ISSN:0031-9228    

DOI:10.1063/1.2815232

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2815233

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2815234

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Some—but by no means all—of the Chernobyl story can now be told. Soviet scientists have assembled enough information from interviews, plant records and computer simulations to describe the chronology of events leading to a severe accident that destroyed a nuclear reactor at Chernobyl on 26 April and spread radiation over much of Europe. A Soviet delegation of 28 specialists headed by V. A. Legasov (Kurchatov Institute) presented a very frank report on the accident's causes and consequences to an experts' meeting sponsored by the International Atomic Energy Agency in Vienna on 25–29 August. Their report places heavy blame on the reactor staff for committing numerous violations of operating rules, one of which left the reactor operating at a power level where the consequences of further violations were greatly exacerbated.

ISSN:0031-9228    

DOI:10.1063/1.2815235

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

In the 20 September issue of theJournal of Geophysical Research, Linwood Callis (NASA) and Murali Natarajan (SASC Technologies) suggest that the recently hyperactive Sun, rather than manmade pollution, bears primary responsibility for the mysterious and troubling “ozone hole” that has for several years been appearing every October over the South Pole. They point out that 1979–80 witnessed one of the most intense solar maxima in centuries. This, they argue, would account for the striking increase in the level of “odd‐nitrogen compounds”—various oxides of nitrogen—observed in the stratosphere between 1979 and 1984. Produced in an atmospheric layer above the stratosphere with the aid of sunlight and solar wind, these molecules can participate catalytically in the destruction of ozone.

ISSN:0031-9228    

DOI:10.1063/1.2815236

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

I finished writing this article while the 23rd International Conference on High‐Energy Physics was taking place in Berkeley. California. It was a wellorganized conference with a variety of theoretical talks, comprehensive plenary lectures and many reports on new experiments. Yet the atmosphere of the conference could be summed up in one word: waiting. The participants knew that no major experimental or theoretical advance in particle physics was to be announced at this conference. They listened to the experimental and theoretical results, but they were prepared to wait until the next conference for a breakthrough.

ISSN:0031-9228    

DOI:10.1063/1.881045

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

Science libraries all over the United States face serious financial problems associated with the increased costs of journals.

ISSN:0031-9228    

DOI:10.1063/1.881046

出版商:AIP    

年代:1986

数据来源: AIP

摘要:

In the 17th century the Dutch physicist Christian Huyghens observed that two clocks hanging back to back on the wall tend to synchronize their motion. This phenomenon is known as phase locking, frequency locking or resonance, and is generally present in dynamical systems with two competing frequencies. The two frequencies may arise dynamically within the system, as with Huyghens's coupled clocks, or through the coupling of an oscillator to an external periodic force, as with the swing and attendant shown in figure 1. If some parameter is varied—the length of a pendulum or the frequency of the force that drives it, for instance—the system will pass through regimes that are phase locked and regimes that are not. When systems are phase locked the ratio between their frequencies is a rational number. For weak coupling the phase‐locked intervals are narrow, so that even if there is an infinity of intervals, the motion is quasiperiodic for most driving frequencies; that is, the ratio between the two frequencies is more likely to be irrational. When the coupling increases, the phase‐locked portions increase, and it becomes less likely that the motion is quasiperiodic. This is a unique situation, where it makes sense, despite experimental uncertainty, to ask whether a physical quantity is rational or irrational.

ISSN:0031-9228    

DOI:10.1063/1.881047

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2815237

出版商:AIP    

年代:1986

数据来源: AIP

ISSN:0031-9228    

DOI:10.1063/1.2815238

出版商:AIP    

年代:1986

数据来源: AIP