近60年农业生产期干旱发生风险分析

采用叶柏寿、朝阳气象站1953—2012 年气象资料,运用积分湿度指数、水平衡和干湿指数,评价辽西地区农业生产期大气降水及农业耗水、农业需水的满足度及不同时期旱涝频率。结果表明：1953—2012 年农业生产期大气降水减少,气候变化率为-9.343 mm/10 a;农业耗水量在增加,气候变化率为6.966 mm/10 a;农业生产期水分平均亏缺-136 mm。降水资源农业满足度为76.3%,缺水概率为90.0%。辽西地区农业生产期属于半湿润半干旱气候类型,重旱及以上年景占5.0%;干旱发生风险近10年增加约10%。总之,辽西地区降水在减少、耗水在增加、农业需水满足度在下降、干旱发生风险在增强。近10年随着气候变暖辽西地区农业生长期从半干旱半湿润气候类型升级为半干旱气候类型。     

Effect of poly‐β‐hydroxybutyrate on growth,enzyme activity and intestinal microbial community of Chinese mitten crab,Eriocheir sinensis (Milne‐Edwards) juveniles

Poly‐β‐hydroxybutyrate (PHB) is microbial carbon and energy storage polymer, which can be degraded into water‐soluble β‐hydroxybutyric acid in the gastrointestinal tract of aquatic animals. A 60‐day culture experiment was performed using Chinese mitten crab, Eriocheir sinensis (Milne‐Edwards) juveniles with an average initial body weight of 0.74 ± 0.06 g which were fed a diet supplemented with 0%, 0.5%, 1%, 3% or 5% PHB. A PHB dietary supplementation of 1% and 3% significantly improved the body weight gain, moulting frequency and concomitantly reduced 2nd–3rd moulting intervals of the crabs (P < 0.05). The dietary PHB level positively related to hepatopancreatic pepsin, trypsin and lipase activity (P < 0.05). Increasing the dietary PHB also improved total superoxide dismutase activity, but reduced alkaline phosphatase and acid phosphatase activity in the serum of hemolymph (P < 0.05). A 16S rRNA gene analysis by denaturing gradient gel electrophoresis indicated that PHB supplementation led to a significantly higher range‐weighted richness, diversity and evenness of the gut bacterial community when dosed at 3% in the feed. The beneficial effects of PHB are discussed in terms of immune defense, metabolism and gut microbiota of the crabs.     

Abnormal morphology in megalopae of the swimming crab,Portunus trituberculatus during seed production: causes and prevention

The occurrence of morphologically immature megalopae, which retain zoeal features such as dorsal spines and furcae of telson, is closely correlated with larval mass mortality during seed production of the swimming crab Portunus trituberculatus in Japanese hatcheries. To determine the cause of immature megalopal morphology, zoeae were reared with various supplementary schedules and density of diets (rotifer, Artemia and phytoplanktons including Chlorella vulgaris and Nannochloropsis oculata). In addition, to assess the relationship between immature morphology and endocrine control, the effect of causative dietary factor was compared with the effect of eyestalk ablation at various timing during zoeal development. Megalopal immature morphology was more distinct in Chlorella‐supplemented groups than in Nannochloropsis‐supplemented groups. High density Chlorella supplementation was associated with the highest incidence of immaturity and resulted in larval mass mortality. The premoult of the third zoeal stage was identified as a critical period at which Chlorella supplementation led to the highest incidence of immaturity. This critical period coincided with the critical period at which larval metamorphosis was regulated by the eyestalk neurosecretory system. Our results suggested that the occurrence of immature megalopal morphology under culture conditions is most likely caused by phytoplankton (especially, Chlorella) supplementation, which disrupts the endocrine regulation. On the basis of our results, we successfully prevented the occurrence of immature megalopal morphology in 500 L tanks by excluding the influence of phytoplankton before the critical period (i.e. discontinuing phytoplankton supplementation and supplying rotifer cultured with non‐phytoplankton materials).     

Effect of nitrogen fertilizers on zinc absorption and translocation in winter wheat

Zinc (Zn) deficiency caused by inadequate dietary intake is a global nutritional problem, so increasing Zn concentrations in crops is a challenging and high-priority research task. A field experiment was conducted to explore the effects of nitrogen (N) fertilizers on Zn absorption and translocation in winter wheat during the 2010–2011 and 2011–2012 crop seasons, in Xinzheng City, Henan Province, China. N was applied at four levels (0, 90, 180, and 270 kg N ha^?1) and Zn was applied at two levels (15 and 30 kg zinc sulfate heptahydrate (ZnSO_4·7H₂O) ha^?1]. The results indicated that reasonable N application increased grain yield, total Zn accumulations, and Zn concentrations of each plant part of winter wheat. Furthermore, appropriate N application increased Zn distribution proportions in grains and decreased Zn distribution proportions in roots, stems, leaves, and spikes, and enhanced Zn removal from roots, stems, leaves, and spikes to grains. Meanwhile, reasonable N combined with higher Zn application had a better effect on Zn absorption and Zn translocation to grain of winter wheat. The results suggested that suitable quantity of N fertilizer combined with higher Zn application is an important measure to obtain both higher grain yield and grain Zn concentration in winter wheat production.     

钢结构仿古建筑双梁柱中节点的受力机理

为研究钢结构仿古建筑双梁柱中节点的抗震性能,对4个全焊双梁柱中节点进行了水平低周反复加载试验。通过观测试件在侧向力作用下的受力过程和破坏形态,分析双梁柱中节点的受力机理。根据梁截面形式的不同,将其分为箱型截面梁与工字型截面梁2类,依据仿古建筑独特的构造特点,将各试件节点核心区划分为上、中、下3个区域。通过量测各区域内的应变大小,分析该类结构节点核心区在侧向力作用下的受理机理及破坏模式,并建立双梁柱节点的斜压杆受力模型。试验结果表明：仿古建筑双梁柱节点的破坏形式主要为沿下核心区对角线的剪切破坏,并通过理论计算分析提出一种考虑轴压比与梁截面形式的双梁柱中节点抗剪承载力修正公式。     

比久和矮壮素对矮牵牛穴盘苗生长的控制作用研究

为了防止矮牵牛穴盘育苗徒长,采用不同浓度的比久(B9)和矮壮素（CCC）溶液叶面喷施矮牵牛穴盘苗。结果表明,B9,CCC及二者混合处理矮牵牛穴盘苗的最佳浓度分别为2500 mg/L B9、0.3% CCC、1500 mg/L B9＋0.3% CCC,适宜浓度分别为1000~2500 mg/L B9、0.05%~0.3% CCC、1500 mg/L B9＋0.3% CCC,3种延缓剂最佳浓度相比,效果从好到坏为：1500 mg/L B9＋0.3%CCC ＞0.3%CCC ＞2500 mg/L B9,但2500 mg/L B9成本最低。当CCC处理浓度大于1%时,出现药害现象。     

崂山奶山羊瘤胃微生物总DNA提取方法的优化

对瘤胃微生物总DNA提取方法进行了改进,将冻融法和CATB法相结合,可以将细菌、真菌和古细菌在内的各种微生物的细胞壁充分的粉碎,且DNA提取效果稳定,可以获得足够大的DNA片段(23 kb),可以满足后续试验的需要.     

3年生南方红豆杉生物量和紫杉醇含量的积累分配研究

对人工栽培的3年生南方红豆杉(Taxus chinensis var.mairei)的生物量和紫杉醇含量进行取样分析,结果表明,株平均鲜重达382.43 g,平均干重为143.00 g;各部位生物量当年生嫩梢叶＞主茎木质部＞根系＞2年生枝叶＞主茎嫩皮;紫杉醇含量以主茎嫩皮最高,达0.000 788%,根系次之,梢叶最低.从保护和合理开发红豆杉资源角度,建议提取紫杉醇应以南方红豆杉枝叶为原料.     

浸泡法五香咸蛋的研制及最佳配方筛选

研究五香咸蛋的腌制方法和筛选最佳配方。精选天然香辛料并与食盐、草木灰调配成复合调味料液来腌制鲜蛋,得到咸香可口的咸蛋。五香料的最佳配方为:花椒15%,八角15%,桂皮10%,丁香15%,茴香8%,豆蔻7%,红茶10%,山楂20%。咸蛋浸泡液的最佳配比为:食盐20.00%,复合香辛料0.60%,草木灰1.50%。结果表明,此法腌制的咸蛋,蛋白鲜美细嫩,蛋黄黄润、松、沙、油,并有特殊的馥郁香味。     

黑龙江省沙尘天气形成因子分析

通过对黑龙江省沙尘天气发生的分布特征及形成的地理因子的研究,可知黑龙江省沙尘天气发生形成的沙源主要为松嫩平原及科尔沁沙地,蒙古低压的活动是其形成的主要原动力,同时其形成也受到全球变暖以及厄尔尼诺等全球事件的影响.