Beishan Rock Carvings in Chongqing,a renowned cultural heritage site in China,flourished during the Tang and Song dynasties and are often referred to as the“Stone Carving Art Museum of the Tang and Song Dynasties.”C...Beishan Rock Carvings in Chongqing,a renowned cultural heritage site in China,flourished during the Tang and Song dynasties and are often referred to as the“Stone Carving Art Museum of the Tang and Song Dynasties.”Cave 168 is a key component of the Beishan Rock Carvings.At present,several through-going cracks have developed in the roof of Cave 168,severely compromising the structural stability of the grotto.The early internal steel plate supports have suffered severe corrosion and can no longer provide effective reinforcement.In addition,the presence of steel columns obstructs visitor access and negatively affects the viewing experience.A new reinforcement method is urgently needed.Therefore,studying the deformation patterns of the structure is of critical importance.This study analyzes the stratigraphic parameters and fracture distribution of Cave 168,considering key influencing factors such as rainfall,self-weight,and the overlying Quaternary soil.On-site monitoring and physical model experiments were conducted to evaluate the changes in roof crack width and displacement before and after reinforcement with negative Poisson's ratio(NPR)anchor cables.The results reveal that the roof of Cave 168 contains several through-going cracks and numerous microcracks,which serve as infiltration channels for surface water.These accelerate the softening of the mudstone and pose a significant threat to the cave's structural safety.During the experiment,the main change in the crack exhibited a“semi-archshaped”propagation pattern.In the first ten minutes,as the rock transitioned from dry to moist conditions,a slight crack closure was observed.As rainfall continued,crack propagation accelerated.After rainfall ceased,crack width remained stable over a short period.Under NPR anchor support,the influence of rainfall on roof settlement was effectively mitigated,ensuring the safety and stability of the roof.The NPR anchors successfully limited the roof settlement to within 0.3 mm and provided effective control over both total and differential settlement.These findings offer valuable insights into the application of NPR anchor cables in the conservation of grotto heritage structures.展开更多
Negative Poisson ratio(NPR)steel is a new material with high strength and toughness.This study conducted tensile tests at elevated temperatures to investigate the mechanical properties of NPR steel at high temperature...Negative Poisson ratio(NPR)steel is a new material with high strength and toughness.This study conducted tensile tests at elevated temperatures to investigate the mechanical properties of NPR steel at high temperatures.The stress−strain curve,ultimate strength,yield strength,modulus of elasticity,elongation after fracture,and percentage reduction of area of NPR steel bars were measured at 9 different temperatures ranging from 20 to 800℃.The experimental results indicate that high-temperature environments significantly affect the mechanical properties of NPR steel.However,compared to other types of steel,NPR steel exhibits better resistance to deformation.When the test temperature is below 700℃,NPR steel exhibits a ductile fracture characteristic,while at 800℃,it exhibits a brittle fracture characteristic.Finally,based on the experimental findings,a constitutive model suitable for NPR steel at high temperatures is proposed.展开更多
The impacts of natural boulders carried by debris flows pose serious risks to the safety and reliability of structures and buildings.Natural boulders can be highly random and unpredictable.Consequently,boulder control...The impacts of natural boulders carried by debris flows pose serious risks to the safety and reliability of structures and buildings.Natural boulders can be highly random and unpredictable.Consequently,boulder control during debris flows is crucial but difficult.Herein,an eco-friendly control system featuring anchoring natural boulders(NBs)with(negative Poisson's ratio)NPR anchor cables is proposed to form an NB-NPR baffle.A series of flume experiments are conducted to verify the effect of NB-NPR baffles on controlling debris flow impact.The deployment of NB-NPR baffles substantially influences the kinematic behavior of a debris flow,primarily in the form of changes in the depositional properties and impact intensities.The results show that the NB-NPR baffle matrix successfully controls boulder mobility and exhibits positive feedback on solid particle deposition.The NB-NPR baffle group exhibits a reduction in peak impact force ranging from 29%to 79%compared to that of the control group in the basic experiment.The NPR anchor cables play a significant role in the NB-NPR baffle by demonstrating particular characteristics,including consistent resistance,large deformation,and substantial energy absorption.The NB-NPR baffle innovatively utilizes the natural boulders in a debris flow gully by converting destructive boulders into constructive boulders.Overall,this research serves as a basis for future field experiments and applications.展开更多
BACKGROUND Patients with schizophrenia may lack awareness of the importance of posttracheotomy care due to the impact of their condition,often showing resistance or misunderstanding of care measures.When coupled with ...BACKGROUND Patients with schizophrenia may lack awareness of the importance of posttracheotomy care due to the impact of their condition,often showing resistance or misunderstanding of care measures.When coupled with the impact of negative symptoms and the risk of complications after tracheotomy,patients may experience emotional fluctuations,restlessness,anxiety,and hostile behaviors,which pose significant challenges to nursing work.CASE SUMMARY We have reported the case of an 87-year-old male patient who was admitted to the hospital because of negative symptoms of schizophrenia and who underwent tracheotomy for severe pneumonia.In this study,we have summarized the nursing experience of a patient with negative symptoms of schizophrenia who underwent tracheotomy.The key nursing strategies included proper tracheotomy care,the management of psychiatric symptoms,a thorough assessment and implementation of enteral and parenteral nutrition,effective skincare,infection prevention,and comprehensive mental care.Individualized nursing skills helped stabilize the patient’s condition,followed by isolation and observation in a psychiatric hospital.CONCLUSION Effective postoperative tracheostomy care in patients with schizophrenia necessitates a tailored,multidisciplinary approach that addresses their psychiatric,physical,and emotional needs to achieve optimal clinical outcomes.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
In the realm of slope monitoring and reinforcement,traditional prestressing anchor cables are extensively used.However,these conventional methods often face limitations when applied to loess slopes,such as potential i...In the realm of slope monitoring and reinforcement,traditional prestressing anchor cables are extensively used.However,these conventional methods often face limitations when applied to loess slopes,such as potential issues with stress concentration and insufficient adaptability to the unique mechanical properties of loess,which may lead to challenges in ensuring long-term stability and effective reinforcement.Negative Poisson's ratio(NPR)anchor cables with constant resistance have emerged as a promising alternative,which can better match the engineering demands of loess slopes by providing more uniform stress distribution and adaptive deformation characteristics.The NPR cable's ability to maintain a constant resistance during deformation offers a distinct advantage over traditional methods as it can more effectively accommodate the complex and variable conditions of loess slopes.To investigate the anchoring performance of NPR cables in loess slope,the stress characteristics of NPR cable in loess medium were simulated and analysed by ABAQUS finite element software.First,static and general quasi-static analysis methods were used to simulate the NPR cable under static tensile conditions.The consistency of the simulated constant resistance deformation characteristics with experimental results found in the literature was verified.Second,the interaction model between the NPR cable coupled with the loess medium was established.Its constant resistance was calculated to be about 24.08%larger than that of NPR anchor cable while its plastic deformation was reduced by about 37.14%.The compressive stress on the contact surface between NPR cable and loess was concentrated near the free end of the sleeve,which indicated that the loess was prone to severe damage at the free end.The research results reveal the typical shear failure mechanism of NPR cable in loess medium,which provides an important theoretical basis for prevention of landslides and monitoring of loess slopes.展开更多
Referring to the questionnaire survey and semi-structured interview,this paper explores the negative transfer of mother tongue in junior high school English writing and analyzes the existing problems.The results show ...Referring to the questionnaire survey and semi-structured interview,this paper explores the negative transfer of mother tongue in junior high school English writing and analyzes the existing problems.The results show that the negative transfer of mother tongue has a significant impact on junior high school students’English writing.The main errors are found at four levels:morphological level,lexical level,syntactic level and textual level.In order to deal with the errors caused by the negative transfer of mother tongue in students’English writing,it is suggested that teachers create an English language environment for students as far as possible and help students form English thinking,use contrastive analysis teaching strategies,making a comparison between English and Chinese expressions and cultural differences and pay attention to the training of students’basic knowledge of English to help students improve their English writing ability.展开更多
Transient negative capacitance(NC),as an available dynamic charge effect achieved in resistor-ferroelectric capacitor(R-FEC)circuits,has triggered a series of theoretical and experimental works focusing on its physica...Transient negative capacitance(NC),as an available dynamic charge effect achieved in resistor-ferroelectric capacitor(R-FEC)circuits,has triggered a series of theoretical and experimental works focusing on its physical mechanism and device application.Here,we analytically derived the effects of different mechanical conditions on the transient NC behaviors in the R-FEC circuit based on the phenomenological model.It shows that the ferroelectric capacitor can exhibit either NC(i.e.,“single NC”and“double NC”)or positive capacitance,depending on the mechanical condition and temperature.Further numerical calculations show that the voltage drop caused by NC can be effectively controlled by temperature,applied stress,or strain.The relationship between NC voltage drop and system configurations including external resistance,dynamical coefficient of polarization,and input voltage are presented,showing diverse strategies to manipulate the NC effect.These results provide theoretical guidelines for rational design and efficient control of NC-related electronic devices.展开更多
Triple-negative breast cancer(TNBC)represents an aggressive breast cancer subtype with poor prognosis and limited targeted treatment options.This investigation examined the anticancer potential of Caerulomycin A(Cae A...Triple-negative breast cancer(TNBC)represents an aggressive breast cancer subtype with poor prognosis and limited targeted treatment options.This investigation examined the anticancer potential of Caerulomycin A(Cae A),a natural compound derived from marine actinomycetes,against TNBC.Cae A demonstrated selective inhibition of viability and proliferation in TNBC cell lines,including 4T1,MDA-MB-231,and MDA-MB-468,through apoptosis induction.Mechanistic analyses revealed that the compound induced sustained endoplasmic reticulum(ER)stress and subsequent upregulation of C/EBP homologous protein(CHOP)expression,resulting in mitochondrial damage-mediated apoptosis.Inhibition of ER stress or CHOP expression knockdown reversed mitochondrial damage and apoptosis,highlighting the essential role of ER stress and CHOP in Cae A's anti-tumor mechanism.Both oxygen consumption rate(OCR)and extracellular acidification rate(ECAR)decreased in TNBC cells following Cae A treatment,indicating reduced mitochondrial respiratory and glycolytic capacities.This diminished energy metabolism potentially triggers ER stress and subsequent apoptosis.Furthermore,Cae A exhibited significant anti-tumor effects in the 4T1 tumor model in vivo without apparent toxicity.The compound also effectively inhibited human TNBC organoid growth.These results indicate that Cae A may serve as a potential therapeutic agent for TNBC,with its efficacy likely mediated through the disruption of glucose metabolism and the induction of ER stress-associated apoptosis.展开更多
With the rapid development of deep resource extraction and underground space construction,the design of anchored support systems for jointed rock masses in complex stress environments faces significant challenges.This...With the rapid development of deep resource extraction and underground space construction,the design of anchored support systems for jointed rock masses in complex stress environments faces significant challenges.This study investigates the influence of prefabricated crack dip angles on the mechanical properties of anchored rock masses in deep soft rock roadways.By constructing similarity models of NPR(Negative Poisson’s Ratio)and PR(Positive Poisson’s Ratio)anchored solids,biaxial compression experiments under varying crack dip angles were conducted.Strain gauges,3D Digital Image Correlation(3D DIC),and acoustic emission monitoring were employed to systematically analyze the strength characteristics,deformation-damage evolution,and energy dissipation mechanisms of the two types of anchor systems.The results show that:(1)The stress-strain curves of anchored solids with prefabricated cracks exhibit a distinct bimodal characteristic.Compared to PR anchors,NPR anchors show 20%and 23%improvements in peak strength and elastic modulus,respectively,with residual strength enhanced by up to 34%.(2)Owing to high pre-tightening force and large deformation capacity,NPR anchors maintain superior integrity under increasing crack dip angles,demonstrating more uniform free-surface displacement and localized shear-tensile composite crack patterns.(3)Acoustic emission analysis reveals that NPR anchors exhibit higher cumulative energy absorption(300%improvement over PR anchors)and lack low-rate energy development phases,indicating enhanced ductility and impact resistance at high crack dip angles.(4)Crack dip angle critically governs failure mechanisms by modulating the connectivity between shear cracks and prefabricated fissures:bimodal effects dominate at low angles,while vertical tensile crack propagation replaces bimodal behavior at high angles.The study proposes prioritizing NPR anchor cables in deep engineering applications and optimizing support parameters based on crack dip angles to mitigate stress concentration and ensure the long-term stability of surrounding rock.展开更多
Information plays a crucial role in guiding behavioral decisions during public health emergencies. Individuals communicate to acquire relevant knowledge about an epidemic, which influences their decisions to adopt pro...Information plays a crucial role in guiding behavioral decisions during public health emergencies. Individuals communicate to acquire relevant knowledge about an epidemic, which influences their decisions to adopt protective measures.However, whether to disseminate specific information is also a behavioral decision. In light of this understanding, we develop a coupled information–vaccination–epidemic model to depict these co-evolutionary dynamics in a three-layer network. Negative information dissemination and vaccination are treated as separate decision-making processes. We then examine the combined effects of herd and risk motives on information dissemination and vaccination decisions through the lens of game theory. The microscopic Markov chain approach(MMCA) is used to describe the dynamic process and to derive the epidemic threshold. Simulation results indicate that increasing the cost of negative information dissemination and providing timely clarification can effectively control the epidemic. Furthermore, a phenomenon of diminishing marginal utility is observed as the cost of dissemination increases, suggesting that authorities do not need to overinvest in suppressing negative information. Conversely, reducing the cost of vaccination and increasing vaccine efficacy emerge as more effective strategies for outbreak control. In addition, we find that the scale of the epidemic is greater when the herd motive dominates behavioral decision-making. In conclusion, this study provides a new perspective for understanding the complexity of epidemic spreading by starting with the construction of different behavioral decisions.展开更多
High-entropy oxides(HEOs),offering reversible lithium storage and moderate operating potential,are considered promising negative electrodes.However,the intricate lithium storage mechanism within HE polycationic system...High-entropy oxides(HEOs),offering reversible lithium storage and moderate operating potential,are considered promising negative electrodes.However,the intricate lithium storage mechanism within HE polycationic systems remains challenging.Here,we conduct comprehensive investigations into the electrochemical properties and structu ral evolution of(CrMnCoNiZn)_(3)O_(4)(HESO)to clarify lithium storage mechanisms.Density functional theory(DFT)calculations reveal that polycationic synergy modulates the electronic structure and d-band centers of HESO,delivering fast electrode kinetics.Exhaustive in-and exsitu analyses demonstrate that the residual crystalline phases acting as seed crystals maintain the spinel/rock-salt lattice persistence under the entropy stabilization effect,lattice distortion effect,and cation synergy,which guide cation crystallization upon the electric field to drive reversible lithium storage.Such properties underlie the HESO electrode with an exceptional rate and long-term capability.This work clarifies the roles of cationic synergy and seed-crystal-driven structural reversibility,providing a blueprint for designing high-performance HEO negative electrodes for next-generation lithium-ion batteries(LIBs).展开更多
文摘Beishan Rock Carvings in Chongqing,a renowned cultural heritage site in China,flourished during the Tang and Song dynasties and are often referred to as the“Stone Carving Art Museum of the Tang and Song Dynasties.”Cave 168 is a key component of the Beishan Rock Carvings.At present,several through-going cracks have developed in the roof of Cave 168,severely compromising the structural stability of the grotto.The early internal steel plate supports have suffered severe corrosion and can no longer provide effective reinforcement.In addition,the presence of steel columns obstructs visitor access and negatively affects the viewing experience.A new reinforcement method is urgently needed.Therefore,studying the deformation patterns of the structure is of critical importance.This study analyzes the stratigraphic parameters and fracture distribution of Cave 168,considering key influencing factors such as rainfall,self-weight,and the overlying Quaternary soil.On-site monitoring and physical model experiments were conducted to evaluate the changes in roof crack width and displacement before and after reinforcement with negative Poisson's ratio(NPR)anchor cables.The results reveal that the roof of Cave 168 contains several through-going cracks and numerous microcracks,which serve as infiltration channels for surface water.These accelerate the softening of the mudstone and pose a significant threat to the cave's structural safety.During the experiment,the main change in the crack exhibited a“semi-archshaped”propagation pattern.In the first ten minutes,as the rock transitioned from dry to moist conditions,a slight crack closure was observed.As rainfall continued,crack propagation accelerated.After rainfall ceased,crack width remained stable over a short period.Under NPR anchor support,the influence of rainfall on roof settlement was effectively mitigated,ensuring the safety and stability of the roof.The NPR anchors successfully limited the roof settlement to within 0.3 mm and provided effective control over both total and differential settlement.These findings offer valuable insights into the application of NPR anchor cables in the conservation of grotto heritage structures.
基金Projects(41702320,52104125)supported by the National Natural Science Foundation of ChinaProject(ZR2021MD005)+2 种基金supported by the Natural Science Foundation of Shandong Province,ChinaProject(TMduracon2022002)supported by the Engineering Research Center of Marine Environmental Concrete Technology,Ministry of Education,China。
文摘Negative Poisson ratio(NPR)steel is a new material with high strength and toughness.This study conducted tensile tests at elevated temperatures to investigate the mechanical properties of NPR steel at high temperatures.The stress−strain curve,ultimate strength,yield strength,modulus of elasticity,elongation after fracture,and percentage reduction of area of NPR steel bars were measured at 9 different temperatures ranging from 20 to 800℃.The experimental results indicate that high-temperature environments significantly affect the mechanical properties of NPR steel.However,compared to other types of steel,NPR steel exhibits better resistance to deformation.When the test temperature is below 700℃,NPR steel exhibits a ductile fracture characteristic,while at 800℃,it exhibits a brittle fracture characteristic.Finally,based on the experimental findings,a constitutive model suitable for NPR steel at high temperatures is proposed.
基金financial support from the National Natural Science Foundation of China(Grant No.41941018).
文摘The impacts of natural boulders carried by debris flows pose serious risks to the safety and reliability of structures and buildings.Natural boulders can be highly random and unpredictable.Consequently,boulder control during debris flows is crucial but difficult.Herein,an eco-friendly control system featuring anchoring natural boulders(NBs)with(negative Poisson's ratio)NPR anchor cables is proposed to form an NB-NPR baffle.A series of flume experiments are conducted to verify the effect of NB-NPR baffles on controlling debris flow impact.The deployment of NB-NPR baffles substantially influences the kinematic behavior of a debris flow,primarily in the form of changes in the depositional properties and impact intensities.The results show that the NB-NPR baffle matrix successfully controls boulder mobility and exhibits positive feedback on solid particle deposition.The NB-NPR baffle group exhibits a reduction in peak impact force ranging from 29%to 79%compared to that of the control group in the basic experiment.The NPR anchor cables play a significant role in the NB-NPR baffle by demonstrating particular characteristics,including consistent resistance,large deformation,and substantial energy absorption.The NB-NPR baffle innovatively utilizes the natural boulders in a debris flow gully by converting destructive boulders into constructive boulders.Overall,this research serves as a basis for future field experiments and applications.
基金Supported by Tianjin Key Medical Discipline(Specialty)Construction Project,No.TJYXZDXK-033A。
文摘BACKGROUND Patients with schizophrenia may lack awareness of the importance of posttracheotomy care due to the impact of their condition,often showing resistance or misunderstanding of care measures.When coupled with the impact of negative symptoms and the risk of complications after tracheotomy,patients may experience emotional fluctuations,restlessness,anxiety,and hostile behaviors,which pose significant challenges to nursing work.CASE SUMMARY We have reported the case of an 87-year-old male patient who was admitted to the hospital because of negative symptoms of schizophrenia and who underwent tracheotomy for severe pneumonia.In this study,we have summarized the nursing experience of a patient with negative symptoms of schizophrenia who underwent tracheotomy.The key nursing strategies included proper tracheotomy care,the management of psychiatric symptoms,a thorough assessment and implementation of enteral and parenteral nutrition,effective skincare,infection prevention,and comprehensive mental care.Individualized nursing skills helped stabilize the patient’s condition,followed by isolation and observation in a psychiatric hospital.CONCLUSION Effective postoperative tracheostomy care in patients with schizophrenia necessitates a tailored,multidisciplinary approach that addresses their psychiatric,physical,and emotional needs to achieve optimal clinical outcomes.
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the State Key Laboratory of Deep Geotechnical Mechanics and Underground Engineering(SKLGDUEK2124)of China University of Mining and Technology(Beijing)for its support for this research。
文摘In the realm of slope monitoring and reinforcement,traditional prestressing anchor cables are extensively used.However,these conventional methods often face limitations when applied to loess slopes,such as potential issues with stress concentration and insufficient adaptability to the unique mechanical properties of loess,which may lead to challenges in ensuring long-term stability and effective reinforcement.Negative Poisson's ratio(NPR)anchor cables with constant resistance have emerged as a promising alternative,which can better match the engineering demands of loess slopes by providing more uniform stress distribution and adaptive deformation characteristics.The NPR cable's ability to maintain a constant resistance during deformation offers a distinct advantage over traditional methods as it can more effectively accommodate the complex and variable conditions of loess slopes.To investigate the anchoring performance of NPR cables in loess slope,the stress characteristics of NPR cable in loess medium were simulated and analysed by ABAQUS finite element software.First,static and general quasi-static analysis methods were used to simulate the NPR cable under static tensile conditions.The consistency of the simulated constant resistance deformation characteristics with experimental results found in the literature was verified.Second,the interaction model between the NPR cable coupled with the loess medium was established.Its constant resistance was calculated to be about 24.08%larger than that of NPR anchor cable while its plastic deformation was reduced by about 37.14%.The compressive stress on the contact surface between NPR cable and loess was concentrated near the free end of the sleeve,which indicated that the loess was prone to severe damage at the free end.The research results reveal the typical shear failure mechanism of NPR cable in loess medium,which provides an important theoretical basis for prevention of landslides and monitoring of loess slopes.
文摘Referring to the questionnaire survey and semi-structured interview,this paper explores the negative transfer of mother tongue in junior high school English writing and analyzes the existing problems.The results show that the negative transfer of mother tongue has a significant impact on junior high school students’English writing.The main errors are found at four levels:morphological level,lexical level,syntactic level and textual level.In order to deal with the errors caused by the negative transfer of mother tongue in students’English writing,it is suggested that teachers create an English language environment for students as far as possible and help students form English thinking,use contrastive analysis teaching strategies,making a comparison between English and Chinese expressions and cultural differences and pay attention to the training of students’basic knowledge of English to help students improve their English writing ability.
基金This work was supported by the National Natural Science Foundation of China(Grants Nos.12222214,12132020,12002400,and 12172386)by Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)+1 种基金by the National Natural Science Foundation of Guangdong Province(Grant No.2021B1515020021)by the Shenzhen Science and Techonlogy Program(Grant Nos.202206193000001 and 20220818181805001).
文摘Transient negative capacitance(NC),as an available dynamic charge effect achieved in resistor-ferroelectric capacitor(R-FEC)circuits,has triggered a series of theoretical and experimental works focusing on its physical mechanism and device application.Here,we analytically derived the effects of different mechanical conditions on the transient NC behaviors in the R-FEC circuit based on the phenomenological model.It shows that the ferroelectric capacitor can exhibit either NC(i.e.,“single NC”and“double NC”)or positive capacitance,depending on the mechanical condition and temperature.Further numerical calculations show that the voltage drop caused by NC can be effectively controlled by temperature,applied stress,or strain.The relationship between NC voltage drop and system configurations including external resistance,dynamical coefficient of polarization,and input voltage are presented,showing diverse strategies to manipulate the NC effect.These results provide theoretical guidelines for rational design and efficient control of NC-related electronic devices.
基金supported by the Science and Education Integration Project by the Innovation and Entrepreneurship Office of Nanjing University(No.0214-1480608207)Jiangsu Provincial Research Hospital(No.YJXYY202204)。
文摘Triple-negative breast cancer(TNBC)represents an aggressive breast cancer subtype with poor prognosis and limited targeted treatment options.This investigation examined the anticancer potential of Caerulomycin A(Cae A),a natural compound derived from marine actinomycetes,against TNBC.Cae A demonstrated selective inhibition of viability and proliferation in TNBC cell lines,including 4T1,MDA-MB-231,and MDA-MB-468,through apoptosis induction.Mechanistic analyses revealed that the compound induced sustained endoplasmic reticulum(ER)stress and subsequent upregulation of C/EBP homologous protein(CHOP)expression,resulting in mitochondrial damage-mediated apoptosis.Inhibition of ER stress or CHOP expression knockdown reversed mitochondrial damage and apoptosis,highlighting the essential role of ER stress and CHOP in Cae A's anti-tumor mechanism.Both oxygen consumption rate(OCR)and extracellular acidification rate(ECAR)decreased in TNBC cells following Cae A treatment,indicating reduced mitochondrial respiratory and glycolytic capacities.This diminished energy metabolism potentially triggers ER stress and subsequent apoptosis.Furthermore,Cae A exhibited significant anti-tumor effects in the 4T1 tumor model in vivo without apparent toxicity.The compound also effectively inhibited human TNBC organoid growth.These results indicate that Cae A may serve as a potential therapeutic agent for TNBC,with its efficacy likely mediated through the disruption of glucose metabolism and the induction of ER stress-associated apoptosis.
基金supported by the National Natural Science Foundation of China(Grant Nos.52174096 and 52304110).
文摘With the rapid development of deep resource extraction and underground space construction,the design of anchored support systems for jointed rock masses in complex stress environments faces significant challenges.This study investigates the influence of prefabricated crack dip angles on the mechanical properties of anchored rock masses in deep soft rock roadways.By constructing similarity models of NPR(Negative Poisson’s Ratio)and PR(Positive Poisson’s Ratio)anchored solids,biaxial compression experiments under varying crack dip angles were conducted.Strain gauges,3D Digital Image Correlation(3D DIC),and acoustic emission monitoring were employed to systematically analyze the strength characteristics,deformation-damage evolution,and energy dissipation mechanisms of the two types of anchor systems.The results show that:(1)The stress-strain curves of anchored solids with prefabricated cracks exhibit a distinct bimodal characteristic.Compared to PR anchors,NPR anchors show 20%and 23%improvements in peak strength and elastic modulus,respectively,with residual strength enhanced by up to 34%.(2)Owing to high pre-tightening force and large deformation capacity,NPR anchors maintain superior integrity under increasing crack dip angles,demonstrating more uniform free-surface displacement and localized shear-tensile composite crack patterns.(3)Acoustic emission analysis reveals that NPR anchors exhibit higher cumulative energy absorption(300%improvement over PR anchors)and lack low-rate energy development phases,indicating enhanced ductility and impact resistance at high crack dip angles.(4)Crack dip angle critically governs failure mechanisms by modulating the connectivity between shear cracks and prefabricated fissures:bimodal effects dominate at low angles,while vertical tensile crack propagation replaces bimodal behavior at high angles.The study proposes prioritizing NPR anchor cables in deep engineering applications and optimizing support parameters based on crack dip angles to mitigate stress concentration and ensure the long-term stability of surrounding rock.
基金Project supported by the National Natural Science Foundation of China (Grant No. 72174121)the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, and the Soft Science Research Project of Shanghai (Grant No. 22692112600)。
文摘Information plays a crucial role in guiding behavioral decisions during public health emergencies. Individuals communicate to acquire relevant knowledge about an epidemic, which influences their decisions to adopt protective measures.However, whether to disseminate specific information is also a behavioral decision. In light of this understanding, we develop a coupled information–vaccination–epidemic model to depict these co-evolutionary dynamics in a three-layer network. Negative information dissemination and vaccination are treated as separate decision-making processes. We then examine the combined effects of herd and risk motives on information dissemination and vaccination decisions through the lens of game theory. The microscopic Markov chain approach(MMCA) is used to describe the dynamic process and to derive the epidemic threshold. Simulation results indicate that increasing the cost of negative information dissemination and providing timely clarification can effectively control the epidemic. Furthermore, a phenomenon of diminishing marginal utility is observed as the cost of dissemination increases, suggesting that authorities do not need to overinvest in suppressing negative information. Conversely, reducing the cost of vaccination and increasing vaccine efficacy emerge as more effective strategies for outbreak control. In addition, we find that the scale of the epidemic is greater when the herd motive dominates behavioral decision-making. In conclusion, this study provides a new perspective for understanding the complexity of epidemic spreading by starting with the construction of different behavioral decisions.
基金supported by the National Natural Science Foundation of China(No.22271101)the R&D Program of Guangzhou(2024A04J2497)+1 种基金the Key Laboratory of Polymer Chemistry&Physics of Ministry of Educationsupported by the High Performance Computing Platform of SCUT。
文摘High-entropy oxides(HEOs),offering reversible lithium storage and moderate operating potential,are considered promising negative electrodes.However,the intricate lithium storage mechanism within HE polycationic systems remains challenging.Here,we conduct comprehensive investigations into the electrochemical properties and structu ral evolution of(CrMnCoNiZn)_(3)O_(4)(HESO)to clarify lithium storage mechanisms.Density functional theory(DFT)calculations reveal that polycationic synergy modulates the electronic structure and d-band centers of HESO,delivering fast electrode kinetics.Exhaustive in-and exsitu analyses demonstrate that the residual crystalline phases acting as seed crystals maintain the spinel/rock-salt lattice persistence under the entropy stabilization effect,lattice distortion effect,and cation synergy,which guide cation crystallization upon the electric field to drive reversible lithium storage.Such properties underlie the HESO electrode with an exceptional rate and long-term capability.This work clarifies the roles of cationic synergy and seed-crystal-driven structural reversibility,providing a blueprint for designing high-performance HEO negative electrodes for next-generation lithium-ion batteries(LIBs).
