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151.
152.
Two examples are given that answer in the negative the following question asked by E. M. Bator: If is bounded and weakly measurable and for each in there is a bounded sequence in such that a.e., does it follow that is Pettis integrable?
153.
Gunnar Karlstrm 《Journal of computational chemistry》1981,2(1):83-86
A modified integral package for evaluation of two-electron integrals over Gaussian basis functions is described. Modifications are implemented in the MOLECULE program system and are especially suited for the study of large molecules and molecular complexes. 相似文献
154.
Sahre K Eichhorn KJ Günther M Suchaneck G Gerlach G 《Analytical and bioanalytical chemistry》2004,378(2):396-401
Thin polyimide (PI) and polyethersulfone (PES) films are widely used as functional layers for microelectronic sensors. Ion implantation modifies the layer structure and morphology of these polymers and hence results in new mechanical and optical properties. However, ion-modified layers also show a change in sensitivity to moisture uptake under specific conditions. This is important for developing humidity sensors. Therefore, the water sorption ability of such modified polymer layers is studied by spectroscopic ellipsometry under definite relative humidity conditions (1–95%). Swelling data were obtained by fitting procedures based on changes of effective layer thickness and optical constants due to water uptake. Irradiation doses from 0.5 to 5×1015 B+ cm–2 at an energy of 180 keV were used for polymer modification. At irradiation doses from 0.5 to 0.7×1015 B+ cm–2, the maximum out-of-plane swelling is reached. At higher doses >2×1015 B+ cm–2, the swelling decreases and corresponds to values of the pure polymer layers. The wetting properties of the layer surfaces determined by contact angle measurements are important to explain this behavior. 相似文献
155.
Björn GustafssonMikael Håkansson Gunnar WestmanSusan Jagner 《Journal of organometallic chemistry》2002,649(2):204-208
The complex 2-allyl-6-methylphenoxocopper(I) has been prepared by reaction between mesitylcopper(I) and 2-allyl-6-methylphenol. Crystallographic studies show that the compound is tetrameric with a distorted cubane-type copper(I)-oxygen core, and with additional π-coordination of the ligand to copper through the alkene functionality (ν(CC)=1520 cm−1). The ligands thus act both as chelates and as bridges between adjacent copper(I) centres. Copper(I) exhibits trigonal pyramidal coordination geometry with CuC distances to the CC group of 1.976(9) and 2.017(11) Å and CuO distances of 1.973(6), 2.021(6) and 2.577(6) Å, respectively. 相似文献
156.
Decarboxylation of allylic esters of 4‐carboxypyrimidines in toluene at 111 °C in the presence of a Pd(0) catalyst, gives a mixture of a 4‐alkenylpyrimidine and a pyrimidine unsubstituted in the 4‐position. If the decarboxylation is carried out in the presence of benzaldehyde, then benzaldehyde is added to the 4‐position. Decarboxylation of 4‐carboxypyrimidines in the presence of different electrophiles, results in incorporation of the electrophile into the 4‐position together with a pyrimidine unsubstituted in the 4‐position. Use of microwave irradiation enhances the rate of the decarboxylations. 相似文献
157.
Accurate calculations of the dipole polarizability tensor of lithium hydride are performed using the finite-field perturbation approach in the SCF and CAS SCF method. The SCF results (α? = 22.1, α⊥ = 25.4 au) are expected to be very close to the HF values. The CAS SCF calculations predict a positive correlation contribution, giving α? = 26.3 and α⊥ = 29.3 au. 相似文献
158.
159.
PRIMARY MECHANISMS OF ERYTHROCYTE PHOTOLYSIS INDUCED BY BIOLOGICAL SENSITIZERS AND PHOTOTOXIC DRUGS 总被引:4,自引:0,他引:4
Robert Nilsson ‡ Gunnar Swanbeck Goran Wennersten 《Photochemistry and photobiology》1975,22(5):183-186
Abstract— The elucidation of the molecular mechanism of photosensitized hemolysis of red blood cells may give important clues to the primary events underlying the phototoxic reactions observed in pathological conditions such as porphyria and induced by photosensitizing drugs. Sensitizers effective in photo-hemolysis are porphyrins, the tryptophan metabolite kynurenic acid, and phototoxic drugs such as chlor-promazine and demethylchlortetracycline. Utilizing the singlet oxygen quenchers. jS-carotene and histi-dine and the large deuterium effect on the lifetime of singlet oxygen previously described by us, good evidence of the participation of this excited molecular species in the photohemolysis in the presence of kynurenic acid was obtained. Chlorpromazine and demethylchlortetracycline clearly act by a non-singlet oxygen pathway. The situation observed with haematoporphyrin is less clear and may represent a mixed Type I-Type II mechanism. 相似文献
160.
Bengt Wessln Gunnar Mattsson 《Journal of polymer science. Part A, Polymer chemistry》1990,28(5):1033-1042
Anionic polymerization of methyl methacrylate in toluene solution has been studied. The polymerizations were initiated by fluorenyllithium as well as by butyl-, benzyl-, and phenylmagnesium halides, and carried out in the presence of polar additives. Especially the organomagnesium initiators gave generally rise to highly isotactic polymers (mm = 0.90-0.95) in the absence of solvating additives. In the presence of the bidentate ligand N,N,N′,N′-tetramethylethylene diamine (TMEDA) at molar ratios of 1–2 relative to magnesium, highly syndiotactic polymers were obtained at ?78°C (rr = 0.8–0.9), while at higher temperatures stereoblock polymers or stereocomplexes were formed. It is proposed that at low temperatures the magnesium cations are strongly solvated under the influence of TMEDA, with the formation of monomeric ion pairs. The large solvated magnesium cations will not have any directional influence on the monomer in the propagation step, with syndiotactic propagation as a result. 相似文献