期刊文献+
共找到674,472篇文章
< 1 2 250 >
每页显示 20 50 100
Protective mechanism of quercetin compounds against acrylamide-induced hepatotoxicity
1
作者 Linzi Li Xueying Lei +6 位作者 Lin Chen Ya Ma Jun Luo Xuebo Liu Xinglian Xu Guanghong Zhou Xianchao Feng 《Food Science and Human Wellness》 SCIE CSCD 2024年第1期225-240,共16页
Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds c... Quercetin compounds have antioxidant,anti-inflammatory and anticancer pharmacological functions.Longterm exposure to acrylamide(AA)can cause liver injury and endanger human health.However,whether quercetin compounds can attenuate AA-induced liver injury and the specific mechanism are not clear.Here,we studied the mechanism and structure-activity relationship of quercetin compounds in reducing AA-induced hepatotoxicity in vivo and in vitro.In vivo studies found that quercetin-like compounds protect against AAinduced liver injury by reducing oxidative stress levels,activating the Akt/m TOR signaling pathway to attenuate autophagy,and improving mitochondrial apoptosis and endoplasmic reticulum stress-mediated apoptosis.In vitro studies found that quercetin compounds protected Hep G2 cells from AA by attenuating the activation of AA-induced autophagy,lowering reactive oxygen species(ROS)levels by exerting antioxidant effects and thus attenuating oxidative stress,increasing mitochondrial membrane potential(MMP),and improving apoptosis-related proteins,thus attenuating AA-induced apoptosis.Furthermore,the conformational differences between quercetin compounds correlated with their protective capacity against AA-induced hepatotoxicity,with quercetin showing the best protective capacity due to its strongest antioxidant activity.In conclusion,quercetin compounds can protect against AA-induced liver injury through multiple pathways of oxidative stress,autophagy and apoptosis,and their protective capacity correlates with antioxidant activity. 展开更多
关键词 Quercetin compounds ACRYLAMIDE Protection mechanism Oxidative stress Antioxidant activity
下载PDF
Study on the Protective Mechanism of Acupuncture Regulating ICAM-5 mRNA Expression in Rats with Ischemic Stroke
2
作者 Yating Shen Ximei Xie +4 位作者 Xiu Bai Hua Bai Xiaofan Chang Yuanyuan Tang Qiuyu Li 《Journal of Behavioral and Brain Science》 2021年第12期313-321,共9页
<b>Objective:</b> The objective is to investigate whether acupuncture can protect brain by regulating the expression of ICAM-5 mRNA in brain tissue. <b>Methods:</b> Male SD rats were used to co... <b>Objective:</b> The objective is to investigate whether acupuncture can protect brain by regulating the expression of ICAM-5 mRNA in brain tissue. <b>Methods:</b> Male SD rats were used to construct a middle cerebral artery occlusion reperfusion injury (Middle cerebral artery occlusion, MCAO) model, and the rats were randomly divided into 4 groups, namely the normal group (group A) and the sham operation group (group B), MCAO group (group C), MCAO + acupuncture group (group D);real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression of ICAM-5 mRNA in the brain tissue of the ischemic area, and HE staining and TUNEL were used to detect the level of neuronal apoptosis to evaluate the therapeutic effect. <b>Results:</b> Acupuncture can improve neuronal morphology and reduce neuronal apoptosis in rats with ischemic stroke. RT-qPCR: compared with group A and group B, the expression level of ICAM-5 mRNA in the brain tissues of group C and group D decreased, while compared with group C, The expression of ICAM-5 mRNA in the brain tissue of group D was significantly up-regulated (P < 0.05). There was no statistical difference between group A and group B (P > 0.05). <b>Conclusion:</b> The effectiveness of acupuncture in the treatment of ischemic stroke may achieve neuroprotection by up-regulating the expression level of ICAM-5 mRNA. 展开更多
关键词 Ischemic Stroke ACUPUNCTURE ICAM-5 mRNA mechanism Study
下载PDF
Research progress on the protective mechanism of osteopontin in ischemic stroke
3
作者 Qun Guo Xiao-Yu Ren +8 位作者 Qi Zhang Mu-Lan Nie Lu Xu Qian-Mei Long Yi-Fan Guo Dong Wang Bin Liu Wei He Yin-Chuan Jin 《Journal of Hainan Medical University》 2021年第12期55-59,共5页
Ischemic stroke has become an important cause of death and disability for residents worldwide.At present,the main treatment methods are thrombolysis and embolectomy.However,a large number of patients miss the window p... Ischemic stroke has become an important cause of death and disability for residents worldwide.At present,the main treatment methods are thrombolysis and embolectomy.However,a large number of patients miss the window period of thrombolysis and embolectomy or have other conditions that are not suitable for thrombolysis.Therefore,cerebral protective drugs or bioactive substances are needed to protect neural tissue and improve the prognosis.However,there is still a lack of strong and effective drugs or bioactive substances for selection.Osteopontin(OPN)is a phosphorylated glycoprotein that plays an important role in cell adhesion,differentiation,survival and repair by binding to cellular integrin receptors and inducing signal transmission.Numerous studies have shown that osteopontin can protect brain tissue and reduce brain injury caused by ischemic stroke by various means such as promoting angiogenesis,and promoting neural stem cell migration in the pathogenesis of ischemic stroke. 展开更多
关键词 Ischemic stroke OSTEOPONTIN RGD sequence Cerebral protection
下载PDF
A Protective Mechanism for the Access Control System in the Virtual Domain 被引量:1
4
作者 Jinan Shen Deqing Zou +3 位作者 Hai Jin Kai Yang Bin Yuan Weiming Li 《China Communications》 SCIE CSCD 2016年第11期129-142,共14页
In traditional framework,mandatory access control(MAC) system and malicious software are run in kernel mode. Malicious software can stop MAC systems to be started and make it do invalid. This problem cannot be solved ... In traditional framework,mandatory access control(MAC) system and malicious software are run in kernel mode. Malicious software can stop MAC systems to be started and make it do invalid. This problem cannot be solved under the traditional framework if the operating system(OS) is comprised since malwares are running in ring 0 level. In this paper,we propose a novel way to use hypervisors to protect kernel integrity and the access control system in commodity operating systems. We separate the access control system into three parts: policy management(PM),security server(SS) and policy enforcement(PE). Policy management and the security server reside in the security domain to protect them against malware and the isolation feather of the hypervisor can protect them from attacks. We add an access vector cache(AVC) between SS and PE in the guest OS,in order to speed up communication between the guest OS and the security domain. The policy enforcement module is retained in the guest OS for performance. The security of AVC and PE can be ensured by using a memory protection mechanism. The goal of protecting the OS kernel is to ensure the security of the execution path. We implementthe system by a modified Xen hypervisor. The result shows that we can secure the security of the access control system in the guest OS with no overhead compared with modules in the latter. Our system offers a centralized security policy for virtual domains in virtual machine environments.Keywords: hypervisor; virtualization; memo- 展开更多
关键词 访问控制系统 内存保护机制 拟域 操作系统内核 系统管理程序 安全服务器 强制访问控制 恶意软件
全文增补中
Protective effect of BlingLife®-berry extract on blue lightinduced eye damage and its mechanism
5
作者 Jiaxiang Ding Chenfeng Shou Kexin Xie 《Asian Journal of Traditional Medicines》 2024年第1期1-9,共9页
This study aims to investigate the protective effects of BlingLife®-berry extract on the eyes.BlingLife®-berry extract is a mixture of high-quality natural berries,including blackcurrant,aromia,bilberry and ... This study aims to investigate the protective effects of BlingLife®-berry extract on the eyes.BlingLife®-berry extract is a mixture of high-quality natural berries,including blackcurrant,aromia,bilberry and maquiberry.The main active ingredient responsible for theeye-protective effects is anthocyanins.Anthocyanins are natural water-soluble pigments belonging to the flavonoid class,and theyhave multiple benefits,including improving vision,anti-inflammatory and antibacterial properties,and antioxidant effects.Dueto the dual benefits of anthocyanins in protecting vision and eliminating free radicals,this study explores the comprehensive eye protective effects of BlingLife®-berry extract in terms of combating blue light-induced eye damage and oxidative stress-inducedvisual fatigue.The results provide robust evidence for the in vivo effects and further technological applications of BlingLife®-berry extract. 展开更多
关键词 BlingLife®-berry extract combination anthocyanins antioxidant protecting vision eliminating radicals
下载PDF
Protective performance of shear stiffening gel-modified foam against ballistic impact:Experimental and numerical study
6
作者 Huan Tu Haowei Yang +9 位作者 Pengzhao Xu Zhe Yang Fan Tang Cheng Dong Yuchao Chen Lei Ren Wenjian Cao Chenguang Huang Yacong Guo Yanpeng Wei 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期510-520,共11页
As one of the most widely used personal protective equipment(PPE),body armors play an important role in protecting the human body from the high-velocity impact of bullets or projectiles.The body torso and critical org... As one of the most widely used personal protective equipment(PPE),body armors play an important role in protecting the human body from the high-velocity impact of bullets or projectiles.The body torso and critical organs of the wear may suffer severe behind-armor blunt trauma(BABT)even though the impactor is stopped by the body armor.A type of novel composite material through incorporating shear stiffening gel(STG)into ethylene-vinyl acetate(EVA)foam is developed and used as buffer layers to reduce BABT.In this paper,the protective performance of body armors composed of fabric bulletproof layers and a buffer layer made of foam material is investigated both experimentally and numerically.The effectiveness of STG-modified EVA in damage relief is verified by ballistic tests.In parallel with the experimental study,numerical simulations are conducted by LS-DYNA®to investigate the dynamic response of each component and capture the key mechanical parameters,which are hardly obtained from field tests.To fully describe the material behavior under the transient impact,the selected constitutive models take the failure and strain rate effect into consideration.A good agreement between the experimental observations and numerical results is achieved to prove the validity of the modelling method.The tests and simulations show that the impact-induced deformation on the human body is significantly reduced by using STG-modified EVA as the buffering material.The improvement of protective performance is attributed to better dynamic properties and more outstanding energy absorption capability of the composite foam. 展开更多
关键词 Ballistic behavior Composite foam Shear stiffening gel Finite element analysis protective mechanism
下载PDF
Anti-tumor,Anti-allergy,Anti-angiogenesis and Hepatoprotective Effects of Deoxypodophyllotoxin and Its Molecular Mechanism
7
作者 Jingchao WANG Mingxinzhi WANG +3 位作者 Quan QUAN Hai CHEN Anqi WANG Chenghao JIN 《Medicinal Plant》 CAS 2023年第2期81-83,89,共4页
Deoxypodophyllotoxin not only has pharmacological effects such as anti-allergy,anti-angiogenesis and liver protection,but also has good anti-tumor activity.It can play an anti-tumor role by inhibiting cell viability,i... Deoxypodophyllotoxin not only has pharmacological effects such as anti-allergy,anti-angiogenesis and liver protection,but also has good anti-tumor activity.It can play an anti-tumor role by inhibiting cell viability,inducing apoptosis,blocking cell cycle and inhibiting cell migration.In this paper,the related research on pharmacological effect and mechanism of deoxypodophyllotoxin is reviewed,to lay a foundation for the follow-up study of deoxypodophyllotoxin and drug development. 展开更多
关键词 DEOXYPODOPHYLLOTOXIN ANTI-TUMOR ANTI-ALLERGY ANTI-ANGIOGENESIS Liver protection
下载PDF
Study of the Ballistic Impact Behavior of Protective Multi-Layer Composite Armor
8
作者 Dongsheng Jia Yingjie Xu +2 位作者 Liangdi Wang Jihong Zhu Weihong Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期171-199,共29页
The abalone shell,a composite material whose cross-section is composed of inorganic and organic layers,has high strength and toughness.Inspired by the abalone shell,several multi-layer composite plates with different ... The abalone shell,a composite material whose cross-section is composed of inorganic and organic layers,has high strength and toughness.Inspired by the abalone shell,several multi-layer composite plates with different layer sequences and thicknesses are studied as bullet-proof material in this paper.To investigate the ballistic performance of this multi-layer structure,the complete characterization model and related material parameters of large deformation,failure and fracture ofAl_(2)O_(3)ceramics andCarbon Fiber Reinforced Polymer(CFRP)are studied.Then,3D finite element models of the proposed composite plates with different layer sequences and thicknesses impacted by a 12.7 mm armor-piercing incendiary(API)are built using Abaqus to predict failure.The simulation results show that the CFRP/Al2O3 ceramic/Ultrahigh Molecular Weight Polyethylene(UHMWPE)/CFRP(1 mm/4 mm/4 mm/1 mm)composite is the optimized stack of layers.The simulation results under specified layer sequence and thickness have a reasonable correlation with the experimental results and reflect the failure and fracture of the multi-layer composite protective armor. 展开更多
关键词 protective armor COMPOSITE bionic design structure design mechanical property
下载PDF
Screening hepatoprotective effective components of Lonicerae japonica Flos based on the spectrum-effect relationship and its mechanism exploring
9
作者 Song Wang Lin Yang +4 位作者 Ajiao Hou Songtao Liu Liu Yang Haixue Kuang Hai Jiang 《Food Science and Human Wellness》 SCIE CSCD 2023年第1期283-294,共12页
Lonicerae japonicae Flos(LF)is a kind of healthcare food with hepatoprotective function.This study was designed to explore the spectrum-effect relationships between UPLC fingerprints and the hepatoprotective effects o... Lonicerae japonicae Flos(LF)is a kind of healthcare food with hepatoprotective function.This study was designed to explore the spectrum-effect relationships between UPLC fingerprints and the hepatoprotective effects of LF.Fingerprints of ten batches of LF were established by UPLC-PDA.The inhibitory levels of AST and ALT were used as pharmacological indexes,and secoxyloganin,isochlorogenic acid A and isochlorogenic acid C were screened as hepatoprotective active compounds by grey relational analysis(GRA)and partial least squares regression analysis(PLSR).Caspase-3 was obtained by network pharmacology as a key target of hepatoprotective active compounds.Molecular docking is used to explore the interaction between small molecules and proteins.This work provided a general model of the combination of UPLC-PDA and hepatoprotective effect to study the spectrum-effect relationship of LF,which can be used to considerable methods and insight for the fundamental research of the material basis of similar healthcare food. 展开更多
关键词 Lonicerae japonicae Flos Hepatoprotective effect Spectrum-effect relationship Molecular docking mechanism
下载PDF
A Cover-Independent Deep Image Hiding Method Based on Domain Attention Mechanism
10
作者 Nannan Wu Xianyi Chen +1 位作者 James Msughter Adeke Junjie Zhao 《Computers, Materials & Continua》 SCIE EI 2024年第3期3001-3019,共19页
Recently,deep image-hiding techniques have attracted considerable attention in covert communication and high-capacity information hiding.However,these approaches have some limitations.For example,a cover image lacks s... Recently,deep image-hiding techniques have attracted considerable attention in covert communication and high-capacity information hiding.However,these approaches have some limitations.For example,a cover image lacks self-adaptability,information leakage,or weak concealment.To address these issues,this study proposes a universal and adaptable image-hiding method.First,a domain attention mechanism is designed by combining the Atrous convolution,which makes better use of the relationship between the secret image domain and the cover image domain.Second,to improve perceived human similarity,perceptual loss is incorporated into the training process.The experimental results are promising,with the proposed method achieving an average pixel discrepancy(APD)of 1.83 and a peak signal-to-noise ratio(PSNR)value of 40.72 dB between the cover and stego images,indicative of its high-quality output.Furthermore,the structural similarity index measure(SSIM)reaches 0.985 while the learned perceptual image patch similarity(LPIPS)remarkably registers at 0.0001.Moreover,self-testing and cross-experiments demonstrate the model’s adaptability and generalization in unknown hidden spaces,making it suitable for diverse computer vision tasks. 展开更多
关键词 Deep image hiding attention mechanism privacy protection data security visual quality
下载PDF
Antibacterial mechanism of kojic acid and tea polyphenols against Escherichia coli O157:H7 through transcriptomic analysis 被引量:1
11
作者 Yilin Lin Ruifei Wang +4 位作者 Xiaoqing Li Keren Agyekumwaa Addo Meimei Fang Yehui Zhang Yigang Yu 《Food Science and Human Wellness》 SCIE CSCD 2024年第2期736-747,共12页
Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity ag... Escherichia coli O157:H7 is one of the major foodborne pathogenic bacterial that cause infectious diseases in humans.The previous found that a combination of kojic acid and tea polyphenols exhibited better activity against E.coli O157:H7 than using either alone.This study aimed to explore responses underlying the antibacterial mechanisms of kojic acid and tea polyphenols from the gene level.The functional enrichment analysis by comparing kojic acid and tea polyphenols individually or synergistically against E.coli O157:H7 found that acid resistance systems in kojic acid were activated,and the cell membrane and genomic DNA were destructed in the cells,resulting in“oxygen starvation”.The oxidative stress response triggered by tea polyphenols inhibited both sulfur uptake and the synthesis of ATP,which affected the bacteria's life metabolic process.Interestingly,we found that kojic acid combined with tea polyphenols hindered the uptake of iron that played an essential role in the synthesis of DNA,respiration,tricarboxylic acid cycle.The results suggested that the iron uptake pathways may represent a novel approach for kojic acid and tea polyphenols synergistically against E.coli O157:H7 and provided a theoretical basis for bacterial pathogen control in the food industry. 展开更多
关键词 Kojic acid Tea polyphenols Antibacterial mechanism Escherichia coli O157:H7 RNA-SEQ
下载PDF
Brain protective effect of dexmedetomidine vs propofol for sedation during prolonged mechanical ventilation in non-brain injured patients
12
作者 Hong-Xun Yuan Li-Na Zhang +1 位作者 Gang Li Li Qiao 《World Journal of Psychiatry》 SCIE 2024年第3期370-379,共10页
BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical venti... BACKGROUND Dexmedetomidine and propofol are two sedatives used for long-term sedation.It remains unclear whether dexmedetomidine provides superior cerebral protection for patients undergoing long-term mechanical ventilation.AIM To compare the neuroprotective effects of dexmedetomidine and propofol for sedation during prolonged mechanical ventilation in patients without brain injury.METHODS Patients who underwent mechanical ventilation for>72 h were randomly assigned to receive sedation with dexmedetomidine or propofol.The Richmond Agitation and Sedation Scale(RASS)was used to evaluate sedation effects,with a target range of-3 to 0.The primary outcomes were serum levels of S100-βand neuron-specific enolase(NSE)every 24 h.The secondary outcomes were remifentanil dosage,the proportion of patients requiring rescue sedation,and the time and frequency of RASS scores within the target range.RESULTS A total of 52 and 63 patients were allocated to the dexmedetomidine group and propofol group,respectively.Baseline data were comparable between groups.No significant differences were identified between groups within the median duration of study drug infusion[52.0(IQR:36.0-73.5)h vs 53.0(IQR:37.0-72.0)h,P=0.958],the median dose of remifentanil[4.5(IQR:4.0-5.0)μg/kg/h vs 4.6(IQR:4.0-5.0)μg/kg/h,P=0.395],the median percentage of time in the target RASS range without rescue sedation[85.6%(IQR:65.8%-96.6%)vs 86.7%(IQR:72.3%-95.3),P=0.592],and the median frequency within the target RASS range without rescue sedation[72.2%(60.8%-91.7%)vs 73.3%(60.0%-100.0%),P=0.880].The proportion of patients in the dexmedetomidine group who required rescue sedation was higher than in the propofol group with statistical significance(69.2%vs 50.8%,P=0.045).Serum S100-βand NSE levels in the propofol group were higher than in the dexmedetomidine group with statistical significance during the first six and five days of mechanical ventilation,respectively(all P<0.05).CONCLUSION Dexmedetomidine demonstrated stronger protective effects on the brain compared to propofol for long-term mechanical ventilation in patients without brain injury. 展开更多
关键词 DEXMEDETOMIDINE PROPOFOL SEDATION Prolonged mechanical ventilation Brain protective
下载PDF
Hydroxytyrosol and Parkinson's disease:protective actions against alpha-synuclein toxicity
13
作者 Ruth Hornedo-Ortega Ana M.Espinosa-Oliva 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1427-1428,共2页
Parkinson’s disease:Parkinson’s disease(PD) is the second most prevalent neurodegenerative disease,after Alzheimer’s disease,affecting 1%of the general population over the age of 65years.According to data from the ... Parkinson’s disease:Parkinson’s disease(PD) is the second most prevalent neurodegenerative disease,after Alzheimer’s disease,affecting 1%of the general population over the age of 65years.According to data from the World Health Organization(WHO),its prevalence has doubled in the past 25 years.In 2019,global estimates indicated over 8.5 million individuals with PD and it is suggested that PD caused 329000 deaths,an increase of over 100% since 2000(WHO,2022). 展开更多
关键词 protective ALZHEIMER PREVALENCE
下载PDF
Ambroxol,the cough expectorant with neuroprotective effects
14
作者 Kristin Patzwaldt Salvador Castaneda-Vega 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第11期2345-2346,共2页
Ambroxol hydrochloride(2-amino-3,5-dibromo-N-methylbenzylamine hydrochloride)has been used as a mucolytic agent in the treatment of respiratory diseases since the late 1970s.Its effects on mucus membranes such as mucu... Ambroxol hydrochloride(2-amino-3,5-dibromo-N-methylbenzylamine hydrochloride)has been used as a mucolytic agent in the treatment of respiratory diseases since the late 1970s.Its effects on mucus membranes such as mucus disruption,increased mucus production,and low toxicity profile were addressed in its original German patent in 1966.These first described properties have kept Ambroxol available worldwide and over the counter in the pharmaceutical market to this day. 展开更多
关键词 protective AGENT GERMAN
下载PDF
Failure mechanism and infrared radiation characteristic of hard siltstone induced by stratification effect
15
作者 CHENG Yun SONG Zhanping +2 位作者 XU Zhiwei YANG Tengtian TIAN Xiaoxu 《Journal of Mountain Science》 SCIE CSCD 2024年第3期1058-1074,共17页
The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and tempora... The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and temporal damage mechanism of hard siltstone. The uniaxial compression tests, coupled with acoustic emission(AE) and infrared radiation temperature(IRT) were conducted on siltstones with different stratification effects. The results revealed that the stratigraphic structure significantly affects the stress-strain response and strength degradation characteristics. The mechanical parameters exhibit anisotropy characteristics, and the stratification effect exhibits a negative correlation with the cracking stress and peak stress. The failure modes caused by the stratification effect show remarkable anisotropic features, including splitting failure(Ⅰ: 0°-22.50°, Ⅱ: 90°), composite failure(45°), and shearing failure(67.50°). The AE temporal sequences demonstrate a stepwise response characteristic to the loading stress level. The AE intensity indicates that the stress sensitivity of shearing failure and composite failure is generally greater than that of splitting failure. The IRT field has spatiotemporal migration and progressive dissimilation with stress loading and its dissimilation degree increases under higher stress levels. The stronger the stratification effect, the greater the dissimilation degree of the IRT field. The abnormal characteristic points of average infrared radiation temperature(AIRT) variance at local stress drop and peak stress can be used as early and late precursors to identify fracture instability. Theoretical analysis shows that the competitive relationship between compaction strengthening and fracturing damage intensifies the dissimilation of the infrared thermal field for an increasing stress level. The present study provides a theoretical reference for disaster warnings in hard sedimentary rock mass. 展开更多
关键词 Hard siltstone Failure mechanism Stratification effect Infrared radiation characteristic Temporal-damage mechanism DISSIMILATION
原文传递
Experimental and numerical study on protective effect of RC blast wall against air shock wave
16
作者 Xin-zhe Nian Quan-min Xie +2 位作者 Xin-li Kong Ying-kang Yao Kui Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期567-579,共13页
Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in diff... Prototype experiments were carried out on the explosion-proof performance of the RC blast wall.The mass of TNT detonated in the experiments is 5 kg and 20 kg respectively.The shock wave overpressure was tested in different regions.The above experiments were numerically simulated,and the simulated shock wave overpressure waveforms were compared with that tested and given by CONWEP program.The results show that the numerically simulated waveform is slightly different from the test waveform,but similar to CONWEP waveform.Through dimensional analysis and numerical simulation under different working conditions,the equation for the attenuation rate of the diffraction overpressure behind the blast wall was obtained.According to the corresponding standards,the degree of casualties and the damage degree of the brick concrete building at a certain distance behind the wall can be determined when parameters are set.The above results can provide a reference for the design and construction of the reinforced concrete blast wall. 展开更多
关键词 Blast wall Shock wave DIFFRACTION OVERPRESSURE Protection
下载PDF
Macro-micro behaviors and failure mechanism of frozen weakly cemented mudstone
17
作者 Xianzhou Lyu Jijie Du +2 位作者 Hao Fu Dawei Lyu Weiming Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1337-1347,共11页
Understanding the mechanical properties and multiscale failure mechanism of frozen soft rock is an important prerequisite for the construction safety of tunnels,artificially frozen ground and other infrastructure in c... Understanding the mechanical properties and multiscale failure mechanism of frozen soft rock is an important prerequisite for the construction safety of tunnels,artificially frozen ground and other infrastructure in cold regions.In this study,the triaxial compression test are performed on mudstone in the weakly cemented soft rock strata in the mining area of western China,and the mechanical characteristics and failure mechanism of weakly cemented mudstone are systematically investigated under the combined action of freezing and loading.Furthermore,the quantitative relationship between the microstructural parameters and the macroscopic strength and deformation parameters is established based on fractal theory.Thus,the failure mechanism of frozen weakly cemented mudstone is revealed on both micro- and macro-scales.The results show that temperature and confining pressure significantly affects the elastic modulus and peak strength of weakly cemented mudstone.With decreasing temperature,the compressive strength increases,while the corresponding peak strain decreases gradually.On the deformation curve,the plastic deformation stage is shortened,and the brittle fracture feature at the post-peak stage is more prominent,and the elastic modulus correspondingly increases with decreasing temperature.Under low-temperature conditions,most of the weakly cemented mudstone undergoes microscopic shear failure along the main fracture surface.The micro-fracture morphology characteristics of weakly cemented mudstone under different temperatures are quantified via the fractal dimension,and an approximately exponential relationship can be obtained among the fractal dimension and the temperature,compressive strength and elastic modulus. 展开更多
关键词 Weakly cemented mudstone Artificial freezing Mechanical properties Linkage destruction mechanism Fractal dimension
下载PDF
Activity-dependent mechanisms of neuroprotection:promising avenues against dementia
18
作者 Davide Tampellini 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1409-1410,共2页
The study of the brain and its complex functions is highly fascinating and,at the same time,extremely important.Indeed,furthering our understanding of the biology of neurons and synapses is a prerequisite to uncover t... The study of the brain and its complex functions is highly fascinating and,at the same time,extremely important.Indeed,furthering our understanding of the biology of neurons and synapses is a prerequisite to uncover the mechanisms involved in memory formation and the coordination of movement as well as their alterations occurring in several neurological disorders. 展开更多
关键词 alterations mechanismS NEUROLOGICAL
下载PDF
Obituary:Prof.Yun Zhang(1963-2023)-A scientist focused on toxins and their underlying mechanisms to decipher human diseases
19
作者 Wenhui Lee Ren Lai 《Zoological Research》 SCIE CSCD 2024年第1期230-232,共3页
Prof.Yun Zhang was born on 9 July 1963 in Kunming,Yunnan,China,during a tumultuous period which he often referenced.Throughout his life,he harbored a steadfast belief in using knowledge to unravel the mysteries of hum... Prof.Yun Zhang was born on 9 July 1963 in Kunming,Yunnan,China,during a tumultuous period which he often referenced.Throughout his life,he harbored a steadfast belief in using knowledge to unravel the mysteries of human diseases.His educational journey was marked by frequent changes in schools due to his parents’occupational relocations.However,despite these challenges,he consistently displayed diligence and was admitted to the East China University of Science and Technology,Shanghai,after completing high school in 1980.He remained an active and loyal member of the School of Biotechnology at the university. 展开更多
关键词 admitted HARBOR mechanismS
下载PDF
A reduced combustion mechanism of ammonia/diesel optimized with multi-objective genetic algorithm
20
作者 Wanchen Sun Shaodian Lin +4 位作者 Hao Zhang Liang Guo Wenpeng Zeng Genan Zhu Mengqi Jiang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期187-200,共14页
For the deep understanding on combustion of ammonia/diesel,this study develops a reduced mechanism of ammonia/diesel with 227 species and 937 reactions.The sub-mechanism on ammonia/interactions of N-based and C-based ... For the deep understanding on combustion of ammonia/diesel,this study develops a reduced mechanism of ammonia/diesel with 227 species and 937 reactions.The sub-mechanism on ammonia/interactions of N-based and C-based species(N—C)/NOx is optimized using the Non-dominated Sorting Genetic Algorithm II(NSGA-II)with 200 generations.The optimized mechanism(named as 937b)is validated against combustion characteristics of ammonia/methane(which is used to examine the accuracy of N—C interactions)and ammonia/diesel blends.The ignition delay times(IDTs),the laminar flame speeds and most of key intermediate species during the combustion of ammonia/methane blends can be accurately simulated by 937b under a wide range of conditions.As for ammonia/diesel blends with various diesel energy fractions,reasonable predictions on the IDTs under pressures from 1.0 MPa to5.0 MPa as well as the laminar flame speeds are also achieved by 937b.In particular,with regard to the IDT simulations of ammonia/diesel blends,937b makes progress in both aspects of overall accuracy and computational efficiency,compared to a detailed ammonia/diesel mechanism.Further kinetic analysis reveals that the reaction pathway of ammonia during the combustion of ammonia/diesel blend mainly differs in the tendencies of oxygen additions to NH_2 and NH with different equivalence ratios. 展开更多
关键词 AMMONIA DIESEL COMBUSTION Kinetic mechanism Multi-objective optimization
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部