A comparison of the isotope-dilution and the difference method for estimating fertilizer nitrogen recovery fractions in crops. III. Experimental

1. Pot culture experiments are described comparing the recovery of nitrogen, and sulphur by the difference and ‘labelled atom’ methods and the recovery of carbon by the latter method. Italian ryegrass was used as the test crop with ammonium sulphate, calcium nitrate and urea as the fertilizers.2. The recovery of fertilizer nitrogen was less using the ‘labelled atom’ technique than the conventional difference method.3. The recovery of sulphur from ammonium sulphate ‘labelled’ with 35S was measured. It was considerably less than the nitrogen, but not inconsiderable especially as a basal dressing of ‘unlabelled’ K2SO4 was applied.4. Using urea ‘labelled’ with 13C there was no evidence that any of the carbon was in the ryegrass four weeks after application.

Download Full-text

Research on the driving mechanism of tourism regional brand development of tea production base based on the difference-in-difference method

Journal of Physics Conference Series ◽

10.1088/1742-6596/1774/1/012050 ◽

2021 ◽

Vol 1774 (1) ◽

pp. 012050

Author(s):

Yanghao Ye ◽

Qing Wang ◽

Jie Zhu ◽

Wei Ma ◽

Yajuan Huang

Keyword(s):

Difference Method ◽

Driving Mechanism ◽

Difference In Difference ◽

Brand Development ◽

Tea Production ◽

The Difference ◽

Regional Brand

Download Full-text

The search of the anisotropy of the primary cosmic radiation by the difference method

EPJ Web of Conferences ◽

10.1051/epjconf/201714503003 ◽

2017 ◽

Vol 145 ◽

pp. 03003

Author(s):

Victor Pavlyuchenko ◽

Romen Martirosov ◽

Natalia Nikolskaya ◽

Anatoly Erlykin

Keyword(s):

Difference Method ◽

Cosmic Radiation ◽

Primary Cosmic Radiation ◽

The Difference

Download Full-text

Study and Simulate the Air Pollution Based on the Finite Difference Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.2820 ◽

2012 ◽

Vol 518-523 ◽

pp. 2820-2824

Author(s):

Yi Ni Guo ◽

Yan Zhang ◽

Jian Wang ◽

Ye Huang

Keyword(s):

Finite Element Method ◽

Air Pollution ◽

Finite Difference ◽

Finite Difference Method ◽

Difference Method ◽

The Finite Element Method ◽

Liquid Diffusion ◽

Continuous Problems ◽

The Finite Difference Method ◽

The Difference

The finite difference method that is the finite element method is used to solve the plane continuous problems. In this article, the theory and method of the finite difference method, as well as the application on the boundary problem are introduced. By analyzing the potential flew field equation and liquid diffusion equation, they are discreted using the difference method and the numerical analysis under certain boundary condition is conducted. In air pollution, the smoke in the diffusion is typical planar continuous problems. In this paper, the finite difference method is used to analyse and simulate the spread of the smoke.

Download Full-text

Asymmetric Fixed Effects Models for Panel Data

10.31235/osf.io/kv8a5 ◽

2018 ◽

Author(s):

Paul D Allison

Keyword(s):

Logistic Regression ◽

Panel Data ◽

Opposite Direction ◽

Difference Method ◽

Fixed Effects ◽

Regression Models ◽

Social Phenomena ◽

Logistic Regression Models ◽

Fixed Effects Models ◽

The Difference

Standard fixed effects methods presume that effects of variables are symmetric: the effect of increasing a variable is the same as the effect of decreasing that variable but in the opposite direction. This is implausible for many social phenomena. York and Light (2017) showed how to estimate asymmetric models by estimating first-difference regressions in which the difference scores for the predictors are decomposed into positive and negative changes. In this paper, I show that there are several aspects of their method that need improvement. I also develop a data generating model that justifies the first-difference method but can be applied in more general settings. In particular, it can be used to construct asymmetric logistic regression models.

Download Full-text