全文获取类型
收费全文 | 215篇 |
免费 | 13篇 |
专业分类
化学工业 | 79篇 |
金属工艺 | 3篇 |
机械仪表 | 5篇 |
建筑科学 | 8篇 |
能源动力 | 10篇 |
轻工业 | 52篇 |
水利工程 | 2篇 |
石油天然气 | 1篇 |
无线电 | 9篇 |
一般工业技术 | 37篇 |
冶金工业 | 4篇 |
自动化技术 | 18篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 8篇 |
2021年 | 10篇 |
2020年 | 12篇 |
2019年 | 9篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 7篇 |
2013年 | 17篇 |
2012年 | 11篇 |
2011年 | 25篇 |
2010年 | 21篇 |
2009年 | 13篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1997年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有228条查询结果,搜索用时 15 毫秒
1.
Ozlem Ozgun Gökhan Apaydin Mustafa Kuzuoglu Levent Sevgi 《Computer Physics Communications》2011,182(12):2638-2654
A MATLAB-based one-way and two-way split-step parabolic equation software tool (PETOOL) has been developed with a user-friendly graphical user interface (GUI) for the analysis and visualization of radio-wave propagation over variable terrain and through homogeneous and inhomogeneous atmosphere. The tool has a unique feature over existing one-way parabolic equation (PE)-based codes, because it utilizes the two-way split-step parabolic equation (SSPE) approach with wide-angle propagator, which is a recursive forward–backward algorithm to incorporate both forward and backward waves into the solution in the presence of variable terrain. First, the formulation of the classical one-way SSPE and the relatively-novel two-way SSPE is presented, with particular emphasis on their capabilities and the limitations. Next, the structure and the GUI capabilities of the PETOOL software tool are discussed in detail. The calibration of PETOOL is performed and demonstrated via analytical comparisons and/or representative canonical tests performed against the Geometric Optic (GO) + Uniform Theory of Diffraction (UTD). The tool can be used for research and/or educational purposes to investigate the effects of a variety of user-defined terrain and range-dependent refractivity profiles in electromagnetic wave propagation.
Program summary
Program title: PETOOL (Parabolic Equation Toolbox)Catalogue identifier: AEJS_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJS_v1_0.htmlProgram obtainable from: CPC Program Library, Queen?s University, Belfast, N. IrelandLicensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.htmlNo. of lines in distributed program, including test data, etc.: 143 349No. of bytes in distributed program, including test data, etc.: 23 280 251Distribution format: tar.gzProgramming language: MATLAB (MathWorks Inc.) 2010a. Partial Differential Toolbox and Curve Fitting Toolbox requiredComputer: PCOperating system: Windows XP and VistaClassification: 10Nature of problem: Simulation of radio-wave propagation over variable terrain on the Earth?s surface, and through homogeneous and inhomogeneous atmosphere.Solution method: The program implements one-way and two-way Split-Step Parabolic Equation (SSPE) algorithm, with wide-angle propagator. The SSPE is, in general, an initial-value problem starting from a reference range (typically from an antenna), and marching out in range by obtaining the field along the vertical direction at each range step, through the use of step-by-step Fourier transformations. The two-way algorithm incorporates the backward-propagating waves into the standard one-way SSPE by utilizing an iterative forward–backward scheme for modeling multipath effects over a staircase-approximated terrain.Unusual features: This is the first software package implementing a recursive forward–backward SSPE algorithm to account for the multipath effects during radio-wave propagation, and enabling the user to easily analyze and visualize the results of the two-way propagation with GUI capabilities.Running time: Problem dependent. Typically, it is about 1.5 ms (for conducting ground) and 4 ms (for lossy ground) per range step for a vertical field profile of vector length 1500, on Intel Core 2 Duo 1.6 GHz with 2 GB RAM under Windows Vista. 相似文献2.
Ayfer Sarac Dolunay Şakar Ozlem Cankurtaran Ferdane Yılmaz Karaman 《Polymer Bulletin》2005,53(5-6):349-357
Summary The retention diagrams of benzene, toluene, ethyl benzene, chloro benzene, n-propyl benzene, isopropyl benzene, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate and isoamyl acetate on the polycaprolactone were plotted at temperatures between 70 and 140oC by inverse gas chromatography technique. Percent crystallinity of polycaprolactone were obtained at temperatures below melting point from the retention diagrams of benzene, toluene and ethyl benzene. It was concluded that the data obtained by inverse gas chromatography were comparable those of obtained by differential scanning calorimetry. Specific retention volume, Vgo, Flory-Huggins polymer-solvent interaction parameters, 12, the weight fraction activity coefficients of the solvents at infinite dilution, 1, effective exchange energy parameters, Xeff were determined. Later, the partial molar heat of sorption, H1,sorp and the partial molar heat of mixing, H1 were obtained from the slope of the logarithm of specific retention volume, Ln Vgo versus 1/T plot and from the slope of the logarithm of the weight fraction activity coefficients, 1versus 1/T plot, respectively. 相似文献
3.
4.
Ozlem Karahan Ozgun Bertan Basak Ceren Eropak Seda Abat Gamze Kirim Emine Girgin Asude Hanedar Elcin Gunes Ercan Citil Erdem Görgün Cigdem Yangin Gomec Fatos Germirli Babuna Suleyman Ovez Aysegul Tanik Izzet Ozturk Cumali Kinaci Yakup Karaaslan Sibel Mine Gucver Esra Siltu Aybala Koc Orhon 《Clean Technologies and Environmental Policy》2017,19(1):105-122
Monitoring and control of dangerous substances discharged into receiving waters have attracted more attention lately. Since it is not possible to analyze every single substance, a prioritization methodology is needed for the selection of those to be monitored. Existing well-developed models require significant amount of data for reliable outcomes. This paper presents a methodology to prioritize the dangerous substances having adverse effects on freshwaters in Turkey, where data are scarce. Such a methodology will also serve as a solid model for other countries with limited background data. The adopted methodology enabled the elimination of chemicals to generate a candidate list composed of 608 substances among more than 5000 substances. Further screening and prioritization were conducted using different assessment methods (i.e., Total Hazard Value, Total Impact Value, Combined Monitoring-based, and Modelling-based Priority Setting) to obtain a proposed Final Candidate Specific Pollutants List of 150 dangerous substances. The proposed Candidate National Pollutant List of Turkey was established by combining 45 priority pollutants of the European Union with a list of candidate specific pollutants. According to the outcomes of this study, monitoring and controlling of 195 dangerous substances in freshwaters are recommended. Further detailed studies should be conducted in order to observe the actual levels of these dangerous substances in freshwaters followed by a review of the monitoring list accordingly. Moreover, further revisions might be required in the proposed list due to some possible versatile conditions in terms of sampling points (i.e., change in the location of industries). 相似文献
5.
Elke Knapen Ozlem Cizer Koenraad Van Balen Dionys Van Gemert 《Construction and Building Materials》2009,23(11):3431-3438
In order to follow the progress of cement hydration by analytical techniques, the ongoing hydration reactions must be stopped by complete removal of free water. A comparison between solvent exchange, oven drying and vacuum drying, using thermal analysis, is presented for early-age hydrated cement pastes. Results show that oven drying at 105 °C accelerates hydration, causes dehydration of some hydrated cement phases and favours carbonation. Solvent exchange with ethanol, ether and methanol results in a strong absorption and an incomplete removal of solvents. FT-IR and XRD gave evidence of the formation of carbonate-like phases due to an interaction upon heating, i.e. during thermal analysis, between the strongly absorbed solvents and the cement compounds or hydrates. Vacuum drying reveals reliable results as no interaction products can be formed and the Ca(OH)2 content, determined by thermal analysis, gives a good approximation of the real amount of Ca(OH)2. 相似文献
6.
The effects of modified atmosphere gas composition on microbiological criteria, color and oxidation values of minced beef meat 总被引:4,自引:0,他引:4
This paper reports the effects of modified atmosphere gas compositions with different concentrations of CO(2)/O(2)/N(2) on color properties (L*, a* and b* values), oxidation stability (TBARS value) and microbiological properties of minced beef meat stored at +4 °C. Sampling was carried out on the 1st, 3rd, 5th, 7th, 9th, 11th and 14th day of storage. The gas mixtures used were as follows: (i) %30O(2) + %70CO(2) (MAP1), (ii) %50O(2) + %50CO(2) (MAP2), (iii) %70O(2) + %30CO(2) (MAP3), (iv) %50O(2) + %30CO(2) + %20N(2) (MAP4), and (v) %30O(2) + %30CO(2) + %40N(2) (MAP5). Control samples (AP) were packaged under atmospheric air. Pseudomonas, lactic acid bacteria, Brochothrix thermosphacta, and Enterobacteriaceae members were monitored. Among these five modified atmosphere gas compositions, the best preservation for minced beef meat was in MAP4 gas combination maintaining acceptable color together with oxidation stability and acceptable microbial loads until the end of storage period of fourteen days. 相似文献
7.
Ozlem Yildiz Johannes Schroth Vittoria Lombardi Valentina Pucino Yoana Bobeva Ping Kei Yip Klaus Schmierer Claudio Mauro Timothy Tree Sian Mari Henson Andrea Malaspina 《International journal of molecular sciences》2022,23(6)
Monocytes expressing the inflammation suppressing active CD11b, a beta2 integrin, may regulate neuroinflammation and modify clinical outcomes in amyotrophic lateral sclerosis (ALS). In this single site, retrospective study, peripheral blood mononuclear cells from 38 individuals living with ALS and 20 non-neurological controls (NNC) were investigated using flow cytometry to study active CD11b integrin classical (CM), intermediate (IM) and non-classical (NCM) monocytes during ALS progression. Seventeen ALS participants were sampled at the baseline (V1) and at two additional time points (V2 and V3) for longitudinal analysis. Active CD11b+ CM frequencies increased steeply between the baseline and V3 (ANOVA repeated measurement, p < 0.001), and the V2/V1 ratio negatively correlated with the disease progression rate, similar to higher frequencies of active CD11b+ NCM at the baseline (R = −0.6567; p = 0.0031 and R = 0.3862; p = 0.0168, respectively). CD11b NCM, clinical covariates and neurofilament light-chain plasma concentration at the baseline predicted shorter survival in a multivariable and univariate analysis (CD11b NCM—HR: 1.05, CI: 1.01–1.11, p = 0.013. Log rank: above median: 43 months and below median: 21.22 months; p = 0.0022). Blood samples with the highest frequencies of active CD11b+ IM and NCM contained the lowest concentrations of soluble CD11b. Our preliminary data suggest that the levels of active CD11b+ monocytes and NCM in the blood predict different clinical outcomes in ALS. 相似文献
8.
Thermally exfoliated graphene oxide reinforced fluorinated pentablock poly(l‐lactide‐co‐ε‐caprolactone) electrospun scaffolds: Insight into antimicrobial activity and biodegradation 下载免费PDF全文
Burcu Saner Okan Azucena Marset Jamal Seyyed Monfared Zanjani Pınar Akkus Sut Ozlem Sen Mustafa Çulha Yusuf Menceloglu 《应用聚合物科学杂志》2016,133(22)
Three‐dimensional fluorinated pentablock poly(l ‐lactide‐co‐ε‐caprolactone)‐based scaffolds were successfully produced by the incorporation of thermally exfoliated graphene oxide (TEGO) as an antimicrobial agent with an electrospinning technique. In a ring‐opening polymerization, the fluorinated groups in the middle of polymer backbone were attached with a perfluorinated reactive stabilizer having oxygen‐carrying ability. The fiber diameter and its morphologies were optimized through changes in TEGO amount, voltage, polymer concentration, and solvent type to obtain an ideal scaffold structure. Instead of the widely used graphene oxide synthesized by Hummer's method, TEGO sheets having a low amount of oxygen produced by thermal expansion were integrated into the fiber structure to investigate the effect of the oxygen functional groups of TEGO sheets on the degradation and antimicrobial activity of the scaffolds. There was no antimicrobial activity in TEGO‐reinforced scaffolds in the in vitro tests in contrast to the literature. This study confirmed that a low number of oxygen functional groups on the surface of TEGO restricted the antimicrobial activity of the fabricated composite scaffolds. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43490. 相似文献
9.
Emrah Sefik Abamor Ozlem Ayse Tosyali Melahat Bagirova Adil Allahverdiyev 《IET nanobiotechnology / IET》2018,12(8):1018
This study is the first to investigate the antileishmanial activities of Nigella sativa oil (NSO) entrapped poly‐ɛ ‐caprolactone (PCL) nanoparticles on Leishmania infantum promastigotes and amastigotes in vitro. NSO molecules with variable initial doses of 50, 100, 150, and 200 mg were successfully encapsulated into PCL nanoparticles identified as formulations NSO1, NSO2, NSO3, and NSO4, respectively. This process was characterised by scanning electron microscope, dynamic light scattering, Fourier transform infrared, encapsulation efficiency measurements, and release profile evaluations. The resulting synthetised nanoparticles had sizes ranging between 200 and 390 nm. PCL nanoparticles encapsulated 98% to 80% of initial doses of NSO and after incubation released approximately 85% of entrapped oil molecules after 288 h. All investigated formulations demonstrated strong antileishmanial effects on L. infantum promastigotes by inhibiting up to 90% of parasites after 192 h. The tested formulations decreased infection indexes of macrophages in a range between 2.4‐ and 4.1‐fold in contrast to control, thus indicating the strong anti‐amastigote activities of NSO encapsulated PCL nanoparticles. Furthermore, NSO‐loaded PCL nanoparticles showed immunomodulatory effects by increasing produced nitric oxide amounts within macrophages by 2–3.5‐fold in contrast to use of free oil. The obtained data showed significant antileishmanial effects of NSO encapsulated PCL nanoparticles on L. infantum promastigotes and amastigotes.Inspec keywords: antibacterial activity, drug delivery systems, nanofabrication, nitrogen compounds, nanomedicine, microorganisms, cellular biophysics, diseases, scanning electron microscopy, oils, polymers, biomedical materials, nanoparticles, encapsulation, Fourier transform infrared spectraOther keywords: encapsulation efficiency measurements, entrapped oil molecules, investigated formulations, NSO‐loaded PCL nanoparticles, Nigella sativa oil entrapped polycaprolactone nanoparticles, antileishmanial activities, poly‐ε‐caprolactone nanoparticles, scanning electron microscope, DLS, Fourier transform infrared, release profile evaluations, Leishmania infantum promastigotes, Leishmania infantum amastigotes, parasites, infection, infection indexes, macrophages, immunomodulatory effects, time 288.0 hour, time 192.0 hour, mass 50.0 mg, mass 100.0 mg, mass 150.0 mg, mass 200.0 mg, size 200.0 nm to 390.0 nm 相似文献
10.
Effectiveness of phase I applications for identifying randomly scattered out‐of‐control observations and estimating control chart parameters 下载免费PDF全文
Murat Caner Testik Christian H. Weiß Yesim Koca Ozlem Muge Testik 《Quality and Reliability Engineering International》2018,34(1):78-92
Estimation of unknown process parameters with fixed‐size samples are studied in the following. The standard textbook approach for phase I control chart implementation with a Shewhart control chart is evaluated for the case of normally distributed independent observations with random sampling. The charts are simultaneously implemented by generating observations that have a given percentage of randomly scattered out‐of‐control observations. Simulating the phase I steps, where out‐of‐control samples are detected iteratively by determining trial control limits, identifying samples exceeding these limits, and revising the control limits, the standard practice is evaluated in terms of both detection performance and quality of parameter estimates. It is shown that standard phase I control chart implementations with 3‐σ‐limits may perform very poorly in identifying true out‐of‐control observations and providing a reference set of in‐control observations for estimation in some practical settings. A chart design with 2‐σ‐limits is recommended for a successful phase I analysis. 相似文献