We propose and investigate a novel stable two-dimensional(2D)AlO_(2)with anomalous stoichiometric ratios based on first-principles calculation.2D AlO_(2)has metallic properties.It possesses the rare in-plane and out-o...We propose and investigate a novel stable two-dimensional(2D)AlO_(2)with anomalous stoichiometric ratios based on first-principles calculation.2D AlO_(2)has metallic properties.It possesses the rare in-plane and out-of-plane negative Poisson's ratio(NPR)phenomenon,originating from its special sawtooth-like structure.The absolute value of the NPR decreases as the number of layers increases.The adsorption of volatile organic compounds(VOCs)including CH_(2)O,C_(2)H_(3)Cl and C_(6)H_(6)by AlO_(2)exhibit small adsorption distance,large adsorption energy,large charge transfer and significant density of states(DOS)changes,indicating the presence of strong interactions.The desorption time of each gas molecule on the AlO_(2)surface is also evaluated,and the results further suggest that the desorption of VOCs can be controlled by changing the temperature to achieve the recycling of AlO_(2).These interesting properties make 2D AlO_(2)a promising material for electronic,mechanical and sensing applications for VOCs.展开更多
BACKGROUND Blonanserin,a novel antipsychotic,has demonstrated efficacy in treating both positive and negative symptoms.However,limited research exists on its dose-dependent effectiveness and safety in patients with an...BACKGROUND Blonanserin,a novel antipsychotic,has demonstrated efficacy in treating both positive and negative symptoms.However,limited research exists on its dose-dependent effectiveness and safety in patients with and without prominent nega-tive symptoms(PNS).AIM To evaluate the effectiveness and safety of blonanserin monotherapy for first-episode schizophrenia in real-world clinical settings and to explore the efficacy and safety of different doses of blonanserin for patients with PNS and without PNS.METHODS A 12-week,multicenter,prospective post-marketing surveillance was conducted.In this study,we included patients with first-episode schizophrenia who received blonanserin monotherapy.Patients were divided into those with PNS and without PNS,based on the Brief Psychiatric Rating Scale(BPRS)negative symptoms subscale scores.Additionally,patients were labeled as high-dose and low-dose was evaluated through the incidence of adverse drug reactions(ADRs).RESULTS A total of 653 patients were included in the analysis,with 613 completing the study.The BPRS total score decreased significantly from 47.94±16.31 at baseline to 26.88±9.47 at 12 weeks(P<0.001).A significant interaction of PNS×dose×time was observed for BPRS total scores(F=3.47,P=0.040)and negative symptom subscale scores(F=6.76,P=0.002).In the PNS group,the high-dose group showed greater reductions in BPRS total scores(P=0.001)and negative symptom subscale scores(P=0.003)than the low-dose group in week 12.In the without PNS group,no significant difference was observed between the high-dose and low-dose groups at any visit.Most adverse reactions were mild or moderate,with extrapyramidal symptoms(9.3%)being most common;1.5%of patients gained≥7%body weight at 12 weeks.CONCLUSION Blonanserin effectively alleviated the clinical symptoms of first-episode schizophrenia with an acceptable safety profile.High-dose blonanserin is particularly beneficial for patients with PNS in the acute phase of first-episode schizophrenia.However,due to the limitation of ADR reporting the real world,the ADR incidence observed in this study may be underestimated.展开更多
Soil structure and nutrient ingredient before and after shattering and returning sugarcane leaf as well as its technologies and methods were comparatively analyzed in this study to discuss the main reasons primarily,w...Soil structure and nutrient ingredient before and after shattering and returning sugarcane leaf as well as its technologies and methods were comparatively analyzed in this study to discuss the main reasons primarily,while the controlling technologies were proposed by combining cultivation,management and technical measures.展开更多
Four mineral admixture concrete specimens werefabricated to study the negative effect improvements ofaccelerated curing on the chloride penetration resistance ofordinary concrete. After reaching different initial stre...Four mineral admixture concrete specimens werefabricated to study the negative effect improvements ofaccelerated curing on the chloride penetration resistance ofordinary concrete. After reaching different initial strengths, the specimens were placed in 40, 60, or 80 t water tanks foraccelerated curing. The Coulomb values of the specimens weemeasured with ASTM C1202 experiment at 28, 100, 200, ad300 d. Partial specimens were also selected for rapid chlorideion migration coefficient and mercury intrusion porosimetryexperiments. The experimental results show that theaccelerated curing for ordinary concrete linealy deterioratesthe chloride penetration resistance, whereas the incorporationof mineral admixtures improves the concrete microscopic pore-structures and negative effects. An upper temperature limit of60 t of the accelerated curing is suitable for obtainingsuperior chloride penetration resistance for the mineraladmixture concrete. Pre-curing at a normal temperature of 20t is beneficial for improving the negative effect, which isalso aieviated with increasing testing age as a result of thesuccessive hydration of binder materials in concrete.展开更多
This paper proposes a three-dimensional(3D)Maltese cross metamaterial with negative Poisson’s ratio(NPR)and negative thermal expansion(NTE)adopted as the core layers in sandwich plates,and aims to explore the relatio...This paper proposes a three-dimensional(3D)Maltese cross metamaterial with negative Poisson’s ratio(NPR)and negative thermal expansion(NTE)adopted as the core layers in sandwich plates,and aims to explore the relations between the mechanical responses of sandwich composites and the NPR or NTE of the metamaterial.First,the NPR and NTE of the metamaterial are derived analytically based on energy conservation.The effective elastic modulus and mass density of the 3D metamaterial are obtained and validated by the finite element method(FEM).Subsequently,the general governing equation of the 3D sandwich plate under thermal environments is established based on Hamilton’s principle with the consideration of the von Kármán nonlinearity.The differential quadrature(DQ)FEM(DQFEM)is utilized to obtain the numerical solutions.It is shown that NPR and NTE can enhance the global stiffness of sandwich structures.The geometric parameters of the Maltese cross metamaterial significantly affect the responses of the thermal stress,natural frequency,and critical buckling load.展开更多
The so-called 'negative difference effect'(NDE) was often defined by the increasing rate of hydrogen evolution from magnesium(Mg) surface under anodic polarization.In this work,a series of electrochemical test...The so-called 'negative difference effect'(NDE) was often defined by the increasing rate of hydrogen evolution from magnesium(Mg) surface under anodic polarization.In this work,a series of electrochemical tests and microstructure observations were performed to provide an evidence that the NDE of Mg-Li alloys can be retarded by increasing lithium content.Potentiostatic,galvanostatic and potentiodynamic polarization experiments using Mg-xLi(x=4,7.5 and 14 wt%) alloys electrodes indicated that Mg-4 Li alloy maintained the enhancing NDE prior to anodic dissolution as that of conventional Mg alloys.However,the emergence of β-Li phase weakened the NDE of duplex Mg-7.5 Li alloy at a low anodic current density,but it was still enhanced apparently after a high applied anodic value(more than 2 mA/cm^2).The surface observations,including the plane and cross-sectional morphologies,confirmed that the cracked surface film derived from the anodic dissolution resulted in the catalytic activity of NDE for Mg-4 Li and Mg-7.5 Li alloys.Furthermore,the NDE of Mg-14 Li alloy was suppressed obviously after a prior applied anodic polarization,which was attributed to the persistent and integrated surface film which endured a higher level of applied anodic potential and current.展开更多
Battery safety has attracted considerable attention worldwide due to the rapid development of wearable electronics and the steady increase in the production and use of electric vehicles.As battery failures are often a...Battery safety has attracted considerable attention worldwide due to the rapid development of wearable electronics and the steady increase in the production and use of electric vehicles.As battery failures are often associated with mechanical-thermal coupled behaviors,protective shielding materials with excellent mechanical robustness and flame-retardant properties are highly desired to mitigate thermal runaway.However,most of the thermal insulating materials are not strong enough to protect batteries from mechanical abuse,which is one of the most critical scenarios with catastrophic consequences.Here,inspired by wood,we have developed an effective approach to engineer a hierarchical nanocomposite via self-assembly of calcium silicate hydrate and polyvinyl alcohol polymer chains(referred as CSH wood).The versatile protective material CSH wood demonstrates an unprecedented combination of light weight(0.018 g cm-3),high stiffness(204 MPa in the axial direction),negative Poisson's ratio(-0.15),remarkable toughness(6.67×105 J m-3),superior thermal insulation(0.0204 W m-1 K-1 in the radial direction),and excellent fire retardancy(UL94-V0).When applied as a protective cover or a protective layer within battery packages,the tough CSH wood can resist high-impact load and block heat diffusion to block or delay the spread of fire,therefore significantly reducing the risk of property damage or bodily injuries caused by battery explosions.This work provides new pathways for fabricating advanced thermal insulating materials with large scalability and demonstrates great potential for the protection of electronic devices.展开更多
Background Good interpersonal relationships can improve the negative mood and, to a certain extent, may help relieve dysmenorrhea symptoms. However, there has been no study examining the role of interpersonal relation...Background Good interpersonal relationships can improve the negative mood and, to a certain extent, may help relieve dysmenorrhea symptoms. However, there has been no study examining the role of interpersonal relationships in dysmenorrhea and how they may interact with negative emotions. Aims To investigate the connection between negative affect and dysmenorrhea, and the role of interpersonal relationships plays in this relationship. Methods The Cox Menstrual Symptom Scale (CMSS), short-form of Depression Anxiety Stress Scale, Interpersonal Comprehensive Diagnostic Scale and UCLA (University of California at Los Angeles) Loneliness Scale were applied to 855 adolescent nursing students to collect information on severity and frequency of dysmenorrheal symptoms, negative emotions (including depression, anxiety and stress), interpersonal problems and subjective experience of loneliness among them, and the relationship among these variables was examined. Results (1) Both the severity and frequency of dysmenorrhea were positively correlated with negative emotions, loneliness experience and interpersonal problems, while negatively correlated with age at menarche.(2) The negative emotions, romantic relationship and menarche age, but not loneliness and interpersonal problems, significantly contributed to both the severity and frequency of dysmenorrhea.(3) Mediation analysis revealed that the effects of loneliness and interpersonal problems on dysmenorrhea were totally mediated by negative emotions. Conclusions This investigation indicates that the relationship between interpersonal relationships and dysmenorrhea is mediated by negative emotions.展开更多
Efficient photogenerated carrier migration/separation plays a critical role in increasing the photocatalytic performance of g-C_(3)N_(4).Herein,sulfonic acid group-functionalized g-C_(3)N_(4)(SACN)was synthesized and ...Efficient photogenerated carrier migration/separation plays a critical role in increasing the photocatalytic performance of g-C_(3)N_(4).Herein,sulfonic acid group-functionalized g-C_(3)N_(4)(SACN)was synthesized and then synchronously strengthened by a facile-solid-state thermal reaction of g-C_(3)N_(4)and sulfamic acid.As a solid strong acid,sulfamic acid can be used to achieve acid etching on the surface of g-C_(3)N_(4)with the assistance of thermal treatment,leading to an enlarged specific surface area and increased surface catalytic reaction sites.More importantly,our experiments and density functional theory calculations indicate that the driving force generated by the negative inductive effect of sulfonic acid groups significantly improves the charge transfer dynamics and effectively inhibits their recombination.Moreover,the negative inductive effect can induce charge redistribution,which reduces the conduction band potential of g-C_(3)N_(4)to enhance the reduction ability of photo-induced electrons.As a result,the SACN-400 sample showed excellent photocatalytic performance in H2 generation with an apparent quantum efficiency of 11.03%at 420±15 nm,as well as an efficient photodegradation rate for organic pollutants.展开更多
This paper summarizes the negative effects on geological environment caused by groundwater exploitation and its distribution. There are seven main types of the geological environment negative effects, which are genera...This paper summarizes the negative effects on geological environment caused by groundwater exploitation and its distribution. There are seven main types of the geological environment negative effects, which are generally as follows:(1) Constant decrease of groundwater level is mainly distributed in China(East Asia), India(South Asia), Tajikistan(Central Asia) and Saudi Arabia(West Asia);(2) land subsidence occurs mainly in eastern plains of East Asia and west Siberian Plain of North Asia;(3) seawater intrusion occurs mainly in China, Japan and South Korea in East Asia, Philippines and Indonesia in Southeast Asia, the Indian coastal areas in South Asia;(4) groundwater level decline caused by groundwater exploitation in oil fields;(5) mining collapse is mainly in 50° to 70° north latitude band;(6) the total area of karst collapse in China of East Asia is as much as 197.05 km^2; and(7) ground fracture is mainly distributed in the North China Plain, Fenwei Plain and the Yangtze River Delta. Asia can be divided into 6 zones in terms of the geological environment negative effect caused by groundwater exploitation. According to analysis, with the increasing intensity of human activities, geological environment issues become more and more serious, therefore it is vital to control the human activities within the scope of 5× 10~5 people/km^2 to 9.9× 10~5 people/km^2 for the effective control of the size of the affected area by geological environment problems.展开更多
Language anxiety is an important emotional variable affecting language learning. There are three factors that cause the foreign language anxiety. The effective measures should be taken to overcome the negative effect ...Language anxiety is an important emotional variable affecting language learning. There are three factors that cause the foreign language anxiety. The effective measures should be taken to overcome the negative effect of language anxiety.展开更多
Two-dimensional(2D)antiferroelectric materials have raised great research interest over the last decade.Here,we reveal a type of 2D antiferroelectric(AFE)crystal where the AFE polarization direction can be switched by...Two-dimensional(2D)antiferroelectric materials have raised great research interest over the last decade.Here,we reveal a type of 2D antiferroelectric(AFE)crystal where the AFE polarization direction can be switched by a certain degree in the 2D plane.Such 2D functional materials are realized by stacking the exfoliated wurtzite(wz)monolayers with“self-healable”nature,which host strongly coupled ferroelasticity/antiferroelectricity and benign stability.The AFE candidates,i.e.,Zn X and Cd X(X=S,Se,Te),are all semiconductors with direct bandgap atΓpoint,which harbors switchable antiferroelectricity and ferroelasticity with low transition barriers,hidden spin polarization,as well as giant in-plane negative Poisson's ratio(NPR),enabling the co-tunability of hidden spin characteristics and auxetic magnitudes via AFE switching.The 2D AFE wz crystals provide a platform to probe the interplay of 2D antiferroelectricity,ferroelasticity,NPR,and spin effects,shedding new light on the rich physics and device design in wz semiconductors.展开更多
A novel negative thermal expansion(NTE) material NdMnO_(3) was synthesized by solid-state method at 1 523 K. The crystal structure, phase transition, pores effect and negative expansion properties of NdMnO_(3) were in...A novel negative thermal expansion(NTE) material NdMnO_(3) was synthesized by solid-state method at 1 523 K. The crystal structure, phase transition, pores effect and negative expansion properties of NdMnO_(3) were investigated by variable temperature X-ray diffraction(XRD), scanning electron microscope(SEM) and variable temperature Raman spectra. The compound exhibits NTE properties in the orderly O' phase crystal structure. When the temperature is from 293 to 759 K, the ceramic NdMnO_(3) shows negative thermal expansion of-4.7×10^(-6)/K. As temperature increases, the ceramic NdMnO_(3) presents NTE property range from 759 to 1 007 K. The average linear expansion coefficient is-18.88×10^(-6)/K. The physical mechanism of NTE is discussed and clarified through experiments.展开更多
Artificial nest boxes are placed to attract birds to nest and breed in a specific location,and they are widely used in avian ecology research and in the attraction of insectivorous birds.There is evidence that artific...Artificial nest boxes are placed to attract birds to nest and breed in a specific location,and they are widely used in avian ecology research and in the attraction of insectivorous birds.There is evidence that artificial nest boxes can adversely affect breeding fitness but no great focus has been placed on this issue by researchers.Therefore,we retrieved 321 research papers regarding artificial nest boxes published from 2003 to 2022 and used the'Biblioshiny'program to extract and integrate keywords;we then summarized the adverse effects of artificial nest boxes on avian breeding success.The studies highlighted many drawbacks and misuses in the designing and placement of nest boxes;furthermore,bird attraction was decreased by their inappropriate selection,thus reducing breeding success.Regarding nest box production,there were shortcomings in the construction material,color,smell,and structural design of the boxes used.Nest boxes were also placed at inappropriate densities,locations,orientations,heights,and managed incorrectly.Finally,we propose suggestions for more efficient and safer artificial nest boxes for future use in avian ecology research and bird conservation.展开更多
The anti-resonant phenomenon of effective electromagnetic parameters of metamaterials has aroused controversy due to negative imaginary permittivity or permeability. It is experimentally found that the negative imagin...The anti-resonant phenomenon of effective electromagnetic parameters of metamaterials has aroused controversy due to negative imaginary permittivity or permeability. It is experimentally found that the negative imaginary permittivity can occur for the natural passive materials near the Fabry Perot resonances. We reveal the nature of negative imaginary permittivity, which is correlated with the magnetoelectric coupling. The anti-resonance of permittivity is a non-inherent feature for passive materials, while it can be inherent for devices or metamaterials. Our finding validates that the negative imaginary part of effective permittivity does not contradict the second law of thermodynamics for metamaterials owing to the magnetoelectric coupling.展开更多
The electronic and transport characteristics of protonated derivatives of naphthalocyanine(Nc)were investigated using density functional theory and non-equilibrium Green's functions.The results indicate that the p...The electronic and transport characteristics of protonated derivatives of naphthalocyanine(Nc)were investigated using density functional theory and non-equilibrium Green's functions.The results indicate that the protonation of external meso-N atoms of Nc preserves its planar structure and is energetically more favorable than the protonation of internal isoindole-N atoms.The protonation shifts the energy levels of system's frontier molecular orbitals closer to the Fermi level,thus creating channels for electron transport.In contrast with the semiconductor transport properties of H2Nc,its protonation products respond more sensitively to bias and exhibit negative differential resistance phenomena at specific bias.展开更多
The present paper discusses three major sources of negative effect of classroom instruction on L2 learners'pragmatic development:inadequate or inappropriate metapragmatic input,non-authentic classroom discourse an...The present paper discusses three major sources of negative effect of classroom instruction on L2 learners'pragmatic development:inadequate or inappropriate metapragmatic input,non-authentic classroom discourse and grammar-oriented pedagogy,then proposes some pedagogical suggestions on developing pragmatic competence.展开更多
This paper attempts to investigate the negative effects of the spread of COVID-19 on low-income families in Egypt.Coronavirus spread is measured by"Coronavirus cases"and"Coronavirus deaths"on a dai...This paper attempts to investigate the negative effects of the spread of COVID-19 on low-income families in Egypt.Coronavirus spread is measured by"Coronavirus cases"and"Coronavirus deaths"on a daily basis.Besides,it is measured by both"new Coronavirus cases"and"new deaths from Coronavirus",in relation to the population of Egypt.The Egyptian government is taking some measures to reduce the negative effects of COVID-19,including increasing personal exemptions by amending some provisions of the Egyptian Income Tax Law promulgated by Law No.91 of 2005 to protect low-income families.Of the negative effects of COVID-19,it is one of the most important tax policies to achieve social justice in distributing the tax burden,according to income levels,in a manner that achieves justice and equality.We find that Personal exemptions did not succeed in achieving tax justice by easing the tax burden on the low-income people in society.展开更多
基金financially supported by National Natural Science Foundation of China(No.22275149)Fundamental Research Funds for the Central Universities(No.SWU118105)the Next-Generation Advanced Energy Materials Program of BatteroTech Co.,Ltd.
文摘We propose and investigate a novel stable two-dimensional(2D)AlO_(2)with anomalous stoichiometric ratios based on first-principles calculation.2D AlO_(2)has metallic properties.It possesses the rare in-plane and out-of-plane negative Poisson's ratio(NPR)phenomenon,originating from its special sawtooth-like structure.The absolute value of the NPR decreases as the number of layers increases.The adsorption of volatile organic compounds(VOCs)including CH_(2)O,C_(2)H_(3)Cl and C_(6)H_(6)by AlO_(2)exhibit small adsorption distance,large adsorption energy,large charge transfer and significant density of states(DOS)changes,indicating the presence of strong interactions.The desorption time of each gas molecule on the AlO_(2)surface is also evaluated,and the results further suggest that the desorption of VOCs can be controlled by changing the temperature to achieve the recycling of AlO_(2).These interesting properties make 2D AlO_(2)a promising material for electronic,mechanical and sensing applications for VOCs.
文摘BACKGROUND Blonanserin,a novel antipsychotic,has demonstrated efficacy in treating both positive and negative symptoms.However,limited research exists on its dose-dependent effectiveness and safety in patients with and without prominent nega-tive symptoms(PNS).AIM To evaluate the effectiveness and safety of blonanserin monotherapy for first-episode schizophrenia in real-world clinical settings and to explore the efficacy and safety of different doses of blonanserin for patients with PNS and without PNS.METHODS A 12-week,multicenter,prospective post-marketing surveillance was conducted.In this study,we included patients with first-episode schizophrenia who received blonanserin monotherapy.Patients were divided into those with PNS and without PNS,based on the Brief Psychiatric Rating Scale(BPRS)negative symptoms subscale scores.Additionally,patients were labeled as high-dose and low-dose was evaluated through the incidence of adverse drug reactions(ADRs).RESULTS A total of 653 patients were included in the analysis,with 613 completing the study.The BPRS total score decreased significantly from 47.94±16.31 at baseline to 26.88±9.47 at 12 weeks(P<0.001).A significant interaction of PNS×dose×time was observed for BPRS total scores(F=3.47,P=0.040)and negative symptom subscale scores(F=6.76,P=0.002).In the PNS group,the high-dose group showed greater reductions in BPRS total scores(P=0.001)and negative symptom subscale scores(P=0.003)than the low-dose group in week 12.In the without PNS group,no significant difference was observed between the high-dose and low-dose groups at any visit.Most adverse reactions were mild or moderate,with extrapyramidal symptoms(9.3%)being most common;1.5%of patients gained≥7%body weight at 12 weeks.CONCLUSION Blonanserin effectively alleviated the clinical symptoms of first-episode schizophrenia with an acceptable safety profile.High-dose blonanserin is particularly beneficial for patients with PNS in the acute phase of first-episode schizophrenia.However,due to the limitation of ADR reporting the real world,the ADR incidence observed in this study may be underestimated.
基金Supported by Agricultural Science and Technology Stride Plan(2009-16)Natural Science Fund in Hainan(808202)Scienceand Technology Project from Chinese Academy of Tropical Agricultural Sciences(Rky09)~~
文摘Soil structure and nutrient ingredient before and after shattering and returning sugarcane leaf as well as its technologies and methods were comparatively analyzed in this study to discuss the main reasons primarily,while the controlling technologies were proposed by combining cultivation,management and technical measures.
基金The National Natural Science Foundation of China(No.51178455)the Transformation Program of Science and Technology Achievements of Jiangsu Province(No.BA2015133)
文摘Four mineral admixture concrete specimens werefabricated to study the negative effect improvements ofaccelerated curing on the chloride penetration resistance ofordinary concrete. After reaching different initial strengths, the specimens were placed in 40, 60, or 80 t water tanks foraccelerated curing. The Coulomb values of the specimens weemeasured with ASTM C1202 experiment at 28, 100, 200, ad300 d. Partial specimens were also selected for rapid chlorideion migration coefficient and mercury intrusion porosimetryexperiments. The experimental results show that theaccelerated curing for ordinary concrete linealy deterioratesthe chloride penetration resistance, whereas the incorporationof mineral admixtures improves the concrete microscopic pore-structures and negative effects. An upper temperature limit of60 t of the accelerated curing is suitable for obtainingsuperior chloride penetration resistance for the mineraladmixture concrete. Pre-curing at a normal temperature of 20t is beneficial for improving the negative effect, which isalso aieviated with increasing testing age as a result of thesuccessive hydration of binder materials in concrete.
基金Project supported by the National Natural Science Foundation of China(No.11872098)。
文摘This paper proposes a three-dimensional(3D)Maltese cross metamaterial with negative Poisson’s ratio(NPR)and negative thermal expansion(NTE)adopted as the core layers in sandwich plates,and aims to explore the relations between the mechanical responses of sandwich composites and the NPR or NTE of the metamaterial.First,the NPR and NTE of the metamaterial are derived analytically based on energy conservation.The effective elastic modulus and mass density of the 3D metamaterial are obtained and validated by the finite element method(FEM).Subsequently,the general governing equation of the 3D sandwich plate under thermal environments is established based on Hamilton’s principle with the consideration of the von Kármán nonlinearity.The differential quadrature(DQ)FEM(DQFEM)is utilized to obtain the numerical solutions.It is shown that NPR and NTE can enhance the global stiffness of sandwich structures.The geometric parameters of the Maltese cross metamaterial significantly affect the responses of the thermal stress,natural frequency,and critical buckling load.
基金supported financially by the National Key Research and Development Program of China (Nos. 2017YFB0702001 and 2016YFB0301105)the National Natural Science Foundation of China Projects (Nos. 51901047,51871211 and51701129)+5 种基金the Doctor Startup Fund of Natural Science Foundation Program of Liaoning Province (No. 2019-BS-200)the Strategic New Industry Development Special Foundation of Shenzhen (No. JCYJ20170306141749970)the Funds of International Joint Laboratory for Light Alloys, the Liaoning Bai Qian Wan Talents Programthe Domain Foundation of Equipment Advance Research of 13th Five-year Plan (No. 61409220118)the Innovation Fund of Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS)the National Basic Research Program of China (No. 2013CB632205)。
文摘The so-called 'negative difference effect'(NDE) was often defined by the increasing rate of hydrogen evolution from magnesium(Mg) surface under anodic polarization.In this work,a series of electrochemical tests and microstructure observations were performed to provide an evidence that the NDE of Mg-Li alloys can be retarded by increasing lithium content.Potentiostatic,galvanostatic and potentiodynamic polarization experiments using Mg-xLi(x=4,7.5 and 14 wt%) alloys electrodes indicated that Mg-4 Li alloy maintained the enhancing NDE prior to anodic dissolution as that of conventional Mg alloys.However,the emergence of β-Li phase weakened the NDE of duplex Mg-7.5 Li alloy at a low anodic current density,but it was still enhanced apparently after a high applied anodic value(more than 2 mA/cm^2).The surface observations,including the plane and cross-sectional morphologies,confirmed that the cracked surface film derived from the anodic dissolution resulted in the catalytic activity of NDE for Mg-4 Li and Mg-7.5 Li alloys.Furthermore,the NDE of Mg-14 Li alloy was suppressed obviously after a prior applied anodic polarization,which was attributed to the persistent and integrated surface film which endured a higher level of applied anodic potential and current.
基金the financial support from the National Key Research and Development Program of China(No.2021YFF0500802)the National Natural Science Foundation of China(No.51890904,No.52022022,and No.52278247)the Scientific Research and Innovation Plan of Jiangsu Province(KYCX21_0090)。
文摘Battery safety has attracted considerable attention worldwide due to the rapid development of wearable electronics and the steady increase in the production and use of electric vehicles.As battery failures are often associated with mechanical-thermal coupled behaviors,protective shielding materials with excellent mechanical robustness and flame-retardant properties are highly desired to mitigate thermal runaway.However,most of the thermal insulating materials are not strong enough to protect batteries from mechanical abuse,which is one of the most critical scenarios with catastrophic consequences.Here,inspired by wood,we have developed an effective approach to engineer a hierarchical nanocomposite via self-assembly of calcium silicate hydrate and polyvinyl alcohol polymer chains(referred as CSH wood).The versatile protective material CSH wood demonstrates an unprecedented combination of light weight(0.018 g cm-3),high stiffness(204 MPa in the axial direction),negative Poisson's ratio(-0.15),remarkable toughness(6.67×105 J m-3),superior thermal insulation(0.0204 W m-1 K-1 in the radial direction),and excellent fire retardancy(UL94-V0).When applied as a protective cover or a protective layer within battery packages,the tough CSH wood can resist high-impact load and block heat diffusion to block or delay the spread of fire,therefore significantly reducing the risk of property damage or bodily injuries caused by battery explosions.This work provides new pathways for fabricating advanced thermal insulating materials with large scalability and demonstrates great potential for the protection of electronic devices.
基金the Sichuan Provincial Science and Technology Department (2017JY0324)Joint Project of Southwest Medical University and Sichuan Luzhou (2017LZXNYD-Z02)+3 种基金Natural Science Foundation of China (81701322)Humanity and Social Science Youth Foundation of Ministry of Education of China (17YJC190001,17YJC190009)the joint project of Southwest Medical University & Affiliated Hospital of Southwest Medical University (2015-QB-003)Sichuan Applied Psychology Research Center Project (CSXL-172012).
文摘Background Good interpersonal relationships can improve the negative mood and, to a certain extent, may help relieve dysmenorrhea symptoms. However, there has been no study examining the role of interpersonal relationships in dysmenorrhea and how they may interact with negative emotions. Aims To investigate the connection between negative affect and dysmenorrhea, and the role of interpersonal relationships plays in this relationship. Methods The Cox Menstrual Symptom Scale (CMSS), short-form of Depression Anxiety Stress Scale, Interpersonal Comprehensive Diagnostic Scale and UCLA (University of California at Los Angeles) Loneliness Scale were applied to 855 adolescent nursing students to collect information on severity and frequency of dysmenorrheal symptoms, negative emotions (including depression, anxiety and stress), interpersonal problems and subjective experience of loneliness among them, and the relationship among these variables was examined. Results (1) Both the severity and frequency of dysmenorrhea were positively correlated with negative emotions, loneliness experience and interpersonal problems, while negatively correlated with age at menarche.(2) The negative emotions, romantic relationship and menarche age, but not loneliness and interpersonal problems, significantly contributed to both the severity and frequency of dysmenorrhea.(3) Mediation analysis revealed that the effects of loneliness and interpersonal problems on dysmenorrhea were totally mediated by negative emotions. Conclusions This investigation indicates that the relationship between interpersonal relationships and dysmenorrhea is mediated by negative emotions.
文摘Efficient photogenerated carrier migration/separation plays a critical role in increasing the photocatalytic performance of g-C_(3)N_(4).Herein,sulfonic acid group-functionalized g-C_(3)N_(4)(SACN)was synthesized and then synchronously strengthened by a facile-solid-state thermal reaction of g-C_(3)N_(4)and sulfamic acid.As a solid strong acid,sulfamic acid can be used to achieve acid etching on the surface of g-C_(3)N_(4)with the assistance of thermal treatment,leading to an enlarged specific surface area and increased surface catalytic reaction sites.More importantly,our experiments and density functional theory calculations indicate that the driving force generated by the negative inductive effect of sulfonic acid groups significantly improves the charge transfer dynamics and effectively inhibits their recombination.Moreover,the negative inductive effect can induce charge redistribution,which reduces the conduction band potential of g-C_(3)N_(4)to enhance the reduction ability of photo-induced electrons.As a result,the SACN-400 sample showed excellent photocatalytic performance in H2 generation with an apparent quantum efficiency of 11.03%at 420±15 nm,as well as an efficient photodegradation rate for organic pollutants.
基金supported by Geological Map of Groundwater Resources and Environment of China and Surrounding Areas(12120113014200)Series Maps of Karst Environment Geology of China and South East Asia(12120114006401,12120114006301)
文摘This paper summarizes the negative effects on geological environment caused by groundwater exploitation and its distribution. There are seven main types of the geological environment negative effects, which are generally as follows:(1) Constant decrease of groundwater level is mainly distributed in China(East Asia), India(South Asia), Tajikistan(Central Asia) and Saudi Arabia(West Asia);(2) land subsidence occurs mainly in eastern plains of East Asia and west Siberian Plain of North Asia;(3) seawater intrusion occurs mainly in China, Japan and South Korea in East Asia, Philippines and Indonesia in Southeast Asia, the Indian coastal areas in South Asia;(4) groundwater level decline caused by groundwater exploitation in oil fields;(5) mining collapse is mainly in 50° to 70° north latitude band;(6) the total area of karst collapse in China of East Asia is as much as 197.05 km^2; and(7) ground fracture is mainly distributed in the North China Plain, Fenwei Plain and the Yangtze River Delta. Asia can be divided into 6 zones in terms of the geological environment negative effect caused by groundwater exploitation. According to analysis, with the increasing intensity of human activities, geological environment issues become more and more serious, therefore it is vital to control the human activities within the scope of 5× 10~5 people/km^2 to 9.9× 10~5 people/km^2 for the effective control of the size of the affected area by geological environment problems.
文摘Language anxiety is an important emotional variable affecting language learning. There are three factors that cause the foreign language anxiety. The effective measures should be taken to overcome the negative effect of language anxiety.
基金supported by Natural Science Foundation of Guangdong Province,China (Grant Nos.2022A1515011990 and 2023A1515030086)National Natural Science Foundation of China (Grant Nos.11774239,11804230 and 61827815)+2 种基金National Key R&D Program of China (Grant No.2019YFB2204500)Shenzhen Science and Technology Innovation Commission (Grant Nos.JCYJ20220531102601004,KQTD20180412181422399 and JCYJ20180507181858539)High-Level University Construction Funds of SZU (Grant Nos.860-000002081209 and 860-000002110711)。
文摘Two-dimensional(2D)antiferroelectric materials have raised great research interest over the last decade.Here,we reveal a type of 2D antiferroelectric(AFE)crystal where the AFE polarization direction can be switched by a certain degree in the 2D plane.Such 2D functional materials are realized by stacking the exfoliated wurtzite(wz)monolayers with“self-healable”nature,which host strongly coupled ferroelasticity/antiferroelectricity and benign stability.The AFE candidates,i.e.,Zn X and Cd X(X=S,Se,Te),are all semiconductors with direct bandgap atΓpoint,which harbors switchable antiferroelectricity and ferroelasticity with low transition barriers,hidden spin polarization,as well as giant in-plane negative Poisson's ratio(NPR),enabling the co-tunability of hidden spin characteristics and auxetic magnitudes via AFE switching.The 2D AFE wz crystals provide a platform to probe the interplay of 2D antiferroelectricity,ferroelasticity,NPR,and spin effects,shedding new light on the rich physics and device design in wz semiconductors.
文摘A novel negative thermal expansion(NTE) material NdMnO_(3) was synthesized by solid-state method at 1 523 K. The crystal structure, phase transition, pores effect and negative expansion properties of NdMnO_(3) were investigated by variable temperature X-ray diffraction(XRD), scanning electron microscope(SEM) and variable temperature Raman spectra. The compound exhibits NTE properties in the orderly O' phase crystal structure. When the temperature is from 293 to 759 K, the ceramic NdMnO_(3) shows negative thermal expansion of-4.7×10^(-6)/K. As temperature increases, the ceramic NdMnO_(3) presents NTE property range from 759 to 1 007 K. The average linear expansion coefficient is-18.88×10^(-6)/K. The physical mechanism of NTE is discussed and clarified through experiments.
基金supported by the National Natural Science Foundation of China(Grant No.32170485,31501867)the Fundamental Research Funds for the Central Universities(Grant No.2572022BE02)。
文摘Artificial nest boxes are placed to attract birds to nest and breed in a specific location,and they are widely used in avian ecology research and in the attraction of insectivorous birds.There is evidence that artificial nest boxes can adversely affect breeding fitness but no great focus has been placed on this issue by researchers.Therefore,we retrieved 321 research papers regarding artificial nest boxes published from 2003 to 2022 and used the'Biblioshiny'program to extract and integrate keywords;we then summarized the adverse effects of artificial nest boxes on avian breeding success.The studies highlighted many drawbacks and misuses in the designing and placement of nest boxes;furthermore,bird attraction was decreased by their inappropriate selection,thus reducing breeding success.Regarding nest box production,there were shortcomings in the construction material,color,smell,and structural design of the boxes used.Nest boxes were also placed at inappropriate densities,locations,orientations,heights,and managed incorrectly.Finally,we propose suggestions for more efficient and safer artificial nest boxes for future use in avian ecology research and bird conservation.
基金Supported by the National Natural Science Foundation of China under Grant No 51102007the Fund for Discipline Construction of Beijing University of Chemical Technology under Grant No XK1702
文摘The anti-resonant phenomenon of effective electromagnetic parameters of metamaterials has aroused controversy due to negative imaginary permittivity or permeability. It is experimentally found that the negative imaginary permittivity can occur for the natural passive materials near the Fabry Perot resonances. We reveal the nature of negative imaginary permittivity, which is correlated with the magnetoelectric coupling. The anti-resonance of permittivity is a non-inherent feature for passive materials, while it can be inherent for devices or metamaterials. Our finding validates that the negative imaginary part of effective permittivity does not contradict the second law of thermodynamics for metamaterials owing to the magnetoelectric coupling.
基金supported by the Postgraduate Inovation Programme of Changchun Wormal University(YJSCX202424)the Science and Technology Project of Jilin Provincial Education Department(JJKH20220828KJ)the Natural Science Foundation of Changchun Normal University(2020-005).
文摘The electronic and transport characteristics of protonated derivatives of naphthalocyanine(Nc)were investigated using density functional theory and non-equilibrium Green's functions.The results indicate that the protonation of external meso-N atoms of Nc preserves its planar structure and is energetically more favorable than the protonation of internal isoindole-N atoms.The protonation shifts the energy levels of system's frontier molecular orbitals closer to the Fermi level,thus creating channels for electron transport.In contrast with the semiconductor transport properties of H2Nc,its protonation products respond more sensitively to bias and exhibit negative differential resistance phenomena at specific bias.
文摘The present paper discusses three major sources of negative effect of classroom instruction on L2 learners'pragmatic development:inadequate or inappropriate metapragmatic input,non-authentic classroom discourse and grammar-oriented pedagogy,then proposes some pedagogical suggestions on developing pragmatic competence.
文摘This paper attempts to investigate the negative effects of the spread of COVID-19 on low-income families in Egypt.Coronavirus spread is measured by"Coronavirus cases"and"Coronavirus deaths"on a daily basis.Besides,it is measured by both"new Coronavirus cases"and"new deaths from Coronavirus",in relation to the population of Egypt.The Egyptian government is taking some measures to reduce the negative effects of COVID-19,including increasing personal exemptions by amending some provisions of the Egyptian Income Tax Law promulgated by Law No.91 of 2005 to protect low-income families.Of the negative effects of COVID-19,it is one of the most important tax policies to achieve social justice in distributing the tax burden,according to income levels,in a manner that achieves justice and equality.We find that Personal exemptions did not succeed in achieving tax justice by easing the tax burden on the low-income people in society.
