检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

多层建筑结构抗震缺陷分析

地震研究 2024年第4期47卷 563-578页

作者：阿拉塔郭迅董孝曜董策罗若帆王波云南省地震局云南昆明650224 防灾科技学院河北三河065201 中国地震局工程力学研究所黑龙江哈尔滨150080 中国地震局地球物理研究所北京100081 嘉应学院土木工程学院广东梅州514015

我国强震多发、震灾严重,小震致灾、大震巨灾的状况时有发生,而多层建筑倒塌则是造成人员伤亡的主要因素。针对这些问题,基于2008年汶川8.0级地震以来川滇地区发生的十余次6.0级以上地震震害调查资料,对比了“破坏”与“未破坏”建筑的... 详细信息

我国强震多发、震灾严重,小震致灾、大震巨灾的状况时有发生,而多层建筑倒塌则是造成人员伤亡的主要因素。针对这些问题,基于2008年汶川8.0级地震以来川滇地区发生的十余次6.0级以上地震震害调查资料,对比了“破坏”与“未破坏”建筑的结构形式、建筑平立面布置、抗侧力构件分布及结构体系,剖析了建筑结构震害特点,总结了房屋破坏、倒塌的原因。认为在强地震中,建筑结构发生破坏及倒塌是因为其自身存在“散”“脆”“偏”“单”等抗震缺陷,其中“偏”的缺陷更为普遍。通过试验研究发现,墙体的约束使结构同层各抗侧力构件的力学性能相差巨大,即硬脆构件和弱延构件同层并存,这有别于传统抗震设计理论将同层所有构件同等对待的情况。

关键词：震害调查倒塌机理硬脆构件弱延构件变形饱和倒塌触发点

维普期刊数据库博看期刊

Urotensin Ⅱ level is elevated in inflammatory bowel disease patients

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2022年第35期28卷 5230-5232页

作者： Yan Zhang guo-xun Chen Department of Gastroenterology Affiliated Puren Hospital of Wuhan University of Science and TechnologyWuhan 430081Hubei ProvinceChina Department of Nutrition The University of TennesseeKnoxvilleTN 37996United States

It was reported that the urotensin Ⅱ(U-Ⅱ) level in inflammatory bowel disease(IBD) patients are significantly higher than in controls. To provide future guidance for the management of cardiovascular risk factors in IBD patients, the sample size of the current study appears to be limited, and more clinical samples to compare U-Ⅱ levels in IBD patients and controls are needed. This will clarify the possible roles of inflammation factors and related signaling pathways(like EPK1/2, NF-κB and Rho/ROCK) in the pathophysiology of IBD. Therefore, large multicenter studies should be done to confirm the findings and underlying mechanisms in the future.

关键词： Inflammatory bowel disease UrotensinⅡ Inflammatory factors High sensitivity C reactive peptide

Osmotic Regulation of Betaine Content in Leymus chinensis Under Saline-alkali Stress and Cloning and Expression of Betaine Aldehyde Dehydrogenase(BADH) Gene

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2008年第2期24卷 204-209页

作者： CUI Xi-yan WANG Yong guo Ji-xun Key Laboratory for Vegetation Ecology of Ministry of Education Institute of Grassland Science Northeast Normal University Changchun 130024 P. R. China School of Life Sciences Jilin Agricultural University Changchun 130118 P. R. China

The potted Leymus chinensis seedlings were treated with saline-alkali solution of six different（from Ⅰ to Ⅵ） concentrations. The results demonstrate that the betaine content and Betaine-aldehyde dehydrogenase（BADH： EC 1.***.1.8） activities have a direct relation with increased stressing time in the same treatment; both exhibit a single peak with increasing the concentration of saline-alkali solution, and number V shows the highest value. The BADH gene of Leyrnus chinensis was cloned by RT-PCR and RACE technology and was designated as LcBADH. The cDNA sequence of LcBADH was 1774bp including the open reading frame（ORF） of 1521bp（coding 506 amino acids）. The vector of prokaryotic expression was constructed by inserting the LcBADH gene fragmcnt into pET30a（＋） and transformed into E. coli BL21（DE3）. The result of SDS-PAGE shows that the idio-protein with a molecular mass of 56.78 kDa was effectively expressed in the recombinant bacteria induced by isopropyl fl-D-thiogalactoside（IPTG）.

关键词： Leymus chinensis Saline-alkali stress BADH RACE Cloning and expression

Synthesis of Schiff Base Calix[4]arene Crowns

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2002年第8期13卷 699-700页

作者： Xiao Bing WAN Chuan Ming JIN xun guo guo Yuan LU Department of Chemistry Nanjing UniversityNanjing 210093

This letter reports the synthesis of Schiff base calix[4]arene crowns containing m-xylylene phenol subunit, in which calix[4]arene Schiff base crowns 2a, 2b and 2c were formed by 1:1 condensation of calix[4]arene diamine 1 with dialdehydes (2, 6-diformyl-4-chlorophenol 3a, 2, 6-diformyl-4-methylphenol 3b, 2, 6-diformyl-4-tert-butylphenol 3c) under high dilute condition in refluxing anhydrous ethanol in 65-70% yield.

关键词： Calixarene Schiff base 2, 6-diformyl-4-substituted phenol 1:1 condensation.

Characterization of Bacillus phage Gxv1,a novel lytic Salasvirus phage isolated from deep-sea seamount sediments

在线全文

学校读者我要写书评

暂无评论

Marine Life Science & Technology 2021年第1期3卷 13-19页

作者： xun guo Tianyou Zhang Min Jin Runying Zeng State Key Laboratory Breeding Base of Marine Genetic Resource Ministry of Natural ResourcesThird Institute of OceanographyXiamen 361005China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519000China

Seamounts are hotspots for marine life,but to date,no bacteriophages have been ***,a novel Bacillus podophage(named as Bacillus phage Gxv1)was isolated from deep-sea seamount sediments of the western Pacifc Ocean(~5790 m).Phage Gxv1 has a hexameric head~42–53 nm in diameter and a short tail of~30 nm long,which is a typical feature of the Podoviridae ***-step curve analysis showed that Gxv1 is a lytic phage that can initiate host lysis within 3.5 h postinfection,and has a relatively large burst *** 21,781-bp genome contains 34 predicted genes,and the G+C content of phage Gxv1 is 39.69%.Whole-genome comparison of phage Gxv1 with known bacteriophages,using BlastN analysis against the IMG/VR database,revealed that phage Gxv1 is closely related to Bacillus phage phi29 that infects Bacillus subtilis,and their genome-wide similarity is 93.62%.Phylogenetic analysis based on DNA polymerase showed that phage Gxv1 belongs to the Salasvirus *** genome alignment showed that phage Gxv1 shares a high level of sequence similarity and common gene order with Bacillus phage ***,some sequences are unique to phage Gxv1,and this region contains genes encoding DNA packing protein,DNA replication protein,and unknown *** sequences exhibit low sequence similarity to known bacteriophages,highlighting an unknown origin of these *** study will help improve our understanding of the Salasvirus genus and phage diversity in deep-sea seamounts.

关键词： Seamount Deep sea Salasvirus Bacillus phage Characterization

考虑半高连续填充墙约束的框架柱抗震性能研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

防灾科技学院学报 2024年第2期26卷 53-64页

作者：徐雨阳郭迅张钦哲罗若帆防灾科技学院土木工程学院河北三河065201 中国地震局建筑物破坏机理与防御重点实验室河北三河065201 嘉应学院土木工程学院广东梅州514015

为研究实际震害,探讨半高连续填充墙约束下的钢筋混凝土框架柱的抗震性能,设计了两组两跨框架模型进行拟静力试验,对比分析半高连续填充墙对柱抗震性能的影响。使用Perform-3D软件建立宏观数值模型,填充墙构件使用对角斜撑杆件模拟,考... 详细信息

为研究实际震害,探讨半高连续填充墙约束下的钢筋混凝土框架柱的抗震性能,设计了两组两跨框架模型进行拟静力试验,对比分析半高连续填充墙对柱抗震性能的影响。使用Perform-3D软件建立宏观数值模型,填充墙构件使用对角斜撑杆件模拟,考察半高连续填充墙的约束效果。分析结果表明:填充墙破坏增加结构耗能,滞回曲线更饱满且具备较优的延性,填充墙对柱有明显约束作用,改变了柱构件原本的破坏模式;数值模拟结果与试验结果一致。鉴于填充墙对结构受力变形影响较大,将其视为非结构构件,忽略其对整体结构的作用是不妥的。

关键词：半高连续填充墙 RC框架柱拟静力试验数值模型非结构构件

在线全文

学校读者我要写书评

暂无评论

水光储互补特微型发电系统设计与评估

中国农村水利水电 2024年第3期 262-267页

作者：杨旭周大庆曹中成汪玉清郭俊勋河海大学能源与电气学院江苏南京211100 河海大学水利水电学院江苏南京210098

针对美丽乡村建设不断增长的绿色发展需求,提出了一种采用虹吸式水轮机和光伏板作为发电装置,配合蓄电池储能的水光储互补特微型发电照明系统方案。虹吸式水轮机使用稳态数值模拟计算出力及效率,结合水位数据计算发电量,光伏板使用面积... 详细信息

针对美丽乡村建设不断增长的绿色发展需求,提出了一种采用虹吸式水轮机和光伏板作为发电装置,配合蓄电池储能的水光储互补特微型发电照明系统方案。虹吸式水轮机使用稳态数值模拟计算出力及效率,结合水位数据计算发电量,光伏板使用面积法结合太阳辐射数据估算月发电量,并计算了提供给夜间照明和电网的电量。分析了系统的建设成本、经济效益和减排效益,结果表明本系统拥有切实可行的推广前景和减排效益。

关键词：水光储互补系统虹吸式水轮机光伏发电效益计算

维普期刊数据库博看期刊

Contribution of Root Respiration to Total Soil Respiration in a Leymus chinensis （Trin.） Tzvel, Grassland of Northeast China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Plant Biology 2006年第4期48卷 409-414页

作者： Wei Wang Ji-xun guo Jiang Feng Takehisa Oikawa Department of Ecology College of Environmental Sciences Peking University Beijing 100871 China Key Laboratory for Vegetation Ecology of the Ministry of Education Northeast Normal University Changchun 130024 China Institutes of Biological Sciences University of Tsukuba Tsukuba Ibaraki 305-8572 Japan

The loss of carbon through root respiration Is an Important component of grassland carbon budgets. However, few data are available concerning the contribution of root respiration to total soil respiration in grasslands in China. We Investigated seasonal variations of soil respiration rate, root blomaaa, microbial blomaaa C and organic C content of the soil In a semi-arid Leymus chinensis （Trin.） Tzvel. grassland of northeast China during the 2002 growing season （from May to September）. The linear regression relationship between soil respiration rate and root blomaaa was used to determine the contribution of root respiration to total soil respiration. Soil respiration rate ranged from 2.5 to 11.9 g C/m^2 per d with the maximum in late June and minimum In September. The microbial blomaaa C and organic C content of the soil ranged from 0.3 to 1.5 g C/m^2 and from 29 to 34 g C/kg respectively. Root blomaaa had two peaks, In early June （1.80 kg/m^2） and mid-August （1.73 kg/m^2）. Root respiration rate peaked In mid-August （6.26 g C/m^2 per d）, whereas microbial respiration rate peaked In late June （7.43 g C/m^2 per d）. We estimated that the contribution of root respiration to total soil respiration during the growing season ranged from 38% to 76%.

关键词： meadow steppe root biomass root respiration soil organic carbon soil respiration.

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

近60年新疆棉花苗期低温冷害时空变化规律

中国农业气象 2024年第6期45卷 678-688页

作者：孙帅李顺澳王森王雪姣火勋国郭燕云雷斌中国气象局乌鲁木齐沙漠气象研究所乌鲁木齐830002 乌兰乌苏生态与农业气象新疆野外科学观测研究站石河子832000 新疆维吾尔自治区农业气象台/新疆兴农网信息中心乌鲁木齐830002 新疆农业科学院核技术生物技术研究所/新疆农作物生物科技重点实验室乌鲁木齐830091

利用新疆不同棉区46个国家基本气象站1961-2022年日平均气温,结合棉花苗期低温冷害监测指标,通过气候倾向率、MK突变检验、累积距平等方法,分析棉花苗期轻度、中度、重度低温冷害的时间和空间变化规律,为新疆不同棉区制定合理的防灾减... 详细信息

利用新疆不同棉区46个国家基本气象站1961-2022年日平均气温,结合棉花苗期低温冷害监测指标,通过气候倾向率、MK突变检验、累积距平等方法,分析棉花苗期轻度、中度、重度低温冷害的时间和空间变化规律,为新疆不同棉区制定合理的防灾减灾措施提供科学依据。结果表明:1961-2022年全疆棉区苗期气温呈极显著上升趋势,气候倾向率为0.30℃·10a^(-1)。北疆、南疆和东疆棉区分别在1999年、2004年和2003年轻度苗期冷害发生频次较少。北疆棉区于2006年、南疆和东疆棉区于2008年中度苗期冷害发生频次较少。1975年、2003年北疆和南疆棉区分别进入重度苗期冷害较少发生的阶段。近60a新疆棉花苗期低温冷害多发生于20世纪80和90年代,轻度和中度冷害发生年份分别占研究时段的79.0%和37.1%,重度冷害发生年份仅占8.1%。棉花苗期低温冷害多发生于北疆棉区,其次是南疆棉区,东疆低温冷害发生最少。

关键词：棉花苗期低温冷害变化规律气候变化