DHF

Modify, add, or dcliM a paranicicr in ihc appropriate file. Use a text editor for a. ixt file or a database program for a. dhf file. 

The Dirac equation can be readily adapted to the description of one electron in the held of the other electrons (Hartree-Fock theory). This is called a Dirac-Fock or Dirac-Hartree-Fock (DHF) calculation. 

DHF (Dirac -Hartree-Fock) relativistic ah initio method DHF (derivative Hartree-Fock) a means for calculating nonlinear optical properties... 

In view of the well-documented inhibition of dihydrofolate reductase by aminopterin (325), methotrexate (326) and related compounds it is generally accepted that this inhibitory effect constitutes the primary metabolic action of folate analogues and results in a block in the conversion of folate and dihydrofolate (DHF) to THF and its derivatives. As a consequence of this block, tissues become deficient in the THF derivatives, and this deficiency has many consequences similar to those resulting from nutritional folate deficiency. The crucial effect, however, is a depression of thymidylate synthesis with a consequent failure in DNA synthesis and arrest of cell division that has lethal results in rapidly proliferating tissues such as intestinal mucosa and bone marrow (B-69MI21604, B-69MI21605). 

Standard heats of reaction of each component, dHf, dHfg, dHf., and dHfp. 

Tetrahydrofuran (THF) impurities acetone, acrolein, 2,3-DHF, butyraldehyde, isopropyl alcohol, THF. 1,3-dioxolane, 2-methyl THF, benzene, and 3-methyl THF... 

In this approach, it is assumed that turbulence dies out at the interface and that a laminar layer exists in each of the two fluids. Outside the laminar layer, turbulent eddies supplement the action caused by the random movement of the molecules, and the resistance to transfer becomes progressively smaller. For equimolecular counterdiffusion the concentration gradient is therefore linear close to the interface, and gradually becomes less at greater distances as shown in Figure 10.5 by the full lines ABC and DEF. The basis of the theory is the assumption that the zones in which the resistance to transfer lies can be replaced by two hypothetical layers, one on each side of the interface, in which the transfer is entirely by molecular diffusion. The concentration gradient is therefore linear in each of these layers and zero outside. The broken lines AGC and DHF indicate the hypothetical concentration distributions, and the thicknesses of the two films arc L and L2. Equilibrium is assumed to exist at the interface and therefore the relative positions of the points C and D are determined by the equilibrium relation between the phases. In Figure 10.5, the scales are not necessarily the same on the two sides of the interface. 

Fig. 4. (a) TEM image of TaN metal electrode gate stack after Ch etching, revealing thick residues formation on the sidewall (etching was done in DPS) SEM image of TaN metal electrode (b) before and (c) after DHF cleaning. 

Fig. 6. AFM images of etched surface of HfN films after 1% DHF dipping with the time (a) 5 s, (b) 15 s, (c) 40 s (d) SEM image of metal gate stack after etching 5min in 1% DFDF, showing HfN film is laterally etched.

There is another fundamental difference between folate utilization in microbial and mammalian cells. Bacteria and protozoa are unable to take up exogenous folate and must synthesize it themselves. This is carried out in a series of reactions involving first the synthesis of dihydropteroic acid from one molecule each of pteridine and p-aminobenzoic acid (PABA). Glutamic acid is then added to form DHF which is reduced by DHFR to THF. Mammalian cells do not make their own DHF, instead they take it up firm dietary nutrients and convert it to THF using DHFR. 

Positional parameters of the non-hydrogen atoms obtained from refinements I and II are in good agreement with those of SC (1980) or Dam, Harkema and Feil (hereafter DHF) [16] from X-ray data as well as those from neutron data [13, 17]. 

Likewise, copolymers 90 have higher EL efficiency than homopolymers DHF-PPV 57 or MEH-PPV 13, due to more balanced charge injection and transport properties. Copolymer 90 with 7.5 wt% loading of dialkoxyphenylene comonomer gave the highest QE. The device with an ITO/PEDOT/90/Ca configuration showed remarkably higher efficiency (2.4cd/A) than devices fabricated with other copolymers in the series (0.65-1.0cd/A) [141],... 

It should be emphasized that n.. and JPS, and therefore c and T, refer to the condition at the pore tip. The dissolution valence and the temperature can be assumed to be independent of pore depth. This is not the case for the HF concentration c. Because convection is negligible in macropores, the mass transport in the pore occurs only by diffusion. A linear decrease in HF concentration with depth and a parabolic growth law for the pores according to Pick s first law is therefore expected, as shown in Fig. 9.18 a. The concentration at the pore tip can be calculated from the concentration in the bulk of the electrolyte c, the pore length l, the diffusion coefficient DHf (Section 1.4) and the flow of HF molecules FHf. which is proportional to the current density at the pore tip ... 

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