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Quantum chemistry is based on the solution of the Schrödinger equation for a molecule. From starting data on the positions and nature of constituent atoms information is provided about the energy of the molecule and its electronic properties. The former can indicate what shapes drugs can adopt in binding to pharmacological receptors whilst electronic details, when compared using computer graphics, may highlight the factors responsible for biological activity. These techniques are beginning to show real successes in the design of drug molecules. 相似文献
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Knight DM 《Endeavour》2000,24(4):165-169
Humphry Davy (1778–1829) was one of the first professional scientists, earning his living and rising spectacularly from an impoverished upbringing in Cornwall to be President of the Royal Society and a baronet. He owed his rise to patronage as well as to his range of abilities: as a lecturer, as a chemical theorist and as a very early applied scientist. But his exalted position brought him little happiness, for he could not satisfy all the hopes put upon him as the successor to Sir Joseph Banks. Admired rather than loved, he became unpopular and was seen as haughty. In his last two years, spent wandering lonely and sickly in Italy and the Alps, he sought to make sense of his life, writing dialogues as his bequest to the new generation. 相似文献
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While there is no universal logic of induction, the probabilitycalculus succeeds as a logic of induction in many contexts throughits use of several notions concerning inductive inference. Theyinclude Addition, through which low probabilities representdisbelief as opposed to ignorance; and Bayes property, whichcommits the calculus to a refute and rescale dynamicsfor incorporating new evidence. These notions are independentand it is urged that they be employed selectively accordingto needs of the problem at hand. It is shown that neither isadapted to inductive inference concerning some indeterministicsystems.
- 1 Introduction
- 2 Failure of demonstrations of universality
- 2.1 Working backwards
- 2.2 The surface logic
- 3 Framework
- 3.1 The properties
- 3.2 Boundaries
- 3.2.1 Universalcomparability
- 3.2.2 Transitivity
- 3.2.3 Monotonicity
- 3.2.2 Transitivity
- 3.2 Boundaries
- 4 Addition
- 4.1 The property: disbelief versus ignorance
- 4.2Boundaries
- 5 Bayes property
- 5.1 The property
- 5.2 Bayes' theorem
- 5.3Boundaries
- 5.3.1 Dogmatism of the priors
- 5.3.2 Impossibilityof prior ignorance
- 5.3.3 Accommodation of virtues
- 5.3.2 Impossibilityof prior ignorance
- 5.2 Bayes' theorem
- 6Real values
- 7 Sufficiency and independence
- 8 Illustrations
- 8.1 All properties retained
- 8.2 Bayes propertyonly retained
- 8.3 Induction without additivity and Bayes property
- 8.2 Bayes propertyonly retained
- 9Conclusion
- 2 Failure of demonstrations of universality
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We present a new paradigm for the automatic creation of document headlines that is based on direct transformation of relevant textual information into well-formed textual output. Starting from an input document, we automatically create compact representations of weighted finite sets of strings, called WIDL-expressions, which encode the most important topics in the document. A generic natural language generation engine performs the headline generation task, driven by both statistical knowledge encapsulated in WIDL-expressions (representing topic biases induced by the input document) and statistical knowledge encapsulated in language models (representing biases induced by the target language). Our evaluation shows similar performance in quality with a state-of-the-art, extractive approach to headline generation, and significant improvements in quality over previously proposed solutions to abstractive headline generation. 相似文献