Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 14

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
Bloom-Cyanobacteria can release phosphorus (P) into overlying water during their decline period, thus inevitably providing available P for the next round of bloom. In order to quantitatively evaluate the contribution of cyanobacterial bloom decline to P amounts in Caohai, a typical cyanobacteria-dominated sub-lake in northern Dianchi Lake, the P concentrations in algae during the peak and bottom of cyanobacterial bloom were measured and calculated. Remote sensing monitoring analysis and monthly monitoring data showed that the cyanobacterial bloom in Caohai developed from June, reached its peak in July to August and then declined to its bottom from December to February. The concentrations of different phosphorus forms contained in algal cells were different between the peak and bottom of the cyanobacterial bloom. Total phosphorus (TP) concentration in algae (TP-A) were higher in summer than in winter, while the TP content per unit Chl-a in winter was much larger than in summer. The annual released TP was approximately 24.12 tons in 2016, and its potential contribution to TP and Ortho-P in water body of Caohai was around 0.958 and 0.647 mg⋅L⁻¹, respectively. The P release amount was 303.30 and 20.57 tons in 2011 and 2014, respectively. For Caohai of Dianchi Lake, the P released from bloom-cyanobacteria could provide adequate P for the next year’s bloom recovery.
In recent years, biochar, a new environmentally functional material, has received widespread attention as a soil amendment for its special structures and characteristics, such as improving soil texture and increasing crop yield. However, controversies still exist for the effects of biochar addition to soil nitrogen(N) cycles. This study focuses on the influences of 350ºC peanut biochar application on N mineralization in abandoned orchard soil during a 46-day incubation. The treatments contained control (CK), 1% biochar (BC), and 3% biochar (BC). Results showed that 350ºC peanut biochar increased soil pH and EC, but decreased soil urease activities significantly. Biochar decreased soil net-mineralized N significantly, and a higher biochar addition content resulted in lower soil mineralized N concentration. NO3–-N content accounted for more than 94% of soil inorganic N for all three treatments during the entire incubation time, while the presence of biochar did not change this characteristic. Conclusions indicated that the addition of 350ºC peanut biochar significantly inhibited orchard soil N mineralization in a short time by altering soil physical and chemical properties.
The effects of species compositions (two-species mixtures or monocultures) and hydraulic retention times (HRT; 1, 4, 8, 16, 24, 48 hours) on total nitrogen (TN) and total phosphorus (TP) removal from eutrophic water were studied in a constructed wetland. Two species mixtures showed higher efficiency to remove TN and TP than monocultures. Average removal efficiency of TN and TP was 49.6% and 34.0%, respectively. A longer HRT enhanced the removal efficiency of TN and TP, which suggested that species mixtures, HRT, and species mixtures × HRT interaction were useful for increasing the wastewater TN and TP removal.
Anaerobic ammonium oxidation (anammox) is an efficient and promising pathway for nitrogen removal from wastewater, but its application is usually confined by the low growth rate and susceptibility to surroundings of anammox bacteria. In this study, cultured anammox sludge was immobilized using polyvinyl alcohol (PVA)-sodium alginate (SA) gel and put into a lab-scale column reactor at a packing ratio of 20%, and nitrogen removal performance was evaluated at two hydraulic retention times (HRTs). Anammox was rapidly initiated in the reactor, with ammonium and nitrite removal efficiency reaching 82.3% and 84.7% after an operation period of 10 d. Nitrogen removal efficiency declined greatly after the reduction of HRT from 24 h to 12 h, but then recovered quickly, with an average TN removal rate of 84.5% and 0.43 kg·m⁻³·d⁻¹ achieved under the steady operational state. The immobilized anammox reactor performed significantly better and was more stable in nitrogen removal than that with anammox sludge inoculated directly, indicating the superiority of cell entrapment of anammox biomass in addition to its easy reservation. Nitrogen removal in the reactor increased after stable operation with the HRT. It has potential to apply immobilized anammox sludge entrapped by PVA-SA gel for the convenient establishment of an anammox reactor with stable and high nitrogen removal rates.
Thirty-two crossbred (Large White × Landrace) gestating sows were used to study the effects of fermented soyabean meal (FSBM) on their reproduction performance and piglet production. Sows were randomly divided into four groups and fed diets containing 0, 5, 10 and 15% FSBM replacing the same amount of soyabean meal, respectively. The experimental periods lasted 58 days including 30 days of pre-farrowing and 28 days of post-farrowing. The results showed that nutrient digestibility of lactating sows as well as survival rate of suckling piglets were improved by FSBM additions during lactation (P < 0.05), but without significant effect on sow’s reproduction during pregnancy (P > 0.05). The results also showed that non-fat milk solids, protease activity and lactic acid bacteria counts in sow’s faeces, total antioxidant capacity, superoxide dismutase activity, glutathione and prolactin concentrations in lactating sow’s serum were significantly increased (P < 0.05), while serum cholesterol and urea nitrogen concentrations, as well as phosphocreatine kinase and aspartate aminotransferase activities were decreased with FSBM addition (P < 0.05). It could be concluded that 10 – 15% FSBM addition in lactating sow’s diets could increase sow’s reproduction and piglet production.
After a series of stresses, detached plant organs such as leafy vegetables and cut flowers begin to appear declining in quality and then finally senescence. Comprehending, plants’ response to multiple stresses may result in new opportunities to extend the shelf life of postharvest. We investigated physiological responses of Arabidopsis plants after harvest and analyzed global gene transcription in dark-stored detached Arabidopsis plants leaves (DSD). Detached darkened plants of Arabidopsis were stored for 12 h in airtight boxes. Multiple stresses caused a distinguished decrease in chlorophyll, protein content and premature senescence of leaves. The microarray analysis revealed that 852 transcripts were upregulated and 1004 transcripts were downregulated, respectively, more than twofold. A gene ontology test and biological process analysis suggested that activated genes were mostly associated with regulation of transcription, secondary metabolism, response to water deprivation, signal transduction, and other stress responses. Meanwhile, genes that were downregulated were involved in protein biosynthesis, protein folding, lipid catabolism, ribosome biogenesis and assembly, ATP binding, and photosynthesis. Gene expression analysis data suggested that the leaves of detached Arabidopsis plants responded to integrated stresses by regulating diverse gene expression in leaves.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.