Stereoselective Synthesis of α-Digitoxosides and α-Boivinosides via Chelation-Controlled Anomeric O-Alkylation

A chelation-controlled anomeric O-alkylation has been developed for the stereoselective synthesis of α-digitoxosides and α-boivinosides bearing a C3-free hydroxyl group. Due to chelation via sodium ion, the anomeric alkoxides are locked in the axial configuration, which leads to the selective production of α-glycosides.     

Standardization of Ayurvedic Formulations Containing Aloe vera by Quantification of a Marker Compound

JPC – Journal of Planar Chromatography – Modern TLC - HPTLC has been used for quantitative analysis of aloin, as marker compound, in commercial Ayurvedic preparations, in the solid...     

Working group report: High energy and collider physics

This is a summary of the projects undertaken by the working group I on high energy and collider physics.     

理解并控制数字马达控制系统的量化误差

设计数字马达控制系统时需要考虑的主要问题是选择合适的处理器,同时,处理器字长也至关重要。设计人员需要关注定点处理器中因定点数表示法而引起的量化误差问题。这些误差将会降低控制系统的性能,使设计人员无法最大限度地发挥出高级算法的优势。     

Glass-forming ability and thermal stability of Se<Subscript>100−x</Subscript>(Ge<Subscript>2</Subscript>Sb<Subscript>2</Subscript>Te<Subscript>5</Subscript>)<Subscript>x</Subscript> glassy alloys

Glassy Se_100?x(Ge₂Sb₂Te₅)_x (x?=?5, 10, 15 and 20) bulk alloys were prepared by melt-quenched technique and studied by using differential scanning calorimetry at different heating rates under non-isothermal condition. The detailed thermal analysis shows that the glass transition temperature (T_g) depends on heating rates and x content. In particular, it is found that the glass-forming ability, thermal stability (T_c???T_g) and crystallization activation energy (E_c) increase with increased x content in amorphous Se, whereas glass transition activation energy (E_g) and fragility index (F) decrease with increased x contents. Variation in these parameters can be explained on the basis of network-forming ability of Se and bonding arrangement among the constituent atoms of alloys.     

From the LHC to future colliders

Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300 fb^?1 of integrated luminosity, of the proposed sLHC luminosity upgrade, of the ILC, of CLIC, of the LHeC and of a muon collider. The four Working Groups considered possible scenarios for the first 10 fb^?1 of data at the LHC in which (i) a state with properties that are compatible with a Higgs boson is discovered, (ii) no such state is discovered either because the Higgs properties are such that it is difficult to detect or because no Higgs boson exists, (iii) a missing-energy signal beyond the Standard Model is discovered as in some supersymmetric models, and (iv) some other exotic signature of new physics is discovered. In the contexts of these scenarios, the Working Groups reviewed the capabilities of the future colliders to study in more detail whatever new physics may be discovered by the LHC. Their reports provide the particle physics community with some tools for reviewing the scientific priorities for future colliders after the LHC produces its first harvest of new physics from multi-TeV collisions.