Effects of Different Nitrogen Treatments on N use Efficiency and Grain Yield of Mechanically-transplanted Hybrid Rice     

Chang YE  Ke LIU  Shaowen LIU  Jian LU  Mengtao GAO  Bilin LU  Yunbo ZHANG 《农业科学与技术》2017,18(2)

In order to investigate effects of topdressing on grain yield and N use efficiency of mechanically-transplanted hybrid rice,this experiment was conducted with 2-line hybrid rice cultivars,Quanliangyou 1 and Quanliangyou 681 with 3 application levels of N fertilizer,No,N1,N2,respectively.The results showed that there were no significant differences in grain yields of the 2 varieties between treatments N1 and N2.It was indicated that N is not the factor which could limit grain yield within limited application levels of N fertilizer.High N fertilizer treatment could contribute to the formation of effective panicles and spikelets per panicle,but it could also lead to the decline in grain filling rate.It was suggested that lowering the amount of Nfertilizer could facilitate improvement of N-use efficiency.  相似文献   

Comments on soil memory and paleo-environmental reconstruction of soil evolution     

Dan Yaalon 《Eurasian Soil Science》2011,44(4):462-463

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Functional porous carbons from waste cotton fabrics for dyeing wastewater purification     

Shuhua Wang  Meixia Wei  Qiaoli Xu  Husheng Jia 《Fibers and Polymers》2016,17(2):212-219

A new functional porous carbons (PC-WF) is prepared by activation-pyrolysis method use waste cotton fabrics (WF) as an abundant, cheap and available precursor for removal of Brilliant Crocein (BC-GR) and Cationic Red 2GL (CR-GL) from aqueous phase. The PC-WF was characterized by BET, FTIR, SEM, and XRD techniques, the surface area, total pore volume, average pore diameter was found as 1463.5 m² g^-1, 0.783 cm³ g^-1 and 2.14 nm, respectively. The influences on BC-GR and CR-GL adsorption of various experimental factors such as initial concentration and temperature were investigated. Adsorption kinetics was found to be best represented by the pseudo-second order model. The adsorption capacity was 319.8 mg g^-1 for BC-GR and 842.5 mg g^-1 for CR-GL at 30 °C, respectively. The results indicate that for waste cotton fabrics in particular, the practical application of this process to the production of porous carbon would be possible.  相似文献   

Pasteur’s quadrant: an appealing <Emphasis Type="Italic">ecophronetic</Emphasis> alternative to the prevalent Bohr’s quadrant in ecosystem services research     

Wei-Ning Xiang 《Landscape Ecology》2017,32(12):2241-2247

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Kristina Roesel and Delia Grace (eds): Food safety and informal markets: animal products in sub-Saharan Africa     

Ann Waters-Bayer 《Agriculture and Human Values》2016,33(2):493-494

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G.M. Turchini,W.-K. Ng and D.R. Tocher (eds): Fish oil replacement and alternative lipid sources in aquaculture feeds     

Malcolm Jobling 《Aquaculture International》2011,19(3):595-596

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Germ cell-specific expression of dead end (dnd) in rare minnow (Gobiocypris rarus)     

Jundan Duan  Gongqing Feng  Pei Chang  Xueyan Zhang  Qingchun Zhou  Xueping Zhong  Chao Qi  Songguang Xie  Haobin Zhao 《Fish physiology and biochemistry》2015,41(2):561-571

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通过转化脂肪酸去饱和酶基因AcoFAD2提高菠萝植株的抗寒能力     

舒海燕  冼淑云  欧艳妃  何卢琼  丁丽芬  李科明  詹儒林  常胜合 《分子植物育种》2021,19(21):7132-7137

为培育抗寒菠萝新品种,本研究通过比较菠萝脂肪酸去饱和酶基因序列和拟南芥脂肪酸去饱和酶基因序列,筛选获得目标基因AcoFAD2;通过农杆菌转化菠萝'台农17'获得过表达AcoFAD2转基因植株TN17FAD2-3;转基因植株和对照在低温条件下进行培养,鉴定转基因植株和对照的不饱和脂肪酸含量及抗寒能力.结果 发现组培苗在7℃条件下处理5d然后转入26℃生长一周,TN17FAD2-3第四片叶坏死比例为(5±1)％,只转化空载体的对照TN17-EV第四片叶坏死比例为(97±2)％.组培苗在7℃条件下生长5d,然后转入26℃生长15d.TN17FAD2-3第二片叶叶面积为(2.15±0.2) cm2,TN17-EV第二片叶叶面积为(0.06±0.01) cm2.TN17FAD2-3的叶片不饱和脂肪酸含量(16∶3+18∶3)为(77.5±0.7)％,对照TN17-EV叶片不饱和脂肪酸(16∶3+18∶3)含量为(58.6±0.8)％.TN17FAD2-3的叶片不饱和脂肪酸含量高于只转化空载体的对照TN17-EV.低温条件下,TN17FAD2-3比TN17-EV生长快,TN17FAD2-3株系比TN17-EV具有更高的抗寒性,载体UBI-pCAMBIA1301不能提高菠萝植株的抗寒能力,通过转化脂肪酸去饱和酶基因AcoFAD2能够提高菠萝植株的抗寒性能,本研究为快速培育抗寒菠萝新品种提供理论基础.  相似文献   

Characterizing long-term forest disturbance history and its drivers in the Ning-Zhen Mountains,Jiangsu Province of eastern China using yearly Landsat observations (1987–2011)     

Mingshi Li  Chengquan Huang  Wenjuan Shen  Xinyu Ren  Yingying Lv  Jingrui Wang  Zhiliang Zhu 《林业研究》2016,27(6):1329-1341

Forest losses or gains have long been recognized as critical processes modulating the carbon flux between the biosphere and the atmosphere. Timely, accurate and spatially explicit information on forest disturbance and recovery history is required for assessing the effectiveness of existing forest management. The major objectives of our research focused on testing the mapping efficacy of the vegetation change tracker (VCT) model over a forested area in China. We used a new version of VCT algorithm built upon the Landsat time series stacks (LTSS). The LTSS consisted of yearly image acquisitions to map forest disturbance history from 1987 to 2011 over the Ning-Zhen Mountains, Jiangsu Province of east China. The LTSS consisted of TM and ETM+ scenes with different projections due to distinct data sources (Beijing remote sensing ground station and the USGS EROS Center). The validation results of the disturbance year maps showed that most spatial agreement measures ranged from 70 to 86 %, comparable with the VCT accuracies reported for many places in USA. Very low accuracies were identified in 1995 (38.3 %) and 1992 (56.2 %) in the current analysis. These resulted from the insensitivity of the VCT algorithm to detect low intensity disturbances and also from the mis-registration errors of the image pairs. Major forest disturbance types existing in our study area were identified as agricultural expansion (39.8 %), urbanization (24.9 %), forest management practice (19.3 %), and mining (12.8 %). In general, there was a gradual decreasing trend in forest cover throughout this region, caused principally by China’s economic, demographic, environmental and political policies and decisions, as well as some weather events. While VCT has largely been used to assess long term changes and trends in the USA, it has great potential for assessing landscape level change elsewhere throughout the world.  相似文献   

Effect of ammonia and nitrite on vigour,survival rate,moulting rate of the blue swimming crab <Emphasis Type="Italic">Portunus pelagicus</Emphasis> zoea     

Yong Yang Liao  Hong Hu Wang  Zhi Gan Lin 《Aquaculture International》2011,19(2):339-350

The effects of ammonia and nitrite on vigour, survival rate, moulting rate of zoea of blue swimming crab, Portunus pelagicus, were studied. A total of five nitrite-N treatments (26.67, 53.34, 106.68, 213.36, 426.72 mg/l) and a control (no nitrite-N added) were set up for the acute nitrite-N toxicity experiment; a total of five ammonia-N treatments (8.43, 16.86, 33.72, 67.44, 134.88 mg/l) and a control (no ammonia-N added) were set up for the acute ammonia-N toxicity experiment. The results showed that the vigour, survival rate and moulting rate of zoea of the blue swimming crabs exposed to over 53.34 mg/l were significantly different (P < 0.05) from the control group. The zoea LC₅₀ values (mg/l) of nitrite-N were 179.47, 76.56, 66.70, 37.49, 25.01, 25.35, 25.34 mg/l for 24, 36, 48, 60, 72, 84, 96 h, respectively. The vigour, survival rate and moulting rate of zoea of the blue swimming crabs exposed to over 16.86 mg/l were significantly different (P < 0.05) from the control group. The zoea LC₅₀ values (mg/l) of ammonia-N were 51.04, 39.62, 38.72, 24.43, 16.90, 13.42, 11.16 mg/l for 24, 36, 48, 60, 72, 84, 96 h, respectively. The zoeae are highly sensitive to ammonia and nitrite, and the toxicity of ammonia and nitrite on Portunus pelagicus decrease with development of this crab.  相似文献