脊尾白虾蜕皮抑制激素基因全长cDNA的克隆及其对环境胁迫的响应     

张美  刘萍  李吉涛  李健 《海洋与湖沼》2015,46(4):764-775

为研究脊尾白虾蜕皮抑制激素基因(MIH)在环境适应中的作用,本文采用RACE技术从蜕皮间期脊尾白虾眼柄中克隆获得MIH-like基因全长c DNA序列,命名为Ec MIH。该基因全长1218bp,包括360bp的开放阅读框,420bp的5'端非编码区和394bp的3'端非编码区;开放阅读框编码120个氨基酸,包括41个氨基酸组成的信号肽和79个氨基酸组成的成熟肽,预测蛋白分子量为13.71k Da,理论等电点p I为8.02。同源性比较分析发现,脊尾白虾MIH-like基因与日本沼虾和罗氏沼虾同源性最高,分别为87%和86%。荧光定量PCR分析结果表明,脊尾白虾MIH-like基因在眼柄中的表达量最高,在卵巢中的表达量最少,而在肝脏、肌肉、鳃和血细胞中不表达。环境胁迫后该基因具有明显的时序性。p H6.5胁迫后24h和48h,眼柄和腹神经节中MIH-like基因的表达量较对照组均显著增加(P0.05);4mg/L氨氮浓度组胁迫后12h和24h,眼柄和腹神经节中MIH-like基因的表达量较对照组均显著增加(P0.05);盐度39胁迫后12h和24h,眼柄和腹神经节中MIH-like基因的表达量较对照组均显著增加(P0.05)。本研究结果表明脊尾白虾mih基因参与了环境胁迫后的机体应激反应。  相似文献   

Experimental research on mechanical characteristics and strength criterion of rock of triaxial unloading tests under different stress pathsEI北大核心CSCD     

Zhao Guo-yanDai BingDong Long-junYang Chen 《岩土力学》2015,(11):3121-+

By carrying out triaxial unloading test under different stress paths on rock, the complete stress-strain curves, deformation characteristics and its strength criterion are studied. The test results show that the relation between lateral strain and confining pressure firstly is linear, and then is nonlinear in the total stage of unloading confining pressure. And its growth rate is about 3 to 5 times the growth rate of the axial strain. It shows obvious lateral dilatancy, and the degree of dilatancy is related to the unloading path. According to the area that is enclosed by confining pressure and volumetric strain curve, it can be seen that the greater the confining pressure is before unloading, the more the energy releases. Deformation modulus decreases gradually with the unloading confining pressure, and increases with the initial confining pressure; the relation between deformation modulus and confining pressure shows negative exponential distribution overall. At the same unloading paths, the reduction of the deformation modulus increases with the increase of initial confining pressure. The Poisson's ratio rises up continually, and the variation law with the confining pressure can be well described by nonlinear. Failure characteristics of rock are mainly shear failure. The strength characteristics of rock can be well characterized by using the Mohr strength criterion of power function. These conclusions provide reliable theoretical reference and guiding significance for the deep mining of the underground metal mine.  相似文献   

高钢级绳索取心钻杆管材残余应力的初步研究          下载免费PDF全文

孙建华  况雪军  肖红  梁健  沈娟  刘秀美  蔡纪雄 《探矿工程》2015,42(1):43-48

有观点认为管材的残余应力是绳索取心钻杆非正常损坏的诱因之一。据此采用环切法对不同热处理和矫直工艺的冷拔绳索取心管材制造过程中的残余应力进行了检测比对,认为冷拔管材制造环节产生的残余应力是存在的,也是可控的。只要制造工艺措施得当,可以将高钢级合金管材的残余应力控制在可接受范围内;合格管材出厂时存在较高残余应力造成的钻杆折断等事故较为罕见。应从管材制造、钻杆加工、现场使用等方面入手,努力降低钻杆断裂事故。  相似文献   

基于LS-DYNA的贯通式潜孔锤反循环钻头强度的优化分析          下载免费PDF全文

李鹏  殷琨  彭枧明  罗永江  李丽佳 《探矿工程》2015,42(3):44-47

通体花键式贯通式潜孔锤反循环钻头在实际施工中尾部较易损坏,影响反循环钻头的使用寿命。为提高反循环钻头的使用寿命,对反循环钻头尾部结构进行了优化设计,并采用非线性动力学仿真软件LS-DYNA对改进前后的反循环钻头进行了仿真分析。分析结果表明：由于在冲锤的高频冲击作用下,反循环钻头尾部易出现较大的局部应力集中,导致钻头体出现疲劳破坏;通过对钻头尾部结构设计优化后,与通体花键式反循环钻头相比,新结构钻头在无泄风槽情况下,应力集中值减小44%,在有泄风槽的情况下,应力集中值减小19%。数值模拟分析表明,优化后能大幅度提高钻头寿命。  相似文献   

应力分散型预应力抗拔桩系列技术研究与应用          下载免费PDF全文

何世鸣 《探矿工程》2015,42(2):74-78

根据目前国内外预应力抗拔抗浮桩、部分粘结预应力抗拔抗浮桩的优缺点以及使用的局限性——长螺旋钻机对于桩径＞800 mm或桩长＞30 m的桩力不从心,研究了应力分散型预应力抗拔桩及钢筋钢绞线笼系列技术,用于一个直径1 m、桩长60 m的抗拔桩工程,采用旋挖成孔,可实现在工程桩上进行大吨位试桩,受力合理,节省资金和工期,实践证明该系列技术有很好的应用前景。  相似文献   

河南下汤温泉与车村—鲁山断裂的关系及电测深法在其勘查中的应用   总被引：1，自引：0，他引：1  

夏中广 《物探与化探》2015,(1):95-99

通过对车村—鲁山大断裂与河南鲁山五大温泉关系的探讨,并应用激电测深法勘探、RGIS软件反演解释技术,查明下汤温泉东西两侧1 500 m范围内水文地质条件,认为下汤温泉即受控于近东西向车村—鲁山断裂(F1),也受控于北东向F4断裂。前者为一级控热导热构造,是深部热源向上对流的主要通道;后者为二级控热导热构造。在地形和水头压差的驱动下,地下水沿着断裂带自西向东缓慢的运移,期间受地壳内部热源传导,在排泄区受到北东向F4断裂的控制,向地表运移,出露成泉。  相似文献   

Triggered seismicity in the Andean arc region via static stress variation by the MW = 8.8, February 27, 2010, Maule earthquake     

《Journal of South American Earth Sciences》2015

We localized crustal earthquakes in the Andean arc, between 35°S and 36°S, from December 2009 to May 2010. This research shows a seismicity increase, in a narrow longitudinal area, of more than nine times after the great M_w 8.8 Maule earthquake.The localized seismicity defines an area of ∼80 km long and ∼18 km wide and NNW to NNE trend. The M_d magnitudes varied from 0.7 to 3.1 except for two earthquakes with M_w of 3.9 and 4.5, located in the northern end of the area. The focal mechanisms for these two last events were normal/strike-slip and strike-slip respectively.During 2011, a network of 13 temporary stations was installed in the trasarc region in Malargüe, Argentina. Sixty earthquakes were localized in the study region during an 8 month period.We explored how changes in Coulomb conditions associated with the mega-thrust earthquake triggered subsequent upper-plate events in the arc region. We assumed the major proposed structures as receiver faults and used previously published earthquake source parameters and slip distribution for the Maule quake. The largest contribution to static stress change, up to 5 bars, derives from unclamping resulting consistent with co-seismic dilatational deformation inferred from GPS observations in the region and subsidence in nearby volcanoes caused by magma migration.Three different Quaternary tectonic settings–extensional, strike-slip and compressional-have been proposed for the arc region at these latitudes. We found that the unclamping produced by the Maule quake could temporarily change the local regime to normal/strike-slip, or at least it would favor the activation of Quaternary NNE to N-trending dextral strike-slip faults with dextral transtensional movement.  相似文献   

联合剖面法在地下热水勘探中的应用   总被引：1，自引：0，他引：1  

李爽  杨国民  卜志伟 《地下水》2015,(3)

联合剖面法是勘查地下热水中一种比较简便的方法,近年来得到了广泛应用。应用此法并结合区域地质和构造特征,了解地热田地质结构、热储、盖层、热储类型等。根据联合剖面装置获得的低阻正交点,推断出断裂构造的位置,为确定井位及温泉开发利用提供重要依据。  相似文献   

作物胁迫无人机遥感监测研究评述   总被引：1，自引：0，他引：1  

黄耀欢  李中华  朱海涛 《地球信息科学学报》2019,21(4):512-523

作物胁迫是全球农业发展的一个重要制约因素,实现快速、大范围、实时的作物胁迫监测对于农业生产具有重要意义。传统的作物胁迫监测方式,如田间调查、理化检测和卫星遥感监测总是受到各种田间条件或大气条件的制约。随着无人机和各种轻量化传感器的快速发展,其凭借高频、迅捷等优势为各种作物胁迫监测提供了一套全新的解决方案。本文在介绍了目前主流的多种无人机和传感器的基础上,首先对目前无人机遥感用于作物监测的主要胁迫类型进行了梳理,然后重点阐述了基于光谱成像和热红外传感器进行作物胁迫无人机遥感监测的应用和技术方法,最后提出了作物胁迫无人机遥感监测尚需解决的关键问题,并展望了未来无人机遥感用于作物胁迫监测的前景。  相似文献   

季冻土区临水内、外拱护墙结构冻胀特征分析及治理     

孙洪伟  翟利杰  任望忠  傅汝进 《吉林大学学报(地球科学版)》2020,50(6):1833-1843

为厘清季冻土区临水内、外拱护墙结构冻胀平位移冻害机理，测试隔离层防冻害装置的有效性，在20101110-20110531、20131110-20140531、20171110-20180531三个观测年内，以长春某湖泊临水内、外拱护墙结构为研究对象，选择内、外拱护墙结构和设隔离层防冻害装置的试验内拱护墙结构三者相对比，用钢尺量距法观测三者寒期的平位移状态。结果表明：内拱护墙结构出现倾斜、裂缝导致的内向冻胀平位移冻害，其内向平位移曲线随气温均呈"半驼峰型"，对应观测年持续降温-持续低温-持续升温-正温时段，内向冻胀平位移呈减小-增大-减小-稳定残余的位移运动，诱因是平冻胀应力的生成-增长-减弱-消失作用；外拱护墙结构出现较小的外向冻胀平位移，外向冻胀平位移曲线均呈"波浪型"，无冻害发生，冰凸拱平冻胀应力推动外拱护墙结构压缩冻土凹拱形成外向冻胀平位移，冻土凹拱限制了外向冻胀平位移发展；设隔离层防冻害装置的试验内拱护墙结构未发生平位移冻害，其内向冻胀平位移较自然冻胀的内拱护墙结构减小83.92%，较外拱护墙结构减小51.74%，表明隔离层防冻害装置防治冻胀平位移冻害有效。  相似文献