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321.
The solution parameters associated with gradient elution reversed phase high-performance liquid chromatography (HPLC) were characterized by evaluating the electrospray ionization mass spectrometry (ESIMS) response of selected smokeless powder additives. Using direct liquid infusion, the positive ion ESIMS responses were determined for three general classes of powder constituents: dialkylphthalate acid esters, N,N'-dialkyl-N,N'-diphenyl urea based stabilizers and nitroso-, nitro-, and dinitro- derivatives of diphenylamine. The relative ESIMS intensities of the powder components were investigated as a function of three solution parameters: ammonium acetate concentration, pH, and percent methanol. The effect of the ammonium acetate concentration demonstrates that the electrolyte is required for efficient ionization and the ESIMS intensity was optimal at a concentration of 2mM for the selected compounds, except 2,4'-dinitrodiphenylamine. The aqueous solution pH, corresponding to the available protons in solution, did not have a significant effect on the ESIMS intensity of the analytes. The percent methanol was evaluated with both decreasing and constant electrolyte concentrations to demonstrate the effects of droplet stability and ion transfer into the gas phase. These findings were applied to the analysis of the selected smokeless powder additives using HPLC-ESIMS to illustrate increased sensitivity for the protonated molecules. 相似文献
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In recent times, juvenile rehabilitation has been attacked both by liberals seeking to insert greater due process rights and protections into the juvenile justice system and by conservatives calling for more stringent handling of serious youthful offenders. The apparent pervasiveness of this attack raises the question, Is the philosophy of child saving dead? Data drawn from a survey conducted in Illinois suggest, however, that juvenile rehabilitation continues to receive support both from the public and from various groups associated with criminal justice practice and policy making. At the same time, there is also support for the notion that young criminals are responsible for their actions and are currently being treated too leniently by our courts. Finally, child saving is embraced most firmly by judges, lawyers, correctional administrators, and prison inmates and least strongly by legislators, prison guards, and the general public. 相似文献
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John H. Laub 《Journal of criminal justice》1983,11(2):129-142
Although the level of crime varies dramatically across the urban-rural dimension, little research has been directed at the issue of the patterns of offending across this dimension. Using National Crime Survey (NCS) victimization data, this paper examines to what extent the patterns of offending by particular age, race, and sex subgroups are similar in urban and rural areas. It was found that the patterns of age, race, and sex offending are essentially the same in both urban and rural areas. Particularly impressive is the consistency in the rankings (from high to low) of the propensity of offending in urban and rural areas when age, race, and sex were examined simultaneously. Also, these NCS data generally parallel Uniform Crime Reports arrest data with respect to the offender characteristics of age, race, and sex. This suggests that existing criminological theories can be applied to rural, as well as urban, crime patterns regarding the issue of offender characteristics. 相似文献
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John Flood 《Law & social inquiry》1981,6(2):377-405
The accomplishments of empirical research are often presented in a context that fails to show the process by which the results came about. This article examines the problems, hitches, and struggles encountered in a research project carried out on the English bar. And emphasis is given to the difficulty of tackling hitherto unexplored occupations that have had a long history of resisting research. 相似文献
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