Ultrafast Science Journal

Physics Today ◽  
2002 ◽  
Vol 55 (9) ◽  
pp. 33-33
Author(s):  
Toni Feder
Keyword(s):  
Science Journal ◽  
Ultrafast Science

Introduction

2018 ◽  
Author(s):  
Roy Livermore
Keyword(s):  
Science Journal ◽  
Scientific Revolutions ◽  
Physical Geology

… it is doubtful whether there will ever again be such a profusion of unexpected discoveries concentrated into so short an interval of time as there has been during the last twenty years.ARTHUR HOLMES, PRINCIPLES OF PHYSICAL GEOLOGY (1965)Scientific revolutions rarely start with a bang. In 1953, a modest article, barely a page in length, appeared in the weekly science journal ...

Multiple regression and nonlinear models

2017 ◽  
Author(s):  
Andrew Gelman ◽  
Deborah Nolan
Keyword(s):  
Regression Analysis ◽  
Social Science ◽  
Multiple Regression ◽  
Nonlinear Model ◽  
Nonlinear Models ◽  
Good Strategy ◽  
Science Journal ◽  
Golf Putting ◽  
Social Science Journal ◽  
To Come

This chapter covers multiple regression and links statistical inference to general topics such as lurking variables that arose earlier. Many examples can be used to illustrate multiple regression, but we have found it useful to come to class prepared with a specific example, with computer output (since our students learn to run the regressions on the computer). We have found it is a good strategy to simply use a regression analysis from some published source (e.g., a social science journal) and go through the model and its interpretation with the class, asking students how the regression results would have to differ in order for the study’s conclusions to change. The chapter includes examples that revisit the simple linear model of height and income, involve the class in models of exam scores, and fit a nonlinear model (for more advanced classes) for golf putting.

The passive voice in scientific writing through the ages: A diachronic study

2020 ◽  
Vol 40 (4) ◽  
pp. 467-489
Author(s):  
Alvin Ping Leong
Keyword(s):  
Nineteenth Century ◽  
Twentieth Century ◽  
Scientific Writing ◽  
Science Journal ◽  
Passive Voice ◽  
Composing Process ◽  
Diachronic Study ◽  
Time Periods ◽  
Current Shift ◽  
Modern Era

AbstractDiachronic studies on scientific writing have indicated an increase in the use of passives from the seventeenth to the twentieth century. With the current shift in focus towards making scientific writing more accessible, there is less certainty on the extent of passive use in the modern era. Although the use of the active voice is presently encouraged, the findings from available studies are mixed. There are also few diachronic studies involving recent articles. This present study investigated the trend in passive use from the nineteenth century to the present day using 80 articles from a multidisciplinary science journal covering four time periods (1880, 1930, 1980, and 2017). The study found that the extent of passive use was stable from 1880 to 1980 (occurring in about 29–36% of all clauses) but declined in 2017 (averaging below 25%). The study also found a decline in the use of finite passives to describe methodological actions and a corresponding increase in the use of first-person pronouns in the 2017 articles. Further work involving a larger corpus and an understanding of writer decisions in the composing process is needed.

scholarly journals Few-Cycle Infrared Pulse Evolving in FEL Oscillators and Its Application to High-Harmonic Generation for Attosecond Ultraviolet and X-ray Pulses

Atoms ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 15
Author(s):  
Ryoichi Hajima
Keyword(s):  
Harmonic Generation ◽  
Short Pulse ◽  
High Harmonic ◽  
High Harmonic Generation ◽  
Pulse Generation ◽  
Solid State Lasers ◽  
Linear Accelerators ◽  
X Ray ◽  
Ultrafast Science ◽  
Historical Remarks

Generation of few-cycle optical pulses in free-electron laser (FEL) oscillators has been experimentally demonstrated in FEL facilities based on normal-conducting and superconducting linear accelerators. Analytical and numerical studies have revealed that the few-cycle FEL lasing can be explained in the frame of superradiance, cooperative emission from self-bunched systems. In the present paper, we review historical remarks of superradiance FEL experiments in short-pulse FEL oscillators with emphasis on the few-cycle pulse generation and discuss the application of the few-cycle FEL pulses to the scheme of FEL-HHG, utilization of infrared FEL pulses to drive high-harmonic generation (HHG) from gas and solid targets. The FEL-HHG enables one to explore ultrafast science with attosecond ultraviolet and X-ray pulses with a MHz repetition rate, which is difficult with HHG driven by solid-state lasers. A research program has been launched to develop technologies for the FEL-HHG and to conduct a proof-of-concept experiment of FEL-HHG.

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