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51.
Shanshan?Chen Jiahuan?Tang Li?Fu Yong?Yuan Shungui?ZhouEmail author 《Journal of Soils and Sediments》2016,16(9):2326-2334
Purpose
The low conductivity of sediments for mass and electron transport is the most severe limiting factor in sediment microbial fuel cells (SMFCs), so that sediment ameliorations yielded more remarkable effects than electrode improvements. The objective of this research was to enhance the electricity generation of SMFCs with amendments of biochar to freshwater sediments for conductivity enhancement.Materials and methods
Laboratory-scale SMFCs were constructed and biochars were produced from coconut shells at different temperatures. Variations in the power output, electrode potential, internal resistance, total organic carbon (TOC) content, and microbial communities were measured.Results and discussion
Amending with biochar reduced the charge transfer resistances of SMFCs and enriched the Firmicutes (mainly Fusibacter sp.) in the sediment, which improved the SMFC power generation by two- to tenfold and enhanced the TOC removal rate by 1.7- to fourfold relative to those without the amendment.Conclusions
The results suggested that biochar amendment is a promising strategy to enhance SMFC power production, and the electrical conductivity of biochar should be considered important when interpreting the impact biochar has on the electrical performance of soil or freshwater sediment MFCs.52.
夷优180系福建省南平市农业科学研究所用自主选育的三系不育系夷A与恢复系南恢180配组而成的杂交中稻新品种。经多年在福建省各地试验、试种表现群体整齐、适应性广、产量高、抗性好等特点,2014年通过福建省农作物品种审定。简述了杂交水稻夷优180的选育及应用。 相似文献
53.
54.
高产优质杂交稻新品种钱优3301系福建省农业科学院生物技术研究所与浙江省农业科学院作物与核技术利用研究所用钱江1A/闽恢3301联合培育的,2014年通过福建省农作物品种审定。2016年引入闽清县种植,平均产量达9 127.9 kg/hm~2,具有株型适中、群体整齐、综合性状好、稻米品质优等特点。总结了钱优3301在闽清县种植表现及高产栽培技术。 相似文献
55.
通过多个粳型水稻品种与籼型品种的对比栽培试验,分析其生物学特性,表明粳型品种分蘖力弱,有效穗少,但穗粒数多,茎秆粗壮,抗倒。粳型品种高产栽培策略是合理密植,创建最优群体结构,增加有效穗,提高结实率,及时预防稻曲病。 相似文献
56.
57.
Tania S. Peña James R. Watson Laura I. González-Guzmán Timothy H. Keitt 《Landscape Ecology》2017,32(8):1643-1656
Context
Many nearshore species are distributed in habitat patches connected only through larval dispersal. Genetic research has shown some spatial structure of such metapopulations and modeling studies have shed light onto possible patterns of connectivity and barriers. However, little is known about human impact on their spatial structure and patterns of connectivity.Objectives
We examine the effects of fishing on the spatial and temporal dynamics of metapopulations of sedentary marine species (red sea urchin and red abalone) interconnected by larval dispersal.Methods
We constructed a metapopulation model to simulate abalone and sea urchin metapopulations experiencing increasing levels of fishing mortality. We performed the modularity analysis on the yearly larval connectivity matrices produced by these simulations, and analyzed the changes of modularity and the formation of modules over time as indicators of spatial structure.Results
The analysis revealed a strong modular spatial structure for abalone and a weak spatial signature for sea urchin. In abalone, under exploitation, modularity takes step-wise drops on the path to extinction, and modules breakdown into smaller fragments followed by module and later metapopulation collapse. In contrast, sea urchin showed high modularity variation, indicating high- and low-mixing years, but an abrupt collapse of the metapopulation under strong exploitation.Conclusions
The results identify a disruption in larval connectivity and a pattern of collapse in highly modular nearshore metapopulations. These results highlight the ability of modularity to detect spatial structure in marine metapopulations, which varies among species, and to show early changes in the spatial structure of exploited metapopulations.58.
Piet?C.?N.?GroenewaldEmail author Carin?S.?Viljoen 《Journal of Agricultural, Biological & Environmental Statistics》2003,8(1):75-83
This article aims to determine the effect of certain covariates, such as season of kidding, parity, and time of kidding on
the characteristics of the lactation curve of Saanen dairy goats. Characteristics investigated are peak milk yield, time of
peak milk yield, total milk production, persistency, and the relationship between fat and protein in milk composition, as
well as between lactation curves of the same animal in successive years. The analysis is carried out using a hierarchical
Bayesian approach, together with Wood’s model, to model lactation. Posterior distributions of quantities of interest are obtained
by means of the Markov chain Monte Carlo (MCMC) methods. These clearly illustrate the significant effect of especially parity,
but also season and time of kidding on the characteristics of the lactation curve. Total and peak milk yield increase with
increasing parity up to about the third or fourth parity, while peak yield is later for first than for later parities. The
analysis also enables estimation of lactation characteristics of untested animals, prediction of future characteristics and
identification of exceptional animals. 相似文献
59.
Mathias?FosuEmail author Ronald?F.?Kühne Paul?L.?G.?Vlek 《Biology and Fertility of Soils》2003,39(2):117-122
In order to understand the efficiency of residue-N use and to estimate the minimum input required to obtain a reasonable level of crop response, it is important to quantify the fate of the applied organic-N. The recovery of N from 15N-labelled Crotalaria juncea was followed in the soil and the succeeding maize crop. Apparent N recovery (ANR) by maize from unlabelled Crotalaria juncea, Crotalaria retusa, Calopogonium mucunoides, Mucuna pruriens and mineral fertilizer at three locations were also evaluated. The maize crop recovered 4.7% and 7.3% of the 15N-labelled C. juncea-N at 42 days after sowing (DAS) and at final harvest, respectively. The corresponding 15N recovery from the soil was 92.4% and 58.5%. The highest mean ANR of 57.4% was with mineral fertilizer, whereas the mean ANR of 14.3% from C. retusa was the lowest. A large pool substitution and added-N interaction effect was observed when comparing N recovery from the labelled and unlabelled C. juncea. The amount of residue-N accounted for by the isotope dilution method at 42 DAS was 97.1% and at final harvest 65.8%. The large residue-N recovery in the soil organic-N pool explains the residual effect usually observed with organic residue application. 相似文献
60.
Maria?Teresa?Dell'AbateEmail author Anna?Benedetti Alessandra?Trinchera Daniele?Galluzzo 《Biology and Fertility of Soils》2003,37(2):124-129
Carbon and nitrogen mineralisation of leather meal fertilisers were studied in two soils characterised by different respiration activity. Both C and N mineralisation were highest in the most active soil, and when leather meal was added as a powder rather than as 2- to 4- and 4- to 6-mm particles. Fast and slow soluble N pools were determined after extraction with cold water and with hot buffer, respectively. The N remaining after the second extraction with hot buffer was named slow-release N. The percentage of slow-release N rose as the size of the applied leather meal particles increased, whereas fast soluble N was highest in the coarsest (4-6 mm) fertiliser. 相似文献