预制混凝土梁柱节点试验及框架受力性能分析

提出了一种预制装配式混凝土梁柱节点采用I字型钢连接的节点方式,并进行了该节点在低周反复荷载作用下的试验.针对型钢连接的特征,提出了一种简化的等效十字连接方式用以模拟该节点.结合试验结果以及二维空间撒点,进行了简化节点的等效混凝土弹性模量以及钢筋屈服强度等关键参数的识别,从而可通过数值分析获得预制装配式节点的滞回曲线.根据预制装配式节点的连接方式形成框架结构,同时根据梁柱的配筋形成了现浇框架结构,采用Pushover分析了2种框架的承载力和刚度.利用简化的节点数值模拟滞回曲线进行了预制装配式框架结构在地震动作用下结构整体的受力非线性全过程分析.试验结果表明,该连接方式滞回环较饱满,节点抗震性能良好;数值分析结果表明采用型钢连接节点的预制装配式框架结构与同样梁柱配筋的现浇结构相比承载力和刚度有所提高,此装配式框架结构可满足我国抗震规范对于框架结构在弹性以及弹塑性阶段侧移限值的要求.     

利用Ti质粒介导的二元载体法向小麦导入几丁质酶基因的初步研究

以小麦ＮＰＦＤ、９４－１６７、鄂恩一号３个品种的幼胚、幼穗为受体材料,利用Ｔｉ质粒介导的二元载体法,将含有几丁质酶基因的质粒ｐＢｃｈ导入小麦,经过抗性筛选,ＰＣＲ检测,获得一株转基因小麦,证实了外源几丁质酶基因已整合到小麦基因组中．     

Meta-analysis of genome-wide association studies identifies common variants associated with blood pressure variation in east Asians

We conducted a meta-analysis of genome-wide association studies of systolic (SBP) and diastolic (DBP) blood pressure in 19,608 subjects of east Asian ancestry from the AGEN-BP consortium followed up with de novo genotyping (n = 10,518) and further replication (n = 20,247) in east Asian samples. We identified genome-wide significant (P < 5 × 10(-8)) associations with SBP or DBP, which included variants at four new loci (ST7L-CAPZA1, FIGN-GRB14, ENPEP and NPR3) and a newly discovered variant near TBX3. Among the five newly discovered variants, we obtained significant replication in the independent samples for all of these loci except NPR3. We also confirmed seven loci previously identified in populations of European descent. Moreover, at 12q24.13 near ALDH2, we observed strong association signals (P = 7.9 × 10(-31) and P = 1.3 × 10(-35) for SBP and DBP, respectively) with ethnic specificity. These findings provide new insights into blood pressure regulation and potential targets for intervention.     

起飞转弯爬升梯度损失分析

起飞转弯爬升会降低飞机的爬升能力,影响起飞安全,为了保障越障安全,需要详细确定梯度损失。通过动力学模型推导出转弯爬升时的梯度损失计算公式,揭示了试飞数据内在原理,分析了固定坡度角转弯、固定转弯半径转弯的梯度损失影响因素和转弯对起飞限重的影响。利用最小二乘法拟合了极曲线参数,计算了某机型的梯度损失数据,与试飞数据相比,计算结果平均偏差不超过0.73%,标准差不超过1.54%。可用于飞机离场程序设计、飞行性能的快速计算以及四维航迹预测。     

紫外光照射下纳米TiO2降解水中有机氯酚类化合物

选取有机氯酚类化合物邻氯苯酚(OCP)、对氯苯酚(PCP)及2,4-二氯苯酚(DCP)为目标化合物,在紫外光照射下(330 nm<λ<380 nm),以P25纳米TiO2作为光催化剂,研究其对目标化合物的降解特性.考察了酸度及紫外光光解对其降解行为的影响,结果表明OCP、PCP及DCP分别在pH 6.0、4.2、5.0酸度条件下降解效果最好.在实验条件下OCP、PCP及DCP分别降解240 min、270 min1、60 min后矿化率达到100%.OCP、PCP及DCP降解速率常数分别为0.004 54、0.003 64及0.005 03.根据实验结果及文献初步探讨了其光催化氧化降解机理.     

A giant thunderstorm on Saturn

Lightning discharges in Saturn's atmosphere emit radio waves with intensities about 10,000 times stronger than those of their terrestrial counterparts. These radio waves are the characteristic features of lightning from thunderstorms on Saturn, which last for days to months. Convective storms about 2,000 kilometres in size have been observed in recent years at planetocentric latitude 35° south (corresponding to a planetographic latitude of 41° south). Here we report observations of a giant thunderstorm at planetocentric latitude 35° north that reached a latitudinal extension of 10,000 kilometres-comparable in size to a 'Great White Spot'-about three weeks after it started in early December 2010. The visible plume consists of high-altitude clouds that overshoot the outermost ammonia cloud layer owing to strong vertical convection, as is typical for thunderstorms. The flash rates of this storm are about an order of magnitude higher than previous ones, and peak rates larger than ten per second were recorded. This main storm developed an elongated eastward tail with additional but weaker storm cells that wrapped around the whole planet by February 2011. Unlike storms on Earth, the total power of this storm is comparable to Saturn's total emitted power. The appearance of such storms in the northern hemisphere could be related to the change of seasons, given that Saturn experienced vernal equinox in August 2009.     

Meta-analysis identifies common variants associated with body mass index in east Asians

Multiple genetic loci associated with obesity or body mass index (BMI) have been identified through genome-wide association studies conducted predominantly in populations of European ancestry. We performed a meta-analysis of associations between BMI and approximately 2.4 million SNPs in 27,715 east Asians, which was followed by in silico and de novo replication studies in 37,691 and 17,642 additional east Asians, respectively. We identified ten BMI-associated loci at genome-wide significance (P < 5.0 × 10(-8)), including seven previously identified loci (FTO, SEC16B, MC4R, GIPR-QPCTL, ADCY3-DNAJC27, BDNF and MAP2K5) and three novel loci in or near the CDKAL1, PCSK1 and GP2 genes. Three additional loci nearly reached the genome-wide significance threshold, including two previously identified loci in the GNPDA2 and TFAP2B genes and a newly identified signal near PAX6, all of which were associated with BMI with P < 5.0 × 10(-7). Findings from this study may shed light on new pathways involved in obesity and demonstrate the value of conducting genetic studies in non-European populations.     

西藏地区发展文化产业的比较优势探析

与开发自然资源相比，西藏地区发展化产业具有明显的比较优势：发展化产业能避开西藏基础设施落后和资金、技术短缺的劣势；西藏地区蕴藏着十分丰富的化资源；西藏地区发展化产业具有良好的市场前景；新发展观的确立为西藏发展化产业提供了重要契机。西藏应采取各种措施推动化产业的发展。     

唐菖蒲组织培养初探

以唐菖蒲的幼嫩叶片为外植体进行组织培养,以MS为基本培养基,分别添加不同的激素组合,以获得最佳的诱导愈伤、诱芽及生根培养基．     

大豆蛋白废水生产单细胞蛋白的菌种选择及其培养条件

针对大豆蛋白生产废水的水质特性,选择了产朊假丝酵母(Candida utilis)、热带假丝酵母(Candida tropicalis)、白地霉(Geotrichum candidum link)、解脂假丝酵母解脂变种(Candida lipolytica)和扣囊拟内孢霉(Endomycopsis fiburiger)等5种工业生产酵母,作为以大豆蛋白废水生产单细胞蛋白(Single Cell Protein,SCP)的菌种,并通过摇瓶培养实验,对其培养生长条件进行了研究。结果表明,白地霉的最佳培养条件为C/N37(马铃薯-葡萄糖培养基),pH6.5,25℃,180r/min;产朊假丝酵母为C/N5(麦氏琼脂培养基),pH6,25℃,180r/min;热带假丝酵母为C/N37(马铃薯-葡萄糖培养基),pH5.5,25℃,210r/min;解脂假丝酵母为C/N37(马铃薯-葡萄糖培养基),pH5.5,25℃,180r/min;扣囊拟内孢霉为C/N37(马铃薯-葡萄糖培养基),pH6,25℃,180r/min。5种酵母菌基本都适合生长在含糖量较高,pH偏酸性,温度在25℃左右的环境当中,比较适合利用大豆蛋白废水生产SCP,为菌种的复配提供了依据,为实现利用大豆蛋白废水生产SCP奠定了基础。