ⅱ) cycling is greatly enhanced in the Fenton reaction meanwhile.And the L-RhB solution could be degraded nearly 100% in 1 min in the MoO2 cocatalytic Fenton system under the optimal reaction condition,which is apparently better than that of the conventional Fenton system(~50%).Different from the conventional Fenton reaction where the ’OH plays an important role in the oxidation process,it shows that 1 O2 contributes most in the MoO2 cocatalytic Fenton reaction.However,it is found that the exposed Mo^4+ active sites on the surface of MoO2 powders can greatly promote the rate-limiting step of Fe^3+/Fe^2+ cycle conversion,thus minimizing the dosage of H2 O2(0.400 mmol/L) and Fe^2+(0.105 mmol/L).Interestingly,the MoO2 cocatalytic Fenton system also exhibits a good ability for reducing Cr(Ⅵ) ions,where the reduction ability for Cr(Ⅵ) reaches almost 100% within 2 h.In short,this work shows a new discovery for M002 cocatalytic advanced oxidation processes(AOPs),which devotes a lot to the practical water remediation application.
基金supported by the State Key Research Development Program of China (No. 2016YFA0204200)the National Natural Science Foundation of China (Nos. 21822603, 21773062, 21577036, 21377038, 21237003)+1 种基金Shanghai Pujiang Program (No. 17PJD011)the Fundamental Research Funds for the Central Universities (No. 22A201514021)
文摘With the development of the human economy and green chemistry, people pay much more attention to environmental safety. Correspondingly, mesoporous TiO_2 and its correlated photocatalysts are able to help people seek for better life. In this review, first of all, we briefly introduce the preparations and applications of mesoporous TiO_2-SiO_2 materials, which exhibit excellent performance in pollutants decomposition and H_2 evolution in photocatalysis. Then, we review the mesoporous composites of TiSiO_2 materials, which are ideal materials used in the photoreduction of air pollutants such as CO_2, NO and NO_2. It is powerfully evident from the literature surveys that these TiO_2 based mesoporous photocatalysts possess a large potential in environment and energy development.
基金the State Key Research Development Program of China(No.2016YFA0204200)Project supported by Shanghai Municipal Science and Technology Major Project(No.2018SHZDZX03)+4 种基金the Program of Introducing Talents of Discipline to Universities(No.B16017)National Natural Science Foundation of China(Nos.2182260321811540394,5171101651,21677048,2177306221577036)the Fundamental Research Funds for the Central Universities(No.22A201514021)。
文摘Although MoS_(2) has been proved to be a very ideal cocatalyst in advanced oxidation process(AOPs),the activation process of peroxy mono sulfate(PMS)is still inseparable from metal ions which inevitably brings the risk of secondary pollution and it is not conducive to large-scale industrial application.In this study,the commercial MoS_(2),as a durable and efficient catalyst,was used for directly activating PMS to degrade aromatic organic pollutant.The commercial MoS_(2)/PMS catalytic system demonstrated excellent removal efficiency of phenol and the total organic carbon(TOC)residual rate reach to 25%.The degradation rate was significantly reduced if the used MoS_(2) was directly carried out the next cycle experiment without any post-treatment.Interestingly,the commercial MoS_(2) after post-treated with H2 O_(2) can exhibit good stability and recyclability for cyclic degradation of phenol.Furthermore,the mechanism for the activation of PMS had been investigated by density functional theory(DFT)calculation.The renewable Mo4+exposed on the surface of MoS_(2) was deduced as the primary active site,which realized the direct activation of PMS and avoided secondary pollution.Taking into account the reaction cost and efficient activity,the development of commercial MoS_(2) catalytic system is expected to be applied in industrial wastewater.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, China (Grant No. XDA20100101)the Foundation for Excellent Youth Scholars of Northwest Institute of Eco-environment and Resources, Chinese Acad emy of Sciences (Y651K91001)
文摘This research was undertaken to clarify the characteristics of vegetation change and its main influencing factors on the Qinghai-Tibet Plateau. Using the greenness rate of change(GRC) and correlation factors, we analyzed the trend of vegetation change and its dominant factors from 2000 to 2015. The results indicate that the vegetation tended to improve from 2000 to 2015 on the Qinghai-Tibet Plateau, with the improved area accounting for 39.93% of the total; and the degraded area accounting for 19.32%. The areas of degraded vegetation are mainly concentrated in the low-relief and intermediate-relief mountains of the high-altitude and extremely high-altitude areas on the Qinghai-Tibet Plateau, as the vegetation characteristics are impacted by the terrain. Temperature and precipitation have obvious response mechanisms to vegetation growth, but the effects of precipitation and temperature on vegetation degradation are not significant over a short time frame. Overgrazing and population growth are the dominant factors of vegetation degradation on the Qinghai-Tibet Plateau.
文摘In this work we used CdS NWs(nanowires)with vanadium carbide(VC)attached via facile electrostatic self‐assembly and calcination method.The results showed that compared to pristine CdS NWs,the photocatalytic activity of CdS NWs loaded with the particular amount of VC was dramatically enhanced.Among them,the VC/CS‐15 indicated the highest enhancement for simultaneous production of H2 with selective oxidation of benzyl alcohol(BO)into benzaldehyde(BD).The highest hydrogen evolution rate of 20.5 mmol g^(-1)h^(-1)was obtained with more than 99%selectivity for BD production under visible light(λ˃420 nm)irradiation for 2 h,which was almost 661 times higher than the pristine CdS NWs.This enhancement of photocatalytic activity is due to the VC,which provides a favorable attraction for BO by lowering the zeta potential,along with the active site for hydrogen production,and retard the recombination of electron‐hole pairs by increasing the conductivity of the photocatalyst.Moreover,the apparent quantum efficiency(AQE)of VC/CS‐15 for BD and H_(2)production at monochromatic 420 nm is about 7.5%.At the end of the hydrogen evolution test,the selective oxidation with more than 99%selectivity was obtained.It hopes this work will prove its future significance and move scientific community toward a more economical way for achieving the commercialization of H_(2) by photocatalysis.
基金supported by the National Natural Science Foundation of China(No.22176060)Project supported by Shanghai Municipal Science and Technology Major Project(No.2018SHZDZX03)+1 种基金the Program of Introducing Talents of Discipline to Universities(No.B16017)the Science and Technology Commission of Shanghai Municipality(No.20DZ2250400)。
文摘Heterogeneous Fenton has been widely used in the disposal of organic pollutants,however,slow regeneration of≡Fe(II)remains limitation for its practical application of long-term treatment.Herein,we come up with a novel Fe-based heterogeneous Fenton catalyst named as FeS_(x)O_(y)-X(X is the ratio of ethylene glycol to N,N-dimethylformamide).With the help of the abundant defect electrons in Sulfur vacancies,≡Fe(Ⅱ)regeneration on the surface of FeS_(x)O_(y)-1:1 was accelerated,resulting in a stable proportion of≡Fe(Ⅱ)on the surface,which maintained continuously stable generation of hydroxyl radical(·OH)and singlet oxygen(^(1)O_(2)).Thus,without any organic reagents or cocatalysts,FeS_(x)O_(y)-1:1 based Fenton system achieved effective long-term degradation of 560 mg/L quinoline within only 7 days,which was evidently better than reported Fe S and SV-Fe S_(2)(SV:Sulfur vacancy).The system had excellent adaptability to water quality and the COD removal rate of biochemical wastewater was as high as 79.8%.
文摘The fabrication of S-scheme heterojunctions with fast charge transfer and good interface contacts,such as intermolecularπ–πinteractions,is a promising approach to improve photocatalytic performance.A unique two-dimensional/two-dimensional(2D/2D)S-scheme heterojunction containing TpPa-1-COF/g-C_(3)N_(4) nanosheets(denoted as TPCNNS)was developed.The established maximum interfacial interaction between TpPa-1-COF NS and g-C_(3)N_(4) NS may result in aπ–πconjugated heterointerface.Furthermore,the difference in the work functions of TpPa-1-COF and g-C_(3)N_(4) results in a large Fermi level gap,leading to upward/downward band edge bending.The spontaneous interfacial charge transfer from g-C_(3)N_(4) to TpPa-1-COF at theπ–πconjugated interface area results in the presence of a built-in electric field,according to the charge density difference analysis based on density functional theory calculations.Such an enhanced built-in electric field can efficiently drive directional charge migration via the S-scheme mechanism,which enhances charge separation and utilization.Thus,an approximately 2.8 and 5.6 times increase in the photocatalytic hydrogen evolution rate was recorded in TPCNNS-2(1153μmol g^(-1) h^(-1))compared to pristine TpPa-1-COF and g-C_(3)N_(4) NS,respectively,under visible light irradiation.Overall,this work opens new avenues in the fabrication of 2D/2Dπ–πconjugated S-scheme heterojunction photocatalysts with highly efficient hydrogen evolution performance.
基金supported by the State Key Research Development Program of China (No. 2016YFA0204200)Project supported by Shanghai Municipal Science and Technology Major Project (No.2018SHZDZX03)+2 种基金the Program of Introducing Talents of Discipline to Universities (No. B16017)National Natural Science Foundation of China (No. 21822603)the Science and Technology Commission of Shanghai Municipality (No. 20DZ2250400)。
文摘In recent years, MoS_(2) catalyzed/cocatalyzed Fenton/Fenton-like systems have attracted wide attention in the field of pollution control, but there are few studies on the effect of H_(2)O_(2) feeding way on the whole Fenton process. Here, we report a new type of composite catalyst (MoS_(2)-Fe_(x)) prepared in a simple way with highly dispersed iron to provide more active sites. MoS_(2)-Fe_(x) was proved to possess selectivity for singlet oxygen (^(1)O_(2)) in effectively degrading sulfadiazine with a wide pH adaptability (4.0~10.0). Importantly, the mechanism of the interaction between H_(2)O_(2) and MoS_(2) on the Fenton reaction activity was revealed through the combination of experiment and density functional theory (DFT) calculations. Compared to the traditional “a large amount for one time” feeding way of H_(2)O_(2), the “small amount for multiple times” of H_(2)O_(2) feeding way can increase the degradation rate of sulfadiazine from 36.9% to 91.1% in the MoS_(2)-Fe_(x) heterogeneous Fenton system. It is demonstrated that the “small amount for multiple times” of H_(2)O_(2) feeding way can reduce the side reaction of decomposition of H_(2)O_(2) by MoS_(2) and effectively improve the utilization rate of H_(2)O_(2) and the stability of MoS_(2)-Fe_(x). Compared with Fe_(2)O_(3)^(-)based Fenton system, MoS_(2)-Fe_(x) can significantly save the amount of H_(2)O_(2). Compared with nano-iron powder, the formation of iron sludge in MoS_(2)-Fe_(x) system was significantly reduced. Furthermore, long-term degradation test showed that the MoS_(2)-Fe75/H_(2)O_(2) system could maintain the effectiveness of degrading organic pollutants for 10 days (or even longer). This study has a guiding significance for the large-scale treatment of industrial wastewater by improved Fenton technology in the future.
基金financially supported by the National Natural Science Foundation of China(No.21575055)the Fundamental Research Funds for the Central Universities(No.561220006)。
文摘As a vital nutrient closely related to the cance r-cells proliferation,phosphate anions have been paid great attention as a promising anticancer agent.Generally,the transport of phosphate anions depends on a protein transport system which is regulated by ion homeostasis regulations.Herein,we designed a reactive anionic nanocarrier based on black phosphorus nanosheets(BPs)and artesunate(ART),which could enter cells through endocytosis to generate phosphate anions,avoiding the regulation of cell homeostasis.The ionic nanocarrier was coated by polydopamine to defend BPs and ART and functionalized by folate(FA)and hyaluronic acid(HA)for targeting factor.With the anchoring groups FA/HA targeted the carrier into cells,polydopamine coating decomposed to expose ART for further generating reactive oxygen species(ROS)in cancer cell microenvironment,providing oxidation conditions.Next,ROS generated by ART makes BPs decompose to phosphate anions with effectively speed,giving rise to the destruction of ion homeostasis to induce necro sis and inhibit the proliferation for cancer cells.In consequence,this research provides novel idea and direction for the ionic carriers and tumor therapeutics.
文摘Prostate artery embolization is a well-known and promising treatment for benign prostatic hyperplasia, with the quantum leaps of research in medicine. We aim to provide an up-to-date review of the novel technique, including large retrospective studies and randomized control trials, ends with discussions of advantages and disadvantages of this minimally invasive technique.
基金Supported by the Fundamental Research Funds for the Central Universities(Grant No.020414380149)the Natural Science Foundation of China(Grant Nos.11674165,11834006 and 11774065)+3 种基金the Fok Ying-Tong Education Foundation of China(Grant No.161006)the National Key R&D Program of China(Grant Nos.2016YFA0300703 and 2019YFA0308404)the Shanghai Municipal Science and Technology Major Project(Grant No.2019SHZDZX04)the Natural Science Foundation of Shanghai(Grant No.19ZR1471400)。
文摘The dynamical axion field is a new state of quantum matter where the magnetoelectric response couples strongly to its low-energy magnetic fluctuations.It is fundamentally different from an axion insulator with a static quantized magnetoelectric response.The dynamical axion field exhibits many exotic phenomena such as axionic polariton and axion instability.However,these effects have not been experimentally confirmed due to the lack of proper topological magnetic materials.Combining analytic models and first-principles calculations,here we predict a series of van der Waals layered Mn2Bi2Te5-related topological antiferromagnetic materials that could host the long-sought dynamical axion field with a topological origin.We also show that a large dynamical axion field can be achieved in antiferromagnetic insulating states close to the topological phase transition.We further propose the optical and transport experiments to detect such a dynamical axion field.Our results could directly aid and facilitate the search for topological-origin large dynamical axion field in realistic materials.
基金supported by the National Key Research and Development Program of China (2022YFB3803600)the National Natural Science Foundation of China (22302067)+2 种基金the Innovation Program of Shanghai Municipal Education Commission (2021-0107-00-02-E00106)the Science and Technology Commission of Shanghai Municipality (22230780200,20DZ2250400)Fundamental Research Funds for the Central Universities (222201717003)。
文摘Photocatalytic water oxidation is a crucial counter-electrode reaction in the process of photoelectrochemical energy conversion.Despite its importance,challenges remain in effectively and sustainably converting water to oxygen,particularly with readily available and inexpensive electrolyte solutions such as seawater.While metal oxide materials have demonstrated their advantages in promoting efficiency by reducing overpotential and improving light utilization,stability remains limited by corrosion in multicomponent seawater.In this paper,we reviewed the relationship between four basic concepts including photoelectrochemistry,metal oxide,water oxidation and seawater to better understand the challenges and opportunities in photoelectrochemical(PEC)seawater oxidation.To overcome these challenges,the advances in material design,interfacial modification,local environment control and reactor design have been further reviewed to benefit the industrial PEC seawater oxidation.Noticeably,we demonstrate engineered layered metal oxide electrodes and cell structures that enable powerful and stable seawater oxidation.We also outline and advise on the future direction in this area.
基金Key Research and Development Project of Hainan Province(ZDYF2021XDNY174)Science and Technology Major Project of Inner Mongolia(2021ZD0023–1)National Transgenic Key Project of the Ministry of Agriculture of China(2018ZX0800801B)。
文摘Background:SCNT(somatic cell nuclear transfer)is of great significance to biological research and also to the livestock breeding.However,the survival rate of the SCNT cloned animals is relatively low compared to other transgenic methods.This indicates the potential epigenetic variations between them.DNA methylation is a key marker of mammalian epigenetics and its alterations will lead to phenotypic differences.In this study,ASMT(acetylserotonin-Omethyltransferase)ovarian overexpression transgenic goat was produced by using SCNT.To investigate whether there are epigenetic differences between cloned and WT(wild type)goats,WGBS(whole-genome bisulfite sequencing)was used to measure the whole-genome methylation of these animals.Results:It is observed that the different m Cp G sites are mainly present in the intergenic and intronic regions between cloned and WT animals,and their CG-type methylation sites are strongly correlated.DMR(differentially methylated region)lengths are located around 1000 bp,mainly distributed in the exonic,intergenic and intronic functional domains.A total of 56 and 36 DMGs(differentially methylated genes)were identified by GO and KEGG databases,respectively.Functional annotation showed that DMGs were enriched in biological-process,cellularcomponent,molecular-function and other signaling pathways.A total of 10 identical genes related to growth and development were identified in GO and KEGG databases.Conclusion:The differences in methylation genes among the tested animals have been identified.A total of 10 DMGs associated with growth and development were identified between cloned and WT animals.The results indicate that the differential patterns of DNA methylation between the cloned and WT goats are probably caused by the SCNT.These novel observations will help us to further identify the unveiled mechanisms of somatic cell cloning technology,particularly in goats.
基金supported by National Science and Technology Major Project of China(2016ZX08008-003).
文摘Background:Gram-negative bacterial infections have a major economic impact on both the livestock industry and public health.Toll-like receptor 4(TLR4)plays a crucial role in host defence against Gram-negative bacteria.Exploring the defence mechanism regulated by TLR4 may provide new targets for treatment of inflammation and control of bacterial infections.In a previous study,we generated transgenic sheep overexpressing TLR4 by microinjection to improve disease resistance.The defence mechanism through which TLR4 overexpression protected these sheep against pathogens is still not fully understood.Results:In the present study,we used Escherichia coli to infect monocytes isolated from peripheral blood of the animal model.The overexpression of TLR4 strongly enhanced the percentage of endocytosis and capacity of elimination in monocytes during the early stages of infection.This phenomenon was mainly due to overexpression of TLR4 promoting caveolae-mediated endocytosis.Pretreatment of the transgenic sheep monocytes with inhibitors of TLR4,Src signalling,or the caveolae-mediated endocytosis pathway reduced the internalization of bacteria,weakened the ability of the monocytes to eliminate the bacteria,and increased the pH of the endosomes.Conclusion:Together,our results reveal the effects of TLR4 on the control of E.coli infection in the innate immunity of sheep and provide crucial evidence of the caveolae-mediated endocytosis pathway required for host resistance to invading bacteria in a large animal model,providing theoretical support for breeding disease resistance in the future.Furthermore,Src and caveolin 1(CAV1)could be potentially valuable targets for the control of infectious diseases.
