Low temperature survival of slender naiad (Najas flexilis) seeds

The response to drying and storage at -20 degrees C or in liquid nitrogen was studied in seeds of the freshwater aquatic plant Najas flexilis. The seeds of this species show some desiccation sensitivity, although post-harvest storage in water at 16 degrees C resulted in improvements in desiccation tolerance. There was 63% germination of seeds dried to 9.5% moisture content (30% RH) following this maturation period. Optimum moisture contents for seeds stored at -20 degrees C for 3 months and in liquid nitrogen for 1 week were ~11% and ~15%, respectively.     

Investigation into the rotational bands of ~(185)Pt with the particle-rotor model

Theoretical calculations have been performed for the ν9/2+[624](i13/2) and ν7/2-[503](f7/2) bands of 185Pt in the framework of particle-rotor model. The band properties of signature splitting and configuration mixing have been analyzed. The level energy and signature splitting before the band crossing can be well interpreted by introducing triaxiality. The positive-parity yrast band is pro posed to be dominated by the ν9/2+[624](i13/2) component, while the negative-parity band shows strong mixing of ν7/2-[5...     

An Anthracene-Based Metal-Organic Framework for Selective Photo-Reduction of Carbon Dioxide to Formic Acid Coupled with Water Oxidation

A Zr-based metal-organic framework has been synthesized and employed as a catalyst for photochemical carbon dioxide reduction coupled with water oxidation. The catalyst shows significant carbon dioxide reduction property with concomitant water oxidation. The catalyst has broad visible light as well as UV light absorption property, which is further confirmed from electronic absorption spectroscopy. Formic acid was the only reduced product from carbon dioxide with a turn-over frequency (TOF) of 0.69 h⁻¹ in addition to oxygen, which was produced with a TOF of 0.54 h⁻¹. No external photosensitizer is used and the ligand itself acts as the light harvester. The efficient and selective photochemical carbon dioxide reduction to formic acid with concomitant water oxidation using Zr-based MOF as catalyst is thus demonstrated here.     

Aspects of heterogeneous enantioselective catalysis by metals

Some aspects of metal-catalyzed heterogeneous enantioselective reactions are reviewed with specific reference to four different systems where the phenomena that control enantioselection appear to be very different. In the case of glucose electro-oxidation, it is clear that any intrinsic chirality present at the metal surface plays a vital role. With α-keto hydrogenation, achiral surfaces modified by the adsorption of chiral agents become effective enantioselective catalysts and the formation of extended arrays of chiral species appears not to be of importance: instead a 1:1 docking interaction controlled by hydrogen bonding between the adsorbed chiral modifier and the prochiral reactant determines the outcome. Hydrogen bonding also plays a central role in β-ketoester hydrogenation, but here fundamental studies indicate that the formation of ordered arrays involving the reactant and chiral ligand is of importance. Asymmetric C═C hydrogenation, though relatively little studied, has the potential for major impact in synthetic organic chemistry both on the laboratory scale and in the manufacture of fine chemicals and pharmaceuticals. The structural attributes that determine whether a given chiral ligand is effective have been identified; the ability to form strong covalent bonds with the metal surface while also resisting hydrogenation and displacement by the strongly adsorbing reactant under reaction conditions is an essential necessary condition. Beyond this, ligand rigidity in the vicinity of the chirality center coupled with resistance to SAM formation is a critically important factor whose absence results in racemic chemistry.     

Die Bestimmung der Weins?ure in Hefe und geringwerthigem Weinstein

Ohne Zusammenfassung     

The Colliery Planning System—A Microcomputer-based Aid to Colliery (Production) Planning

The Colliery Planning System (C.P.S.) is a medium- to long-term planning aid written in APL and running on a Superbrain microcomputer. It was developed by and has been used extensively within the Operational Research Executive (O.R.E.) of the National Coal Board and has been in routine use by planning staff in one of the N.C.B.'s Areas for over two years. This paper discusses the Colliery Planning System and outlines the problems it has been necessary to overcome to achieve implementation.