含铈固体超强酸SO2-4/ZrO2-CeO2催化合成乙酸丁酯的研究

以固体超强酸SO42-/ZrO2-CeO2作催化剂,冰醋酸和正丁醇为原料合成了乙酸丁酯.采用正交实验法对影响反应的因素进行了考察.结果表明最佳反应条件为n(醇)∶n(酸)=2∶1,催化剂用量为反应混合物总量的1.5%(质量分数),反应时间为3h,酯化率可达92.6%.     

含铈固体超强酸SO_4~(2-)/ZrO_2-CeO_2催化合成乙酸丁酯的研究

以固体超强酸 SO42 - / Zr O2 - Ce O2 作催化剂 ,冰醋酸和正丁醇为原料合成了乙酸丁酯。采用正交实验法对影响反应的因素进行了考察。结果表明 :最佳反应条件为 n(醇 )∶ n(酸 ) =2∶ 1,催化剂用量为反应混合物总量的 1.5 %(质量分数 ) ,反应时间为 3h,酯化率可达 92 .6 %。     

稀土固体超强酸Gd3+- SO2-4/ZrO2催化合成乙酸正丁酯

采用乙酸、正丁醇为原料,以固体超强酸Gd3+ -SO2-4/ZrO2作为催化剂,催化合成乙酸正丁酯.用固体超强酸Gd3+ -SO2-4/ZrO2和SO2-4/ZrO2进行催化活性对比试验,考察浸渍硫酸浓度、浸渍时间、焙烧温度对催化剂活性的影响以及原料酸醇比、反应时间、催化剂用量对酯化率的影响,从而确定固体超强酸的最佳制备条件.试验结果表明:在反应温度105～110℃,催化剂用量1.5g,n(正丁醇)∶n(乙酸)=2.5∶1,反应时间2.5h条件下,酯化率可达98.86％;催化剂重复使用效果明显;加Gd3+的固体超强酸的催化活性明显增强.     

稀土固体超强酸Gd3+-SO2-4/ZrO2催化合成乙酸正丁醋

采用乙酸、正丁醇为原料,以固体超强酸Gd3+-SO24-/ZrO2作为催化剂,催化合成乙酸正丁酯。用固体超强酸Gd3+-SO42-/ZrO2和SO24-/ZrO2进行催化活性对比试验,考察浸渍硫酸浓度、浸渍时间、焙烧温度对催化剂活性的影响以及原料酸醇比、反应时间、催化剂用量对酯化率的影响,从而确定固体超强酸的最佳制备条件。试验结果表明:在反应温度105～110℃,催化剂用量1.5g,n(正丁醇)∶n(乙酸)=2.5∶1,反应时间2.5h条件下,酯化率可达98.86%;催化剂重复使用效果明显;加Gd3+的固体超强酸的催化活性明显增强。     

三氧化二钕催化制备乙酸异丁酯

研究了以三氧化二钕为固体催化剂,由冰乙酸和异丁醇合成乙酸异丁酯,讨论了影响酯化反应的因素,找出了合成乙酸异丁酯的最佳工艺条件。本工艺特点是催化剂用量少,是异丁醇的5%,反应时间短(3h),温度为110℃,酯收率可达80%。     

LaCl3·7H2O催化合成异丁酸酯

以LaCl3·7H2O替代传统液体无机酸为催化剂,以合成异丁酸正丁酯为探针反应考察催化酯化反应的优化条件,并在此条件下合成了多种异丁酸酯,比较了不同催化剂对催化合成异丁酸正丁酯的影响.实验结果表明,LaCl3·7H2O对酯化反应具有良好的催化活性,并能避免液体无机酸催化剂所引起的弊端,异丁酸正丁酯的酯化率可达96.5 %.且催化剂易回收,反应后处理简单,无废酸排放,是一种环境友好型催化剂.     

用环境友好催化剂合成丙酸异丁酯的研究

报道了以固载杂多酸盐TiSiW12O40/TiO2为环境友好催化剂，对以丙酸和异丁醇为原料合成丙酸异丁酯的反应条件进行了研究。实验表明：TiSiW12O40/TiO2是合成丙酸异丁酯的良好催化剂，最佳反应条件为：n（醇）：n(酸）=1.2:1，催化剂用量为反应物料总质量的2.0%。反应时间1.0h，反应温度106-125℃，上述条件下，丙酸异丁酯的收率可达79.1%。     

稀土复合固体超强酸SO42-/ZrO2-2%Sm2O3催化合成乙酸辛酯

采用共沉淀法制备了稀土复合固体超强酸SO42-/ZrO2-2%Sm2O3催化剂,并对以乙酸和辛醇为原料合成乙酸辛酯的反应条件进行了探索.研究表明,当辛醇与乙酸的摩尔比为1:2,反应时间为6h,反应温度为120℃,催化剂用量为6%辛醇的质量时,酯化率可达91.73%,选择性高达100%.研究发现,该催化剂可重复使用,并能活化再生.     

稀土复合固体超强酸SO42-/ZrO2- 2% Gd2O3催化合成乙酸戊酯

制备了稀土复合固体超强酸SO₄2-/ZrO_2- 2%Gd₂O₃催化剂,并对以乙酸和戊醇为原料合成乙酸戊酯的反应条件进行了研究。研究表明:当戊醇与乙酸的摩尔比为1:1.5,反应时间为6h,反应温度为130℃,催化剂用量为6%戊醇的质量时,反应酯化率最高,酯化率可达98.93%,选择性高达100%。研究发现,该催化剂可重复使用,并能活化再生。      

固体酸La2O3-Ga2O3/硅胶的研制及其催化合成丙酸异丁酯

采用自制固体酸La2O3-Ga2O3/硅胶为催化剂催化丙酸与异丁醇进行酯化反应合成了丙酸异丁酯,并采用IR分析对催化剂进行了表征。催化剂的制备条件为La2O3∶Ga2O3∶硅胶=5∶20∶75(质量比),500℃焙烧2 h。考察了催化剂用量、醇酸物质的量比、反应时间、带水剂种类和催化剂的重复使用性等因素对酯化率的影响。结果表明,适宜的反应条件为0.20 mol丙酸,催化剂用量1.00 g、醇酸物质的量比1.8,反应时间90 min,酯化率可达98.2%。     

Voices of fear and anxiety and sadness and depression: The effects of speech rate and loudness on fear and anxiety and sadness and depression.

Two studies investigated the role of expressive vocal behavior (specifically, speech rate and loudness) in fear and anxiety and in sadness and depression. In the 1st study, participants spoke about personally experienced fear and anxiety-arousing and neutral events using 3 different voice styles: fast and loud, normal, and slow and soft. In the 2nd study, participants spoke about personally experienced sad or depressing and neutral events using the same 3 voice styles. In both studies, the participants' highest levels of subjective affective and cardiovascular (CV) arousal occurred when they spoke about the emotional events in a mood-congruent voice style: fast and loud in the case of fear and anxiety, and slow and soft in the case of sadness or depression. Mood-incongruent voice styles canceled the heightened levels of CV arousal normally associated with these negative emotions. The voice-style manipulation had no significant effect on the participants' levels of CV arousal during the neutral discussions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis and analysis of mixed chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans and assessment of formation and occurrence of the fluorinated and chlorinated-fluorinated dibenzo-p-dioxins and dibenzofurans

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.     

Sexuality and aging--usual and successful

BACKGROUND: As aging research increasingly reflects an effort to dissociate true time-driven changes from those that can be improved, sexuality in later life remains largely unexplored. Several problems are evident. There is a lack of normative data, a lack of a conceptual framework relating to the biology, psychology, and sociology of sex, and an attitudinal resistance that obscures the entire topic. METHODS: We conducted a three-part instructional series on major topics involved with sexuality and aging. We surveyed our group of attendees (n 158, average age 68 for males, 65 for females) before and after the series. RESULTS: A remarkably robust sex life was evidenced by both the men and the women, even until advanced old age. Yet, a substantially decreased involvement was reported from 10 years earlier. Despite current activities, people of both sexes wished they were participating even more than they currently were. Impotency was identified as the major negative feature for the men; relationship problems were for the women. A questionnaire 6 months after the series reported improved sexual attitudes, but no change in sexual activities from the earlier survey. CONCLUSION: Sexuality is a major quality-of-life issue which persists into old age. Our study showed that the usual sexual practices reported by our group were not considered by them to be ideal. The intervention of this instructional series provided improved sexual attitudes but not performance. Additional studies are encouraged.     

Spondylolysis and spondylolisthesis and sports

Spondylolysis and spondylolisthesis occur predominantly in the lower lumbar spine. Besides congenital defects such as predisposition of spondylolysis the correlation between competitive sports activities and an increased incidence of spondylolysis is proved. In early stages, complete healing can be achieved by conservative treatment (abstinence from sports activities for 3 months, orthesis). Persistence of pain, neurologic symptoms and progression of vertebral slipping are indications for operative treatment (reconstruction of the isthmus, dorso-ventral spondylodesis). The exercise tolerance depends on the extent of instability, progression of vertebral slipping and clinical symptoms. The limits of exercise tolerance vary among the individual athletes and require the decision of the physician. Backstroke swimming, abdominal and back muscle strengthening exercises, and types of sport involving smooth movements are advisable. Sports education in school is possible without restriction in patients with stable spondylolysis and in those with spondylolisthesis without unfavourable concomitant factors.     

Larks and owls and health, wealth, and wisdom

OBJECTIVE: To test the validity of Benjamin Franklin's maxim "early to bed and early to rise makes a man healthy, wealthy, and wise." DESIGN: Cross sectional analysis of sleeping patterns in a nationally representative group of elderly people, and longitudinal investigation of mortality. SETTING: Eight areas in Britain (five in England, two in Scotland, and one in Wales). SUBJECTS: 1229 men and women aged 65 and over who in 1973-4 had taken part in a survey funded by the Department of Health and Social Security and for whom data on sleeping patterns, health, socioeconomic circumstances, and cognitive function had been recorded. MAIN OUTCOME MEASURES: Self reported income, access to a car, standard of accommodation, performance on a test of cognitive function, state of health and mortality during 23 years of follow up. RESULTS: 356 people (29%) were defined as larks (to bed before 11 pm and up before 8 am) and 318 (26%) were defined as owls (to bed at or after 11 pm and up at or after 8 am). There was no indication that larks were richer than those with other sleeping patterns. On the contrary, owls had the largest mean income and were more likely to have access to a car. There was also no evidence that larks were superior to those with other sleeping patterns with regard to their cognitive performance or their state of health. Both larks and owls had a slightly reduced risk of death compared with the rest of the study sample, but this was accounted for by the fact that they spent less time in bed at night. In the study sample as a whole, longer periods of time in bed were associated with increased mortality. After adjustment for age, sex, the presence of illness, and other risk factors, people who spent 12 or more hours in bed had a relative risk of death of 1.7 (1.2 to 2.5) compared with those who were in bed for 9 hours. The lowest risk occurred in people who spent 8 hours in bed (adjusted relative risk 0.8; 0.7 to 1.0). CONCLUSION: These findings do not support Franklin's claim. A "late to bed and late to rise" lifestyle does not seem to lead to socioeconomic, cognitive, or health disadvantage, but a longer time spent in bed may be associated with increased mortality.     

Craniometaphyseal and craniodiaphyseal dysplasia, head and neck manifestations and management

Mechanical allodynia (MA) following hand injury is a well-documented clinical problem. The purpose of this pilot study was to examine the relationship between hand MA and the upper limb tension test (ULTT). The ULTT mechanically stresses the neural structures from the C5/6/7 neural foramina to the median nerve distally. This study examined 29 subjects with unilateral hand MA before and after a 2-week neural self-mobilization programme. There was a significant difference between the subjects' affected and unaffected sides when tested using the ULTT, both in reproduction of symptoms and in reduced range of motion of the ULTT. Following the self-mobilization program, there was an improvement in the range of the ULTT, and subjects reported a reduction in their symptoms. Complete recovery was not obtained in all cases. The results of this study suggest that the ULTT is a useful tool both in assessment and treatment of subjects with hand MA.     

深云立交桥梁检测及加固改造

根据深云立交桥梁的检测结果，对该桥目前的整体状况、工作状态，及其使用情况做出综合评价，对桥的病害原因进行了分析，并提出合理的加固方案。     

关于摩尔浓度及其与硬度转换关系问题的讨论

众所周知，国际单位制物质的量采用摩尔(mol)表示，近几年出版的给排水专业书籍，为了与国际单位制接轨，逐渐将摩尔的使用频率不断提高，被给排水技术人员广泛应用的新版给排水设计手册，将表示物质浓度的单位“当量／升”或“毫克当量／升”．改为mol／l或mmol／l，虽然编者对其基本单元定义作了说明，但在实际运用上仍会出现误解，     

《儿子与情人》的语码转换与男女二元对立

劳伦斯小说《儿子与情人》一个鲜明的语言特色就是标准英语和当地方言频繁的语码转换。莫瑞尔用方言来对抗妻子,而妻子坚持用标准英语,偶尔也用方言来讽刺、挖苦丈夫。语码转换反映了劳伦斯男女二元对立的哲学思想。