排序方式: 共有65条查询结果,搜索用时 477 毫秒
1.
Hari Prasad 《Resonance》2002,7(12):48-64
Berzelius, the Swedish chemist in 1807 introduced the term ‘organic compounds’ as those substances derived from once living
organisms (organized systems). Carbon exhibits the property of catenation (formation of chains) and forms a plethora of compounds
on earth. Silicon on the other hand which is placed below carbon in the periodic table does not exhibit this property. This
article is a brief account of some of the several reagents and classes of compounds encountered in organosilicon chemistry. 相似文献
2.
T R Shankar Raman 《Resonance》1996,1(7):52-61
Deer are some of the commonest, most visible, and attractive mammals in many forests and grasslands of India. They display a fascinating variety in their antlers, social systems, herd-forming behaviour, and ecology. Unfortunately, several factors have brought some species to the brink of extinction today. 相似文献
3.
4.
Priti Shankar 《Resonance》1996,1(10):26-36
Linear algebraic codes are an elegant illustration of the power of Algebra. We introduce linear codes, and try to explain how the structure present in these codes permits easy implementation of encoding and decoding schemes. 相似文献
5.
6.
An accurate measurement of force and biomechanical energy that people can impart through kicking is useful for kick-related sports training. Existing methods are indirect measurements or focus on force and not on the total energy of the kick. A kick test rig was designed, constructed and instrumented to measure the force and displacement of a vertical target subjected to kicking. The kick energy was calculated from the recorded force and displacement histories. The methodology for measurement of kick force and energy was validated by an open stance front kick test by 52 volunteers. The results showed that 67% of the participants could achieve an average energy above 100 J. An increasing trend of kick energy with increasing body weight of participant was observed. The participant’s gender had a strong influence on the kick energy, while training in martial arts does not appear to be a significant parameter. A probability analysis showed that one in one hundred adults will be able to kick with energies exceeding 215 J. 相似文献
7.
In our previous article ‘On observing the night sky’1 we had introduced the reader to the stars and constellations and suggested how they may be observed. In this article we will
provide a few technical details, which we had deliberately left out earlier and also introduce the reader to a number of the
other remarkable objects that may be seen in the sky. 相似文献
8.
Plant Growth Promoting Rhizobacteria 总被引:1,自引:0,他引:1
Jay Shankar Singh 《Resonance》2013,18(3):275-281
Plant Growth Promoting Rhizobacteria (PGPR) are a group of bacteria that enhances plant growth and yield via various plant growth promoting substances as well as biofertilizers. Given the negative environmental impact of artificial fertilizers and their increasing costs, the use of beneficial soil microorganisms such as PGPR for sustainable and safe agriculture has increased globally during the last couple of decades. PGPR as biofertilizers are well recognized as efficient soil microbes for sustainable agriculture and hold great promise in the improvement of agriculture yields. 相似文献
9.
In 1904, Prandtl proposed the concept of boundary layers that revolutionised the study of fluid mechanics. In this article we present the basic ideas of boundary layers and boundary-layer separation, a phenomenon that distinguishes streamlined from bluff bodies. 相似文献
10.