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91.

Purpose

Organo-mineral biochar fertiliser has the potential to replace conventional biochar and organic fertiliser to improve soil quality and increase plant photosynthesis. This study explored mechanisms involved in nitrogen (N) cycling in both soil and ginger plants (Zingiber officinale: Zingiberaceae) following different treatments including organic fertiliser, commercial bamboo biochar fertiliser, and organo-mineral biochar fertiliser.

Materials and methods

Soil received four treatments including (1) commercial organic fertiliser (5 t ha?1) as the control, (2) commercial bamboo biochar fertiliser (5 t ha?1), (3) organo-mineral biochar fertiliser at a low rate (3 t ha?1), and (4) organo-mineral biochar fertiliser at a high rate (7.5 t ha?1). C and N fractions of soil and plant, and gas exchange measurements were analysed.

Results and discussion

Initially, organo-mineral biochar fertiliser applied at the low rate increased leaf N. Organo-mineral biochar fertiliser applied at the high rate significantly increased N use efficiency (NUE) of the aboveground biomass compared with other treatments and improved photosynthesis compared with the control. There was N fractionation during plant N uptake and assimilation since the 15N enrichment between the root, leaf, and stem were significantly different from zero; however, treatments did not affect this N fractionation.

Conclusions

Organo-mineral biochar fertiliser has agronomic advantages over inorganic and raw organic (manure-based) N fertiliser because it allows farmer to put high concentrations of nutrients into soil without restricting N availability, N uptake, and plant photosynthesis. We recommend applying the low rate of organo-mineral biochar fertiliser as a substitute for commercial organic fertiliser.
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92.
High-density polyethylene (HDPE), bagasse fibers treated by four pulping processes (AS-AQ (alkaline sulfite anthraquinone), SODA-AQ (soda anthraquinone), MEA (monoethanolamine) and chemical–mechanical pulping (CMP)), three levels of nano-SiO2 (0, 2, and 5?wt%), and maleic anhydride polyethylene as coupling agent were used to produce pulp–plastic composites (PPCs) by injection molding. The physical and mechanical properties of corresponding composites were evaluated according to ASTM standards. The results showed that compared to untreated bagasse/HDPE composite, the addition of bagasse pulp fibers increased significantly the mechanical properties such as tensile strength and modulus, flexural strength and modulus, and hardness. The chemical pulps-reinforced composites showed better mechanical strengths than that of CMP-reinforced composites, but in some properties, CMP pulp composites have comparable results to the chemical pulp-reinforced composites. Natural fibers (untreated and treated) increased water absorption and thickness swelling of composites compared to pure HDPE. The addition of nano-SiO2 particles showed both increasing and decreasing trends on physical and mechanical properties ofPPCs.  相似文献   
93.
Information on different rangeland plants' nutritive values on different plant parts and for various habitats is important in rangelands management. Effects of different plant parts (stems and leaves) of the Jasminum fruticans L. plant species on forage quality indicators were investigated in two regions in 2015. Plant samples were collected from Sharlogh rangelands and cultivated in the Research and Education Center of Agricultural and Natural Resources (RECANR) in Iran with completely randomized design with three replications in each plant sample. The plant leaves and stems samples were oven-dried at 80°C for 24 hr, and then analyzed for crude protein (CP), crude fiber (CF), dry matter (DM), ether extract (EE), crude ash (CA), metabolizable energy (ME), and mineral elements, including calcium (Ca) and phosphorus (P). Results showed that the forage quality indicators in different regions were statistically significant, except for the CA. Also, nutritive values differed significantly (p < 0.01) between different plant parts, except ME parameter. Results also indicated that J. fruticans due to its high tissue CP content is a valuable source of forage for livestock.  相似文献   
94.
This study aimed to assess the effect of date palm (Phoenix dactylifera) seed (DPS) extract at 0.5%, 1%, 2% and 4% as a dietary supplement over 60 days, on the growth and immune‐physiology of common carp (Cyprinus carpio) fingerlings. The weight gain in fish fed with 0.5% DPS was significantly greater than other treatments and fish fed a control diet with no DPS (p < 0.05). With increasing DPS dosage above 0.5%, weight gain and growth rate gradually declined. Feed conversion ratio in fish fed 0.5% DPS was lower than other treatments, but not significantly so, except for the highest DPS concentration (4%). With respect to immunophysiological variables, fish treated with 0.5% DPS leucocyte, neutrophil, lymphocyte and monocyte counts that were generally equivalent to fish on a control diet, but significantly lower than fish treated with greater concentrations of DPS (p < 0.05). Chemilumincene response and lysozyme activity, as well as levels of total protein and albumin, were higher in all treated groups than the control. The highest levels of iron and high density lipoprotein (HDL) were observed in fish fed with 0.5% DPS, while the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP), glucose, cholesterol, triglyceride, low density lipoprotein (LDH), thyrotropin, thyroxine and triiodothyronine were lower level in fish fed with 0.5% DPS than in all other treatments. In aquaculture practice, use of 0.5% DPS in commercial carp feed can improve the growth rate and condition of fish.  相似文献   
95.
Intraspecific variability in morphological and ecophysiological leaf traits might be theorized to be present in declining populations,since they seem to be exposed to stress and plasticity could be advantageous.Here we focused on declining Persian oaks(Quercus brantii Lindl.var.persica(Jaub and Spach)Zohary)in the Zagros Mountains of western Iran,representing the most important tree species of this region.We selected trees with contrasting crown dieback,from healthy to severely defoliated,to investigate the relationships between canopy dieback and leaf morphology,water content and pigments.We also measured esterase and peroxidase,as enzymatic antioxidants and indicators of contrasting genotypes.Trees showing moderate to severe defoliation showed higher leaf mass area(LMA),reduced relative water content(RWC),and lower stomatal density(SD).Increasing LMA indicates a more sclerophyllic structure,according to drier conditions.We did not find significant differences in leaf pigments(chlorophyll a and b,and carotenoids)among crown dieback classes,suggesting that Persian oak trees are able to maintain accurate photochemical efficiency,while reduced RWC and SD suggest hydraulic limitations.Our results do not provide a consistent pattern as regards enzymatic antioxidant defense in Persian oak.Morphological leaf traits would be important drivers of future adaptive evolution in Persian oak,leading to smaller and thicker leaves,which have fitness benefits in dry environments.Nonetheless,drought responses may be critically affecting carbon uptake,as photosynthetic compounds are less effectively used in leaves with higher sclerophylly.  相似文献   
96.
New Forests - Mixed species plantings of teak (Tectona grandis) and flueggea (Flueggea flexuosa) were introduced as a method for overcoming the reluctance of local growers to thin their teak....  相似文献   
97.
Purpose

High demand for teak (Tectona grandis L.f.), a species of economic importance, was the reason Solomon Islands experienced a surge in community-wide planting of monoculture teak stands in the last two decades. Mixed species planting of teak and flueggea (Flueggea flexuosa Muell. Arg.) was introduced to overcome the reluctance of growers to thin their stands. However, there is lack of information on the effect of changing from monoculture to mixed species plantings on the cycling of nutrients especially carbon (C) and nitrogen (N).

Materials and methods

This study assessed litter quantity and quality, total C (TC), total N (TN), C:N ratio and C and N isotope compositions (δ13C and δ15N) over 18 months at two sites (Ringgi and Poitete). The treatments included teak planted at 833 stems per hectare (sph) (T1), teak planted in rows with two rows of flueggea at 833 sph (T2), 625 sph (T3) and 416 sph (T4), and teak planted in alternating rows with flueggea at 833 sph (T5).

Results and discussion

Treatment 1 (T1) produced significantly higher total litter than T4 at Ringgi. However, based on individual tree litterfall production, teak in T4 (lowest stocking rate) at both trials produced higher litter per tree than the teak in T3, T2, T5 and T1 while there was no significant difference with litter production of flueggea. An enrichment of litter δ15N was observed over time in either species, which suggested an increased N loss and transformations in both experimental sites. When comparing each treatment and using individual tree productivity, T4 significantly produced and returned higher litter TC and TN than T3, T2, T5 and T1.

Conclusions

Overall, individual tree productivity demonstrated that mixed species stands had a significant potential for cycling higher rates of C and N than monoculture teak stands. Therefore, establishment of mixed species stands, especially T4 and T3, was recommended as a practical measure to address the widely experienced problem of reluctance by growers to thin high value trees while preserving the balance of C and N inputs into the ground.

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98.
We have employed both common and novel methods to measure the amount of silver released from nanoparticle composite packaging. Forty-eight packages of green tiger prawns (Penaeus semisulcatus) were prepared: 24 packages with nanoparticle packaging and 24 packages without nanoparticle packaging. The normal shelf life of P. semisulcatus in the refrigerator is 1–2 days, and we therefore we tested the packages after 0, 1, 2, 3, 4, 5 and 6 days. We measured the diameter of the inhibition zone of the targeted microorganisms (Escherichia coli and Staphylococcus aureus) and examined scanning electron microscopy (SEM) images, using both titration and migration methods, to measure the amounts of silver nanoparticles released. Compared to the standard amount allowed by standard 13737-3 of the National Information Standards Organization, our results indicated the superior sensitivity of the titration method over the migration method in terms of determining the remaining amount of nanoparticles (P < 0.05). The evaluation of SEM images indicated the homogeneity of the surface of the silver nanoparticle packaging and the even exchange capacity of titanium dioxide. The average size of the nanoparticles in the packaging films was determined to be 30–48 nm. The diameter of the inhibition zone in the silver nanoparticle, measured at the six time points, was significantly larger than that seen with other packaging, except for the phosphomycin and penicillin antibiogram disks (P < 0.01). The sensitivity of the titration method using the titration equipment was significantly higher than that of the migration method (P < 0.05). The findings indicate that nanoparticle packaging decreased the microbial count and enhanced the shelf life of P. semisulcatus, leading us to recommend the utilization of silver nanoparticle packaging.  相似文献   
99.
The application of biochar in soils has been hypothesised to improve soil quality whilst enhancing carbon (C) sequestration. However, its effect on nitrogen (N) dynamics in the soil–plant system is still not fully understood. In the present work, N isotope composition (δ15N) was used to facilitate the understanding of the processes involved in the N cycling when biochar is applied. We evaluated, through a wheat pot trial, the effect of different application rates of two types of biochar produced from jarrah and pine woodchips on the wheat biomass at harvest and on the soil and plant C and N contents and δ15N. In addition, the potential benefit of using nutrient-saturated biochar for the soil–plant system was also investigated. Whilst biochar produced from different feedstocks had similar effects on soil and plant nutrient contents, they induced differences in wheat grain biomass and plant δ15N. The effect of the biochar application rate was more pronounced, and at rates higher than 29 t ha?1, the application of biochar decreased grain biomass by up to 39 % and potentially increased N losses. Isotopic analyses indicated that this acceleration of N dynamics had probably occurred before the stage of wheat grain formation. The application of nutrient-enriched biochar resulted in an improved wheat grain production, most likely due to the enhanced nutrient availability, and in reduced N cycling rates in the plant–soil system, which could offset the competition between biochar and plants for nutrients and could decrease adverse environmental impacts due to N losses.  相似文献   
100.
ABSTRACT

In the present study, the effect of fish gelatin coating (FG; 4%, w/v) containing oregano (Origanum vulgare L.) essential oil (OEO; 1.2% w/v) on shelf-life extension of rainbow trout (Oncorhynchus mykiss) fillet stored under refrigerated storage (4 ± 1ºC) was investigated. The control and the treated fish samples were analyzed periodically for chemical (pH; total volatile basic nitrogen, TVB-N; peroxide value, PV; thiobarbituric acid, TBA) and microbiological (total viable count, TVC; psychrotrophic count) characteristics. The FG + OEO treatment produced significantly lower (p < 0.05) TVB-N values as compared to control and FG-coated samples after Day 6 and until the end of the storage period. The TBA values remained low and were found to fluctuate during storage. Results showed that TVC exceeded 6 log CFU g?1 on Day 8 of storage for control and FG-coated samples and Day 12 for samples coated with FG + OEO. The reduction of 1.05 and 0.83 log CFU g?1 of psychrotrophic counts was achieved by FG + OEO coating in trout fillet (p < 0.05) as compared with control and FG-coated samples, respectively. Therefore, the incorporation of OEO into FG coating may be a promising method of maintaining the storage quality of the rainbow trout fillet stored at refrigerated temperature.  相似文献   
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