《盲校义务教育化学课程标准》解读

在《全日制盲校义务教育课程设置实验方案》核心思想的指导下,将之与普通学校《义务教育化学课程标准(2011年版)》对比分析,结合盲校教育对象及其教学特点,解读《盲校义务教育化学课程标准(2016年版)》的理论基础、研制原则和修订内容等。     

Conditions for the Chemical Precipitation of the Starting Substances from Solutions for the Synthesis of Aluminospinels

The precipitation of hydroxides from the Mg^{2 +}-Al^{3 +}-An^--H₂O system (An = NO₃ ^-, Cl^-, SO₄ ^{2 -}) at the initial spinel molar ratio Mg^{2 +} : Al^{3 +} = 1 : 2 was studied. The optimal conditions were found for obtaining the precipitates exhibiting the best properties in the manufacturing sense; their subsequent heat treatment yields a single phase of aluminomagnesium spinel.     

Comparison of two methods for the optimization of the analytical conditions for the determination of total sulfur

Response surface and simplex methods were used for optimizing the determination of total sulfur present in gaseous samples using a quartz crystal microbalance. The optimization methodology increased the analytical signal from three to five times. The simplex method showed the highest efficiency in the search for the maximum sensor response. However, the response surface allows ranking the variables according to their effects and highlights the existence of a plateau in the optimal region.     

A single-laboratory validated method for the generation of DNA barcodes for the identification of fish for regulatory compliance

The U.S. Food and Drug Administration is responsible for ensuring that the nation's food supply is safe and accurately labeled. This task is particularly challenging in the case of seafood where a large variety of species are marketed, most of this commodity is imported, and processed product is difficult to identify using traditional morphological methods. Reliable species identification is critical for both foodborne illness investigations and for prevention of deceptive practices, such as those where species are intentionally mislabeled to circumvent import restrictions or for resale as species of higher value. New methods that allow accurate and rapid species identifications are needed, but any new methods to be used for regulatory compliance must be both standardized and adequately validated. "DNA barcoding" is a process by which species discriminations are achieved through the use of short, standardized gene fragments. For animals, a fragment (655 base pairs starting near the 5' end) of the cytochrome c oxidase subunit 1 mitochondrial gene has been shown to provide reliable species level discrimination in most cases. We provide here a protocol with single-laboratory validation for the generation of DNA barcodes suitable for the identification of seafood products, specifically fish, in a manner that is suitable for FDA regulatory use.     

Screening method for the evaluation of asymmetric catalysts for the reduction of aliphatic ketones

ATH reductions of aliphatic ketones in water catalyzed by ruthenium coordinated by prolinamide ligands produce alcohols with moderate enantiomeric excesses in most cases. A set of seven aliphatic ketones is proposed for a rapid evaluation of the enantioselectivity of catalysts by one-pot multi-substrates reduction. The screening of a library of prolinamides shows that according to the structure of the ketones different ligands give the best asymmetric inductions.     

A Convenient Procedure for the Preparation of Reactive Zinc for the Reformatsky Reaction

A reactive zinc powder is obtained by addition of ZnCl₂ to a lithium dispersion suspended in ether. Reformatsky Reactions with the zinc powder are described.     

New method for allowance for the activity of the nucleophile in calculations of the reactivities of heteroaromatic compounds

A new method for allowance for the activity of the nucleophile in calculations of the reactivities of heteroaromatic compounds that is based on the special application of the valence molecular orbital (VMO) theory in the form of Dewar reactivity numbers is proposed. It is shown that there is a correspondence between the proposed method and the general VMO theory. The 5-azacinnoline molecule was calculated by both methods. According to the calculations, the 6-C atom should be the most active in reactions with hard bases, whereas the 4-C atom should be the most active in reactions with soft bases. A qualitative correspondence between the proposed method and the DMTS (delocalization model of the transition state) method is also demonstrated in the case of the quinolinium cation.More complex computational methods are presently not applicable to many-atom systems and not found in the literature.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 403–405, March, 1979.     

An affinity-based strategy for the design of selective displacers for the chromatographic separation of proteins

We describe an affinity-based strategy for designing selective protein displacers for the chromatographic purification of proteins. To design a displacer that is selective for a target protein, we attached a component with affinity for the target protein to a resin-binding component; we then tested the ability of such displacers to selectively retain the target protein on a resin relative to another protein having a similar retention time. In particular, we synthesized displacers based on biotin, which selectively retained avidin as compared to aprotinin on SP Sepharose high performance resin. In addition, we have extended this approach to develop an affinity-peptide-based displacer that discriminates between lysozyme and cytochrome c. Here, a selective displacer was designed from a lysozyme-binding peptide that had been identified and optimized previously using phage-display technology. Our results suggest a general strategy for designing highly selective affinity-based displacers by identifying molecules (e.g., peptides) that bind to a protein of interest and using an appropriate linker to attach these molecules to a moiety that binds to the stationary phase.     

Reinterpretation of the evidence for the structure of isoaurostatin

The spectroscopic parameters used to assign the structure to isoaurostatin (4',6-dihydroxyisoaurone), a metabolite isolated from Thermomonospora alba, have been reinterpreted. It is suggested that isoaurostatin is identical to the isoflavone daidzein.     

Quasispin symmetry for the derivation of coupled cluster equations for the Hubbard model of benzene

The concept of quasispin is applied to a special case of the Pariser–Parr–Pople (PPP ) model of the benzene molecule, namely, the Hubbard Hamiltonian. Added to the spin, space, and alternancy symmetries already taken into account in the PPP Hamiltonian, this new symmetry, called quasispin symmetry, has the effect of reducing the size of the CI matrix. Coupled cluster (CC ) equations are then obtained after applying the CC approach with doubles as well as its extension that accounts for triexcited clusters (CCSDT -1). The derivation of these equations following the use of quasispin to the Hubbard model of benzene constitutes the most simple nontrivial example of CC results. In addition, the CC equations can be written in explicit algebraic form using the symbolic computation language MAPLE.     

Explanation for the 3.4-power law for viscosity of polymeric liquids on the basis of the tube model

The viscosity η₀(M) of polymeric liquids of molecular weight M is calculated on the basis of the tube model formulated by Doi and Edwards (ref. 3). The contour length fluctuation of polymers along the tube, which was neglected in ref. 3, is now explicitly taken into account. The result is where M_c = 2M_e, and M_e is the molecular weight between the entanglement points. This result is numerically close to the empirical 3.4-power law, η₀(M) = η₀(M_c)(M/M_c)^3.4, for 10M_c ? M ? 100M_c but approaches the result in ref. 3 for very high molecular weight. We thus conclude that the 3.4-power law is actually an approximate expression for the real curve which slowly approaches the asymptotic form calculated in ref. 3.     

Instrument for the mechanization of the capillary radioimmunoassay

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Instrument for the mechanization of the capillary radioimmunoassay

     

Models for the Investigation of the Structure of Vulcanizates

For the investigation of vulcanizates structure, new models have been developed relating the modulus of vulcanizates and the volume fraction of filler. The parameters of the models are the filler distribution and the properties of the shell surrounding the filler particles. Three functions of filler distribution have been assumed. Dynamic mechanical properties of a series of vulcanizates were tested and the parameters of the models were computed. The obtained data allows estimating the properties of the shell formed around filler particles in vulcanizates and to distinguish the functions of filler distribution.