桔梗种子成熟与主要气象要素的关系     

张卓  吴基日  严一字  吴松权  牛艳凯 《东北林业大学学报》2007,35(1):86-87

在桔梗开花期,计算桔梗开花后每5 d的千粒质量和成熟度的增长量,分析桔梗种子成熟度与主要气象要素之间的关系。结果表明:在吉林省桔梗种子要完全成熟,开花后需要55 d以上的时间;种子成熟与主要气象要素之间没有显著的相关性,种子成熟主要受桔梗本身发育规律支配。  相似文献   

Polyphenolic Compounds and Antioxidant Activity in Berries of Four Russian Cultivars of Lonicera kamtschatica (Sevast.) Pojark     

Tunde Jurikova  Jiri Sochor  Jiri Mlcek  Stefan Balla  Sezai Ercisli  Luba Durisova  Jindrich Kynicky 《Erwerbs-Obstbau》2014,56(4):117-122

Nowadays increasing attention has been focused on polyphenolic compounds as the main representants of antioxidants in horticultural crops including fruits. The edible honeysuckle has an unique position among lesser known fruits due to its high level of antioxidants. In the present study we determined polyphenolic profile and antioxidant capacity of four Russian cultivars of edible honeysuckle including ‘Gerda 25’, ‘Amfora’, ‘Morena’, ‘Lipnicka’, which found together in a single location in Mendel University in Brno, The Czech Republic. Polyphenolic compounds were detected by high performance liquid chromatography coupled with electrochemical detector (HPLC-ED). The antioxidant capacity was measured by DPPH test. According to the results there were differences among cultivars in terms of polyphenolic content and antioxidant activity and Lonicera kamtschatica ‘Gerda 25’ were found to be possessed the highest content of phenolic compounds corresponding to the highest value of antioxidant activity.  相似文献   

Kinematic Viscosity and Shear Stress of Used Engine Oil     

Vojtech Kumbar  Petr Dostal  Jiri Votava 《农业科学与技术》2013,(12):982-988

The goal of this paper describes kinematic viscosity and shear stress of two used engine oils, which have been taken from two different passenger cars. Kinematic viscosity and shear stress are two of the most important physical behaviours of fluids, especially lubricating fluids. In this paper the authors have focused on engine oil. Knowledge of these properties of engine oil is very important due to its lifetime. The experiments have been done using digital rotary rheometer Anton Paar DV-3 P with use of TR8 spindle and special adapter for a small amount of sample （20 mL）. Two different engine oils have been observed--first from passenger car Renault Scenic with petrol engine （engine capacity 1.6 dm3） and the second from passenger car Skoda Roomster with diesel engine （engine capacity 1.4 dm3）. Castrol Magnatec 10W-40 engine oil has been taken from Renault car and Shell Helix Ultra Extra 5W-30 engine oil has been taken from ~koda car. Service interval of change oil has been set to 15,000 km and samples of used engine oils have been taken after 1,500 km. Only first samples of used engine oils have been taken after raid of 20 km. All samples of used engine oils have been compared with new （unused） engine oils same specification. The measured values of kinematic viscosity and shear stress have been modeled using linear function. The coefficients of correlation R have been achieved high values （0.88-0.96）. The obtained models can be used to prediction of engine oil flow behaviour.  相似文献   

The effect of fish size and stocking density on the weaning success of pond-cultured pikeperch Sander lucioperca L. juveniles     

Tomas Policar  Vlastimil Stejskal  Jiri Kristan  Peter Podhorec  Viktor Svinger  Martin Blaha 《Aquaculture International》2013,21(4):869-882

The effect of initial fish size (small with TL = 40.3 ± 2.3 mm and W = 0.42 ± 0.15 g, medium with TL = 56.2 ± 2.7 mm and W = 1.66 ± 0.4 g, and big with TL = 71.0 ± 3.2 mm and W = 2.95 ± 0.65 g) and stocking density of identical fish with TL = 40.3 ± 2.3 mm and W = 0.42 ± 0.15 g (1; 2; 4; 8 fish l^?1) on weaning success was evaluated in pond-cultured pikeperch. The trial was divided into weaning (12 days) and post-weaning (16 days) periods. Small juveniles reached significantly higher specific growth rate (SGR = 1.6 ± 0.2 % day^?1) and survival rate (S = 81.7 ± 2.7 %) and lower cannibalism (C = 3.0 ± 0.75 %) compared to medium and large juveniles (SGR = 0.3–0.5 % day^?1, S = 65.3–76.5 %, C = 6.5–7.5 %) during the weaning period. The higher survival rate was found at the two higher densities (S = 72.0–79.1 %) during the weaning period. The lowest survival rate (S = 38.9 ± 2.7) was observed at the lowest fish density. Fish stocking density did not affect growth, condition, or cannibalism rate during the weaning period. Similar trends of growth, survival, and cannibalism of weaned juveniles were observed during the post-weaning period. A mass weaning trial verified experimental results showing small pikeperch juveniles to reach satisfactory growth rate (SGR = 1.4 ± 0.1 and 7.2 ± 0.2 % day^?1), survival (S = 78.7 ± 3.0 % and 97.6 ± 1.0 %), and cannibalism (C = 4.0 ± 1.5 % and 2.5 ± 1.0 %) rates during the weaning and post-weaning periods. No body or fin deformities of weaned juveniles were observed.  相似文献   

Thermo-acoustic behaviour of 3D knitted spacer fabrics     

Veerakumar Arumugam  Rajesh Mishra  Jiri Militky  Jan Novak 《Fibers and Polymers》2015,16(11):2467-2476

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Investigation of mechanical properties of basalt woven fabrics by theoretical and image analysis methods     

Rajesh Mishra  Hafsa Jamshaid  Jiri Militky 《Fibers and Polymers》2017,18(7):1369-1381

This paper explains a study conducted to evaluate mechanical properties of woven structures of basalt. The mechanical properties like shear strength and tensile strength were studied. Tensile properties of basalt hybrid and non-hybrid fabrics are predicted by computational tool and verified with experimental data. The shear strength was investigated by using picture frame fixture. The tests were recorded by a CCD monochrome camera during displacement of specimen at various positions. The images were used for image analysis program developed in MATLAB. The results of image analysis were compared with the actual experimental results. The results illustrate that the mechanical properties of fabrics experience a marked improvement when hybridization of basalt with polyester and polypropylene in different sets of weaves takes place. These findings are important requirements for using such fabrics for high-tech applications and composite forming.  相似文献   

Basalt nanoparticle reinforced hybrid woven composites: Mechanical and thermo-mechanical performance     

Rajesh Mishra  Hafsa Jamshaid  Jiri Militky 《Fibers and Polymers》2017,18(12):2433-2442

Nanoparticles are gaining wider importance and increasing utility in many areas of engineering and technology. This investigative work is conducted to study the effect of incorporating basalt nano particles in composites with basalt/basalt and basalt/jute woven structures as reinforcement. The nanoparticles were developed from basalt, they were characterized and used for reinforcing composites of basalt and jute hybrid fabrics. The mechanical and thermo-mechanical properties of hybrid woven basalt reinforced epoxy composites were evaluated. Microscopic examination was carried out in order to analyze the internal structure and fractured surfaces. Interfacial characteristics, material morphology and failure was studied by use of Scanning Electron Microscope (SEM) and optical microscopy. Thermal stability was characterized by TGA. The results elaborated that the incorporation of basalt nanoparticles exhibited superior properties compared to the pure epoxy resin impregnated basalt fabric reinforced composites in terms of mechanical and thermal stability.  相似文献   

Egg oxidation status,antioxidant enzyme activities,lipid classes,fatty acid composition profile and embryo survival rates during in vitro oocyte ageing in tench Tinca tinca (Linnaeus, 1758)          下载免费PDF全文

Azadeh Mohagheghi Samarin  Sabine Sampels  Anna Krzyskow  Viktoriia Burkina  Jiri Kristan  David Gela  Martin Flajshans  Tomas Policar  Azin Mohagheghi Samarin 《Aquaculture Research》2018,49(6):2305-2316

The effect of in vitro storage of oocytes on embryos survival rate, egg oxidation status, antioxidant enzyme activities, lipid classes and fatty acid composition profile was investigated in common tench Tinca tinca. In order to identify the role of oxidative stress in the progress of oocyte ageing the levels of thiobarbituric acid reactive substances (TBARS) and carbonyls as indicators of lipid and protein oxidation were measured and the activity of antioxidant enzymes were examined. Stripped ova from six females were stored in cell culture plates at 20°C for up to 10 hr post‐stripping (HPS). The stored ova were fertilized and the embryo survival rates were assessed. The results indicated that tench eggs could be successfully stored in vitro for 4 hr after stripping at 20°C. Superoxide dismutase enzyme activity increased at 6 HPS, whereas glutathione peroxidase and glutathione reductase activities decreased in oocytes during in vitro storage (p < .05) at 4 and 8 HPSs, respectively. The level of malondialdehyde did not show any significant changes during the progress of oocyte ageing. Carbonyls increased up to 2 HPS and thereafter decreased significantly. However, ova ageing did not affect the main lipid class composition and the fatty acid composition of the eggs. Lower quality eggs exhibited lower levels of cholesterol but higher levels of triacylglycerol.  相似文献   

Breeding for value in a changing world: past achievements and future prospects     

Tim White  John Davis  Salvador Gezan  Jiri Hulcr  Eric Jokela  Matias Kirst  Timothy A. Martin  Gary Peter  Greg Powell  Jason Smith 《New Forests》2014,45(3):301-309

Large-scale tree improvement programs began in the 1950s. Tree improvement is now part of operational silviculture programs in many companies and countries around the world and tree breeding programs have produced very impressive results: (1) realized gains in plantations being established today of some 40–50 % in volume yield above unimproved material for many programs; (2) increased efficiencies in all aspects of breeding, selection, testing and deployment; and (3) a shortening of the generation interval by a factor of two from approximately 30 years in the first generation to less than 15 years today for pine programs. What about the future? What should tree breeders be thinking, planning and doing to ensure that results 60 years from now are even more impressive than those from the previous 60 years? Tree breeders today live in a rapidly changing world faced with: increasing demands for food, energy and water; globalization leading to an interconnectedness of markets and rapid spread of exotic organisms; climate change and its implications for genetic deployment; burgeoning technology in robotics, communications and molecular tools; shifting ownership patterns of forest land; and the real possibility of completely new forest products and markets in the future. Three ideas for “Breeding for Value in a Changing World” are: (1) adopt a robust philosophy that aims to ensure maximum value produced per ha even in a future world that will be quite different; (2) embrace technology at every phase in the tree improvement process; and (3) encourage interdisciplinary teams of scientists to solve complex problems that require expertise ranging from molecular to landscape scales.  相似文献   

Photoproduction of proton gradients with pi-stacked fluorophore scaffolds in lipid bilayers     

Bhosale S  Sisson AL  Talukdar P  Fürstenberg A  Banerji N  Vauthey E  Bollot G  Mareda J  Röger C  Würthner F  Sakai N  Matile S 《Science (New York, N.Y.)》2006,313(5783):84-86

Rigid p-octiphenyl rods were used to create helical tetrameric pi-stacks of blue, red-fluorescent naphthalene diimides that can span lipid bilayer membranes. In lipid vesicles containing quinone as electron acceptors and surrounded by ethylenediaminetetraacetic acid as hole acceptors, transmembrane proton gradients arose through quinone reduction upon excitation with visible light. Quantitative ultrafast and relatively long-lived charge separation was confirmed as the origin of photosynthetic activity by femtosecond fluorescence and transient absorption spectroscopy. Supramolecular self-organization was essential in that photoactivity was lost upon rod shortening (from p-octiphenyl to biphenyl) and chromophore expansion (from naphthalene diimide to perylene diimide). Ligand intercalation transformed the photoactive scaffolds into ion channels.  相似文献