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排序方式: 共有848条查询结果,搜索用时 15 毫秒
91.
Robert J. Buszek C. Michael Lindsay Jerry A. Boatz 《Propellants, Explosives, Pyrotechnics》2013,38(1):9-13
Ab initio electronic structure calculations at the MP2/cc‐pVTZ level predict the vibrational stability of the theoretical molecule tetrakis(nitratoxycarbon)methane, designated CLL‐1. The gas phase enthalpy of formation, predicted to be +1029.3 kJ mol−1 using the G3(MP2) method, and the estimated density of 1.87 g cm−3 are used to predict the explosive performance properties using the equilibrium thermochemical code CHEETAH. The predicted detonation velocity (8.61 km s−1) and pressure (33.1 GPa) are similar to those of RDX, but with a significantly higher detonation temperature (6740 K). Finally, the stability of this theoretical molecule is investigated by calculating the lowest energy unimolecular decomposition pathways of the HCO3N model compound as well as barriers to rearrangement upon interaction of two HCO3N molecules. 相似文献
92.
C. Michael. Lindsay George C. Butler Chad G. Rumchik Ben Schulze Ryan Gustafson Warren R. Maines 《Propellants, Explosives, Pyrotechnics》2010,35(5):433-439
We report the development of a new methodology for analyzing CYLEX tests streak images. In these tests, the displacement of the wall of an explosive filled cylinder is obtained by backlighting the cylinder. The profile is imaged through a slit and streaked across a film record as the cylinder is detonated. A critical step in processing this data is the spatial calibration of the film and extraction of the profile of the cylinder from the image. Historically this has been a tedious task as it was performed by eye with the assistance of an optical comparator. Recently we developed an algorithm which automates the data calibration and extraction process of digitized streak records utilizing the Shen‐Castan edge detection algorithm and the image processing capabilities found in the IGOR PRO software. The new processing methodology greatly increases the resolution of the data, removes human subjectivity, and reduces analysis time from hours to seconds. The higher resolution of the new method has enabled much greater accuracy in measuring early‐time (<15 µs) expansion. With the aid of CTH hydrocode calculations, new fitting functions were developed to model both the early and late‐time expansion data. These functions contain physically meaningful fitting parameters and include terms which mimic the intensity and time scales of the shock and gas induced expansion of the cylinder independently. We demonstrate the methodology and hydrocode calculations on a recent CYLEX test series aimed at examining the effects of a plastic liner on high‐purity oxygen‐free copper cylinders filled with a high explosive. 相似文献
93.
94.
S Stretton S Techkarnjanaruk AM McLennan AE Goodman 《Canadian Metallurgical Quarterly》1998,64(7):2554-2559
Two broad-host-range vectors previously constructed for use in soil bacteria (A. G. Matthysse, S. Stretton, C. Dandie, N. C. McClure, and A. E. Goodman, FEMS Microbiol. Lett. 145:87-94, 1996) were assessed by epifluorescence microscopy for use in tagging three marine bacterial species. Expression of gfp could be visualized in Vibrio sp. strain S141 cells at uniform levels of intensity from either the lac or the npt-2 promoter, whereas expression of gfp could be visualized in Psychrobacter sp. strain SW5H cells at various levels of intensity only from the npt-2 promoter. Green fluorescent protein (GFP) fluorescence was not detected in the third species, Pseudoalteromonas sp. strain S91, when the gfp gene was expressed from either promoter. A new mini-Tn10-kan-gfp transposon was constructed to investigate further the possibilities of fluorescence tagging of marine bacteria. Insertion of mini-Tn10-kan-gfp generated random stable mutants at high frequencies with all three marine species. With this transposon, strongly and weakly expressed S91 promoters were isolated. Visualization of GFP by epifluorescence microscopy was markedly reduced when S91 (mini-Tn10-kan-gfp) cells were grown in rich medium compared to that when cells were grown in minimal medium. Mini-Tn10-kan-gfp was used to create an S91 chitinase-negative, GFP-positive mutant. Expression of the chi-gfp fusion was induced in cells exposed to N'-acetylglucosamine or attached to chitin particles. By laser scanning confocal microscopy, biofilms consisting of microcolonies of chi-negative, GFP+ S91 cells were found to be localized several microns from a natural chitin substratum. Tagging bacterial strains with GFP enables visualization of, as well as monitoring of gene expression in, living single cells in situ and in real time. 相似文献
95.
96.
97.
Maddox A.J. Downs R.D. Lindsay J.F. Quesada M.T. 《IEEE transactions on nuclear science》1990,37(5):1589-1593
Lucifer, a fastbus module functioning as part of the Delphi track trigger hardware in the first- and second-level trigger sequences, is described. This module is designed for flexibility, ease of testing, and usage. These aims are achieved in limited area by extensive use of application-specific IC devices. Hardware implementation, control requirements, and data bus architecture are described 相似文献
98.
99.
V Breuil F Cosman L Stein W Horbert J Nieves V Shen R Lindsay DW Dempster 《Canadian Metallurgical Quarterly》1998,13(11):1721-1729
A 10-center cooperative clinical study with a new formulation of epirubicin hydrochloride injectable solution (Epirubicin-RTU) was conducted in patients with breast cancer. One course of treatment consisted of one intravenous administration of Epirubicin-RTU at the dose of 60 mg/m2 followed by a 3-week drug-free interval and concomitant daily administration of oral cyclophosphamide at 100 mg/day during the period between Days 1 through 14. At least, two courses of treatment were given. Among 20 registered cases, all 20 cases were eligible and 16 cases completed the whole course of the study. In 16 completers, PR was observed in 5 cases, indicating the efficacy rate of 31.3% (5/16).. No local irritation was observed at the injection sites. Adverse reactions frequently observed were leukopenia, neutropenia, anorexia, alopecia, and nausea/vomiting, which were all reversible and tolerable. From the above results, Adverse reactions both locally and systemically were tolerable. Intravenous administration of Epirubicin-RTU was considered to be useful for the treatment of breast cancer. 相似文献
100.
RL Garnett A MacIntyre P Lindsay GG Barber CW Cole G Hajjar NV McPhail TD Ruddy R Stark D Boisvert 《Canadian Metallurgical Quarterly》1996,43(8):769-777
PURPOSE: The goal of this randomized study was to determine whether combined general and epidural anaesthesia with postoperative epidural analgesia, compared with general anaesthesia and postoperative intravenous analgesia, reduced the incidence of perioperative myocardial ischaemia in patients undergoing elective aortic surgery. METHOD: Patients were randomly assigned to one of two groups. One group (EPI, n = 48) received combined general and epidural anaesthesia and postoperative epidural analgesia for 48 hrs. The other group (GA, n = 51) received general anaesthesia followed by postoperative intravenous analgesia. Anaesthetic goals were to maintain haemodynamic stability (+/- 20% of preoperative values), and a stroke volume > 1 ml.kg-1. A Holter monitor was attached to each patient the day before surgery. Leads 11, V2, and V5 were monitored. Myocardial ischaemia was defined as ST segment depression > 1 mm measured at 80 millisec beyond the J point or an elevation of 2 mm 60 millisec beyond the J point which lasted > 60 sec. An event that lasted > 60 sec but returned to the baseline for > 60 sec and then recurred, was counted as two separate events. The Holter tapes were reviewed by a cardiologist blind to the patient's group. RESULTS: There were no demographic differences between the two groups. Myocardial ischaemia was common; it occurred in 55% of patients. In hospital, preoperative ischaemia was uncommon (GA = 3, EPI = 8). Intraoperative ischaemia was common (GA = 18, EPI = 25). Mesenteric traction produced the largest number of ischaemic (GA = 11, EPI = 11) events. Postoperative ischaemia was most common on the day of surgery. Termination of epidural analgesia produced a burst of ischaemia (60 events in 9 patients). CONCLUSION: Combined general and epidural anaesthesia and postoperative epidural analgesia do not reduce the incidence of myocardial ischaemia or morbidity compared with general anaesthesia and postoperative intravenous analgesia. 相似文献