2016年5月7日 · During a transition between allowed orbits an electron emits the extra energy in form of a photon of energy: E = hf where: h is a constant (Planck's Constant; f is the frequency. You can imagine this photon as a packet of energy bigger or smaller depending on the frequency: The higher the frequency the larger the energy. UV radiation has higher frequency than infrared so its energy (carried by ...

2017年6月6日 · Let r be radius of the lens. As such its area is =pir^2 W be average intensity of solar radiation reaching earth's surface P_(IR) be percent composition of Infrared energy (component responsible for generating heat) of W T be transmission coefficient or transmittance of lens material. A be absorption coefficient of the lens material. Assuming perpendicular incidence angle of light on the lens ...

2016年1月16日 · Here are just a few of the ways that spectroscopy is used in forensics. > Different techniques are often used on the same samples, because each method gives different information. Near-IR and Fourier Transform IR spectroscopy measurement of blood alcohol content analysis of drug, fibre, and paint samples visualization of bruises and bite marks on tissue detection of blood and explosives ...

2016年12月19日 · r selection is a method of rearing offspring with an emphasis on high growth rate and population increase (explanation shows comparison to K selection) r and K selection refer to the selection of the combination of traits in an organism relating to how they rear their offspring. r selection: emphasis on high growth rate and population increase many offspring short gestation can reproduce ...

2016年1月20日 · When cyclohexane is substituted by 2 heteroatoms, cis-trans isomerism, and optical isomerism ARE possible. Let's take a simple (achiral) example, 1,4-dihalocyclohexane, 1,4-X_2C_6H_10. The halogen atoms can be trans with respect to the plane of the ring, or cis , each on the same side of the ring. If the heteratoms are cis , then one heteroatom is in an axial position, whereas the other one is ...

2015年4月12日 · Yes they are. In fact real numbers refers to natural numbers(1,2,3,4...), integers(... -3, -2, -1, 0, 1, 2, 3), rational numbers(1/3, 5/6, 3/2) and irrational numbers ...

2018年5月17日 · The ventricles need Ventricles are more muscular because they must pump the blood farther than the atria. As shown in the diagram below, the blood from the ventricles does away from the heart to the lungs or to the body. Because they must pump the blood a great distance, often against gravity, they must be much more muscular than the atria. The atria receive the blood and push it through the ...

2016年3月3日 · If we try to calculate the limit directly, we can see that is an indeterminate form: lim x→0 x sinx = 0 sin0 = 0 0? To solve it, we can apply the L'Hôpital's rule: Given two functions f and g differentiable at x = a, it holds that: If lim x→a f (x) g(x) = 0 0 or lim x→a f (x) g(x) = ∞ ∞ then: lim x→a f (x) g(x) = lim x→a f '(x) g'(x) So we have: lim x→0 x sinx = lim x→0 1 ...

2015年4月13日 · We can write the derivative of this function in a ricorsive way. Ricorsive way means that also in the definition there is the concept of derivate! y^((1))=1*e^(2x)+x ...

2018年3月20日 · No. To be pure, a substance needs to have constant composition--this is the case for elements and compounds, but not for solutions. A solution is basically a homogenous mixture, and all mixtures are classified as impure substances with variable composition. :) Here’s a diagram to illustrate the compositional differences between pure substances and solutions: