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Ultrasound imaging-guided protocol for monitoring tumor growth in orthotopic rat model of hepatocellular carcinoma
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作者 Aswathy R Devan Sithara Manakkaparambil Sasidharan +5 位作者 Kannoth Panicker Sreekumar Ayalur Kodakara Kochugovindan Unni Sabitha Mangalathillam Abna Ansar Ashok R Unni Lekshmi R Nath 《World Journal of Hepatology》 2025年第10期260-274,共15页
BACKGROUND Syngeneic orthotopic tumor models offer an optimal functional tumor–immune interface for hepatocellular carcinoma research.Yet,unpredictable growth kinetics and spontaneous regression pose major obstacles.... BACKGROUND Syngeneic orthotopic tumor models offer an optimal functional tumor–immune interface for hepatocellular carcinoma research.Yet,unpredictable growth kinetics and spontaneous regression pose major obstacles.Efficient induction protocols and continuous monitoring are therefore essential.Routine exploratory surgeries are ethically untenable,making non-invasive imaging modalities attractive alternatives.High-resolution magnetic resonance imaging and microcomputed tomography deliver detailed insights but incur substantial equipment costs,radiation risks,time demands,and require specialized expertise—challenges that limit their routine use.In contrast,ultrasound(US)imaging emerges as a cost-effective,radiation-free,and rapid approach,facilitating practical and ethical longitudinal assessment of tumor progression in preclinical studies.AIM To optimize the orthotopic hepatocellular carcinoma model and evaluate the potential of US imaging for accurate and cost-effective tumor monitoring.METHODS Hepatocellular carcinoma was induced in 28 Sprague Dawley rats by implanting 5×10^(6) N1S1 cells into the left lateral hepatic lobe.Tumor progression was monitored weekly via US.Upon reaching 100-150 mm^(3),an experimental group(n=14)received Sorafenib(40 mg/kg)orally on alternate days for 28 days;efficacy was compared to untreated controls.US accuracy was validated against micro-computed tomography,gross caliper measurements and histopathological analysis.Reliability and operator proficiency in US assessment were also evaluated.RESULTS US images procured 7-day post-surgery revealed a well-defined hypoechoic nodule at the left liver lobe tip,confirming successful tumor induction(mean volume 130±39 mm^(3)).Only three animals exhibited spontaneous regression by week 2,underscoring the model’s stability.Sorafenib treatment elicited a marked tumor reduction(678±103 mm^(3))vs untreated control(6005±1760 mm^(3)).US assessment demonstrated robust intra and interobserver reproducibility with high sensitivity and specificity for tumor detection.Moreover,US derived volumes correlated strongly with gross caliper measurements,histopathological analysis,and microcomputed tomography imaging,validating its reliability as a non-invasive monitoring tool in preclinical hepatocellular carcinoma studies.CONCLUSION The results demonstrate that US imaging is a reliable,cost-effective,and animal sparing approach with an easy tomaster protocol,enabling monitoring of tumor progression and therapeutic response in orthotopic liver tumor models. 展开更多
关键词 Hepatocellular carcinoma syngeneic n1s1 orthotopic model Ultrasound imaging Tumor growth monitoring Therapeutic response Cost-effective imaging tool Inter-observer reproducibility Receiver operating characteristics analysis
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Comparison of the S-, N- or P-Deprivations’ Impacts on Stomatal Conductance, Transpiration and Photosynthetic Rate of Young Maize Leaves 被引量:1
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作者 Dimitris L. Bouranis Styliani N. Chorianopoulou +4 位作者 Alexandros Dionias Giouli Sofianou Aristotelis Thanasoulas Georgios Liakopoulos Dimosthenis Nikolopoulos 《American Journal of Plant Sciences》 2012年第8期1058-1065,共8页
Seven-day-old maize (Zea mays) plants were grown hydroponically for ten days in deprived nutrient solutions against the corresponding control grown under full nutrition;the effects of S-, N- or P-deprivation on lamina... Seven-day-old maize (Zea mays) plants were grown hydroponically for ten days in deprived nutrient solutions against the corresponding control grown under full nutrition;the effects of S-, N- or P-deprivation on laminas’ mean stomatal conductance (gs), transpiration rate (E) and photosynthetic rate (A) were monitored, along with the impact on the laminas’ total dry mass (DM), water amount (W), length and surface area (Sa). Furthermore, a time series analysis of each parameter’s response ratios (Rr), i.e. the treatment’s value divided by the corresponding control’s one, was performed. Under S-deprivation, the Rr of laminas’ mean gs, E, and A presented oscillations within a ±15% fluctuation zone, notably the “control” zone, whilst those of laminas’ total DM, water amount, surface area, and length included oscillation during the first days and deviation later on, presenting deviation during d10. Under the N-deprivation conditions all Rr time courses except the A one, included early deviations from the control zone without recovering. The deviation from the control zone appeared at d4. Under P-deprivation, all Rr time courses represented oscillations within the control zone. P-deprivation’s patterns resembled those of S-deprivation. Compared to the one of the S-deprivation, the P-one’s oscillations took place within a broader zone. Linear relationships among the various Rr patterns were found between gs-E, gs-A, E-A, DM-W and DM-Sa. In conclusion, the impact of P-deprivation appeared in an early stage and included an alleviation action, the one of N-deprivation appeared early with no alleviation action, whilst that of S-deprivation appeared later, being rather weaker when compared to the impact of the P-deprivation’s impact. 展开更多
关键词 s-Deprivation n-Deprivation P-Deprivation Hydroponics Zea Mays sTOMATAL Conductance TRAnsPIRATIOn RATE Photosynthetic RATE Response Ratios Fluctuation Analysis
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The Fourier Notation of the Geomagnetic Signals Informative Parameters 被引量:1
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作者 Osvaldo Faggioni 《Journal of Signal and Information Processing》 2018年第3期153-166,共14页
The paper discusses the quantitative definition of the s/n (signal to noise ratio) by means of new computational parameters derived (and computed) by the Fourier analysis. The theme is of great relevance when the geom... The paper discusses the quantitative definition of the s/n (signal to noise ratio) by means of new computational parameters derived (and computed) by the Fourier analysis. The theme is of great relevance when the geomagnetic observed field has high transient noise and high energy content (i.e.geomagnetic signal interfered by human activity magnetic band) and when the signal analysis action is oriented to the detection of magnetic sources characterized by quasi-punctiform size, low energy level and kinetic mechanical status (i.e.uw armed terrorist). The paper shows the results obtained introducing two new informative spectral parameters: the informative capability “C” and the enhanced informative capability “eC”. These parameters are depending on the comparison of the energy of the target signal with total field energy and they are characteristics of each elementary signal. C classifies the energy of the spectrum in two metrological bands: elementary signal informative energy EI (band or single signal) and passive energy EP. This metrological classification of the energy overtakes the concept of noise: each signal is part of the noise band when it is not under observation and becomes out of the band when it is under observation (numerical observation→computation). C (and eC) allows to compute the value of the “visibility” of the informative signals in a high energy geomagnetic field (or spectrum). C is a fundamental parameter for the evaluation of the effectiveness of singularity magnetic metrology in the passive detection of small magnetic sources in high noised magnetic field. 展开更多
关键词 Geomatic InFORMATIVE signal AnALYsIs FOURIER AnALYsIs GEOMAGnETIsM Metrology of singularity Frequency Domain Observations s/n Manipulation
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A Self-Sacrifice Template Method to Produce FeS Encapsulated into N,S Co-Doped Carbon for Improved Lithium Storage Performance
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作者 Xu Liu Lan-Yun Yang +7 位作者 Li-Ting Zeng Yun Peng Chen-Xi Xu Lei Li Jia-Le Sun Yang-Yang Chen Liang Chen Zhao-Hui Hou 《Acta Metallurgica Sinica(English Letters)》 2025年第9期1637-1644,共8页
The development of high-performance transition metal sulfide(TMS)/carbon composites to replace conventional graphite anode remains a critical challenge for advancing lithium-ion batteries(LIBs).In this study,a facile ... The development of high-performance transition metal sulfide(TMS)/carbon composites to replace conventional graphite anode remains a critical challenge for advancing lithium-ion batteries(LIBs).In this study,a facile self-sacrifice template method is developed to prepare FeS encapsulated into N,S co-doped carbon(FeS/NSC)composite using melamine-cyanuric acid(MCA)supermolecule as a multifunctional template precursor.The function of MCA supermolecule for material synthesis is explored,revealing its special function as a dispersant,dopant and pore-forming agent.Furthermore,the effect of Fe source dosage on the morphology,structure and composition of the final products is explored.The resultant FeS/NSC-0.1(where 0.1 represents the mass of added Fe source)exhibits the most optimal proportion,characterized by a good dispersion status of FeS within the NSC matrix,effective N,S co-doping and ample porosity.Benefiting from these merits,the FeS/NSC-0.1 anode demonstrates significantly improved cycling stability and rate capability when compared to the counterparts.Undoubtedly,this work offers a universal method to produce advanced transition metal sulfide/carbon composite electrodes for energy storage and conversion systems. 展开更多
关键词 Lithium-ion batteries Lithium storage performance self-sacrifice template method Melamine-cyanuric acid(MCA)supermolecule Fes encapsulated into n s co-doped carbon(Fes/nsC)composite
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The Collaboratory for the Study of Earthquake Predictability in China:Experiment Design and Preliminary Results of CSEP2.0
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作者 ZHANG Shengfeng ZHANG Yongxian +3 位作者 Maximilian J.WERNER Kenny G.RAHAM David A.RHOADES JoséA.BAYONA 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第S01期94-97,共4页
Since the inaugural international collaboration under the framework of the Collaboratory for the Study of Earthquake Predictability(CSEP)in 2007,numerous forecast models have been developed and operated for earthquake... Since the inaugural international collaboration under the framework of the Collaboratory for the Study of Earthquake Predictability(CSEP)in 2007,numerous forecast models have been developed and operated for earthquake forecasting experiments across CSEP testing centers(Schorlemmer et al.,2018).Over more than a decade,efforts to compare forecasts with observed earthquakes using numerous statistical test methods and insights into earthquake predictability,which have become a highlight of the CSEP platform. 展开更多
关键词 earthquake forecasting seismicity modeling CsEP2.0 Pattern Informatics(PI)algorithm long-to-intermediate-term forecast Relative Intensity(RI)algorithm Completeness Magnitude s test n test
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Asynchronous Secret Reconstruction and Its Application to the Threshold Cryptography 被引量:2
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作者 Lein Harn Changlu Lin 《International Journal of Communications, Network and System Sciences》 2014年第1期22-29,共8页
In Shamir’s(t,n) threshold of the secret sharing scheme, a secret is divided into n shares by a dealer and is shared among n shareholders in such a way that (a) the secret can be reconstructed when there are t or mor... In Shamir’s(t,n) threshold of the secret sharing scheme, a secret is divided into n shares by a dealer and is shared among n shareholders in such a way that (a) the secret can be reconstructed when there are t or more than t shares;and (b) the secret cannot be obtained when there are fewer than t shares. In the secret reconstruction, participating users can be either legitimate shareholders or attackers. Shamir’s scheme only considers the situation when all participating users are legitimate shareholders. In this paper, we show that when there are more than t users participating and shares are released asynchronously in the secret reconstruction, an attacker can always release his share last. In such a way, after knowing t valid shares of legitimate shareholders, the attacker can obtain the secret and therefore, can successfully impersonate to be a legitimate shareholder without being detected. We propose a simple modification of Shamir’s scheme to fix this security problem. Threshold cryptography is a research of group-oriented applications based on the secret sharing scheme. We show that a similar security problem also exists in threshold cryptographic applications. We propose a modified scheme to fix this security problem as well. 展开更多
关键词 shamir’s(t n)secret sharing scheme sECRET RECOnsTRUCTIOn THREsHOLD CRYPTOGRAPHY THREsHOLD DECRYPTIOn AsYnCHROnOUs networks
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Oxidative stress modulation in hepatitis C virus infected cells 被引量:6
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作者 Sonia A Lozano-Sepulveda Owen L Bryan-Marrugo +2 位作者 Carlos Cordova-Fletes Maria C Gutierrez-Ruiz Ana M Rivas-Estilla 《World Journal of Hepatology》 CAS 2015年第29期2880-2889,共10页
Hepatitis C virus(HCV) replication is associated with the endoplasmic reticulum, where the virus can induce cellular stress. Oxidative cell damage plays an important role in HCV physiopathology. Oxidative stress is tr... Hepatitis C virus(HCV) replication is associated with the endoplasmic reticulum, where the virus can induce cellular stress. Oxidative cell damage plays an important role in HCV physiopathology. Oxidative stress is triggered when the concentration of oxygen species in the extracellular or intracellular environment exceeds antioxidant defenses. Cells are protected and modulate oxidative stress through the interplay of intracellular antioxidant agents, mainly glutathione system(GSH) and thioredoxin; and antioxidant enzyme systems such as superoxide dismutase, catalase, GSH peroxidase, and heme oxygenase-1. Also, the use of natural and synthetic antioxidants(vitamin C and E, N-acetylcysteine, glycyrrhizin, polyenylphosphatidyl choline, mitoquinone, quercetin, S-adenosylmethionine and silymarin) has already shown promising results as co-adjuvants in HCV therapy. Despite all the available information, it is not known how different agents with antiviral activity can interfere with the modulation of the cell redox state induced by HCV and decrease viral replication. This review describes an evidence-based consensus on molecular mechanisms involved in HCV replication and their relationship with cell damage induced by oxidative stress generated by the virus itself and cell antiviral machinery. It also describes some molecules that modify the levels of oxidative stress in HCV-infected cells. 展开更多
关键词 Hepatitis C virus Oxidative stress Reactiveoxygen species VITAMIn E Antioxidants GLYCYRRHIZIn s-ADEnOsYLMETHIOnInE n-ACETYLCYsTEInE sILYMARIn
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Flexible Conductive Anodes Based on 3D Hierarchical Sn/NS-CNFs@rGO Network for Sodium-Ion Batteries 被引量:7
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作者 Linqu Luo Jianjun Song +6 位作者 Longfei Song Hongchao Zhang Yicheng Bi Lei Liu Longwei Yin Fengyun Wang Guoxiu Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2019年第4期133-146,共14页
Metallic Sn has provoked tremendous progress as an anode material for sodium-ion batteries(SIBs).However,Sn anodes suffer from a dramatic capacity fading,owing to pulverization induced by drastic volume expansion duri... Metallic Sn has provoked tremendous progress as an anode material for sodium-ion batteries(SIBs).However,Sn anodes suffer from a dramatic capacity fading,owing to pulverization induced by drastic volume expansion during cycling.Herein,a flexible three-dimensional(3D)hierarchical conductive network electrode is designed by constructing Sn quantum dots(QDs)encapsulated in one-dimensional N,S codoped carbon nanofibers(NS-CNFs)sheathed within two-dimensional(2D)reduced graphene oxide(rGO)scrolls.In this ingenious strategy,1D NS-CNFs are regarded as building blocks to prevent the aggregation and pulverization of Sn QDs during sodiation/desodiation,2D rGO acts as electrical roads and“bridges”among NS-CNFs to improve the conductivity of the electrode and enlarge the contact area with electrolyte.Because of the unique structural merits,the flexible 3D hierarchical conductive network was directly used as binder-and current collectorfree anode for SIBs,exhibiting ultra-long cycling life(373 mAh g?1 after 5000 cycles at 1 A g?1),and excellent high-rate capability(189 mAh g?1 at 10 A g?1).This work provides a facile and efficient engineering method to construct 3D hierarchical conductive electrodes for other flexible energy storage devices. 展开更多
关键词 FLEXIBLE electrodes n s CO-DOPED carbon nanofibers Reduced graphene oxide sn quantum DOTs sodium-ion batteries
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Inherited susceptibility for aggressive prostate cancer
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作者 William B Isaacs 《Asian Journal of Andrology》 SCIE CAS CSCD 2012年第3期415-418,I0006,共5页
Whether or not there is inherited basis for prostate cancer aggressiveness is not clear, but advances in DNA analysis should provide an answer to this question in the very near future.
关键词 AGGREssIVEnEss GERMLInE Genome Wide Association studies GWAs InHERITED linkage mutation single nucleotidepolymorphisms s n Ps susceptibility
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扩散抛物化Navier-Stokes方程数值解法评述 被引量:12
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作者 王汝权 申义庆 《力学进展》 EI CSCD 北大核心 2005年第4期481-497,共17页
20世纪60年代末期在边界层理论基础上发展起来的各种简化Navier-Stokes(N-S)方程(统称为扩散抛物化N-S方程)及其算法,较为彻底地解决了无黏流及黏流的相互干扰问题,并为高雷诺数大型复杂黏性流场的数值模拟开辟了新的途径。本文将系... 20世纪60年代末期在边界层理论基础上发展起来的各种简化Navier-Stokes(N-S)方程(统称为扩散抛物化N-S方程)及其算法,较为彻底地解决了无黏流及黏流的相互干扰问题,并为高雷诺数大型复杂黏性流场的数值模拟开辟了新的途径。本文将系统地评述这一领域的主要成果,包括各种简化N-S模型的优缺点;数学奇性及正则化方法;代表性的数值解法以及最近几年的新进展。 展开更多
关键词 nAVIER-sTOKEs方程 边界层方程 Pns方程 TLns方程 DPns方程 广义DPns方程 差分法
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Effect of CO_2 enrichment on the glucosinolate contents under different nitrogen levels in bolting stem of Chinese kale (Brassica alboglabra L.) 被引量:7
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作者 Gui-xiao LA Ping FAN +2 位作者 Yi-bo TENG Ya-juan LI Xian-yong LIN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2009年第6期454-464,共11页
The effects of CO2 enrichment on the growth and glueosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/... The effects of CO2 enrichment on the growth and glueosinolate (GS) concentrations in the bolting stem of Chinese kale (Brassica alboglabra L.) treated with three nitrogen (N) concentrations (5, 10, and 20 mmol/L) were investigated. Height, stem thickness, and dry weights of the total aerial parts, bolting stems, and roots, as well as the root to shoot ratio, significantly increased as CO2 concentration was elevated from 350 to 800 μl/L at each N concentration. In the edible part of the bolting stem, 11 individual GSs were identified, including 7 aliphatic and 4 indolyl GSs. GS concentration was affected by the elevated CO2 concentration, N concentration, and CO2×N interaction. At 5 and 10 mmol N/L, the concentrations of aliphatic GSs and total GSs significantly increased, whereas those ofindolyl GSs were not affected, by elevated atmospheric CO2. However, at 20 mmol N/L, elevated CO2 had no significant effects on the concentrations of total GSs and total indolyl GSs, but the concentrations of total aliphatic GSs significantly increased. Moreover, the bolting stem carbon (C) content increased, whereas the N and sulfur (S) contents decreased under elevated CO2 concentration in the three N treatments, resulting in changes in the C/N and N/S ratios. Also the C/N ratio is not a reliable predictor of change of GS concentration, while the changes in N and S contents and the N/S ratio at the elevated CO2 concentration may influence the GS concentration in Chinese kale bolting stems. The results demonstrate that high nitrogen supply is beneficial for the growth of Chinese kale, but not for the GS concentration in bolting stems, under elevated CO2 condition. 展开更多
关键词 Carbon dioxide (CO2) Brassica alboglabra nitrogen n Growth Bolting stem Aliphatic glucosinolates Indolyl glucosinolates Carbon/nitrogen ratio (C/n nitrogen/sulfur ratio n/s
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Preliminary Study on Strategic Water Transfer Project in Western China
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作者 WU Li gongEngineer, Design Institute, Changjiang Water Resources Commission, Wuhan 430010,China 《人民长江》 北大核心 2001年第S1期33-36,共4页
Strategic Water Transfer Project of Western China will transfer water from the Dadu river, the Yalong river, the Jinsha river, the Lancang river and the Nujiang river to the Daliushu project as head work of main canal... Strategic Water Transfer Project of Western China will transfer water from the Dadu river, the Yalong river, the Jinsha river, the Lancang river and the Nujiang river to the Daliushu project as head work of main canal on the Yellow river. And then,the water will be diverted to Neimongol and Xinjiang Uygur autonomous regions,with transfered annual volume of water 80 billion m\+3. The project possesses great comprehensive benefit. The construction of the project will not only change the appearance of the whole Northwest China, but also open up a wide way for the sustainable development of China in future. 展开更多
关键词 transbasin WATER DIVERsIOn WATER resources utilization nORTHWEsT region s-n WATER TRAnsFER PROJECT
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Numerical Simulation of Boundary Layer with Spectral Method
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作者 Zhiyong Liang Lewen Zhang Xianfu Wang(Wuhan Transportation University,Wuhan 430063, P.R.China) 《武汉理工大学学报(交通科学与工程版)》 1999年第S1期64-67,共4页
It is important to improve the speed of a ship,the friction resistance can be reduced by injection air at the bottom of a ship when the ship is running on the water.As the first part of the studying project,here numer... It is important to improve the speed of a ship,the friction resistance can be reduced by injection air at the bottom of a ship when the ship is running on the water.As the first part of the studying project,here numerical simulation study method,boundary condition and governing equations are presented.It is easy to study complicated problems from simple conditions,so the program concerning boundary layer condition is compiled to solve the problem.Here the spectral method is introduced,and the results are tested by Dorod’s results. 展开更多
关键词 micro BUBBLEs resistance reduction n s EQUATIOn numerical simulation BOUnDARY layer sPECTRAL method
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一种基于材料S-N曲线参数及应力相互作用的疲劳累积损伤模型
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作者 张禄 晋杰 《机械设计》 北大核心 2026年第1期167-175,共9页
为了有效且准确地预测疲劳损伤,尤其是高周疲劳寿命和低周疲劳寿命相结合的预测问题,提出了一种基于材料S-N曲线参数及应力相互作用的疲劳累积损伤模型。新模型仅需材料S-N曲线公式S=KN^(-b)中的参数b,K和前后应力之比。结合前人的二级... 为了有效且准确地预测疲劳损伤,尤其是高周疲劳寿命和低周疲劳寿命相结合的预测问题,提出了一种基于材料S-N曲线参数及应力相互作用的疲劳累积损伤模型。新模型仅需材料S-N曲线公式S=KN^(-b)中的参数b,K和前后应力之比。结合前人的二级和三级应力试验数据,分别计算并对比了与Miner模型、Manson-Halford模型及其改进模型和新模型的疲劳损伤预测结果。结果表明:新模型的疲劳损伤预测精度整体较优,具有一定的鲁棒性。 展开更多
关键词 疲劳损伤 疲劳寿命 多级应力 s-n曲线参数 应力相互作用
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Cycling of Carbon and Other Elements in a Beech Forest Hestehave, Jutland, Denmark, in the Past 50 Years
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作者 Folke O. Andersson 《Open Journal of Forestry》 2015年第3期296-312,共17页
Plant biomass, primary production and mineral cycling in the beech forest (Fagus sylvatica L.), Hestehave in Jutland, Denmark were studied over a 50-year period. The role of the forest as a carbon sink was also assess... Plant biomass, primary production and mineral cycling in the beech forest (Fagus sylvatica L.), Hestehave in Jutland, Denmark were studied over a 50-year period. The role of the forest as a carbon sink was also assessed. Aboveground tree biomass was 226 t·ha-1 in 1970 and after a 50-year 539 t·ha-1 in 2014, an unexpected increase with 313 t·ha-1. Annual production at those two points in time was 13.4 and 20.5 t·ha-1, respectively. It was apparent that the tree biomass was still acting as a sink for carbon, which was the dominant element in the aboveground parts. The concentration of other elements (N > K > Mg > P > S > Na > Mn > Zn > Fe > Cu) ranged from 495 to 0.4 kg·ha-1. Annual litterfall restored 3.2 t·ha-1 to the soil as organic matter or 1.6 t·ha-1 as carbon. Over the year 53% of the litterfall was decomposed. A pH decrease of 0.95 units in the soil was observed between 1968 and 1993. This was attributed to fallout from a neighbouring thermal heating station affecting sulfur deposition and increasing soil acidification. After 1993, when filters were fitted in the heating station, the pH decrease in the soil was smaller, only 0.09 pH-units up to 2011. The increased tree growth is an additional, likely explanation for the observed soil acidification. Deposition of the growth-limiting element nitrogen increased during later years and is now, most likely around 20 kg·ha-1 per annum, which may partly contribute to the increased production. 展开更多
关键词 Plant BIOMAss Primary Production LITTERFALL Deposition CYCLInG of C n P s and CARBOn sInK
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基于灰色系统理论的小样本P-S-N曲线拟合方法
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作者 张震 刘俭辉 +1 位作者 程玲玲 牛富超 《兰州理工大学学报》 北大核心 2026年第1期63-67,共5页
Bootstrap法在处理小样本疲劳试验数据时,只能在原始数据中进行抽样,所得数据信息有限.为此,引入灰色系统理论对小样本数据进行处理,建立数据的灰微分方程,并挖掘原始数据的隐藏关系,得到更多数据的潜在信息.首先,借助灰色系统理论处理... Bootstrap法在处理小样本疲劳试验数据时,只能在原始数据中进行抽样,所得数据信息有限.为此,引入灰色系统理论对小样本数据进行处理,建立数据的灰微分方程,并挖掘原始数据的隐藏关系,得到更多数据的潜在信息.首先,借助灰色系统理论处理原始数据;其次,通过Bootstrap法对已处理的数据进行抽样得到再生样本;最后,对再生样本进行处理得到小样本数据的P-S-N曲线.结果表明,与Bootstrap法相比,通过灰色Bootstrap法处理所得小样本P-S-N曲线精度更高. 展开更多
关键词 小样本 BOOTsTRAP法 灰色系统理论 P-s-n曲线
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Study of neutron production and moderation for sulfur neutron capture therapy 被引量:2
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作者 Meng Peng Guo-Zhu He +3 位作者 Qi-Wei Zhang Bin Shi Hong-Qing Tang Zu-Ying Zhou 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第1期59-66,共8页
Neutron capture therapy with Sulfur-33, similar to boron neutron capture therapy with Boron-10, is effective in treating some types of tumors including ocular melanoma. The key point in sulfur neutron capture therapy ... Neutron capture therapy with Sulfur-33, similar to boron neutron capture therapy with Boron-10, is effective in treating some types of tumors including ocular melanoma. The key point in sulfur neutron capture therapy is whether the neutron beam flux and the resonance capture cross section of ^(33)S(n;α)^(30) Si reaction at 13.5 keV can achieve the requirements of radiotherapy. In this research,the authors investigated the production of 13.5 keV neutron production and moderation based on an accelerator neutron source. A lithium glass detector was used to measure the neutron flux produced via near threshold^7 Li(p,n)~7 Be reaction using the time-of-flight method. Furthermore, the moderation effects of different kinds of materials were investigated using Monte Carlo simulation. 展开更多
关键词 sULFUR nEUTROn CAPTURE THERAPY BOROn nEUTROn CAPTURE THERAPY 33s(n α)3 si resonance reaction 7Li(p n)^7 Be nEUTROn source
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The Effect of Tool Construction and Cutting Parameters on Surface Roughness and Vibration in Turning of AISI 1045 Steel Using Taguchi Method
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作者 Rogov Vladimir Aleksandrovich Ghorbani Siamak 《Modern Mechanical Engineering》 2014年第1期8-18,共11页
This paper presents an experimental investigation focused on identifying the effects of cutting conditions and tool construction on the surface roughness and natural frequency in turning of AISI1045 steel. Machining e... This paper presents an experimental investigation focused on identifying the effects of cutting conditions and tool construction on the surface roughness and natural frequency in turning of AISI1045 steel. Machining experiments were carried out at the lathe using carbide cutting insert coated with TiC and two forms of cutting tools made of AISI 5140 steel. Three levels for spindle speed, depth of cut, feed rate and tool overhang were chosen as cutting variables. The Taguchi method L9 orthogonal array was applied to design of experiment. By the help of signal-to-noise ratio and analysis of variance, it was concluded that spindle speed has the significant effect on the surface roughness, while tool overhang is the dominant factor affecting natural frequency for both cutting tools. In addition, the optimum cutting conditions for surface roughness and natural frequency were found at different levels. Finally, confirmation experiments were conducted to verify the effectiveness and efficiency of the Taguchi method in optimizing the cutting parameters for surface roughness and natural frequency. 展开更多
关键词 surface ROUGHnEss Cutting Condition natural Frequency VIBRATIOn TURnInG AnOVA Taguchi Method s/n Ratio
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Ultralong nitrogen/sulfur Co-doped carbon nano-hollowsphere chains with encapsulated cobalt nanoparticles for highly efficient oxygen electrocatalysis 被引量:8
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作者 Wei Zhang Xingmei Guo +6 位作者 Cong Li Jiang-Yan Xue Wan-Ying Xu Zheng Niu Hongwei Gu Carl Redshaw Jian-Ping Lang 《Carbon Energy》 SCIE CSCD 2023年第8期15-30,共16页
The development of simple and effective strategies to prepare electrocatalysts,which possess unique and stable structures comprised of metal/nonmetallic atoms for oxygen reduction reaction(ORR)and oxygen evolution rea... The development of simple and effective strategies to prepare electrocatalysts,which possess unique and stable structures comprised of metal/nonmetallic atoms for oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is currently an urgent issue.Herein,an efficient bifunctional electrocatalyst featured by ultralong N,S-doped carbon nano-hollow-sphere chains about 1300 nm with encapsulated Co nanoparticles(Co-CNHSCs)is developed.The multifunctional catalytic properties of Co together with the heteroatom-induced charge redistribution(i.e.,modulating the electronic structure of the active site)result in superior catalytic activities toward OER and ORR in alkaline media.The optimized catalyst Co-CNHSC-3 displays an outstanding electrocatalytic ability for ORR and OER,a high specific capacity of 1023.6 mAh gZn^(-1),and excellent reversibility after 80 h at 10mA cm^(-2)in a Zn-air battery system.This work presents a new strategy for the design and synthesis of efficient multifunctional carbon-based catalysts for energy storage and conversion devices. 展开更多
关键词 Co nanoparticles n s co-doping oxygen electrocatalysts rechargeable Zn-air batteries ultralong carbon nano-hollow-sphere chains
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From Nikolay Umov E=kmc^(2) via Albert Einstein’s E=γmc^(2) to the Dark Energy Density of the Cosmos E=(21 22)mc^(2)
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作者 Mohamed S.El Naschie 《World Journal of Mechanics》 2018年第4期73-81,共9页
The paper starts from the remarkable classical equation of the great nineteenth century Russian physicist Nikolay Umov E=kmc2 where 1/2&le;k&le;1, m is the mass, c is the speed of light and E is the equivalent... The paper starts from the remarkable classical equation of the great nineteenth century Russian physicist Nikolay Umov E=kmc2 where 1/2&le;k&le;1, m is the mass, c is the speed of light and E is the equivalent energy of m. After a short but deep discussion of the derivation of Umov we move to Einstein’s formula E=&gamma;mc2?where &gamma;is the Lorentz factor of special relativity and point out the interesting difference and similarity between Umov’s k and Lorentz-Einstein &gamma;. This is particularly considered in depth for the special case which leads to the famous equation?E=mc2?that is interpreted here to be the maximal cosmic energy density possible. Subsequently we discuss the dissection of E=mc2 into two components, namely the cosmic dark energy density E(D)=(21/22)MC2 and the ordinary energy density E(O)=MC2/22? where?E(D)+E(O)=MC2. Finally we move from this to the three-part dissection where we show that E is simply the sum of pure dark energy E(PD) plus dark matter energy E(DM) as well as ordinary energy E(O). 展开更多
关键词 n.Umov Energy A.Einstein Energy El naschie Energy Ordinary Cosmic Energy Cosmic Dark Energy F.Hasenohrl’s Electromagnetic Energy H.Poincaré History of special Relativity
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