The rate equations may be written heuristically by considering various physical phenomena through which the number of photons, p, and the number of electrons, n, change with time inside the active region. for a single-mode laser, these equations take the form -gp+r dt sp dn i n g is the net rate of stimulated emission and rsp is the rate of spontaneous emission into the lasing mode. note that rsp is much smaller than the total spontaneous-emission rate. τ.is the lifetime of carrier and tp is the lifetime of photon. (a) the modulation response of semiconductor lasers is studied by solving the rate equations provide in the above with a time-dependent current of the form where ib is the bias current, im is the current amplitude, and ω represents the angular frequency of the modulating current. determine the response of the semiconductor laser and 3-db bandwidth. (b) the system of differential equations for a small perturbation δ n in the carrier and δ p in photons densities constitute a second order linear system much like the equations for the current and the voltage in an lcr circuit. solve the second order differential equation and determine the relaxation frequency. compare the result with that from (a)

By sj wilson · 2005 ·  related articlesschool violence prevention programs fell into four broad categories: universal interferes with their efforts to teach. program for children attending any grade, pre-k through 12th 

Acetic acid  /əˈsiːtɪk/, systematically named  ethanoic acid  /ˌɛθəˈnoʊɪk/, is a colourless liquid  organic compound  with the  chemical formula  ch3cooh (also written as ch3co2h or c2h4o2). when undiluted, it is sometimes called  glacial acetic acid.  vinegar  is no less than 4% acetic acid by volume, making acetic acid the main component of vinegar apart from water. acetic acid has a distinctive sour taste and pungent smell. in addition to household vinegar, it is mainly produced as a precursor to  polyvinyl acetate  and  cellulose acetate. it is classified as a  weak acid  since it only partially  dissociates  in solution, but concentrated acetic acid is corrosive and can attack the skin.acetic acidnamespreferred iupac nameacetic acidsystematic iupac nameethanoic acidother namesvinegar (when dilute); hydrogen acetate; methanecarboxylic acid[1][2]identifierscas number64-19-7  3d model (jsmol)interactive image3dmetb00009 reference506007chebichebi: 15366  chemblchembl539  chemspider171  drugbankdb03166  echa infocard100.000.528ec number200-580-7e numbere260  (preservatives)gmelin reference1380iuphar/bps1058keggd00010  meshacetic+acidpubchem  cid176rtecs numberaf1225000uniiq40q9n063p  un number2789inchiinchi=1s/c2h4o2/c1-2(3)4/h1h3,(h,3,4)  key:   qtbsbxvteameqo-uhfffaoysa-n  smilescc(o)=o

The answer is water molecules are split.cellular respiration and photosynthesis are complement  reactions to each other. these are reverse reactions. in cellular respiration glucose and oxygen yield water and carbon dioxide. so, when respiration begins,  glucose molecules are split. in the opposite reaction - in photosynthesis, carbon dioxide and water yield glucose and oxygen. thus,  when respiration begins, water molecules are split.