毛蚶在不同底质与撒播方式下潜沙行为的观测与分析

为了探究不同底质与撒播方式对毛蚶(Scapharca subcrenata)潜沙行为的影响,在实验室条件下,观察了壳长(10.0±0.9)mm毛蚶的潜沙过程,并研究了沙质(粒径251~500μm)和泥沙质(粒径120μm)两种底质和播散方式(集中和分散)对毛蚶潜沙时间和潜沙率的影响。结果显示,毛蚶潜沙过程分为准备、潜沙及结束3个阶段。在两种底质条件下,集中播撒方式的毛蚶潜沙时间均短于分散播撒方式,但同种底质不同播撒方式下的毛蚶潜沙时间差异不显著(P0.05)。无论是集中播撒还是分散播撒,沙质条件下毛蚶的潜沙时间均短于泥沙质的潜沙时间,并且在分散播撒方式下,两种底质的差异达到显著水平(P0.05);两种底质条件下,毛蚶的潜沙率均表现为集中播撒高于分散播撒。研究表明,与泥沙质底质相比,毛蚶在沙质条件下更易于快速潜底;与分散播散方式相比,集中播撒更利于毛蚶快速潜底。     

Bloom or bust: synchrony in jellyfish abundance,fish consumption,benthic scavenger abundance,and environmental drivers across a continental shelf

Increases in gelatinous zooplankton (GZ) populations, their dominance of some ecosystems, their impacts to other taxa, and their questionable trophic value remain global concerns, but they are difficult to quantify. We compared trends in GZ abundance from direct sampling for the northeast U.S. continental shelf and tested their association with GZ consumption by spiny dogfish (Squalus acanthias); the abundance of two benthic scavengers: Atlantic hagfish (Myxine glutinosa) and grenadiers (Family: Macrouridae); and four environmental indices: Atlantic Multidecadal Oscillation, North Atlantic Oscillation, and sea surface and bottom temperatures. Defined as scyphozoans, siphonophores, ctenophores, and salps, the abundance of GZ on the shelf has oscillated with blooms approximately every 10–15 yr. Conservative estimates of annual removal of GZ by spiny dogfish ranged from approximately 0.3–298 g individual^?1 with spiny dogfish being the primary GZ feeder sampled on the shelf. The examination of three abundance series for GZ identified one shelf‐wide trend and strong relationships with 2‐yr lagged consumption and scavenger abundance (namely hagfish), and sea surface temperature. With multimodel inference, these covariates led to an optimal model of GZ abundance. Blooms of GZ abundance on this shelf were influenced by environmental change, provide surges of food for spiny dogfish, and may offer ‘food falls’ for scavenging fishes. The bioenergetic tradeoffs of consuming greater amounts of GZ compared to other major prey (e.g., fishes) remain unknown; however, these surges of food in the northwest Atlantic appear to be important for fishes, including support for benthic scavenger productivity.     

Effect of LED light quality on the phototaxis and locomotion behaviour of Haliotis discus hannai

Abalones were reared in a laboratory to determine the percentage response rate, response time, average crawling speed and the time taken to recover an upright posture under nine light‐emitting diode light quality treatments (red, orange, yellow, green, cyan, blue, purple, white and grey) and a dark environment. Animals were placed in the centre of an experimental device, and the tropism of each animal was continuously monitored by video. The highest percentage response rate (80% in dark adapted abalones, 60% in light adapted abalones) was observed in the dark environment, followed by red and orange light (27% and 30% in dark adapted abalones, respectively, 22% and 24% in light adapted abalones). Two induction materials (substrate and brown algae Laminaria japonica) were used to assess the effect of light quality on the tropism of abalones, with the highest percentage response rate (76% in the L. japonica treatment, 22% in the substrate treatment) also observed in the dark environment, followed by red and orange light (both 25% in the L. japonica treatment, and 26% and 32%, respectively, in the substrate treatment). The tropism order of the abalones under dark, red, orange and yellow light was as follows: dark > orange > red, yellow, but fewer abalones chose to stay in blue, green, cyan and purple light. The response time (about 700 s) in the dark environment was significantly longer than for the other light quality treatments. Compared with the average crawling speed in the other light quality treatments, abalones were relatively slower (about 3.8 mm s^?1) in red and orange light, and the dark environment. The mean time required for the recovery of an upright posture in red light and the dark environment was longer than in the other light quality treatments, with the average recovery time reaching a maximum of 60 s in the dark environment. The results demonstrate the phototaxis and locomotion behaviour of abalones, as well as confirming the necessity of a dark, orange or red environment for their management and aquaculture.     

中国北方农牧交错带中段近60年气温序列变化研究

利用1955-2014年中国北方农牧交错带中段10个气象观测站的气温时间序列资料,在分析气温变化结构的基础上运行气候突变检验和小波分析,用以解释气温变化的多时间尺度的复杂结构,分析不同时间尺度下气候气温变化的突变点和周期性变化规律。结果表明：近60 a来研究区内平均气温呈现普遍升高趋势,尤其在20世纪80年代以后升高趋势更加显著,达到99%置信度,升温速率达到0.45℃·10a^-1,高于全国和全球的气温增长率。2008年后区域进入降温过程,冬季降温尤为明显,其原因是全球变化发生停滞;气候突变检验表明区域年平均气温的升温突变发生在1986年,显著升温开始于1991年,冬季升温突变时间最早,发生在1978年,夏季升温突变时间滞后,出现于1991年;周期检验表明区域内气温存在5~10 a和30 a的多重时间尺度结构的变化特征,预计2008年后年平均气温和季节平均气温增加速度将变缓,甚至可能发生变暖停滞。     

施肥对饲草高粱生长及营养品质的影响

研究施用氮、磷,钾肥对饲草高粱生长及营养品质动态的影响结果表明,氮肥、磷肥和钾肥配合施用可大幅提高饲草高粱生物产量,增加饲草高粱植株粗蛋白质、粗纤维和粗脂肪的单位面积产出量;氮素是影响高粱生物产量的首要养分因素,其次为磷素,第三是钾素;饲草高粱植株高度以及粗蛋白质、粗纤维和粗脂肪含量的变化规律,主要取决于品种特性;施肥主要通过影响饲草高粱生物产量,对饲草高粱植株粗蛋白质、粗纤维和粗脂肪的单位面积产出量产生作用.从饲草高粱的生物产量和品质综合考虑,确定饲草高粱的适宜收割期,以开花末期至成熟中期之间为宜,过早收割饲草高粱生物产量较低,过晚收割则饲草高粱生物产量较低且品质变劣.     

不同栽培法和收割期对甘蔗单产及含糖量影响的分析

本研究利用1975～2008年33年间日本南大东岛甘蔗生产数据, 分析了甘蔗栽培方法[新苗种植(包括夏植和春植)、宿根]和收割时期对其产量、品质和经济性的影响.结果表明, 不同栽培法甘蔗多年平均产量依次为夏植>宿根>春植; 新植甘蔗的种植期越早产量越高; 宿根甘蔗产量与前茬甘蔗的收割期呈二次函数曲线关系, 前茬甘蔗收割过早或过迟均对宿根甘蔗生长不利; 宿根甘蔗产量随宿根次数增加呈下降趋势; 宿根甘蔗含糖量通常高于新植甘蔗, 且不同栽培法下3月下旬前收获的甘蔗含糖量随收割期后延而逐渐增加.在此基础上, 建立了依据栽培方法、收割时期预测甘蔗单产和含糖量的数学模型, 模型对我国甘蔗种植业具有理论和实际的参考价值.     

太行山丘陵区不同龄级栓皮栎人工林养分循环特征

为定量分析植被恢复进程的变化特征,以太行山丘陵区的栓皮栎人工林为研究对象,在样方调查的基础上,对其各器官N、P、Ca 3种营养元素的含量、积累、分配和养分循环变化情况进行研究。结果表明：1）不同植物器官中,营养元素含量差异明显;各龄级中,营养元素含量最多的器官是树叶,树干含量最低;营养元素含量的排序为Ca〉N〉P。2）林地土壤有机质、N和P含量随龄级增加呈明显增长趋势,植被恢复能明显加快土壤肥力的提高。3）20-40 a栓皮栎人工林营养元素积累量为2764.58-3689.38 kg/hm^2,年存留量为89.88-138.17 kg/（hm^2·a）,归还量为229.80-262.06 kg/（hm^2·a）。随龄级增加,营养元素储存总量随之升高,而存留量反而降低;吸收量和归还量呈现先升高后降低的趋势;不同营养元素的储存量、吸收量、归还量和存留量的大小排列次序均为Ca〉N〉P。4）循环系数和周转时间随龄级增加而升高,利用系数则呈现下降趋势;各元素之间Ca的周转时间最长（12.73-16.19a）,利用系数最小。     

A quantitative real‐time PCR assay for detection of Colletotrichum lindemuthianum in navy bean seeds

Bean anthracnose is a seedborne disease of common bean (Phaseolus vulgaris) caused by the fungal pathogen Colletotrichum lindemuthianum. Using seed that did not test positive for the pathogen has been proven to be an effective strategy for bean anthracnose control. To quantify the extent of anthracnose seed infection, a real‐time PCR‐based diagnostic assay was developed for detecting C. lindemuthianum in seeds of the commercial bean class navy bean. The ribosomal DNA (rDNA) region consisting of part of the18S rDNA, 5^.8S rDNA, internal transcribed spacers (ITS) 1, 2 and part of the 28S rDNA of seven races of C. lindemuthianum, 21 isolates of Colletotrichum species and nine other bean pathogens were sequenced with the universal primer set ITS5/ITS4. Based on the aligned sequence matrix, one primer set and a probe were designed for a SYBR Green dye assay and a TaqMan MGB (minor groove binder) assay. The primer set was demonstrated to be specific for C. lindemuthianum and showed a high sensitivity for the target pathogen. The detection limit of both assays was 5 fg of C. lindemuthianum genomic DNA. To explore the correlation between the lesion area and the DNA amount of C. lindemuthianum in bean seed, seeds of the navy bean cultivar Navigator with lesions of different sizes, as well as symptomless seeds, were used in both real‐time PCR assays.     

基于边沿捕获的IRIG—B（DC）码解码的研究与应用

通过研究IRIG—B（DC）iLt3原理,提出了基于定时器脉冲边沿捕获技术来实现IRIG—B（DC）码解码的新方法,并选用STM8S103芯片完成了IRIG—B（DC）码解码器的设计。功能仿真和实际测试表明该设计方法是一种解决自动化系统IRIG—B码解码对时的有效方案。目前,该设计已经成功应用于某变电站中的GPS＆IRIG—B（DC）对时系统。     

蛇床子素分散片处方筛选及溶出度的研究

目的优选蛇床子素分散片处方,并建立溶出度测定方法。方法在单因素试验基础上,采用正交试验以崩解时限、分散均匀性为指标对蛇床子素分散片处方进行优化;采用紫外分光光度法测定分散片中蛇床子素的溶出度,测定波长为322nm。结果最佳处方为蛇床子素10%,崩解剂交联聚维酮20%(外加),填充剂微晶纤维素和乳糖分别为30%和40%,黏合剂为75%乙醇进行湿法制粒压片,优选处方的崩解时间小于10s,分散均匀且全部通过二号筛;蛇床子素在为6～16μg.mL-1(n=6,r=0.999 9)时,线性关系良好,蛇床子素分散片60min内累积溶出百分率为88%。结论蛇床子素分散片制备工艺简单,溶出度高,符合《中国药典》2010年版的相关规定,具有实用价值。