流体静压下研究电场畴的形成机制

利用流体静压方法研究了掺杂弱耦合GaAs/AlAs超晶格中电场畴的形成机制。对于第一个电流类平台区域，观察到两种级联菜振隧穿过程，即当p≤2kbar时，高场畴为Г-Г级联共振隧穿过程，而当p>2kbar时，高场畴为Г-X级联共振隧穿过程。对于第二个电流类平台区域，高场畴常压下为Г-X级联共振隧穿

低温和高压条件对GaAs/AlAs弱耦合超晶格电场畴形成的影响

El objetivo fue describir la depresión y su asociación con el nivel de estrés en estudiantes de la Universidad Continental de Huancayo. Es un estudio con diseño descriptivo – correlacional, con una muestra de 973 estudiantes; de la facultad de Ciencias de la Salud 244, Ingeniería 376 y Ciencias de la Empresa 353. Para la recolección de datos se utilizó el Inventario de Autoevaluación del Estrés y el Inventario de Depresión BDI – II. Respecto a la cuantificación sintomatológica, el nivel de depresión leve en Ciencias de la Salud es 35,2%, Ingeniería 31,6%, y Ciencias de la Empresa 32%. El nivel de depresión moderada en Ciencias de la Salud es 18,9%; Ingeniería 15,7%; y Ciencias de la Empresa 21,2%. El nivel de estrés normal en Ciencias de la Salud 66%, Ingeniería, 66% y Ciencias de la Empresa 66,6%; el nivel de estrés alto en Ciencias de la Salud 17,9%, Ingeniería 16,7%, y Ciencias de la Empresa 19,3%. Por otro lado, las variables de acuerdo al resultado global la depresión y estrés son independientes por el valor P = 0,102<a. De acuerdo a la correlación del puntaje global de la depresión y estrés según síntomas refleja un valor P = 0,003<a, en relación con la dimensión personalidad de estrés representa un valor P = 0,004<a, indicando correlación entre estas. En conclusión se determina que no existe una relación estadísticamente significativa entre los niveles de estrés y depresión. En tanto, se encuentra relacionadas la depresión con el estrés de síntomas y personalidad

流体静压力下窄势垒GaAs/AlAs超晶格的低温纵向输运

研究了77K温度下掺杂弱耦合GaAs/AlAs窄垒超晶格在流体静压力下的垂直输运，发现其输运性质与宽垒超晶格有很大不同。当在压力下AlAs垒层中的X基态子能级降至E_(Γ1)子能级和E_(Γ2)子能级中间或更低能量位置时，未观察到Γ-Γ共振隧穿到Γ-X共振隧穿的转 变,I-V曲线上的平台并未随压力增大而收缩，反而稍有变宽。同时，平台电流随压力增大而增加，直到与E_(Γ1)-E(Γ1)共振峰电流相当。认为，由于垒层很薄，Γ电子隧穿通过垒层的几率很高，E_(Γ1)-E_(Γ1)共振峰显著高于E_(Γ1)-E_(X1)共振峰，因此，高场畴区内的输运机制在压力下仍由Γ-Γ级联共振隧穿控制。但由于X子级能随压力升高而降低，导致隧穿通过Γ-X垒的几率增加，非共振背景电流增大。由于电流连续性条件的要求，高场区的电场强度增强，导致在高压力下平台宽度随压力稍微变宽

Study on Heavy Metals Migration of Surface Seawater in Xiamen Bay

为探讨厦门湾表层海水中重金属元素迁移过程的规律,采集九龙江上游段的淡水端样品与大嶝岛附近的海水端样品,开展影响重金属迁移过程的环境因子如盐度、PH、悬浮物(SPM)、总有机碳(TOC)的模拟实验.结果表明:1)随着盐度的增加,各重金属含量均有不同程度的降低,尤其是Cu、zn和Cd,盐度增加到31.539 1时,含量仅约为淡水端含量的60%;2)随着PH的增加,各重金属含量亦有不同程度的降低,尤其是zn和Cd,PH增加到8.30时,含量仅分别为淡水端含量的20%和40%左右;3)随着SPM含量的增加,各重金属含量均有不同程度的增加,尤其是zn和Pb,SPM增加到427.3Mg/l时,含量分别为淡水端含量的45倍和8倍左右;SPM与Cr之间存在显著的线性负相关关系,随SPM含量的增加,Cr含量略有下降,但降幅不大,SPM增加到427.3Mg/l时,Cr含量仍约为淡水端含量的80%;4)随着TOC含量的增加,各重金属含量均有不同程度的增加,尤其是Cu、zn和Cr;5)在天然水体多因素的共同作用下,重金属与盐度、PH及SPM之间仍存在线性相关,但受其影响的程度要较单个因素影响小;重金属与TOC之间亦存在正相关,但较单个因素影响不同.综上所述厦门湾表层海水重金属含量在从河口向外海扩散过程中,受环境因子的影响作用是较为复杂的,其迁移过程的规律具有复杂性.The single factor and mixing simulation experiments of freshwater end in Jiulong River Estuary and seawater end in Dadeng Island in Xiamen Bay were taken to discuss the effects of environmental factors including salinity,pH,suspended matter(SPM) and total organic carbon(TOC) on heavy metals including Cu,Pb,Zn,Cd and Cr in migration process.The results of single factor simulation experiments indicated that salinity,pH,SPM and TOC were the main influencing factors of these five heavy metals during the spread process from estuary to open sea due to significantly correlated with heavy metals.1) The concentration of heavy metals decreased on a different degree with the increase of salinity.When salinity was 31.539 1,the concentration of Cu,Zn and Cd were about 60% of those in freshwater end;2) The concentration of heavy metals all went down with the increase of pH.When pH was 8.30,the concentration of Zn and Cd were only 20% and 40% of those in freshwater end,respectively;3) With the increase of SPM,the concentration of Cu,Pb,Zn and Cd increased while that of Cr decreased on a lesser degree.When SPM increased to 427.3 mg/L,the concentration of Zn and Pb were about 45-fold and 8-fold in freshwater end while the concentration of Cr were about 80% of that in freshwater end;4) The concentration of heavy metals especially Cu,Zn and Cr increased with the increase of TOC.The mixing simulation experiment showed that under the multi-factor functions in natural water,heavy metals were still correlated with salinity,pH and SPM but on a lesser degree and correlated with TOC in a different way.In a word,the effects of environmental factors on heavy metals in surface seawater were complicated during the migration process from estuary to open sea in Xiamen Bay.国家海洋局公益性项目(2011418015); 国家海洋局第三海洋研究所基本科研业务费(海三科2011014

毛翼管鼻蝠性二型特征及其在湖北和浙江的分布新纪录

哺乳动物的性别二态性(Sexual dimorphism)是动物中的一种普遍现象,常表现为雄性个体大于雌性个体,而在蝙蝠中则表现出雌性个体体型大于雄性的偏雌性二型现象,其具体的驱动机制仍未明确。本文对采集于广东、广西、江西、湖南、海南、湖北和浙江的32只毛翼管鼻蝠(Harpiocephalus harpia)进行头骨与翼型在两性特征上的多元统计分析,尝试探讨其性二型驱动机制。结果表明:毛翼管鼻蝠雌雄在头骨中与牙齿及咀嚼力相关的区域存在明显分化,而翼型(含翼指标和翼面积)在整体和局部特征上均无显著性差异,该结果提示雌雄可能存在食性上的分化,更倾向于"资源竞争假说"而非"大母蝠优势假说"。本研究于2017年7～10月分别在湖北(3雄,2雌)和浙江(2雄,5雌)采集12只毛翼管鼻蝠,为二省翼手目分布新纪录,该发现丰富和完善了我国翼手目分布信息。上述标本保存于广州大学华南生物多样性保护与利用重点实验室

EFFECT OF COASTAL RECLAMATION ON BENTHIC MACROFAUNA IN COASTAL AREA OF CAOFEIDIAN, BOHAI BAY

To investigate the impact of coastal reclamation on benthic macrofauna, its community characters, as indicated by species number, abundance, biomass, and biodiversity indices were analyzed based on the samples collected in two surveys of autumn 2013 and spring 2014 in Caofeidian coastal waters, Bohai Bay. The dominant species were Musculus senhousei and Amphioplus japonicas, and showed the same tendency of miniaturization on individual body size, simplicity composition of dominant species, and community structure. All these indicators to the macrobenthos community in the waters of Caofeidian area were similar to adjacent waters in the two surveys, except for the biodiversity indices, higher in spring 2014 than that of 2013 autumn, which indicated a slow recovery of the macrofauna. In addition, the macrofauna was undergone moderate disturbance as indicated by the ABC curves (abundance/biomass curves), and the health status of Caofeidian area was worse than other areas as indicated in M-AMBI analysis. The coastal reclamation activities in history have shown a negative impact on the microbenthic inhabitants. As the local environment has been damaged and the fauna affected in different degrees, the normal states of them are expected to recover in hope; however, it will be a long term course

Effect of seasonal hypoxia on macrobenthic communities in the Muping Marine Ranch, Yantai, China

由于气候变化和人类活动的影响,世界许多海区尤其是近岸海区发生了不同程度的低氧现象,导致海洋动物大量死亡,对海洋生态系统产生了不同程度的影响。为明确烟台牟平海洋牧场低氧对大型底栖动物的生态效应,我们于2016年夏季(6月、8月、9月共3个航次)在该海域进行现场调查,分析低氧对大型底栖动物群落时空变化的影响。结果表明:牟平海洋牧场8月低氧事件发生时,大型底栖动物群落的优势种为短叶索沙蚕(Lumbrinereis latreilli)、不倒翁虫(Sternaspis scutata)和内肋蛤(Endopleura lubrica)。低氧在一定程度上改变了大型底栖动物的群落结构,表现为物种组成和优势种变化上。例如,耐受低氧的机会种数量增加,如短叶索沙蚕;敏感种数量减少,如微小海螂(Leptomya minuta)、长吻沙蚕(Glycera chirori)、大蝼蛄虾(Upogebia major)、极地蚤钩虾(Pontocrates altamarimus)、塞切尔泥钩虾(Eriopisella sechellensis)等。同时,低氧也导致了物种多样性的降低,但丰度和生物量受其影响不明显,这主要是由于机会种短叶索沙蚕丰度和生物量的剧增所致。大型底栖动物不同物种耐受低氧的阈值不同。例如,短叶索沙蚕在溶解氧(DO)<1.0 mg/L受影响最大,在DO=2.0 mg/L时受到的影响不明显,而其他敏感种如微小海螂、大蝼蛄虾、极地蚤钩虾、塞切尔泥钩虾等在DO<2.5 mg/L时,已表现出明显的不适。低氧事件之后,大型底栖动物群落得到一定程度的恢复,其恢复程度和需要的时间长短与低氧发生的程度有关