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Widespread potassium (K) deficiencies in cotton (Gossypium hirsutum L.) have been documented throughout cotton producing countries. Potassium fertilizer is needed for high production of cotton yield. This study was conducted to determine whether K fertilizer management can improve efficiency of K nutrition in cotton. The effects of K source, rate, and application timing on yield and K use efficiency of cotton were investigated under conditions of cottonstalk recycling to the field in the North China Plain (NCP). The results showed that there was no significant difference in yield between K sources of K2SO4 and KCl. However, we found that the low rate produced a 2 to 4% higher K agronomic efficiency (AEK) and a 12 to 93% higher K apparent recovery efficiency (REK) than the other rates, although there was little difference in yield among different K rates (45, 90, and 180 kg K2O ha-1). In addition, our results of application timing showed that the later split application at peak bloom acquired the highest lint yield as well as a 35 to 103% higher AEK and 23 to 58% higher REK than the earlier split application at peak squaring and full dose at preplanting. In conclusion, KCl should be the preferred K source because of its lower cost and fair effect on yield compared with K2SO4. The 45 kg K2O ha-1 of K rates is adequate for cotton in the NCP. The later split application of K at peak bloom is the best timing of K fertilizer for cotton yield and K use efficiency. [ABSTRACT FROM AUTHOR]

Cotton (Gossypium hirsutum L.) yield is severely limited by waterlogging in some global production areas. The objective was to study physiological and biochemical mechanisms of cotton root recovery after waterlogging during different reproductive stages. Cotton plants (cultivar Simian 3) were subjected to waterlogging for 10 d and then permitted to recover for 20 d. Waterlogging significantly reduced root dry matter, root vigor, and net photosynthetic rate (Pn). After the termination of waterlogging, root growth showed a significant recovery. Root dry matter of waterlogged plants increased quickly, but remained 20 to 30% lower than controls. Total N content in waterlogged cotton roots was the same as controls at 20 d after waterlogging during the squaring stage, but was significantly lower during the flowering and boll-forming stage. The activities of superoxide dismutase, catalase, and peroxidase in waterlogged plants increased for 10 d after waterlogging, then declined slowly. The malondialdehyde content in waterlogged roots continued to increase for 5 d after waterlogging, then declined to a significantly lower level than the control. Root vigor recovered rapidly after waterlogging, and was much higher than the control during the squaring stage, but significantly lower during flowering and boll-forming stage. Pn of waterlogged cotton was suppressed after a 10-d recovery period, and remained lower than well-watered controls. These results suggest (i) roots of waterlogged cotton recovered more quickly than shoots, (ii) cotton roots recover better from oxidant damage due to waterlogging during the squaring stage than during the flowering and boll-forming stage. [ABSTRACT FROM AUTHOR]

[Objective] The aim was to study the effects of cotton straw extract on wheat root growth and define the allelopathic effect of cotton straw on wheat root. [Method] A sand culture experiment was conducted under different cotton straw extract levels (0%, 1.0%, 2.0%, 4.0%, 8.0% and 10.0%), and the morphology and physiological activity of wheat (Yangmai 13) root were studied. [Result] The cotton straw extract inhibited the elongation of wheat roots, but increased the root diameter, resulting in the decreased root surface area and volume; The extract treatments induced the increase of root reactive oxygen species (ROS) level, which led to an increased root membrane lipid peroxidation, thereby reducing the root vigor and inhibiting the root water uptake and formation of biomass; With the increase of concentration of cotton straw extract, the total phenolic acid content in the extract increased continuously, and the total phenolic acid content was closely related to the morphogenesis and physiological activity of wheat root. [Conclusion] The cotton straw extract inhibited the morphogenesis and physiological activity of wheat root through affecting the root ROS level, and the total phenolic content was one of the main limiting factors. [ABSTRACT FROM AUTHOR]

[Objective] This study aimed to investigate the effects of waterlogging in different growth stages on nitrogen (N) uptake, distribution, and utilization of cotton. [Method] A pool-culture experiment in field was conducted to investigate the effects of waterlogging through comparing WL1 (waterlogging at peak squaring stage) and WL2 (waterlogging at flowering and boll-forming stage) treatments with their controls respectively. [Result] The results showed that the effect of WL1 on N uptake of cotton root was stronger than WL2. At 20 days (d) after WL1 treatment, the root biomass (RB), N uptake (NU), and N uptake rate (NUR) significantly decreased by 38.1%, 48.6%, and 53.0% respectively. At 20 d after WL2 treatment, the RB, NU, and NUR significantly decreased by 27.3%, 46.0%, and 44.8% respectively. More N was distributed to root and leaf after WL1 treatment, and to square, flower, and boll after WL2 treatment. N physiological use efficiency increased by 11.4% and 44.4% after WL1 and WL2 treatments respectively. Further analysis showed that the effects of WL1 on yield and its components of cotton were stronger than WL2. The boll number, boll weight, and lint yield per plant significantly reduced by 40.5%, 12.4%, and 49.5% after WL1 treatment, and significantly decreased by 23.1%, 6.9%, and 29.9% after WL2 treatment, respectively. [Conclusion] The negative effects of waterlogging at peak squaring stage on N nutrition and yield of cotton were stronger than waterlogging at flowering and boll-forming stage, indicating that more attention should be paid to waterlogging at peak squaring stage and sound N management can improve cotton regrowth and reduce yield loss after waterlogging. [ABSTRACT FROM AUTHOR]

[Objective] The aim was to propose a new entropy weight fuzzy comprehensive evaluation method for assessing cotton salt tolerance, realizing the objective, accurate and comprehensive evaluation of salt tolerance of cotton. [Method] A sand culture experiment under salt stress of 150 mmol/L of NaCI was designed. The indicator weight was determined with the entropy weight fuzzy comprehensive evaluation method, based on the salt injury index of indicators. The salt tolerance of cotton was evaluated comprehensively. [Result] At the germination stage, the entropy and weight of salt injury index of germination energy, vigor index, hypocotyl length and fresh weight were highest, followed by germination rate and germination index, and of root length were lowest. At the seedling stage, the entropy and weight of salt injury index of plasma membrane permeability, root vigor and leaf expansion rate were highest, followed by plant height and net photosynthetic rate, and of shoot dry weight and root dry weight were lowest. The salt tolerance of cotton differed among growth stages and cultivars. Among the 11 cultivars, CCRI-44 and CCRI-75 were steadily salt-tolerant at both germination and seedling stages; CCRI-17, Sumian 22, Sumian 15 and Dexiamianl had a stable moderate salt tolerance; while Sumian 12 and Simian 3 were steadily salt-sensitive. [Conclusion] The evaluated result was objective and exact, which indicated that this method could be used in comprehensive evaluation of salt tolerance of cotton. [ABSTRACT FROM AUTHOR]

Stress will enhance the local anodic dissolution rate of nickel-based alloys at crack tip and accelerate the crack propagation in high temperature water environments. The relationship between stress and corrosion was studied by the elastic plastic finite element method. The effects of stress intensity factor on the surface electrochemical corrosion potential (ECP) at the crack tip of alloys 600 with a 1T-CT specimen in simulated boiling water reactor environment were analyzed. The effects of plastic deformation and elastic deformation on the changes of the electro-chemical corrosion potential around the crack tip were also discussed. The results indicate that the effects of stress intensity factors on ECP changes of the crack tip surface have the maximum values in the front of the crock propagation, and they decrease gradually towards the sides of the crack. The values of ECP changes increase with the increase of stress intensity factor. The effect of plastic deformation is more obvious than that of elastic deformation. [ABSTRACT FROM AUTHOR]

Background: On 23 May 2012, a university in Jiangxi, China reported a gastroenteritis outbreak. We investigated the outbreak to identify the agent, source and mode of transmission and to recommend control measures. Methods: A case was defined as any person from the university with onset of diarrhoea (≥3 times/24h) from 1 to 31 May 2012. Active case finding was conducted by reviewing university hospital and drug-store records and interviewing students, workers and teachers. We then conducted a case-control study in which we compared food, water and environmental exposure history. Water samples were collected and tested. Results: We identified 417 cases – an attack rate (AR) of 4.7% (417/8781) for the university. There were 416 student cases (AR = 5.7%) distributed across all 11 colleges, five of which were more heavily affected (AR range = 5.9%–14%). In the case-control study, cases had higher odds of having drunk bottled water (odds ratio [OR] = 4.1; 95% confidence interval [CI] = 1.7–9.9), and there was a dose–response relationship (χ2trend = 4.6, P < 0.05). Drinking boiled bottled water was inversely associated with being a case (OR = 0.22, 95% CI = 0.07–0.71). Eating in any of the three university canteens or drinking water from the city water supply was not associated with being a case. Pathogenic Escherichia coli was isolated from two unopened bottled water specimens and from four student cases. Conclusion: This gastroenteritis outbreak was most likely caused by contaminated bottled water. The company in question has been shut down and no further cases have been reported. Increased regulation of bottled water plants and better coordination between different investigators for future outbreaks is recommended. [ABSTRACT FROM AUTHOR]

Based on the discrete algebraic reconstruction technique (DART), this study aims to address and test a new improved algorithm applied to incomplete projection data to generate a high quality reconstruction image by reducing the artifacts and noise in computed tomography. For the incomplete projections, an augmented Lagrangian based on compressed sensing is first used in the initial reconstruction for segmentation of the DART to get higher contrast graphics for boundary and non-boundary pixels. Then, the block matching 3D filtering operator was used to suppress the noise and to improve the gray distribution of the reconstructed image. Finally, simulation studies on the polychromatic spectrum were performed to test the performance of the new algorithm. Study results show a significant improvement in the signal-to-noise ratios (SNRs) and average gradients (AGs) of the images reconstructed from incomplete data. The SNRs and AGs of the new images reconstructed by DART-ALBM were on average 30%–40% and 10% higher than the images reconstructed by DART algorithms. Since the improved DART-ALBM algorithm has a better robustness to limited-view reconstruction, which not only makes the edge of the image clear but also makes the gray distribution of non-boundary pixels better, it has the potential to improve image quality from incomplete projections or sparse projections. [ABSTRACT FROM AUTHOR]

The microstructure evolution and tensile properties of the Fe-10Mn-10Al-0.7C low-density steel annealed at the temperature range from 700 °C to 1200 °C for 1 h were investigated in the present study. The phases in the annealed specimens mainly included ferrite (a), austenite (β) and κ-carbide (κ). The dissolution temperature for κ-carbide is between 850 °C and 900 °C. At the annealing temperature of 700 °C, all the β phase transformed to a phase and κ-carbide by eutectoid reaction. As the annealing temperature rose from 700 °C to 900 °C, a phase and κ-carbide fraction decreased and β phase fraction increased, and ultimate elongation increased, while ultimate strength and yield strength had a decreasing trend. The β phase fraction in the specimen dominated the ultimate elongation, and the κ-carbide strengthened the specimen and weakened ductility. As the annealing temperature rose from 900 °C to 1200 °C, the phase fraction change was small but the grain size increased greatly. The rapid growth of the grains was the main reason why ultimate tensile strength and ultimate elongation decreased with the increase of annealing temperature over 900 °C. The steel designed here possessed a density of 6.80 g/cm3, which is about 13% lower than pure iron. [ABSTRACT FROM AUTHOR]