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研究了用新试剂5-(5-硝基-2-吡啶偶氮)-2,4-二氨基甲苯(5-NO2-PADAT)分光光度法测定微量铱(Ⅲ)的适宜条件。结果表明,在pH5.0-6.4的NaAc-HAc缓冲溶液中,5-N02-PADAT与Ir(Ⅲ)反应生成稳定的络合物。在0.12mol/LH2SO4溶液中其最大吸收波长,表现摩尔吸光系数铱浓度在0-0.7ug/ml范围内遵守比尔定律。以DCTA为掩蔽剂。大量的常见金属离子对测定无干扰,方法灵敏度高,选择性好,用于催化剂中微量铱的测定,结果满意。 相似文献
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在pH2.4~3.5的酸性介质中及加热条件下,钼(VI)与2-(3,5一二溴-2-吡啶偶氮)-5-二乙氨基苯酚(3,5-diBr-PADAP)及羟胺反应形成一种稳定的蓝色络合物,组成比为1:1:1。在十二烷基硫酸钠存在下,其最大吸收波长为6l8nm,表现摩尔吸光系数为4.8×l0 ̄4,钼含量在0~25μg/10ml时服从比尔定律。毫克量钨无干扰。铜、钴、镍、铁等高厂的干扰可通过离厂交换分离除去。本法用于测定软磁合金中的铝,获得了满意的结果。 相似文献
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用BDAS—W(Ⅵ)—CPB三元配合物测定钼精矿中微量钨 总被引:1,自引:0,他引:1
研究了BDAS(2-Bromo-4,5-dihydroxyazobenzene-4′-sulfomate(abbreviatedasBDAS)-W(Ⅵ)-CPB(溴化十六烷吡啶)混合配位体系的分光光度特性,该体系适宜酸度为pH2.3~4.5氯乙酸介质,干扰离子少。BDAS-W(Ⅵ)-CPB三元配合物的最大吸收波长λmax=493nm在CPB存在下W(Ⅵ)与BDAS所形成的配合物组成比为1:2。在0 相似文献
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Kerns John G.; Docherty Anna R.; Martin Elizabeth A. 《Canadian Metallurgical Quarterly》2008,117(4):735
Two studies examined whether self-reported anhedonia is associated with 2 facets of emotional experience, valence and arousal. In Study 1, in multiple assessments of emotional experience (e.g., naturalistic and lab contexts and social and nonsocial situations), people with elevated social anhedonia (n = 40) reported less intensity of positive affect than both controls (n = 30) and people with elevated perceptual aberration-magical ideation (n = 29). Social anhedonia was also associated with providing less emotional content when describing what it is like to experience positive situations. In contrast, both social anhedonia and perceptual aberration-magical ideation were associated with increased frequency of negative affect for their daily experiences. Moreover, social anhedonia was not associated with a decrease specifically in high-arousal emotions. In Study 2 (n = 339), social and physical anhedonia (but not perceptual aberration-magical ideation) were again associated with decreased self-reported positive affect to lab stimuli. In these studies, results were not statistically accounted for by personality, current mood, or current distress. Overall, results suggest anhedonia may be associated with a general decrease in self-reported positive affect intensity. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Aqueous solutions of trichloroethylene (TCE) and tetrachloroethylene (PCE) were treated in a flow-through reactor equipped with ultrasound and ultraviolet light sources. The reactor was operated as sonolysis (US), photolysis (UV), and simultaneous photosonolysis (UV/US) reactors; then as US, UV, and sequential UV/US reactors with the installation of a partition in the reactor. The reactor without the partition was simulated by using one continuously stirred-tank-reactor (1-CSTR) model, and the reactor with the partition was simulated by using the sequential CSTR model. Through model calibration, the decomposition rate constants and reactor efficiencies for the removal of TCE and PCE were evaluated. The results suggest that the combined effect of UV and US on the decomposition of TCE and PCE is synergistic in both the simultaneous and sequential UV/US modes, that the rate constants of sonolysis and photolysis are greater with the sequential combination than with the simultaneous combination, and that overall efficiency is higher for the reactor with the partition than for the one without it. 相似文献
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Oscar-Berman Marlene; Hutner Nancy; Bonner Robert T. 《Canadian Metallurgical Quarterly》1992,106(4):613
36 male alcoholics (13 with Korsakoff's syndrome) and 24 controls performed visual and auditory delayed-response tasks sensitive to prefrontal cortical damage in nonhuman primates. Korsakoff patients were consistently impaired compared with other Ss. Impairments by Korsakoff patients were evident when demands were placed on visual processing time (brief stimulus durations), and the deficits became exaggerated with increased demands on short-term memory. Under the most difficult experimental conditions, controls and non-Korsakoff alcoholics who were over 50 yrs old performed somewhat worse compared with younger groups 27–49 yrs old. Age-linked deficits were mild compared with Korsakoff's deficits, and age-group differences disappeared with easier task demands. The results implicate cortical pathology in alcoholism and normal chronological aging and suggest that prefrontal damage accompanies Korsakoff's syndrome. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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ДрицМ .Е .[1,2 ] reportedthatscandium ,com paringwiththeotherrareelements ,isthemosteffec tiveadditiontopromotethestrengthofaluminumal loys .Thestrengthofas extrusionAl 6 5Mgalloyrodcontaining 0 .2 %Screaches 4 0 0MPa (σb)and 2 5 0MPa (σ0 .2 ) ,higherthanAl 6 5Mgalloywithoutscandiumonetime .Willey[3] fromAluminumCompa nyofAmericapatentedthefirstaluminumscandiumalloyin 1971.Since 70′soflastcentury ,theformerSovietUnionengagedcompletelyresearchonthepro ductionandapplicationofalum… 相似文献
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Séguin Monique; Boyer Richard; Lesage Alain; McGirr Alexandre; Suissa Amnon; Tousignant Michel; Turecki Gustavo 《Canadian Metallurgical Quarterly》2010,24(3):541
The aim of this study was to evaluate suicides with a history of problem gambling (PG) and others with no such history (NPG) and to compare the two on mental health problems and service utilization. Data on a sample of 49 PG suicides and 73 NPG suicides were obtained from informants and hospital records. Psychopathology was prevalent in both groups, but problem gamblers were twice as likely to have a personality disorder. Moreover, PG suicides were less in contact with mental health services in their last month, their last year, and their lifetime. NPG suicides consulted specialized services from 3 (last month and last year) to 13 times (lifetime) as often as their PG counterparts. Lower service utilization associated with PG suicides argues in favor of stepping up detection, engagement in care and treatment with respect to problem gambling, especially when comorbidity is present. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Despite the use of multimodal therapy, higher-grade glioma is still uniformly fatal in the adult population. There is a considerable difference between the length of survival in each given patient, even within the same tumor type and malignancy grade group, suggesting that there are factors that might differentially influence outcome. To identify such factors, 107 patients with anaplastic or malignant glioma were retrospectively investigated. Clinical parameters and paraclinical data on the p53, mdm2, and EGFR genes at the DNA or protein level were evaluated by univariate analysis and Cox proportional hazards regression modeling. Kaplan-Meier survival estimation demonstrated that immunohistochemical positivity for mdm2 protein in patients with anaplastic astrocytoma or with glioblastoma multiforme was associated with a shorter survival time (p = 0.02). P53 gene mutations and immunopositivity for the epidermal growth factor receptor (EGFR) protein were not significantly related to poor prognosis. The Cox proportional hazards model revealed immunohistochemical positivity for p53, mdm2, or for both of them, the presence of postoperative irradiation, and the extent of surgical resection of tumor to be variables significantly associated with prolonged survival. EGFR overexpression, age over 60 years, and Karnofsky performance score below 40 points did not significantly shorten survival time. In conclusion, the present study identified immunohistochemically detected mdm2-protein overexpression as a statistically significant negative prognostic parameter in patients bearing anaplastic or malignant glioma. Association analysis of variables revealed a possible correlation between mdm2 and p53, which is also consistent with the biological interaction mode of both proteins in vivo. 相似文献
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从15万m3高压橡胶膜密封煤气柜的特点出发,与同容积的稀油密封圆形煤气柜进行技术经济分析比较,分析两种柜型的优缺点,指出两种柜型的适用范围。 相似文献
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Raz Naftali; Rodrigue Karen M.; Kennedy Kristen M.; Acker James D. 《Canadian Metallurgical Quarterly》2007,21(2):149
The impact of vascular health on the relations between structural brain changes and cognition was assessed in a longitudinal study of 46 adults, 23 of whom remained healthy for 5 years and 23 of whom had hypertension at baseline or acquired vascular problems during follow-up. At both measurement occasions, the volume of white matter hyperintensities (WMH) and regional brain volumes correlated with age. In 5 years, WMH volume more than doubled in the vascular risk group but did not increase in healthy participants. The frontal lobes had the highest WMH load at baseline and follow-up; the parietal WMH showed the greatest rate of expansion. In the vascular risk group, systolic blood pressure at follow-up correlated with posterior WMH volume. The fastest cortical shrinkage was observed in the prefrontal cortex and the hippocampus. Fluid intelligence correlated with WMH burden and declined along with faster WMH progression. In the vascular risk group, WMH progression and shrinkage of the fusiform cortex correlated with decline in working memory. Thus, poor vascular health contributes to age-related declines in brain and cognition, and some of the age-related declines may be limited to persons with elevated vascular risk. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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BACKGROUND: Serotonergic abnormalities are found in both major depressive disorder (MDD) and schizophrenia. Depressive symptoms commonly occur alongside the negative or defect symptoms in schizophrenia and antiserotonergic drugs may be particularly effective in their treatment. We wished to explore whether these symptoms could be distinguished biologically by directly comparing serotonergic function in these two illnesses. METHOD: Fifteen patients with MDD and 13 patients with schizophrenia underwent testing with the specific serotonin releasing agent D-fenfluramine (D-FEN). Prolactin and cortisol responses were measured to ascertain central serotonergic function. Individual patient results were compared with their own carefully matched control to correct for the effect of age, sex, weight and menstrual cycle, before the two patient groups were then compared. RESULTS: Prolactin responses differed significantly between the two patient groups, being lower in MDD patients and higher in schizophrenia patients than their individually matched controls. Cortisol responses did not differ. Within the schizophrenia group, increased serotonergic function correlated positively with depressive symptoms, but there was no such correlation with defect symptoms. Depressive scores were negatively correlated with the presence of negative symptoms in the schizophrenic group. CONCLUSIONS: Schizophrenia and MDD have distinct and opposite neuroendocrine responses to D-FEN. There is no evidence that depressive symptoms in these two conditions have a common serotonergic basis. Moreover, these responses distinguished between negative and depressive symptoms in our schizophrenic group. 相似文献