鲢鲫鳃丝的扫描电镜观察

本文报道了采用扫描电镜观察鲢(Hypoph(?)halm ch(?)hys molitrix)和鲫鱼(Carassius auratus)鳃丝的微细结构。发现二种鱼的鳃小片差别很大。在相同的鳃小片面积下,鲢的鳃小片长度约为鲫的2倍,表面平坦;后者表面凹凸不平。盐细胞的数量鲢为鲫的1/2～1/3,在鳃小片的边缘也有少量分布。鲫则没有。作者认为鲢的低矮平坦型鳃小片能减小对水的阻力,满足滤食所需的较大滤过水量,降低能量消耗。由于鳃小片平坦且相对呼吸面积小,所以鲢的摄氧效率较鲫低,这可能是其不耐缺氧的重要原因。鲢的耐盐能力低的一个原因是盐细胞数量少。     

长江常熟江段似鳊的生长特征及形态特性

根据2009年8月—12月在长江常熟江段采集的362尾似鳊Pseudobrama simoni样本,对其年龄、生长特征和形态特征进行了研究。结果表明:似鳊种群由1³龄共3个年龄组组成,1龄鱼为优势群体,占总数的51.3%;体长分布范围为62.333龄共3个年龄组组成,1龄鱼为优势群体,占总数的51.3%;体长分布范围为62.33¹33.65 mm,优势体长范围为75133.65 mm,优势体长范围为75¹10 mm(占总数的75.41%),体质量分布范围为3.70110 mm(占总数的75.41%),体质量分布范围为3.70⁴6.10 g,优势体质量范围为3.7046.10 g,优势体质量范围为3.70¹8.70 g(占总数的80.11%);雌、雄个体的体长、体质量差异极显著(P<0.01),丰满度、体高、头长等31个形态指标无显著性差异(P>0.05);体长与鳞径的关系式为L♀=391.67R4-2211.8R3+4609.7R2-4171.4R+1463.2(n=156,P<0.001,r2=0.6973),L♂=171.22R4-895.44R3+1719.8R2-1406.4R+486.47(n=178,P<0.001,r2=0.7821);体长和体质量的关系式为W♀=4.52×10-6L3.2901(n=156,r2=0.94),W♂=1.09×10-5L3.0915(n=178,r2=0.98);Von Bertalanffy生长方程为Lt♀=142.31×[1-e-0.1125(t+8.3442)],Lt♂=153.73×[1-e-0.1024(t+6.8309)]。研究表明,雌性似鳊体质量生长拐点年龄为2.24龄,雄性为3.96龄,常熟江段似鳊呈低龄化态势。     

氢还原重量法测定氯化钯产品中的钯

系统研究了氢还原重量法测定氯化钯产品中钯含量的测定条件,考察了杂质元素对钯分析结果的误差影响。结果表明:于选定条件下,测定59.78%⁶0.03%含量的钯,极差、标准偏差(SD)、相对标准偏差(RSD,n=22)和重复性限(r)分别为±0.01%,0.0047%60.03%含量的钯,极差、标准偏差(SD)、相对标准偏差(RSD,n=22)和重复性限(r)分别为±0.01%,0.0047%⁰.0050%,0.0079%0.0050%,0.0079%⁰.0083%和0.009%0.0083%和0.009%⁰.014%,样品加标回收率达到99.98%,钯分析结果准确、可靠、精密度高。     

石墨烯基电化学传感器检测菊花和杏仁中锌的含量

实使用石墨烯修饰电极阳极溶出伏安法，在pH=4.30的HAc-NaAc缓冲溶液中检测菊花和杏仁中锌的含量。峰电流与锌浓度1×10^(-6)～3.2×10-5 mol/L范围内呈优良的线性关系，I=1.5201c-1.0141×10(-6)～3.2×10-5 mol/L范围内呈优良的线性关系，I=1.5201c-1.0141×10^(-6)。r=0.9916。RSD=3.13%。D=1.6×10(-6)。r=0.9916。RSD=3.13%。D=1.6×10^(-7) mol/L。用该方法测定菊花和杏仁中的锌，回收率在94.56%～98.00%、93.67%～97.68%范围之内，方法简单，结果准确可靠。     

测定新疆阔克阿木提果皮中绿原酸和芦丁的含量

目的:建立采用超声波提取,高效液相色谱法测定新疆阔克阿木提果皮中绿原酸和芦丁的含量的方法。方法:色谱柱:安捷伦HC-C18柱(250mm×4.6mm,5μm);流动相体积比50∶50的甲醇-0.4%磷酸溶液;检测波长为360nm;柱温为30℃;流速为1.0ml/min低压梯度洗脱。结果:绿原酸和芦丁分别在12.5¹50μg/ml(r=0.9998)和12.5150μg/ml(r=0.9998)和12.5¹50μg/ml(r=0.9998)浓度范围内呈良好的线性关系,平均回收率分别为101.08%(RSD=1.38%,n=5)和99.56%(RSD=1.17%,n=5)。结论:该方法简便快速、重现性好、准确可靠,适用于新疆阔克阿木提果皮中绿原酸和芦丁的含量测定。     

渤海金州湾放流海域中国明对虾生长特性研究

为研究渤海金州湾海域放流中国明对虾Fenneropenaeus chinensis的生长特性,于2016年7—10月共计回捕中国明对虾2195尾,并对其头胸甲长(L_T)、体长(L_t)及体质量(W_t)进行测量和分析。结果表明:中国明对虾头胸甲长与体长呈线性关系,即雌虾L_t=2.8737L_T+28.905 (R²=0.8914),雄虾L_t=3.067 L_T+22.209 (R2=0.8914),雄虾L_t=3.067 L_T+22.209 (R²=0.8427);体长与体质量成幂函数关系,即雌虾W_t=0.546402×102=0.8427);体长与体质量成幂函数关系,即雌虾W_t=0.546402×10^(-5)L_t(-5)L_t^(3.131265)(P=2.2×10(3.131265)(P=2.2×10^(-16)),雄虾W_t=1.180508×10(-16)),雄虾W_t=1.180508×10^(-5)L_t(-5)L_t^(2.969245)(P=2.2×10(2.969245)(P=2.2×10^(-16));采用Von Bertallanffy生长方程拟合体长、体质量的生长方程,即雌虾L_t=220.2139×[1-e(-16));采用Von Bertallanffy生长方程拟合体长、体质量的生长方程,即雌虾L_t=220.2139×[1-e^{(-0.018(t-52.4)})]、W_t=118.4623×[1-e(-0.018(t-52.4))]、W_t=118.4623×[1-e^{(-0.018(t-52.4)})](-0.018(t-52.4))]^(3.131265),雄虾L_t=153.5412×[1-e(3.131265),雄虾L_t=153.5412×[1-e^{(-0.0409(t-59.71)})]、W_t=36.6021×[1-e(-0.0409(t-59.71))]、W_t=36.6021×[1-e^{(-0.0409(t-59.71)})](-0.0409(t-59.71))]^(2.969245);体长、体质量生长速度方程,雌虾dL_t/dt=3.9639e(2.969245);体长、体质量生长速度方程,雌虾dL_t/dt=3.9639e^{(-0.018(t-52.4)})、dW_t/dt=6.6769e(-0.018(t-52.4))、dW_t/dt=6.6769e^{(-0.018(t-52.4)})[1-e(-0.018(t-52.4))[1-e^{(-0.018(t-52.4)})](-0.018(t-52.4))]^(2.131265),雄虾dL_t/dt=6.2798e(2.131265),雄虾dL_t/dt=6.2798e^{(-0.0409(t-59.71)})、dW_t/dt=4.445e(-0.0409(t-59.71))、dW_t/dt=4.445e^{(-0.0409(t-59.71)})[1-e(-0.0409(t-59.71))[1-e^{(-0.0409(t-59.71)})](-0.0409(t-59.71))]^(1.969245)。研究表明:雌虾与雄虾的体长和体质量在生长过程中表现出明显差异,在体质量生长方面,雌虾体质量生长拐点是115.8 d(约8月29日),雄虾体质量生长拐点是86.3 d(约7月30日),此时中国明对虾仍处于生长期;建议今后在渤海海域可适当延后开捕时间,以期实现资源的最大利用。     

游三国,学数学(连载十五)

<正>第十五回三兄弟团聚——实数话说,张飞与赵云顺利回到了营地,他们将在曹营的所见所闻仔仔细细地向刘备、诸葛亮做了汇报。张飞还解答出了曹冲最后留下的问题:"商n"能走出根号。(n(n/(n²-1)))2-1)))^(1/2)=(n(n/(n(1/2)=(n(n/(n²-1)))2-1)))^(1/2)(n为大于1的正整数),理由是:(n(n/(n(1/2)(n为大于1的正整数),理由是:(n(n/(n²-1)))2-1)))^(1/2)=((n(n(1/2)=((n(n²-1)+n)/(n2-1)+n)/(n²-1))2-1))^(1/2)=((n(1/2)=((n³-n+n)/(n3-n+n)/(n²-1))2-1))^(1/2)=(n(1/2)=(n³/(n3/(n²-1))2-1))^(1/2)=((n(1/2)=((n²×n)/(n2×n)/(n²-1))2-1))^(1/2)=n(n/n(1/2)=n(n/n²-1)2-1)^(1/2).赵云也熟练地解答出了     

内蒙古岗更湖瓦氏雅罗鱼年龄结构及生长特征

为研究岗更湖(岗更诺尔湖)瓦氏雅罗鱼Leuciscus waleckii渔业资源利用的可持续性，2017年7月和9月在内蒙古自治区赤峰市岗更湖采集224尾样本，以其耳石为鉴定材料，对瓦氏雅罗鱼的年龄结构和生长特征进行研究。结果表明：渔获物中瓦氏雅罗鱼雌性体长范围为120～264 mm,体质量范围为31.9～367.8 g,雄性体长范围为100～253 mm,体质量范围为16.7～310.9 g;雌性群体年龄组成为1～7 a,雄性群体年龄组成为1～6 a;体长与体质量关系式为W_雌=2.333×10^(-5)L(-5)L^(2.973)(R(2.973)(R²=0.961,n=120),W_雄=1.220×102=0.961,n=120),W_雄=1.220×10^(-5)L(-5)L^(3.084)(R(3.084)(R²=0.949,n=104);Von Bertalanffy生长方程显示，瓦氏雅罗鱼雌性和雄性的渐进体长(L_∞)分别为497.370、415.926 mm,渐进体质量(W_∞)分别为2 427.41、1 456.82 g,生长系数(k)分别为0.199、0.270,理论上体长等于零时的年龄(t_0)分别为-0.216、-0.149a;通过生长加速度方程估算出雌、雄个体的拐点年龄分别为5.3、4.0 a,对应的体长分别为330.1、281.0 mm。研究表明，岗更湖瓦氏雅罗鱼生长属于快速生长类型，为合理开发及可持续性利用岗更湖该鱼的种群资源，建议捕捞规格在5 a以上。     

甲基红褪色光度法测定司帕沙星含量的研究

建立了褪色光度法测定司帕沙星含量的方法。室温下,在pH=3.5的HAc-NaAc缓冲体系中,司帕沙星与甲基红溶液反应10 min形成配位比1∶1的荷移络合物,在波长553 nm处有最大的褪色吸收峰。在此波长下,司帕沙星的浓度c在1.00×10^(-6)～3.00×10(-6)～3.00×10^(-6)mol/L遵守朗伯比尔定律,线性方程为A=0.14936 c+0.09909,相关系数r=0.997,检出限D=6.00×10(-6)mol/L遵守朗伯比尔定律,线性方程为A=0.14936 c+0.09909,相关系数r=0.997,检出限D=6.00×10^(-7)mol/L。在该浓度范围内,表观摩尔吸光系数K=2.10×10(-7)mol/L。在该浓度范围内,表观摩尔吸光系数K=2.10×10⁵L/(mol·cm);样品平均回收率为101.5%,RSD为1.52%,可用于准确测定药剂中司帕沙星的含量。     

藏药二十一味寒水石丸中的总鞣质、没食子酸和鞣花酸的含量测定

目的:建立二十一味寒水石丸中总鞣质、没食子酸和鞣花酸的含量测定方法.方法:以干酪素作为吸附剂,碱性条件下显色,以磷钼钨酸为氧化剂,用紫外可见分光光度法测定鞣质含量;采用HPLC法同时测定没食子酸和鞣花酸的含量.使用迪马Diamonsil-2 C18(4.6 mm×250mm,5μm)色谱柱,以乙腈--0.1磷酸水梯度洗脱,体积流量分别为1.0mL/min,柱温为30℃;检测波长270nm,测定.结果:以没食子酸计的鞣质含量在0.5⁵μg?ml-1的范围内线性关系良好(r=0.9991),平均回收率为95.77%,RSD为0.70%(n=6);没食子酸在0.325μg?ml-1的范围内线性关系良好(r=0.9991),平均回收率为95.77%,RSD为0.70%(n=6);没食子酸在0.32¹.6μg范围内线性关系良好(r=0.9999),平均回收率为98.70%,RSD为1.01%(n=9),鞣花酸在0.3721.6μg范围内线性关系良好(r=0.9999),平均回收率为98.70%,RSD为1.01%(n=9),鞣花酸在0.372^.1.86μg范围内线性关系良好(r=0.9999),平均回收率为99.63%,RSD为0.75%(n=9).结论:本方法准确、可靠简便,具有较强专属性,可用于常用藏药二十一味寒水石丸中总鞣质、没食子酸和鞣花酸的含量测定.     

Gill reactivity of aluminium-species following liming

In acidified aluminium (Al) rich freshwater positively charged Al-species (Al(i)) are the key toxic components due to the accumulation in fish gills. As a countermeasure, liming is used to increase the pH and reduce the concentration of Al(i)-species; in particular low molecular mass (LMM) Al(i)-species by hydrolyses. However, very toxic high molecular mass (HMM) Al polymers can form in the unstable mixing zone immediately after liming. In the present work gill reactivity of LMM and HMM Al-species was studied under controlled conditions in eight channel-tank mixing zone systems in the field where Atlantic salmon (Salmo salar L.) kept in cages were exposed to defined mixing zone water. Mixing zones were created by continually liming acid river water (pH 5.0-5.7) high in LMM Al(i) to pH 6.0 and 6.4, respectively. Transformation processes affecting the Al-speciation as a function of time after liming were documented by in situ hollow fibre ultrafiltration interfaced with ion chromatography, while the Al accumulation in fish gills was used as bioindicator. For fish exposed to mixing zone water immediately after liming (1 min) the Al accumulation in gills (mug Al g(-1)) was higher (factor of 2) than for fish exposed to acid water prior to liming, due to the formation of gill reactive HMM Al(i)-species. The Al accumulation in gills followed a first order kinetic expression reaching steady-state conditions after 24-h exposures. The deposition rate of Al in gills (mug Al g(-1) h(-1)) correlated with the water concentrations of HMM Al(i) (R(2)=0.80) in the mixing zones, and for LMM Al(i) in the acid water (R(2)=0.92). Due to the transient nature of HMM Al(i) the deposition rate of Al decreased from the point of liming with a factor of 10 downstream the channel-tank system (i.e. 100 min after liming). The concentration of gill accumulated Al was higher (factor of 3) immediately after high level liming (pH 6.4) than following low level liming (pH 6.0). However, high level liming was more efficient in detoxifying Al in downstream waters. Furthermore, the bioavailability of a given LMM Al(i) concentration as well as bioreactivity following liming was dependent on the TOC and silicon concentration in the acid water. Increased concentration of TOC (1.5 to 4.3 mg l(-1)) and silicon (0.3 to 1.0 mg l(-1)) reduced the gill reactivity of Al(i) by approximately 50%.     

Gill and head kidney antioxidant processes and innate immune system responses of yellow perch (Perca flavescens) exposed to different contaminants in the St. Lawrence River, Canada

Biomarkers of oxidative stress metabolism and the innate immune response were examined in gill and head kidney tissue of wild-caught yellow perch (Perca flavescens) collected from four sites ranging in type and degree of metal pollution in the St. Lawrence River, Quebec, Canada. Sites were ranked as follows: Île Dorval < Îles aux Sables < Îlet Vert < Beauharnois. Biomarker measurements did not correspond completely to the perceived pollution gradient. Total protein content was highest at a site 4 km downstream of municipal effluents (Îlet Vert) exposed to moderate and high levels of heavy metals and faecal coliforms, respectively. Thiol content was highest at the reference site (Île Dorval) with the lowest contaminant levels. Glutathione-S-transferase (GST) activity was highest in fish from the site furthest downstream that was exposed to moderate metal contamination (Îles aux Sables). Glutathione reductase (GRd) activity was high in both gill and head kidney tissue of fish from the reference site (Île Dorval) and highest in the kidney of fish from the most contaminated site (Beauharnois). Catalase activity was highest in head kidney tissue in fish from this latter site. Ceruloplasmin activity was lowest in head kidney from fish collected at the reference site and highest at Beauharnois. Lysozyme activity was lowest in head kidney tissue from fish at the reference site and highest in tissue from fish at Îlet Vert, downstream of municipal effluents. These results suggest that the direction and magnitude of oxidative stress biomarker response and innate immune function biomarker response vary between tissues and among complex mixtures of contaminants, complicating interpretation of results. Results further suggest that bacterial loading, as measured by faecal coliforms, affects the oxidative stress metabolism and the innate immune response.     

Considerations on Stability of Embankments on Clay

This paper is part of a Special Lecture presented at the International Symposium on Coastal Geotechnical Engineering, IS Yokohama 2000, held in Yokohama in September 2000. It examines the different approaches that have been proposed for the evaluation of stability of embankments on soft clays. Stability of embankments constructed in one stage is well controlled. However, experience shows that engineers have to be careful when they want to apply in a given geological context an empirical approach that has been developed in a different one. For stage-constructed embankments, there are indications that the methods proposed up to now have a tendency to underestimate stability.     

城市边缘区村庄规划初探

一、引言 城市边缘区是指城市建成区的外围地带,从城市形态上看,该地带位于市区向郊区过渡的地带。位于城市边缘区的村庄是指集镇规模以下的中心村、行政村、自然村等。城市边缘区村庄作为城市发展中较活跃、变化迅速的地域实体,其功能及结构逐步发生了变化,与广大的乡村存在很大的差异,在社会经济、土地利用等方面均有不同,主要体现在以下几个方面: (一)经济发展条件的优势明显:村庄的经济发展之所以迅速,与其所处的良好区位而产生的边缘效应是密切相关的。1、城市边缘区村庄有着优越的地理位置,可优先吸收市区经济、技术、信息等,而…     

从业主的角度看BIM——BIM在上海中心的全过程运用研究

这一年BIM发展很快,年初我们以BIM专栏开场,现在又要以BIM收尾。作为同类期刊中最早全面报道BIM的,我们一直关注它的发展态势。不得不承认,它势头强劲,比我们想象的更猛——观望质疑的越来越少,投入其中的越来越多;既有设计大院全员参与的磅礴大气,又有中小院采用团队配合的四两拨千斤,更有越来越多业主的强势要求和强力推进——总包、分包不得不BIM或者说是"被BIM"……,让我们不得不感慨:BIM时代来临了。作为媒体的我们,也只能认清行业发展的趋势,随行就市,推波助澜。为此,本期特精选了2011年欧特克AU大师汇及中国建筑设计研究院第二届BIM大会的部分报告并邀请更多精彩内容,力争从业主、设计院管理、规划、设计、营建、服务多角度深入探讨BIM的应用,以期给读者更多的启示,也从而推动BIM在建筑行业的全面发展。(注:BIM=Bilding Information Model,三维建筑信息模型。若您还没听说过或听说过但不知道是干啥的,那就离out不远了,就也快hold不住了,得抓紧跟上了——编者笑批)     

从业主的角度看BIM——BIM在上海中心的全过程运用研究

项目地点 上海市浦东新区陆家嘴金融中心高度632m项目总用地面积/总建筑面积30 368m2/573 223m2建设单位 上海中心大厦建设发展有限公司方案及初步设计Gensler施工图设计 同济大学建筑设计研究院(集团)有限公司施工单位 上海建工集团动工时间/预计竣工时间2008年11月29日/2014年底缘起我个人接触BIM是在2007年,当时上海中心正处在方案设计阶段.除了超高、超大规模、系统超复杂外,大楼没有一个标准层,项目该怎么表达?参与单位接近40个,而业主团队整个技术管理人员不到10个人,采用什么方法才不会导致因为很多人为的错误而引起现场大量返工?作为这幢楼的技术主管,我内心非常忐忑不安.因此当有人跟我提到BIM理念的时候,我马上意识到它将会对我们有非常大的帮助.上海中心从2007年筹划使用BIM到现在已经过去4年的时间了,从我个人感觉来说,有非常多的体会,在这里跟大家交流一下.     

骨料对混凝土力学性能的影响分析

利用颗粒流方法,实现了相同条件下混凝土的骨料大小和空间位置对其破坏形态、应力-应变曲线、峰值应力和割线模量的影响规律研究.通过对比砂浆与骨料的不同质量比(5∶5,4∶6,3∶7,2∶8)以及不同级配(一级配、二级配、三级配、四级配)骨料的混凝土单轴压缩仿真试验结果,发现骨料有阻止混凝土裂纹扩展的作用,且骨料越大,阻止混凝土裂纹扩展的作用越强,而微裂纹多绕骨料产生和发展;砂浆中加入骨料对混凝土强度和变形特性具有明显的改善作用,相对于砂浆的峰值应力5.2MPa和割线模量30.7GPa而言,在砂浆与骨料质量比为5∶5和4∶6时,不同级配混凝土的峰值应力约增加22%~48%、割线模量增加-8%~99%,其平均值基本维持在6.5MPa和7.2MPa,37.4GPa和42.6GPa;在砂浆与骨料质量比为3∶7和2∶8时,不同级配混凝土的峰值应力急剧增加40%~228%、割线模量急剧减小79%~92%,其平均值分别为9.2MPa和15.4MPa,15.8GPa和4.4GPa.当砂浆与骨料的质量比相同时,骨料级配越高,越容易形成架空结构,造成局部不稳定,影响骨料增强效果;级配相同时,混凝土强度随骨料质量占比的增大而增大,且其应力-应变曲线呈现出单峰到双峰再到单峰的变化趋势,这说明骨料空间结构的稳定程度决定了混凝土应力-应变曲线的形状变化.     

水对高速公路路基影响的探讨

探讨了地下水位变化对路基的影响,分析了考虑地下水位影响的路基高度的确定,研究了高速公路路基综合排水的设计,以不断完善道路排水系统,从而延长公路的使用寿命。