Sharply decreases

Positive-Tone Photoresists based on Dissolution Inhibition by Diazonaphthoquinones. The intrinsic limitations of bis-azide—cycHzed mbber resist systems led the semiconductor industry to shift to a class of imaging materials based on diazonaphthoquinone (DNQ) photosensitizers. Both the chemistry and the imaging mechanism of these resists (Fig. 10) differ in fundamental ways from those described thus far (23). The DNQ acts as a dissolution inhibitor for the matrix resin, a low molecular weight condensation product of formaldehyde and cresol isomers known as novolac (24). The phenoHc stmcture renders the novolac polymer weakly acidic, and readily soluble in aqueous alkaline solutions. In admixture with an appropriate DNQ the polymer s dissolution rate is sharply decreased. Photolysis causes the DNQ to undergo a multistep reaction sequence, ultimately forming a base-soluble carboxyHc acid which does not inhibit film dissolution. Immersion of a pattemwise-exposed film of the resist in an aqueous solution of hydroxide ion leads to rapid dissolution of the exposed areas and only very slow dissolution of unexposed regions. In contrast with crosslinking resists, the film solubiHty is controUed by chemical and polarity differences rather than molecular size. 

Simple alkyl radicals such as methyl are considered to be nonnucleophilic. Methyl radicals are somewhat more reactive toward alkenes bearing electron-withdrawing substituents than towards those with electron-releasing substituents. However, much of this effect can be attributed to the stabilizing effect that these substiments have on the product radical. There is a strong correlation of reaction rate with the overall exothermicity of the reaction. Hydroxymethyl and 2-hydroxy-2-propyl radicals show nucleophilic character. The hydroxymethyl radical shows a slightly enhanced reactivity toward acrylonitrile and acrolein, but a sharply decreased reactivity toward ethyl vinyl ether. Table 12.9 gives some of the reactivity data. 

The reactivity of arylhalides in the acetylenic condensation sharply decreases in the series Ar—I, Ar—Br, Ar—Cl. The rate of reaction of phenylacetylene with iodo derivatives is 800 times higher than that of the reaction with bromo derivatives and is 10 higher than that of the reaction with corresponding chlorides (75JOM253). Taking into account the very low activity of halogenopyrazoles (66AHC347), the catalytic variant of acetylenic condensation mainly involves the most active iodo derivatives. 

The addition of LCP sharply decreased the viscosity of PP in the melt blends, but increased it in the composites. The increase in viscosity effected by the solid LCP fibers was nevertheless surprisingly small. 

Modulus Decreases sharply Decreases slowly Increases slowly Does not change Decreases slowly... 

Irradiation with UV light isomerized the azobenzene units from the trans to the cis form, while the reverse isomerization occurred thermally in the dark. The cis to trans conversion is catalyzed by both protons and hydroxyl ions. Hence, the catalyzed dark process for tethered azobenzene is greatly modified in comparison with that for free azobenzene. For the tethered azobenzene, beginning at pH 6, the cis to trans return rate sharply decreased with increasing pH up to 10, whereas the rate for free azobenzene rapidly increased in the same pH range owing to OH- catalysis. These observations can be explained by the electrostatic repulsion which lowers the local OH concentration on the polyion surface below that in the bulk aqueous phase. 

Since the electrostatic potential sharply decreases with increasing distance from the polyelectrolyte cylinder, the degree of reactivity modification by functional groups fixed to the polyion is strongly dependent on the distance from the cylinder surface. Considerable electrostatic potential effects on the photoinduced forward and thermal back electron transfer reactions, which will be discussed in the following chapters, can be attributed to the functional chromophore groups directly attached to the polyelectrolyte back-bone through covalent bonds. 

The flow of polymerization-filled composites is, as shown in [338] for composites with chalk coated with copolymer of methyl methcrylate and methacrylate, also largely dependent on the composition of the copolymer and sharply decreases when the percentage of methyl methacrylate in the copolymer increases. 

The important action of electrostatic forces between a cationic model and an anionic polynucleotide is clearly shown in Fig. 7. The hypochromicity sharply decreased with the ionic strength of the solution, which indicates that the base-base interactions between A12 and Poly U supported by the electrostatic attractive forces are weakened by the shielding effects of added salts. 

The authors believe the Pd(0) complex to be dimeric, containing Pd(0) and Pd(II). At 5 °C, is of the order of 1.0 l.mole". sec", but it is influenced in a curious manner by addition of bromide ion, being increased initially and then sharply decreased. The effect itself is very temperature-dependent. 

With the introduction of FAB in 1981, interest in the development of both DCI and FD sharply decreased. Indeed, on highly polar substances FAB provides more valuable results than DCI or FD and a more stable signal. On the other hand, nonpolar substances with high molecular weight are not amenable to FAB, since they are poorly ionised and also they cannot be easily dissolved in the most common FAB matrices. Thus, alternative ionisation methods have to be employed with such compounds. DCI-MS of nonvolatile compounds has been reviewed [40]. 

Overall, insecticides seriously affect invertebrates in the soil, especially insects, but affect microorganisms much less [3,6]. The most toxic OCPs for soil invertebrates are heptachlor and chlordan. They sharply decrease the numbers of almost all invertebrate groups, including insects, earthworms, and ticks [6]. 

By sharply decreasing biodiversity in the soil ecosystem, pesticides negatively affect all soil organisms on which soil productivity depends. Pesticides affect the biological activity in soil, especially through long-term use and accumulation (or accumulation of their residues). 

Species targeted by pesticides usually make up only several tenths of a percent of the total number of species in an agricultural environment. Natural enemies and parasites usually decrease a species mass reproduction reliably. Destroying, or sharply decreasing the number of, such enemies through pesticide use often leads to a population explosion in the suppressed species chemical protection thus creates a greater threat to the protected cultivars [1]. 

Pesticides may change the soil s element content. Some pesticides may increase plants micro- and macroelement content, such as nitrogen, phosphorus, calcium, potassium, magnesium, manganese, iron, copper, barium, aluminum, strontium and zinc, whereas others decrease these or other elements. Pesticides may cause ammoniac compounds to accumulate in the soil. Dimethoate and fluometuron increase nitrates in the soil, while DDT, carbaryl and HCH sharply decrease them. When prometrin was used, soil nitrate content decreased by 30-40% [3]. 

Crison and Amidon [47,48] recently used the mass balance approach to study the variability in absorption due to intestinal transit time for water-insoluble drugs. As expected, for low dose drugs, such as digoxin, the variability in absorption sharply decreases with the increase of dissolution number via micronization. For high dose drugs, such as griseofulvin, little effect was observed when the dissolution number was increased by micronization. 

However, these results are probably the result of the method of detecting particles and thereby provide an operational definition of "particle". All of these studies use a condensation nuclei counter to determine the presence of "particles". These devices have been found to have sharply decreasing efficiency for detecting particles less than 0.01 ym (Leong, et al., 1983, for example). 

The radioactive signals of radio-GC show the 1 -methanol derivates and its common derivates with non radioactive methyl iodide (Fig. lb). The nC-methanol derivates take part in new molecule formation with non-radioactive methyl iodide or/and its derivates on catalyst surface. The C-methyl iodide as a newly formed radioactive product was detected while the selectivity to hydrocarbons sharply decreased (Fig. 2b). 

As noted briefly above, the readout noise level is sharply decreased when reading-out rate is low. Cameras allowing a slow readout are called slow-scan CCD cameras. 

The experiments were conducted in a down-flow tubular reactor with continuous feed and product withdrawal. For phosphine resins, establishment of equilibrium was exhibited by the fact that rhodium concentrations in solution were proportional to percent loading. The concentration was also dependent on solvent. As the solvent polarity increased, rhodium concentration increased. Typical concentrations in the effluent were 0.2-2.0 X 10-5 A/ Rh for reaction at 85°C, 1500 psi 1/1 H2/CO. An increase in CO pressure increased the concentration of rhodium in solution, and an increase in temperature sharply decreased the metal concentration. These are understood as factors that influence the equilibrium between phosphine and carbonyl complexes. 

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