Diamond-like AgGaS_(2)(DL AGS),as the typical infrared nonlinear optical(IR NLO)material,has suffered from its intrinsic drawbacks like narrow band gap(E_(g))and low laser-induced damage threshold(LIDT).In this work,b...Diamond-like AgGaS_(2)(DL AGS),as the typical infrared nonlinear optical(IR NLO)material,has suffered from its intrinsic drawbacks like narrow band gap(E_(g))and low laser-induced damage threshold(LIDT).In this work,by first introducing[NaS_(8)]polyhedral unit into the A_(2)^(Ⅰ)Q^(Ⅵ)-Ag_(2)Q^(Ⅵ)-C_(2)^(Ⅲ)Q_(3)^(Ⅵ) system,a new Ag-based sulfide NaAg_(3)Ga_(8)S_(14) with diamond-like framework(DLF)has been successfully synthesized via a high-temperature solid-state method in experiment.The compound shows a wide Eg(~3.0 eV),high LIDT(3.0×AGS)and moderate phase-matching NLO response(~0.7×AGS),effectively balancing the E_(g)(≥3.0 eV)and NLO response(≥0.5×AGS),demonstrating its promise for IR NLO applications.Theoretical calculations elucidate the orbital hybridization between Na 3s,Ag 4d5s and S 3p enhances E_(g),and the aligned NLO-active units([AgS_(4)]and[GaS_(4)])induce moderate NLO response in the compound.These findings not only expand the chemical and structural diversities of Ag-based chalcogenides,but also provide effective strategies for designing DLF functional materials derived from diamond-like structures.展开更多
Comparing with lithofacies palaeogeography of several great plains,the authors analyzed four great plains in Quaternary diastrophism,the sedimentary facies,sedimentary environment and their evolution from the independ...Comparing with lithofacies palaeogeography of several great plains,the authors analyzed four great plains in Quaternary diastrophism,the sedimentary facies,sedimentary environment and their evolution from the independent embryonic and river system of ancient Heilongjiang finally to the Halar highland,Songnen Plain,Sanjiang Plain,the Xingkai Lake Plain and various river systems,collected the unification outside the system of Heilongjiang River to release into the sea,south ancient Xialiao River finally piracy Dongliao River,Xialiao River had released into the sea the ancient water law vicissitude and the evolved rule.展开更多
Polymer fiber filters play a vital role in removing particulate matter(PM),reducing environmental risk factors and cardiovascular diseases.However,the contradiction between high filtration efficiency and low airflow r...Polymer fiber filters play a vital role in removing particulate matter(PM),reducing environmental risk factors and cardiovascular diseases.However,the contradiction between high filtration efficiency and low airflow resistance limits the filtration performance of polymer filters,while exacerbating the microplastic contamination.Herein,we proposed an interface polarization strategy to fabricate a biodegradable fiber membrane with a high relative dielectric constant to filter the PM in a high-efficiency and low-resistance way.The membrane was constructed by silk fibroin(SF)and wool fiber membrane(Wool),where the SF bonded on the wool surface to form a crosslinked network.Specifically,polar groups(-NH_(2)/-OH)on SF form a dynamic hydrogen-bonding network with airborne water molecules,enhancing the interface polarization and elevating the relative dielectric constant to 8.4.Based on this high dielectric constant,Wool loaded with 20 mg of SF(SF@Wool)reaches PM_(0.3)filtration efficiency of 99.69%,with air resistance of 8 Pa.Meanwhile,SF@Wool exhibits filtration efficiency decay of less than 0.5%over 30 d,demonstrating excellent long-term stability.Furthermore,the biodegradable properties of SF@Wool effectively prevent microplastic pollution(it can be completely degraded in soil within 14 d after treatment with alkaline solution).展开更多
Aims Biological soil crusts(BSCs)can affect soil properties including water dynamics and cycling of soil carbon and nitrogen in dryland ecosystems.Previous research has mostly focused on effects of BSCs on soil water ...Aims Biological soil crusts(BSCs)can affect soil properties including water dynamics and cycling of soil carbon and nitrogen in dryland ecosystems.Previous research has mostly focused on effects of BSCs on soil water distribution or carbon and nitrogen fixation in the surface soil layer.Thus,little is known about effects of BSCs on properties throughout the soil profile.In the current study,we assessed the effects of BSCs on the distribution of soil water content(SW),soil organic carbon content(SOC)and soil total nitrogen content(STN)throughout the soil profile as well as the influence of water conditions on the effects of BSCs.Methods In a field investigation in Mu Us Sandland,North China,soil samples were taken from plots with and without BSCs on 13 and 28 September 2006,respectively.On the two sampling dates,average soil gravimetric water content was 3.83%(61.29%)and 5.08%(60.89%),respectively,which were regarded as low and high water conditions.Soil samples were collected every 5 cm to a depth of 60 cm,and SW,SOC and STN were measured in the laboratory.Important Findings(i)BSCs affected profile distribution of SW,SOC and STN.In addition,water conditions within the plots significantly modified BSCs’effects on the profile distribution of SW,but marginally affected the effects on SOC and STN.(ii)Under high water conditions,SW in the surface soil layer(0–10 cm)was higher in soils with BSCs compared to those without BSCs,while the opposite was true in the deep soil layer(30–55 cm).(iii)Under low water conditions,SW was lower with BSCs compared with no BSCs in near-surface(5–20 cm)and deep(25–40 cm)soil layers.(iv)BSCs affected SOC and STN only in the surface soil layer(0–5 cm)and were modified by plot water conditions.展开更多
Aims Our aim was to study how diversity and dominance of plant species and plant functional types(PFTs)change and covary across three dune fixation stages in the Chinese steppe zone.Methods In the Chinese steppe zone,...Aims Our aim was to study how diversity and dominance of plant species and plant functional types(PFTs)change and covary across three dune fixation stages in the Chinese steppe zone.Methods In the Chinese steppe zone,we measured coverage,mean height and density of each plant species in three types of dunes(mobile,semi-fixed and fixed dunes)in four sites(Mu Us,Otindag,Hulunbeir and Horqin).Plant species were grouped into 24 PFTs according to their lifespan,photosynthetic pathway,reproductive mode and life form.Dominance of each plant species and PFT were determined,and species diversity and PFT diversity were quantified using Shannon–Wiener index.Important Findings PFT diversity was positively related to plant species diversity in each dune stage,but PFT diversity increased more with increasing plant species diversity in the mobile and semi-fixed dunes than in the fixed dunes.Dune fixation stage explained 87.2%of the variation in plant species diversity and 84.8%of the variation in PFT diversity.Dominant species and PFTs differed among the three dune fixation stages;the more fixed the dunes were,the more perennial,shrubby,clonal and C3 species co-dominated.Specifically,in mobile dunes annual C4 non-clonal herbs were the most dominant,and in semi-fixed and fixed dunes perennial C3 clonal shrubs were most dominant.展开更多
基金supported by the Tianshan Talent Training Program(2024TSYCLJ0035)the Natural Science Foundation of the Xinjiang Uygur Autonomous Region(2024D01E30,2025D01B157)+3 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0880000)the Open Fund of the Anhui Key Laboratory of Photonic Materials and Devices(AHKL2024KF02)the National Natural Sci-ence Foundation of China(22475234,52402017)the support from Tianchi Doctor Plan of Xinjiang Uygur Autonomous Region.
文摘Diamond-like AgGaS_(2)(DL AGS),as the typical infrared nonlinear optical(IR NLO)material,has suffered from its intrinsic drawbacks like narrow band gap(E_(g))and low laser-induced damage threshold(LIDT).In this work,by first introducing[NaS_(8)]polyhedral unit into the A_(2)^(Ⅰ)Q^(Ⅵ)-Ag_(2)Q^(Ⅵ)-C_(2)^(Ⅲ)Q_(3)^(Ⅵ) system,a new Ag-based sulfide NaAg_(3)Ga_(8)S_(14) with diamond-like framework(DLF)has been successfully synthesized via a high-temperature solid-state method in experiment.The compound shows a wide Eg(~3.0 eV),high LIDT(3.0×AGS)and moderate phase-matching NLO response(~0.7×AGS),effectively balancing the E_(g)(≥3.0 eV)and NLO response(≥0.5×AGS),demonstrating its promise for IR NLO applications.Theoretical calculations elucidate the orbital hybridization between Na 3s,Ag 4d5s and S 3p enhances E_(g),and the aligned NLO-active units([AgS_(4)]and[GaS_(4)])induce moderate NLO response in the compound.These findings not only expand the chemical and structural diversities of Ag-based chalcogenides,but also provide effective strategies for designing DLF functional materials derived from diamond-like structures.
文摘Comparing with lithofacies palaeogeography of several great plains,the authors analyzed four great plains in Quaternary diastrophism,the sedimentary facies,sedimentary environment and their evolution from the independent embryonic and river system of ancient Heilongjiang finally to the Halar highland,Songnen Plain,Sanjiang Plain,the Xingkai Lake Plain and various river systems,collected the unification outside the system of Heilongjiang River to release into the sea,south ancient Xialiao River finally piracy Dongliao River,Xialiao River had released into the sea the ancient water law vicissitude and the evolved rule.
基金Fundamental Research Funds for the Central Universities(2232025A-05)National Key Research and Development Program of China(2022YFB3803502)+2 种基金National Natural Science Foundation of China(42442040,52408122)International Cooperation Fund of the Science and Technology Commission of Shanghai Municipality(24520713300)Interdisciplinary Frontier Innovation Team Development Special Fund of Donghua University,and Shanghai Rising-Star Program(24QA2700100).
文摘Polymer fiber filters play a vital role in removing particulate matter(PM),reducing environmental risk factors and cardiovascular diseases.However,the contradiction between high filtration efficiency and low airflow resistance limits the filtration performance of polymer filters,while exacerbating the microplastic contamination.Herein,we proposed an interface polarization strategy to fabricate a biodegradable fiber membrane with a high relative dielectric constant to filter the PM in a high-efficiency and low-resistance way.The membrane was constructed by silk fibroin(SF)and wool fiber membrane(Wool),where the SF bonded on the wool surface to form a crosslinked network.Specifically,polar groups(-NH_(2)/-OH)on SF form a dynamic hydrogen-bonding network with airborne water molecules,enhancing the interface polarization and elevating the relative dielectric constant to 8.4.Based on this high dielectric constant,Wool loaded with 20 mg of SF(SF@Wool)reaches PM_(0.3)filtration efficiency of 99.69%,with air resistance of 8 Pa.Meanwhile,SF@Wool exhibits filtration efficiency decay of less than 0.5%over 30 d,demonstrating excellent long-term stability.Furthermore,the biodegradable properties of SF@Wool effectively prevent microplastic pollution(it can be completely degraded in soil within 14 d after treatment with alkaline solution).
基金Chinese Academy of Sciences grant(KZCX2-YW-431)State Key Laboratory of Vegetation and Environmental Change(VEWALNE-project).
文摘Aims Biological soil crusts(BSCs)can affect soil properties including water dynamics and cycling of soil carbon and nitrogen in dryland ecosystems.Previous research has mostly focused on effects of BSCs on soil water distribution or carbon and nitrogen fixation in the surface soil layer.Thus,little is known about effects of BSCs on properties throughout the soil profile.In the current study,we assessed the effects of BSCs on the distribution of soil water content(SW),soil organic carbon content(SOC)and soil total nitrogen content(STN)throughout the soil profile as well as the influence of water conditions on the effects of BSCs.Methods In a field investigation in Mu Us Sandland,North China,soil samples were taken from plots with and without BSCs on 13 and 28 September 2006,respectively.On the two sampling dates,average soil gravimetric water content was 3.83%(61.29%)and 5.08%(60.89%),respectively,which were regarded as low and high water conditions.Soil samples were collected every 5 cm to a depth of 60 cm,and SW,SOC and STN were measured in the laboratory.Important Findings(i)BSCs affected profile distribution of SW,SOC and STN.In addition,water conditions within the plots significantly modified BSCs’effects on the profile distribution of SW,but marginally affected the effects on SOC and STN.(ii)Under high water conditions,SW in the surface soil layer(0–10 cm)was higher in soils with BSCs compared to those without BSCs,while the opposite was true in the deep soil layer(30–55 cm).(iii)Under low water conditions,SW was lower with BSCs compared with no BSCs in near-surface(5–20 cm)and deep(25–40 cm)soil layers.(iv)BSCs affected SOC and STN only in the surface soil layer(0–5 cm)and were modified by plot water conditions.
基金Chinese Academy of Sciences(KZCX2-YW-431-04)National Natural Science Foundation of China(30821062)VEWALNE(VEgetation-WAter Long-term Networked Experiment in Chinese Steppe zone)project.
文摘Aims Our aim was to study how diversity and dominance of plant species and plant functional types(PFTs)change and covary across three dune fixation stages in the Chinese steppe zone.Methods In the Chinese steppe zone,we measured coverage,mean height and density of each plant species in three types of dunes(mobile,semi-fixed and fixed dunes)in four sites(Mu Us,Otindag,Hulunbeir and Horqin).Plant species were grouped into 24 PFTs according to their lifespan,photosynthetic pathway,reproductive mode and life form.Dominance of each plant species and PFT were determined,and species diversity and PFT diversity were quantified using Shannon–Wiener index.Important Findings PFT diversity was positively related to plant species diversity in each dune stage,but PFT diversity increased more with increasing plant species diversity in the mobile and semi-fixed dunes than in the fixed dunes.Dune fixation stage explained 87.2%of the variation in plant species diversity and 84.8%of the variation in PFT diversity.Dominant species and PFTs differed among the three dune fixation stages;the more fixed the dunes were,the more perennial,shrubby,clonal and C3 species co-dominated.Specifically,in mobile dunes annual C4 non-clonal herbs were the most dominant,and in semi-fixed and fixed dunes perennial C3 clonal shrubs were most dominant.
