4种拟除虫菊酯类农药对海带生长及叶绿素a含量的影响

为研究不同拟除虫菊酯类农药对海带（Laminaria japonica）生长和叶绿素a（Chl a）含量的影响,选取溴氰菊酯、联苯菊酯、氰戊菊酯、醚菊酯等4种拟除虫菊酯类农药,设置1、5、10、50、100、500 μg/dm3 6个梯度对海带进行半静置染毒。结果表明：低浓度(1 μg/dm3)组4种拟除虫菊酯类农药对海带生长均具有促进作用（P<0.05）,高浓度（100、500 μg/dm3）对海带生长具有显著抑制作用（P<0.01）。溴氰菊酯、联苯菊酯、氰戊菊酯、醚菊酯对海带的24 d半抑制效应浓度（EC50 ）分别为82.4、53.0、10.7、14.6 μg/dm3,抑制作用大小为氰戊菊酯≈醚菊酯>联苯菊酯>溴氰菊酯。低浓度（1、5 μg/dm3）组海带体内Chl a含量均出现升高,具有一定促进作用（P<0.05）;高浓度（100、500 μg/dm3 ）组海带体内Chl a含量均出现明显下降,具有显著抑制作用（P<0.01）,抑制作用大小为醚菊酯>氰戊菊酯>联苯菊酯>溴氰菊酯。4种拟除虫菊酯类农药对海带生长和Chl a含量的影响均表现为低浓度促进、高浓度抑制作用,且随着浓度升高和暴露时间延长,呈促进作用减弱,抑制作用增强之势。     

壳寡糖与三甲酰氯界面聚合制备纳滤膜及其染料分离性能

界面聚合制备方法通常用于制备纳滤膜或反渗透膜,单体一般为间苯二胺或哌嗪。但是这些水相单体具有较大的毒性、刺激性等不利因素,会对环境及人体造成危害。壳寡糖（chitosan oligosaccharide, COS）是壳聚糖经特殊的生物酶处理得到的较低分子量的海洋多糖类高分子聚合物,绿色无毒,与壳聚糖相比其溶解性大大提高。壳寡糖与壳聚糖的化学性质相似,其分子中含有氨基、羟基,适合作为水相单体通过界面聚合反应制备复合纳滤膜。本研究以壳寡糖为水相单体,均苯三甲酰氯（trimesoyl chloride, TMC）为油相单体,通过界面聚合法在聚醚砜超滤膜（PES）上成功制备COS/PES复合纳滤膜。采用场发射扫描电子显微镜（SEM）和原子力显微镜（AFM）对膜表面进行分析表征;通过错流过滤测试膜通量及染料分离性能。实验结果显示,COS/PES 2复合纳滤膜表面出现斑点状结构,具备较高的膜通量;根据Zisman的临界表面张力外推方法将液体的表面张力与cosθ作图,发现COS/PES复合纳滤膜具有较好的防生物黏着的性能;进一步采用牛血清蛋白质模拟生物质膜污染物,开展了比通量（J/Jw）下降的实验,结果表明COS/PES复合纳滤膜的比通量始终高于商业PES超滤膜,说明交联壳寡糖活性层具有一定的抗生物质膜污染的性能;染料分离实验结果显示,壳寡糖复合纳滤膜对甲基橙的截留率在0.45 ~ 0.53之间,樱草灵的截留率在0.66~0.77之间,染料分子量大于600 Da时,不同浓度（1%、2%、3%,wt）制备的壳寡糖复合膜的染料截留率均保持在90%以上,证明所制备的复合膜属于纳滤的范畴。本研究制备的COS/PES复合纳滤膜符合国内外对发展环境友好型海洋新材料的需求,在环保、医药方面极具应用潜力。     

海南文昌沿岸海草床的现状及其退化因素分析

通过对比2012、2018、2020年海南文昌沿岸海草床的调查数据,对文昌海草床的现状、退化状况以及退化因素进行分析。结果表明,2020年文昌海域海草有2科6属6种,分别为泰来草（Thalassia hemprichii）、圆叶丝粉草（Cymodocea rotunda）、单脉二药草（Halodule uninervis）、海菖蒲（Enhalus acoroides）、卵叶喜盐草（Halophila ovalis）及针叶草（Syringodium isoetifolium）。文昌海草床的分布呈明显退化的趋势,海草床面积由2012年的31.8 km2减少到2018年的24.2 km2,2020年进一步降低至18.8 km2。分析数据显示, Cu、Cd、Cr等重金属离子与调查区海草床的盖度显著负相关,表明在低营养负载时文昌周边虾塘养殖废水排放带来的重金属污染也会导致文昌海草床的退化。     

钦州湾沉积物中重金属的多元统计分析：空间关系、生态风险和来源识别

海湾是海洋和陆地相互作用和人类活动最强烈的区域,沉积物中重金属的含量和分布都受到人类活动的影响。为了探究钦州湾沉积物中重金属的含量水平、污染程度和可能来源,本研究分析了钦州湾表层沉积物中Cu、Pb、Zn、Cd、Cr、Hg和As的含量及空间分布,采用地质累计指数（Igeo）和潜在生态风险指数（PERI）定量分析了重金属的污染程度和生态风险,并利用自组织映射(SOM)和正定矩阵因子分解法(PMF)模型评估了重金属的可能来源。结果表明：钦州湾表层沉积物重金属中Zn的平均含量最高,Hg平均含量最低;除个别站位的Pb含量符合海洋沉积物质量第二类标准外,其他重金属含量均符合海洋沉积物质量第一类标准;Igeo结果表明钦州湾表层沉积物主要的污染元素为Pb、Hg和Cu;PERI结果表明Hg是钦州湾表层沉积物主要的生态风险元素。SOM和PMF模型结果表明钦州湾表层沉积物重金属主要受自然来源、农业活动、工业生产活动的共同影响,各来源的相对贡献率分别为39.65%、29.15%和31.20%。     

无人机航测技术在海草床调查中的试点应用

通过无人机飞行参数、飞行高度、潮汐条件和调查范围等试验,采用无人机对东郊椰林近岸海域海草进行航拍,利用PIX4D软件处理得到了高分辨率海草分布影像图,利用ArcGIS软件对海草分布区进行了矢量化提取,选择有代表性的区块结合实地调查进行验证,得出了试验区的海草分布特征和海草种类。结果表明：海草分布在离岸300 m范围内的珊瑚礁砰上,呈斑块状、间隔式分布特征,在试验区中海草分布面积为2 449.6 m2,占比为24.5%。实地调查到海草种类有圆叶丝粉草（Cymodocea rotundata）、单脉二药草（Halodule uninervis）、海菖蒲（Enhalus acoroides）、泰来草（Thalassia hemprichii）和卵叶喜盐草（Halophila ovalis）等5种海草,泰来草为优势种,单脉二药草和卵叶喜盐草分布在潮间带有淤泥的低潮区;圆叶丝粉草分布在低潮带至潮下带的上部,海底堆积和冲刷区的交界处;泰来草在不同水深处均有分布,分布面积最大。     

大黄鱼FcRs基因的克隆及其在免疫应答中的初步功能分析

Fc受体（Fc Receptors,FcRs）是一类与免疫球蛋白的Fc段特异性结合,介导多种免疫反应的受体分子。本研究克隆得到了大黄鱼（Larimichthys crocea）6个FcRs基因,分别是LcFcγRⅠL、LcFcγRⅡ、LcFcγRⅡaL、LcFcγRⅢ、LcFcRL5和LcFcRLA,其开放阅读框（ORF）大小分别为1 070、2 486、1 145、 1 955、4 125、1 659 bp。大黄鱼的6个LcFcRs都具有一个信号肽和2~8个免疫球蛋白（Ig）结构域,LcFcγRⅡ、LcFcγRⅢ和LcFcRL5还包含一个跨膜区。实时荧光定量PCR结果显示LcFcγRⅠL、LcFcγRⅡ、LcFcγRⅡaL和LcFcγRⅢ主要在鳃或肠等黏膜组织中表达,而LcFcRL5和LcFcRLA主要在脾和头肾等系统免疫组织中表达;革兰氏阴性细菌细胞壁脂多糖（LPS）刺激后,这6个LcFcRs基因头肾和脾脏中的表达在不同时间出现了显著上调;双链RNA病毒类似物Poly(I:C)刺激后,6个LcFcRs在头肾和脾脏中的表达出现不同程度的上调,而LcFcRL5在脾脏中的表达显著上调,在头肾中则明显下调,提示大黄鱼FcRs可能在LPS和Poly(I:C)诱导的免疫反应中起着重要但又不同的作用。     

基于高分辨率卫星和无人机的广西滨海盐沼面积变化监测

滨海盐沼作为重要的海岸带生态系统,在海岸保护、生物多样性维持、固碳减污等方面发挥了重要的生态服务功能。及时准确地监测滨海盐沼分布情况和动态变化,对于科学地管理和保护本地滨海盐沼生态系统意义重大。本研究基于2019年和2021年多源国产高空间分辨率卫星数据,结合无人机自主性强、灵活机动、不受云遮挡影响的优势,对广西壮族自治区滨海盐沼开展遥感跟踪监测。研究结果表明,广西2021年滨海盐沼总面积为1 341.40 hm2,其中,北海市、防城港市和钦州市3个海滨城市的滨海盐沼面积分别为1 247.82 hm2、49.73 hm2和43.85 hm2。与2019年相比,广西2021年滨海盐沼总面积减少108.96 hm2,其中,北海市互花米草（Spartina alterniflora）面积减少107.05 hm2,钦州市短叶茳芏（Cyperus malaccensis）和芦苇（Phragmites australis）面积减少1.91 hm2,防城港市滨海盐沼面积不变。广西当地对入侵种互花米草的治理卓有成效,互花米草大范围减少,但局部区域的互花米草分布仍呈不断增长的趋势,仍需重视对互花米草的监测与防控工作。     

伊姆裸甲藻溶藻菌LD-B3的分离鉴定及溶藻作用

近年来,有害藻华频繁发生给海洋生态系统甚至人类健康带来严重影响。伊姆裸甲藻（Gymnodinium impudicum）是一种典型有害藻华原因种,开展其溶藻菌筛选工作,将有利于该种藻华的防控研究。本研究从伊姆裸甲藻藻华发生海域,分离一株针对藻华原因种的溶藻菌LD B3,16S rDNA序列分析表明,该菌株属于假交替单胞菌属（Pseudoalteromonas）。菌藻共培养结果显示,2.0%终浓度LD B3菌液添加72 h后,伊姆裸甲藻溶藻率达81.06%,且溶藻效应呈现浓度和时间依赖性。显微观察和生理参数测定结果表明,菌株LD B3可导致伊姆裸甲藻细胞链断裂,最大光合效率（Fv/Fm）下降。溶藻方式研究发现,菌株LD B3主要通过分泌胞外物质实现溶藻,且这类物质对温度较为敏感,初步推断其可能为蛋白类物质。本研究结果表明菌株LD B3在伊姆裸甲藻溶藻剂开发方面有一定应用前景。     

补肾清透方对肾虚型慢性荨麻疹小鼠模型细胞因子的影响

目的：研究补肾清透方（以下简称“补清方”）对肾虚型慢性荨麻疹的作用机制。方法：选取昆明种雄性小鼠50只,随机分为空白对照组、模型组、氯雷他定组及补清方高、低剂量组,每组各10只。将除空白组外的40只小鼠与发情期雌鼠同笼,诱导其房事不节以制备肾虚模型,并采用注射卵白蛋白、氢氧化铝结合百日咳疫苗模拟荨麻疹模型。眼眶取血并分离血清,采用双抗夹心ELISA法测试血清免疫球蛋白E（IgE）、组胺（HIS）;剥取小鼠主动脉,中性甲醛固定,采用免疫组织化学法检测血管壁组织中白细胞介素-4（IL-4）、细胞干扰素-γ（IFN-γ）的表达量。结果：与空白组比较,模型组血清IgE、HIS水平及血管壁组织中IL-4、IFN-γ的表达量均显著升高,差异有统计学意义（P<0.05）。与模型组比较,补清方高、低剂量组及氯雷他定组小鼠IgE、HIS、IL-4、IFN-γ含量明显降低,差异有统计学意义（P<0.05）;3个用药组各个指标差异均无统计学意义（P>0.05）。结论：补清方可调整T细胞对相关细胞因子异常分泌以改善荨麻疹病情,是本病行之有效的治疗方剂。     

石斑鱼转录因子NR1D1和NR1D2在冷胁迫中的调控作用

NR1D1和NR1D2转录因子属于核受体转录因子家族,二者通过调控靶基因表达参与众多生物学过程,尤其在昼夜节律调节中发挥重要作用。本研究通过分析NR1D1和NR1D2的蛋白质分子特征以及在冷胁迫下珍珠龙胆石斑鱼(Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂)的基因调控关系以及它们所参与的通路,揭示它们在鱼类低温环境中的功能作用。生物信息学比较分析显示〖STBX〗NR1D1和NR1D2〖ST〗基因序列均有23个开放阅读框,编码的蛋白质均属于不稳定的亲水性蛋白质。NR1D1和NR1D2蛋白质均含有ZF C4类锌脂蛋白结构域和Hormone_Recep核激素受体的配体结合域,主要配体为含铁原卟啉IX。这两种蛋白主要在细胞核中发挥调控基因表达的作用,且与昼夜节律通路的多个关键基因有直接作用关系。结果表明,在冷胁迫下NR1D1和NR1D2作为转录因子可通过调控靶基因的表达,参与昼夜节律调节并促进糖脂代谢、线粒体氧化等过程,为珍珠龙胆石斑鱼提供必要的能量,有助于增强其耐寒性。     

相变存储材料Ge1Sb2Te4和Ge2Sb2Te5薄膜的结构和电学特性研究

采用射频磁控溅射方法制备了两种用于相变存储器的Ge₁Sb₂Te₄和Ge₂Sb₂Te₅相变薄膜材料,对其结构、电学输运性质和恒温下电阻随时间的变化关系进行了比较和分析.X射线衍射(XRD)和原子力显微镜(AFM)的结果表明:随着退火温度的升高,Ge₁Sb₂Te₄薄膜逐步晶化,由非晶态转变为多晶态,表面出现均匀的、     

The density functional calculations on the structural and electronic properties of the endohedral fullerene dimer (N2@C60)2

The generalised gradient approximation based on density functional theory is used to study the structural and electronic properties of the endohedral fullerene dimer (N₂@C₆₀)₂. Four N atoms sit at the cage centres in the form of two N_2 molecules. The density of states and Mulliken charge analysis explore that the energy levels from -6 to -10 eV are mainly influenced by the N₂ molecules.     

Carbonate chemistry and projected future changes in pH and CaCO3 saturation state of the South China Sea

To study the dissolved carbonate system in the South China Sea (SCS) and to understand the water mass exchange between the SCS and the West Philippine Sea (WPS), pH, total alkalinity and total CO₂ were measured aboard the R/V Ocean Researcher 1. Because of the sill that separates these two seas in the Luzon Strait with a maximum depth of 2200 m, the SCS Deep Water has characteristics similar to those of water at about 2200 m in the WPS. The minimum pH and the maxima of normalized alkalinity and total CO₂ commonly found in the open oceans at mid-depth also prevail in the WPS but are, however, very weak in the SCS. Rivers and inflows from Kuroshio Surface and Deep Waters through the Luzon Strait as well as those through the Mindoro Strait transport carbon to the SCS year-round. Meanwhile, the outflowing Taiwan Strait water as well as the SCS Surface and Intermediate Waters of the Luzon Strait transports carbon out of the SCS year-round. The Sunda Shelf is also a channel for carbon transport into the SCS in the wet season and out of the SCS in the dry season.fCO₂ data and mass balance calculations indicate that the SCS is a weak CO₂ source in the wet season but an even weaker CO₂ sink in the dry season. With these facts taken together, the SCS is likely a very weak CO₂ source. Anthropogenic CO₂ penetrates to about 1500 m in depth in the SCS, and the entire SCS contains 0.60 ± 0.15 × 10¹⁵ g of excess carbon. Typical profiles of pH as well as the degree of saturation of each of calcite and aragonite in 1850 and 1997 are presented, and those for 2050 AD are projected. The maximum decrease in pH is estimated to be 0.16 pH units in the surface layer when the amount of CO₂ is doubled. It is anticipated that aragonite in the upper continental slope will likely start to dissolve, thereby neutralizing excess CO₂ by around 2050 AD. This paper is unique in that it presents the results of the first attempt ever to estimate the past, present and future physico-chemical properties of the world's largest marginal sea.     

Sr掺杂Eu1-xSrxMnO3体系的磁相变以及输运特性研究

对Eu_1-xSr_xMnO₃ (ESMO, x=0—1)体系的结构和磁性进行了系统的研究,结果表明Sr的掺入使EuMnO₃反铁磁母体的磁结构发生巨大的变化.通过磁化和电输运测量,深入探讨了高掺杂浓度Eu_0.4Sr_0.6MnO₃和Eu_0.3Sr_0.7MnO_{3相似文献}   

Distributions and air-sea fluxes of CO2 in the summer Bering Sea

The 3rd Chinese National Arctic Research Expedition(CHINARE–Arctic III) was carried out from July to September in 2008. The partial pressure of CO2(pCO2) in the atmosphere and in surface seawater were determined in the Bering Sea during July 11–27, 2008, and a large number of seawater samples were taken for total alkalinity(TA) and total dissolved inorganic carbon(DIC) analysis. The distributions of CO2 parameters in the Bering Sea and their controlling factors were discussed. The pCO2 values in surface seawater presented a drastic variation from 148 to 563 μatm(1 μatm = 1.013 25×10-1 Pa). The lowest pCO2 values were observed near the Bering Sea shelf break while the highest pCO2 existed at the western Bering Strait. The Bering Sea generally acts as a net sink for atmospheric CO2 in summer. The air-sea CO2 fluxes in the Bering Sea shelf, slope, and basin were estimated at-9.4,-16.3, and-5.1 mmol/(m2·d), respectively. The annual uptake of CO2 was about 34 Tg C in the Bering Sea.     

Sb2 Te3 纳米结构的制备与表征

以室温热电性能优异的传统热电材料Sb₂Te₃为研究对象,利用化学气相沉积法制备Sb₂Te₃单晶纳米结构,并研究其生长机理.实验结果表明,不加催化剂时Sb₂Te₃易生长成六方纳米盘,在金催化剂条件下定向生长成纳米线.Sb₂Te₃的形貌与其晶体结构和生长机理有关.Sb₂Te₃为三角结构,Sb和     

Effects of high-pressure heat treatment on the solid-state phase transformation and microstructures of Cu61.13Zn33.94Al4.93 alloys

The phase transformation activation energy of the Cu_61.13Zn_33.94Al_4.93 alloys, which were treated at 4 GPa and 700 °C for 15 minutes, was calculated by means of differential scanning calorimetry curves obtained at various heating and cooling rates. Then, the effects of high-pressure heat treatments on the solid-state phase transformation and the microstructures of Cu_61.13Zn_33.94Al_4.93 alloys were investigated. The results show that high-pressure heat treatments can refine the grains and can change the preferred orientation from (111) to (200) of α phase. Compared with the as-cast alloy, the sample with high-pressure heat treatment has finer grains, lower β' → β and β → β ' transformation temperature and activation energy. Furthermore, we found that high cooling rate favours the formation of fine needle-like α phase in the range of 5--20 °C/min.     

淡水和海水环境下沉积物搬运过程碳释放通量的模拟研究

基于室内物理模拟实验, 对长江沉积物进行淡水和海水环境下沉积物搬运过程碳释放通量实验模拟。结果表明, 模拟实验初期, 淡水和海水均为大气CO₂的源, 但淡水CO₂释放通量略高于海水;淡水、海水两种环境下, CH₄释放通量均较小, 为弱释放-弱吸收过程。对两种环境下碳通量对比研究发现,Eh 值可能是造成淡水和海水环境下CO₂通量差别的主要原因, 而pH 值可能对CO₂通量差别的影响较小。两种环境下温室气体通量差别的具体原因仍需进一步研究。通过模拟对比试验, 旨在为系统地认识长江流域水库的温室效应与减排提供科学依据, 为我国清洁水电能源发展提供理论参考。     

Improvement in the calculation of anti-Stokes energy transfer and experimental justification based on Er0.01YbxY1 - 0.01 - xVO4 crystal

The improvement on the calculation of anti-Stokes energy transfer rate is studied in the present work. The additional proportion coefficient between Stokes and anti-Stokes light intensities of quantum Raman scattering theory as compared with the classical Raman theory is introduced to successfully describe the anti-Stokes energy transfer. The theoretical formula for the improvement on the calculation of anti-Stokes energy transfer rate is derived for the first time in this study. The correctness of introducing coefficient exp{ΔE / kT} from well-known Raman scatter theory is demonstrated also. Moreover, the experimental lifetime measurement in Er_0.01Yb_xY_{1 - 0.01 - x}VO₄ crystal is performed to justify the validity of our important improvement in the original phonon-assisted energy transfer theory for the first time.