一种新型装配式钢骨混凝土节点的抗震性能研究

为了避免装配式钢骨混凝土节点核心区的破坏,提出一种可实现损伤部位转移的新型节点形式.以框架边节点为研究对象,建立7组节点数值模型,开展低周反复荷载试验.从混凝土等效塑性应变、钢筋骨架Mises应力、节点滞回曲线和骨架曲线等方面计算分析,探究混凝土强度等级、柱轴压比、焊接位置、梁柱强度比等参数的影响.结果表明:装配式节点可将损伤位置从核心区转移到梁端;增加混凝土强度等级,可提高节点承载能力,但节点耗能能力和延性会下降;调整柱轴压比,可减小等效塑性应变,但对钢筋骨架应力、耗能能力、承载能力等影响极小;增加焊接位置至柱边距离,可使节点损伤部位外移,屈服后刚度和承载力有所提高,但耗能能力有所下降;增加梁柱强度比能够改善节点的耗能能力和承载力,但当强度比超过0.6时,梁端与节点核心区应力差变小.     

一种新型装配式钢骨混凝土节点的抗震性能研究

为了避免装配式钢骨混凝土节点核心区的破坏,提出一种可实现损伤部位转移的新型节点形式.以框架边节点为研究对象,建立7组节点数值模型,开展低周反复荷载试验.从混凝土等效塑性应变、钢筋骨架Mises应力、节点滞回曲线和骨架曲线等方面计算分析,探究混凝土强度等级、柱轴压比、焊接位置、梁柱强度比等参数的影响.结果表明:装配式节点可将损伤位置从核心区转移到梁端;增加混凝土强度等级,可提高节点承载能力,但节点耗能能力和延性会下降;调整柱轴压比,可减小等效塑性应变,但对钢筋骨架应力、耗能能力、承载能力等影响极小;增加焊接位置至柱边距离,可使节点损伤部位外移,屈服后刚度和承载力有所提高,但耗能能力有所下降;增加梁柱强度比能够改善节点的耗能能力和承载力,但当强度比超过0.6时,梁端与节点核心区应力差变小.     

新型装配式双舱综合管廊节点的力学性能试验

预制装配综合管廊结构中,节点是结构的薄弱环节,其力学性能直接影响整体结构的变形和承载力等。本文提出了一种“U型套箍插筋连接”新型装配式双舱综合管廊结构,通过4个节点足尺试件力学性能试验,包括1个底部L型现浇边节点试件,1个底部L型装配边节点试件,1个顶部L型装配节点试件和1个底部T型装配节点试件,以此来验证“U型套箍插筋”连接技术的有效性。试验得到了节点足尺试件的开裂荷载、裂缝发展规律、承载能力、破坏方式、构件延性等力学性能。试验结果表明:新型装配式管廊节点试件都在靠近角点区域发生弯剪破坏,具有较高的承载力和延性;采用“U型套箍插筋”连接性能可靠,能够获得与现浇节点试件相当的力学性能。      

高钛重矿渣纤维混凝土力学性能试验研究

考虑纤维掺量、水胶比和粉煤灰掺量3个主要因素,采用正交试验设计20组高钛重矿渣纤维混凝土试件,结合SEM分析研究纤维掺量、水胶比等因素对高钛重矿渣纤维混凝土力学性能的影响。试验结果表明:水胶比对高钛重矿渣混凝土的抗折与抗压强度影响最大;玄武岩纤维可以显著提高高钛重矿渣混凝土抗折强度,塑钢纤维可以明显提高高钛重矿渣混凝土抗压强度。当水胶比为0.32,玄武岩纤维掺量1 kg,粉煤灰掺量5%时,高钛重矿渣纤维混凝土抗折强度为5.61 MPa,比未掺纤维的高钛重矿渣混凝土提高10%。当水胶比为0.34,塑钢纤维掺量2 kg,粉煤灰掺量5%时,高钛重矿渣混凝土的抗压强度为60.45 MPa,达到GB50010—2010《混凝土结构设计规范》规定的C55等级。     

锈蚀植筋下新老混凝土黏结面压剪试验研究

为研究锈蚀植筋下新老混凝土的黏结性能,采用某工程锈蚀钢筋作为植筋,制备了不同植筋率（0、0.223%、0.446%、0.502%、0.893%、1.004%、1.396%、1.786%和2.792%）的新老混凝土试件.在RYL-600微机控制岩石伺服剪切流变仪上进行了不同初始静压力（0、1、2、3和4 MPa）下混凝土试件的剪切试验.对试件的剪应力-位移曲线进行了归纳总结,得到了锈蚀植筋下新老混凝土试件在外力作用下产生变形乃至破坏的演化规律;分析了锈蚀植筋下新老混凝土黏结面的抗剪强度,得到了抗剪强度随植筋率及初始静压力变化的规律.同时根据试件试验破坏结果,着重分析了不同植筋率和不同初始静压力对其破坏模式的影响.试验结论为新老混凝土力学性能的研究提供了理论依据.      

废旧橡胶喷射混凝土力学性能研究

为改善巷道喷射混凝土的变形性,研究了不同粒径(26、40、60目)、不同掺量(5%、10%、15%、20%)废旧橡胶颗粒对喷射混凝土力学性能的影响,结果表明:橡胶颗粒的掺入能够提高喷射混凝土的断裂挠度、折压比,改善了喷射混凝土的变形能力;试验研究中粒径为40目,掺量为10%时,喷射混凝土的韧性指标最佳;橡胶颗粒的掺入使喷射混凝土的抗压强度和劈裂抗拉强度均有所降低,抗折强度略有增长。     

地聚合物混凝土配比及力学性能研究

混凝土是巷道支护过程中的重要建筑材料,然而混凝土在巷道施工中常常出现质量问题,为了不影响正常生产,需要对其进行修补。地聚合物混凝土凝结时间快,早期强度高,界面结合能力强,耐高温性和抗冻性强,耐腐蚀性良好,具有用作修补材料的潜力。以粉煤灰和矿粉为原料,Na₂SiO₃溶液和NaOH为碱激发剂制备地聚合物胶砂,研究不同的碱激发剂模数（1.0、1.2、1.4）和掺量（10%、15%、20%）对不同龄期胶砂力学性能的影响。结果表明：当碱激发剂模数为1.2,碱掺量为15%时,胶砂强度达到最大值。设计正交试验,研究了不同水胶比（0.45、0.50、0.55）、粉煤灰掺量（30%、50%、70%）和砂率（30%、35%、40%）对不同龄期地聚合物混凝土的工作性能和力学性能的影响。结果表明：粉煤灰掺量对抗压强度影响最为显著,水胶比次之,而砂率对强度发展几乎没有影响。最优的配合比为水胶比为0.50,粉煤灰掺量为50%,砂率为35%。     

变形量对旋转锻造钨合金组织及绝热剪切敏感性影响

对烧结态93W-4.9Ni-2.1Fe合金进行不同变形量旋转锻造,研究变形量对钨合金微观组织及绝热剪切敏感性的影响。微观组织观察结果表明,旋转锻造形变后钨颗粒沿变形方向被拉长为椭球形,随变形量由3.45%增加至42.11%,钨颗粒变形程度加剧,长径比由1.32增加至2.41;位于钨颗粒间的粘结相则沿变形方向逐渐拉长为细长的条状组织。对不同变形量的旋转锻造钨合金,沿棒料径向取样进行动态压缩试验后发现:当变形量增加至15.84%(钨颗粒长径比1.47)时,旋转锻造钨合金塑性变形方式发生改变,合金中开始出现绝热剪切现象;此后,随旋转锻造变形量(钨颗粒长径比)的增加,旋转锻造钨合金中绝热剪切带宽度减小,合金绝热剪切敏感性增大。随旋转锻造变形量(钨颗粒长径比)的增大,合金应变硬化能力减小,同时动态加载时绝热温升数值增大,软化效应增强,这是旋转锻造钨合金绝热剪切敏感性随变形量(钨颗粒长径比)增加而增大的主要原因。     

曲柄摇杆式,双曲柄式飞剪机运动学分析与比较

用解析法对具有两种不同的铰链四杆式剪机构的飞剪机进行运动学分析,利用电算结果,分析了在剪切厚轧件时,为了有利于提高剪切质量,减小飞剪机负载所应采用的最佳铰链四杆式剪切机构。     

钢-混凝土组合板的弹性整体剪切屈曲分析

为了研究钢-混凝土组合板的弹性整体剪切屈曲性能,采用夹层板理论推导了组合板弹性屈曲方程,分析了界面剪切刚度的影响.通过在钢与混凝土之间设置假想的剪切薄层,模拟钢-混凝土组合板界面滑移效应,建立考虑滑移效应的组合板分析模型,推导出四边简支矩形组合板在均匀受剪状态下的弹性屈曲方程,并分析了界面剪切滑移刚度对屈曲荷载的影响.通过参数分析拟合了防止完全剪力连接四边简支组合板整体屈曲所需混凝土板最小厚度的计算公式.结果表明,剪切刚度较小时,屈曲荷载增长较快;剪切刚度较大时,屈曲荷载变化缓慢并逐渐趋于稳定,与完全剪力连接组合板的屈曲值接近.该结果与有限元计算结果吻合较好.     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.     

Quality of life of relatives of mental patients

Usage of quality of life of psychiatric patients' relatives as the parameter of estimation of the quality of psychiatric care is considered. By means of standard questionnaire elaborated by the authors as well as by means of both individual and group conversations the quality of life was analyzed in 40 relatives which lived together with psychiatric patients. Different spheres of their life and difficulties (financial, social-psychologic, production) were examined in families with such patients. The defects of psychiatric care that had direct influence on the quality of life of the psychiatric patients' relatives are outlined.