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161.
Wenying Wei Zhen Wang Yanhua Yin Jinyu Han Wen Xu 《Korean Journal of Chemical Engineering》2008,25(3):562-567
Composition Group Vector Space (CGVS) method for estimating melting and boiling point T
m
, T
b
of organic compound has been proposed, and the principle of this method has been elucidated. The models for estimating T
m
, T
b
have been established and the numerical values of relative parameters have been presented. The average percentage deviations
of T
m
, T
b
estimation are 7.53 and 1.58, respectively, which show that the present method demonstrates significant improvement in applicability
to predict the above properties, compared to conventional group methods. 相似文献
162.
介绍在Windows XP家庭版下成功安装与配置ⅡS和ASP.NET的方法。 相似文献
163.
164.
CONTEXT: Adolescent smoking prevalence is tracked annually and has increased since 1991. In contrast, little is known about trends in smoking among college students, a group that has previously been more resistant to tobacco use than other young adults. OBJECTIVE: To examine changes in cigarette smoking among college students between 1993 and 1997 and among different types of students and colleges. DESIGN: Self-administered survey (Harvard School of Public Health College Alcohol Study). SETTING: One hundred sixteen nationally representative 4-year colleges. SUBJECTS: A total of 15103 randomly selected students in 1993 (70% response rate) and 14251 students in 1997 (60% response rate). MAIN OUTCOME MEASURES: Self-reports of cigarette smoking in the past 30 days and in the past year, age at smoking first cigarette, and number of attempts to quit. RESULTS: Over 4 years, the prevalence of current (30-day) cigarette smoking rose by 27.8%, from 22.3% to 28.5% (P<.001). The increase was observed in 99 of 116 colleges and was statistically significant (P<.05) in 27 (23%) of them. Current smoking increased across all student subgroups (defined by sex, race/ethnicity, and year in school) and in all types of colleges. Smoking is rising faster in public schools (from 22.0% to 29.3%) than in private schools (from 22.9% to 26.8%). Eleven percent of college smokers had their first cigarette and 28% began to smoke regularly at or after age 19 years, by which time most were already in college. Half of current smokers tried to quit in the previous year; 18% had made 5 or more attempts to quit. CONCLUSIONS: Cigarette use is increasing on campuses nationwide in all subgroups and types of colleges. Substantial numbers of college students are both starting to smoke regularly and trying to stop. National efforts to reduce smoking should be extended to college students. 相似文献
165.
无向网络K终端可靠度的分解算法中,包括多边形→链简化在内的等可靠度简化和分解定理结合,可以降低算法的复杂度。本文完善了边随机无向网络和混合随机无向网络的4#,6#,7#型多边形→链简化定理。计算机编程验证了其正确性。 相似文献
166.
An acute pulpalgia and temporomandibular disorders can produce many of the same symptoms. To illustrate identification of an acute pulpalgia as a component in TMD, the authors review the evaluation of 11 patients at a clinic that specializes in TMD treatment. During the evaluation, thermal testing and periodontal ligament anesthesia were used to identify the offending tooth. After receiving endodontic treatment or having the tooth extracted, patients reported either complete or partial relief of TMD symptoms. The authors provide questions that may help practitioners identify a tooth with an acute pulpalgia as a contributing factor to TMD symptoms and suggest a technique to confirm this diagnosis. 相似文献
167.
颗粒表面改性法制备PTC粉体的研究 总被引:5,自引:0,他引:5
本文介绍了一种通过液相颗粒表面改性技术添加二次掺杂物来制备PTC粉体的新方法。即将烧结助熔剂Al2O3,SiO2以及受主杂质MnO采用溶液形式,包裹在BaTiO3基粉体颗粒表面进行改性,由此可以得到二次掺杂物Al2O3、SiO2和MnO分布均匀的PTC粉体。 相似文献
168.
JD Ragland DM Censits RC Gur DC Glahn F Gallacher RE Gur 《Canadian Metallurgical Quarterly》1996,60(2-3):135-145
The Paired Associate Recognition Test (PART) was developed to measure declarative memory using Wisconsin Card Sorting Test (WCST) stimuli, so that both tasks could be administered during functional neuroimaging to differentiate memory and executive function, and associated frontal and temporal lobe activation in schizophrenia. The current study was designed to compare PART and WCST performance in schizophrenic patients and to examine effects of medication and symptomatology. The PART, WCST, and standard declarative memory tasks were administered to 30 chronic schizophrenic patients and 30 matched healthy control subjects. Supporting task validity was the finding that patients were equally impaired on the PART and the WCST. Neuroleptics did not appear to affect performance. The effect of anticholinergic medication correlated negatively with WCST performance in a small subsample. Severity of schizophrenia-specific symptoms measured at intake on the Brief Psychiatric Rating Scale correlated negatively with performance on the WCST. These results support the application of the PART and WCST in future functional neuroimaging studies. 相似文献
169.
周冰毅 《有色金属(冶炼部分)》1996,(6):14-17
亚铜离子氨浸法作为大洋多金属结核处理方法之一,一直被认为是一个很有前途的冶金处理工艺,是催化化学还原技术在冶金生产中的具体应用,具有流程简单,能耗低,浸出选择性好,产品结构灵活,市场适应能力强,浸出试剂腐蚀性与毒性小,环境污染小等优点。 相似文献
170.
RY Lin DC Saha CJ Bernstein ME Astiz EC Rackow 《Canadian Metallurgical Quarterly》1996,27(5-6):303-317
Sepsis and trauma have similarities in their immunopathologic profiles. Both conditions can result in multi-system organ failure which is sometimes associated with cytokine generation and inflammatory cell activation. Furthermore, decreases in peripheral blood monocyte expression of HLA-DR have been noted in both human sepsis and trauma. However, the magnitude, onset, and time course of such stimuli are often difficult to ascertain in human studies. Thus, to study a more detailed in vivo immunologic profile in these conditions, rat models were employed. Our aim was to describe and analyze cytokine and peripheral blood immunophenotype patterns in bacterially induced rat sepsis and to compare this to rat ischemia-reperfusion injury. Sprague-Dawley rats underwent either bacterial injection with enterotoxin producing Staphylococcus aureus or hind limb ischemia/ reperfusion. Two bacterial doses which were either lethal or sublethal at 24-48 hours were utilized. Peripheral blood neutrophils and B-lymphocytes were studied for expression of beta-integrins (CD11b and CD11b/c) and I-A, respectively, using flow cytometry. Corresponding plasma levels of TNF alpha and interferon gamma were measured by ELISA. At 24 hr, a lethal bacterial lethal bacterial dose injection resulted in significantly higher levels of neutrophil CD11b/c expression (p < 0.005) compared with ischemia-reperfusion treatment. B-cell I-A expression was also higher in lethal sepsis. Gamma interferon levels were significantly higher in lethal sepsis compared with ischemia-reperfusion (p = 0.005). Studies over time showed that CD11b expression and interferon gamma were both more marked at 6 hr than at 24 hr in lethal sepsis. This pattern was not observed in sublethal sepsis or in ischemia-reperfusion. CD11b/c expression on the other hand remained elevated at comparable levels at 6 and 24 hr in lethal sepsis. B-cell I-A expression in ischemia-reperfusion and sublethal sepsis decreased at 24 hr compared with baseline. Lethal sepsis in rats injected with enterotoxin producing staphylococcus results in phasic alterations in neutrophil CD11b and plasma interferon levels prior to death. In analogy to the findings of monocyte decreases in DR expression observed in human trauma and sepsis, rat B-cell I-A expression showed decreases in sublethal sepsis as well as in ischemia-reperfusion injury. However, this was not observed in lethal sepsis. These findings have implications in understanding the immunologic/inflammatory changes observed in human sepsis and trauma. 相似文献