全文获取类型
收费全文 | 93篇 |
免费 | 6篇 |
专业分类
化学工业 | 31篇 |
机械仪表 | 4篇 |
建筑科学 | 6篇 |
能源动力 | 4篇 |
轻工业 | 23篇 |
石油天然气 | 2篇 |
无线电 | 5篇 |
一般工业技术 | 10篇 |
冶金工业 | 5篇 |
自动化技术 | 9篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 8篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 9篇 |
2011年 | 2篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 3篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 2篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1994年 | 4篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1984年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有99条查询结果,搜索用时 15 毫秒
81.
Parametric analysis and yearly performance of a trigeneration system driven by solar‐dish collectors
Evangelos Bellos Sasa Pavlovic Velimir Stefanovic Christos Tzivanidis Branka B. Nakomcic‐Smaradgakis 《国际能源研究杂志》2019,43(4):1534-1546
Solar‐driven polygeneration systems are promising technologies for covering many energy demands with a renewable and sustainable way. The objective of the present work is the investigation of a trigeneration system, which is driven by solar‐dish collectors. The examined trigeneration system includes an organic Rankine cycle (ORC), which operates with toluene, and an absorption heat pump, which operates with LiBr/H2O. The absorption heat pump is fed with heat by the condenser of the ORC, which operates at medium temperature levels (120°C to 150°C). The absorption heat pump produces both useful heat at 55°C and cooling at 12°C. The ORC produces electricity, and it is fed by the solar dishes. The examined ORC is a regenerative cycle with superheating. The total analysis is performed with a developed model in Engineering Equation Solver (EES). The system is investigated parametrically for different ORC heat‐rejection temperatures, different superheating levels in the turbine inlet, and various solar‐beam irradiation levels. Furthermore, the system is investigated on a yearly basis for the climate conditions of Athens (Greece) and for Belgrade (Serbia). It is found that the yearly system energy and exergy efficiencies are 108.39% and 20.92%, respectively, for Athens, while 111.38% and 21.50%, respectively, for Belgrade. The values over 100% for the energy efficiency are explained by the existence of a heat pump in the examined configuration. For both locations, the payback period is found close to 10 years and the internal rate of return close to 10%. The final results indicate that the examined configuration is a highly efficient and viable system, which operates only with a renewable energy source. 相似文献
82.
Dunja Šamec Branimir Urlić Branka Salopek-Sondi 《Critical reviews in food science and nutrition》2019,59(15):2411-2422
ABSTRACTKale (Brassica oleracea var. acephala) is a cruciferous vegetable, characterized by leaves along the stem, which, in recent years, have gained a great popularity as a ´superfood´. Consequently, in a popular culture it is listed in many ´lists of the healthiest vegetables´. Without the doubt, a scientific evidences support the fact that cruciferous vegetables included in human diet can positively affect health and well-being, but remains unclear why kale is declared superior in comparison with other cruciferous. It is questionable if this statement about kale is triggered by scientific evidence or by some other factors. Our review aims to bring an overview of kale's botanical characteristics, agronomic requirements, contemporary and traditional use, macronutrient and phytochemical content and biological activity, in order to point out the reasons for tremendous kale popularity. 相似文献
83.
Svetlana Trifunovi Branka oi Jurjevi Nataa Risti Nataa Nestorovi Branko Filipovi Ivana Stevanovi Vesna Begovi-Kupreanin Milica Manojlovi-Stojanoski 《International journal of molecular sciences》2023,24(1)
As the mediator between the mother and fetus, the placenta allows the most appropriate environment and optimal fetal growth. The placenta of one sex sometimes has a greater ability over the other to respond to and protect against possible maternal insults. Here, we characterized sex differences in the placenta’s morphological features and antioxidant status following dexamethasone (Dx) exposure. Pregnant rats were exposed to Dx or saline. The placenta was histologically and stereologically analyzed. The activity of the antioxidant enzymes, lipid peroxides (TBARS), superoxide anion and nitric oxide (NO) was measured. The decrease in placental zone volumes was more pronounced (p < 0.05) in female placentas. The volume density of PCNA-immunopositive nuclei was reduced (p < 0.05) in both sexes. The reduced (p < 0.05) antioxidant enzyme activities, enhanced TBARS and NO concentration indicate that Dx exposure triggered oxidative stress in the placenta of both fetal sexes, albeit stronger in the placenta of female fetuses. In conclusion, maternal Dx treatment reduced the size and volume of placental zones, altered placental histomorphology, decreased cell proliferation and triggered oxidative stress; however, the placentas of female fetuses exerted more significant responses to the treatment effects. The reduced placental size most probably reduced the transport of nutrients and oxygen, thus resulting in the reduced weight of fetuses, similar in both sexes. The lesser ability of the male placenta to detect and react to maternal exposure to environmental challenges may lead to long-standing health effects. 相似文献
84.
Branka B. Radanov Srbislav B. Genić Branislav M. Jaćimović 《American Institute of Chemical Engineers》2016,62(7):2579-2584
This article presents the research results of direct contact condensation of steam on freely formed falling liquid jets. After the comparison of experimental data and open literature correlations it was concluded that published correlations does not provide accurate coverage of experimental data. A new correlation was established in the following form © 2016 American Institute of Chemical Engineers AIChE J, 62: 2579–2584, 2016 相似文献
85.
Branka Mihaljević Ivana Tartaro Nada Filipović Vinceković 《European Journal of Lipid Science and Technology》2012,114(11):1292-1303
The effect of molecular environment on the peroxidation of linoleic acid (LA), a polyunsaturated fatty acid (PUFA), initiated by ferrous ions was investigated in acidic and neutral pH conditions. Mixed nonionic surfactants TWEEN®‐20/LA micelles were established as a model system to obtain a surfactant‐in‐lipid aqueous system at high acidity level. The peroxidation of LA was induced by ferrous ions and the kinetics of the produced conjugated dienes was followed by UV measurements and the ferric thiocynate method. Ferrous ions were oxidized only by the preformed LA hydroperoxides, which under established conditions produced lipid alkoxyl and peroxyl radicals as the sole initiators of propagation. The results revealed the LA peroxidation process remained mainly unaffected within the 2.5<pH<5.5 range, while highly pH sensitive around pH 7. The propagation process prevailed at optimal concentrations of 500 µM of LA and 280 µM TWEEN®‐20, and at the ferrous ion concentration up to 75 µM, irrespective of the buffer used. Practical applications: A simple model system in water, suitable for the selective study of the lipid peroxidation propagation phase induced by ferrous ion is presented here. Fatty acids serve as model compounds susceptible to processes associated with oxidative radical initiated‐modifications of lipids. The obtained results contribute to a better understanding of the oxidative behavior of lipids, particularly those soluble in nonionic surfactant micelles in acidic medium. The oxidative stability of the PUFA in model systems containing TWEEN®‐20 and ferrous ion at low pH could be predicted and controlled by measuring the lipid hydroperoxide formation. The experimental conditions presented may also provide a suitable system for the study of the termination phase of lipid peroxidation. 相似文献
86.
Branka Mušič Miha Drofenik Peter Venturini Andrej Žnidaršič 《Ceramics International》2012,38(4):2693-2699
We have investigated an organic resin solution designed for EM wave absorption based on a magnetic filler, composed of phases within the Mn0.66Zn0.27Fe2.07O4 system, embedded in an absorber composite with concentration ratios of 50:50, 75:25 and 90:10 by weight. The formation of the manganese zinc ferrite particles, as the principal magnetic phases, was achieved via the conventional ceramic method. The electromagnetic parameters of the composites were measured with a vector network analyser at 100 MHz to 10 GHz. The subject of the paper was a study of the electromagnetic absorber properties and the rheological properties of the resin composite based on ferrite particles with respect to using the materials in architectural coatings. 相似文献
87.
Franc F. Barbi
Dragomir M. Bracilovi
Miodrag V. Djindji
Svetozar M. Djorelijevski Jordan S. Zivkovi
Branka V. Krajin
ani
《Water research》1974,8(11):895-898
From an examination of water samples and of relevant plates (glass and metal ones) in the water of Ranney wells, iron and manganese bacteria have been studied. 相似文献
88.
Sandra Radi? Dra?enka Stipani?ev Marija Marijanovi? Raj?i? Branka Pevalek-Kozlina 《The Science of the total environment》2010,408(5):1228-20
Screening for mutagens in complex environmental mixtures, such as surface water or industrial wastewater, is gradually being accepted as a routine method in environmental monitoring programs. In the present work, the simplified Alliumcepa root assay was utilized to evaluate the possible cyto- and genotoxic effects of surface and wastewaters collected near the Sava River (Croatia) over a three-month monitoring period. Physicochemical characterization of the water samples included measurements of conductivity, chemical and biological oxygen demand, levels of suspended matter and salts, nitrate, nitrite, ammonium, total nitrogen and total phosphorus. Morphological modifications of the A. cepa roots, inhibition of root growth, cell division and induction of mitotic and chromosomal aberrations were observed. The most highly polluted water samples (industrial effluents) caused an inhibition of root growth of over 50%, a decrease in the mitotic index of over 40%, and a considerable increase in chromosomal aberrations compared to the control. The measured biological effects of some water samples appeared related to the physicochemical characteristics. Therefore, mutagenicity/genotoxicity assays should be included, along with conventional chemical analysis, in water quality monitoring programs. Their use would allow the quantification of mutagenic hazards in surface and wastewaters. 相似文献
89.
Increasingly, spread spectrum systems are being proposed which support a range of data rates and traffic types in a band limited
environment. One way to achieve a range of data rates with fixed bandwidth is to allow the use of different processing gains.
If the range of data rates supported is large, the lower bound on the processing gain can become quite small. Receivers based
on LMMSE algorithms offer high efficiency for CDMA systems through interference suppression, however at small processing gains,
the sequence set correlation properties prove to be a significant limitation on the system efficiency. This paper provides
examples of sets of short length spreading sequences which have good auto-correlation (AC) and cross-correlation (CC) properties
which are essential to allow relatively high system efficiency. A CDMA system using an LMMSE receiver is examined with selected
short length sets to demonstrate the application of the sequences. The sets proposed are compared to system performance when
using well known sequence families.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
90.
Adhesion of topcoats to a variety of painted thermoplastic olefin (TPO) substrates, varying in the ratio of poly(propylene) to elastomer components, was determined in the presence of gasoline. Adhesion to TPO substrates was achieved through the use of chlorinated polyolefin (CPO) adhesion promoters. The adhesion promoter utilized in this study was a solventborne thermoplastic CPO, the penetration of which into the TPO substrate was monitored through the use of fluorescent tagging and subsequent optical microscopy. The topcoats utilized consisted of both one-component (1K) melamine crosslinked systems as well as two-component (2K) isocyanate crosslinked systems. Ultimate adhesion of the coatings in the presence of gasoline was found to be directly proportional to the depth of the CPO adhesion promoter diffusion into the substrate as well as the resistance of the clearcoat to gasoline permeation. Methods of analysis and supporting data are presented. 相似文献