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An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
A new method for assessing the similarity of material compositions is described. A similarity measure is important for the classification and clustering of compositions. The similarity of the material compositions is calculated utilizing a data-mined ionic substitutional similarity based upon the probability with which two ions will substitute for each other within the same structure prototype. The method is validated via the prediction of crystal structure prototypes for oxides from the Inorganic Crystal Structure Database, selecting the correct prototype from a list of known prototypes within five guesses 75% of the time. It performs particularly well on the quaternary oxides, selecting the correct prototype from a list of known prototypes on the first guess 65% of the time.
The intramolecular addition of beta-ketoesters to unactivated alkynes under neutral conditions and at room temperature is described. The method employs triphenylphosphinegold(I) cation as a catalyst for the formation of exo-methylenecycloalkanes. Both monocyclic and bicyclic cyclopentanes and cyclohexanes can be formed in excellent yields and with good diastereoselectivity.
Abstract: This study investigated the rate of psychological impairment and stressful life events in survivors of motor vehicle accidents. Fifty‐six patients who had been hospitalised because of motor‐vehicle‐accident‐related injuries were reviewed twelve months after the accident. In this sample, 41 per cent of patients reported significant levels of psychological impairment. Patients reporting psychological disturbance were characterised by having more pain, unemployment, substance abuse, avoidance of road transport and compensation claims. Only 44 per cent of patients reporting significant psychological impairment had sought professional help for their conditions. Psychological dysfunction following motor vehicle accidents appears to be a common occurrence, and education of medical personnel and survivors is required to enhance identification and management of this problem.
We present a new approach for modeling and rendering existing architectural scenes from a sparse set of still photographs. Our modeling approach, which combines both geometry-based and imagebased techniques, has two components. The first component is a photogrammetric modeling method which facilitates the recovery of the basic geometry of the photographed scene. Our photogrammetric modeling approach is effective, convenient, and robust because it exploits the constraints that are characteristic of architectural scenes. The second component is a model-based stereo algorithm, which recovers how the real scene deviates from the basic model. By making use of the model, our stereo technique robustly recovers accurate depth from widely-spaced image pairs. Consequently, our approach canmodel large architectural environmentswith far fewer photographs than current image-based modeling approaches. For producing renderings, we present view-dependent texture mapping, a method of compositing multiple views of a scene that better simulates geometric detail on basic models. Our approach can be used to recover models for use in either geometry-based or image-based rendering systems. We present results that demonstrate our approach's ability to create realistic renderings of architectural scenes from viewpoints far from the original photographs.
Deflation has replaced inflation as the principal challenge for monetary policy in many countries. But influential voices question whether deflation is properly seen as a problem for economic growth and financial stability. They question whether recent experience with deflation is more than a transitory phenomenon associated with the aftermath of the financial crisis and record-low oil prices. And they doubt whether monetary policy can be used to address the deflation problem without creating even more serious risks. Historical experience as I read it generally confirms that deflation is a problem whose solution should be a priority for central banks. Japan's experience in particular suggests that deflation problems do not solve themselves. The jury is still out on whether, once deflation is underway, concerted monetary policy action can return inflation to its positive target levels. My own view is that it can. If the policies to date have not achieved their goal, then the central bank or banks in question need to do more. If doing more threatens financial stability, then tools other than monetary policy -- so-called macroprudential tools -- are appropriate for addressing these risks. If a central bank runs out of government securities to buy or worries about dangerously reducing the liquidity of the government bond market, then it can buy other assets. The policy response to deflation is straightforward. The only question is whether the relevant authorities will pursue it.
The mechanism of wear-particle formation during unlubricated sliding wear of several carbon and alloy steels has been investigated by scanning (SEM) and transmission electron microscopy (TEM). Individual debris particles are plate-like and typically 200 to 400 nm in thickness. The thinner particles are generally iron oxides except at low temperatures or in inert atmospheres when predominantly metallic particles result. The mean debris-particle width was 1 to 2 ..mu..m. TEM revealed a fine dislocation cell structure typical of large strain deformation to a depth of 10 to 50 ..mu..m. The subsurface cell dimensions and bending of pearlite colonies indicate that the shear strain near to the surface is at least 5. In many instances, a 200 to 300 nm wide zone of lower dislocation density, indicative of recovery, we noted immediately below the surface. Some cracks formed along dislocation cell walls at the boundary of the recovered zone; others were associated with decohesion of particle interfaces of subgrain triple points. Some oxidation then occurs during separation of the platelet from the parent material as a consequence of the highly pyrophoric nature of thin metal flakes. The sequence of the dry sliding wear process is discussed. 16 figures.
The Cardiac Purkinje Fiber (CPF) is the last branch of the heart conduction system, which is meshed with the normal ventricular myocyte. Purkinje fiber plays a key role in the occurrence of ventricular arrhythmia and maintenance. Does the heart Purkinje fiber cells have the same memory function as the cerebral nerve? In this paper, the cardiac Hodgkin–Huxley equation is taken as the object of study. In particular, we find that the potassium ion-channel [Formula: see text] and the sodium ion-channel [Formula: see text] are memristors. We also derive the small-signal equivalent circuits about the equilibrium points of the CPF Hodgkin–Huxley model. According to the principle of local activity, the regions of Locally-Active domain, Edge of Chaos domain and Locally-Passive domain are partitioned under parameters [Formula: see text], and the domain exhibiting the normal human heartbeat frequency range (Goldilocks Zone) is identified. Meanwhile, the Super-Critical Hopf bifurcation of the CPF Hodgkin–Huxley model is identified. Finally, the migration changes between different state domains under external current [Formula: see text] excitation are analyzed in detail. All of the above complex nonlinear dynamics are distilled and mapped geometrically into a surreal union of intersecting two-dimensional manifolds, dubbed the Hodgkin–Huxley’s magic roof.
