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991.
Removal of early fruiting branches with greater potassium doses caused more source and no sink at early stages of growth, leading to improved yield, yield components, and fiber quality traits in Bt cotton. The study used manual alteration of plant architecture (F1, no branch removal; F2, removal of first fruiting branch; F3, removal of first and second fruiting branches; F4, removal of all squares from first fruiting branch; F5, removal of all squares from first and second fruiting branches) and potassium rates (50, 100, and 150 kg ha?1) in a randomized complete block design and was repeated for 2 years (2011 and 2012). Increasing potassium application increased total bolls per plant and cotton yield to the greatest levels in F3 and F5, against lowest level in the control. Ginning out turn, fiber length, seed oil, and seed protein content were influenced by fruiting branch or square removal but the difference was less. Increasing potassium improved seed and fiber quality.  相似文献   
992.
Levisticum officinale Koch is one of the most important plants producing essential oil. An experiment was conducted to determine the effect of drought stress on growth, total protein and essential oil content of L. officinale. The experiment was conducted in a greenhouse, in a completely randomized design using five replications. Aridity levels of field capacity irrigation (as control), ?0.6 and ?1.0 MPa were applied. There was a significant effect of aridity on the leaf area in L. officinale. The highest leaf area values were found in the lowest aridity (FC) level. The root weight and root length in the ?0.6 MPa aridity level were more than that of the control aridity level, but shoot height and shoot weight were highest in the control treatment. The total soluble protein content under ?0.6 MPa drought stress was numerically lower than that in the control treatment, but statistically there was no significant difference between protein contents in the ?0.6 MPa and the control treatment. Compared to the control treatment, the total soluble protein content of L. officinale significantly decreased in the ?1.0 MPa drought treatment. The essential oil content of L. officinale was significantly increased in the ?0.6 MPa drought treatment compared to the control. Compared to control treatment, a significant reduction was found in essential oil content of L. officinale in the ?1.0 MPa aridity treatment. The results suggest that in the drought levels between ?0.6 and ?1.0 MPa, L. officinale could be used for arid and semi-arid lands economical use.  相似文献   
993.
ABSTRACT

The remediation technologies of soils contaminated with petroleum products are developed in two main directions: the first one encompasses searching for new effective bioagents and the other one explores the ways to activate those microorganisms present in the soil that are capable of degrading oil. The objective of this research was to determine if it is possible to increase the effectiveness of biodegradation of petroleum products by using chemical additives. The soil was supplemented with additives: CuSO4, MnSO4, KMnO4, H2O2, 5% and 10% chemical industry plants sludge, 5% and 10% Stock Company ‘Klaipedos vanduo’ (SC‘KV’) municipal wastewater treatment plants sludge. The data suggest that all the additives statistically significantly stimulated the degradation of diesel fuel (F = 12.01; p = .001) and black oil (F = 9.93; p = .001) compared with the control. It was determined that diesel fuel was degraded the fastest in samples with KMnO4, where efficiency of degradation was 90%, and 88% efficency in samples with 10% chemical industry plants sludge. Black oil was degraded the best in samples, where KMnO4 was added: efficiency of degradation was up to 63%. In the samples with 10% of sewage sludge from chemical industry plant degradation efficiency was 62%.  相似文献   
994.
研究了300 MW轴封型核主泵循环油泵的螺旋轴流式叶轮结构功能和性能特点,对循环油泵过流部件的内部流动进行了三维数值模拟,并预测了油泵的水力性能,论证了螺旋轴流式叶轮和径向导叶设计及参数选取的合理性.通过对循环油泵在不同介质温度下的水力性能试验,分析不同油温下滑油黏度对水力性能的影响及其机理.结果表明:在大流量工况下,循环油泵性能的预测结果和试验结果具有较好的一致性;螺旋轴流式结构使循环油泵具有高抗汽蚀性能和高可靠性,但效率仅为10%左右;循环油泵的效率和扬程均随着温度的升高而升高,这是由于滑油黏度随温度升高而减小,叶轮的圆盘摩擦损失、叶轮和导叶流道内部的流动损失均明显减小;循环油泵的水力特性完全满足核主泵推力轴承滑油系统的的运行要求,研究结果可为润滑油系统的分析与设计提供依据.  相似文献   
995.
为提高管道输油泵水力性能,以某型号大型管道输油泵为研究对象,针对导叶相位角度对其水力性能的影响进行研究.采用Pro/E与Gambit软件对该输油泵全流道内流场进行三维造型与网格划分.应用计算流体动力学软件CFX对输油泵在6个导叶相位(0°,6°,12°,18°,24°和30°)及5个流量工况(0.8Qd,0.9Qd,1.0Qd,1.1Qd和1.2Qd)下的内流场进行定常数值计算,得到了不同导叶相位下输油泵的性能曲线,对比分析了不同导叶相位下输油泵的内部流动情况.研究结果表明:不同相位时,在设计工况下扬程差别较大,扬程最大相差6%,大流量及小流量工况下扬程的差别较小;设计工况下效率差别较小,大流量及小流量工况下效率的差别增大,效率最大相差2%;导叶叶片背面出口处的低速区是影响输油泵水力性能的重要因素,不同导叶相位下,蜗壳隔舌处的流场不同,进而影响输油泵的水力性能;受导叶流道出口低速区的影响,导叶相位为6°,12°及18°时,蜗壳扩散段流态较差,导致输油泵效率偏低,且蜗壳出口速度分布非常不均,不利于输油泵高效平稳地运行.  相似文献   
996.
Brown rot (Monilinia spp.) affects the shelf life, fruit quality and marketability of peaches (Prunus persica L.). Increasing consumer concern regarding food safety makes it necessary to search for natural environmentally friendly alternative products for postharvest disease control. In this investigation, polyethylene terephthalate (PET) punnets containing thyme oil (TO sachets) and sealed with chitosan/boehmite nanocomposite lidding films significantly reduced the incidence and severity of brown rot caused by Monilinia laxa in artificially inoculated peach fruits (cv. Kakawa) held at 25 °C for 5 days. Furthermore, PET punnets containing TO sachets and sealed with chitosan/boehmite nanocomposite lidding films significantly reduced the brown rot incidence to 10% in naturally infected fruits stored at 0.5 °C, 90% RH for 7 days and at the simulated market shelf conditions for 3 days at 15 °C, 75% RH. The chitosan/boehmite nanocomposite lidding films maintained the active components of thyme oil, thymol (56.43% RA), caryophyllen (9.47% RA) and β-linalool (37.6% RA) within the (head space volatiles) punnet. Panellists preferred fruits packed from commercial punnet containing thyme oil (sachets) and sealed with chitosan/boehmite nanocomposite lidding films due to overall appearance, taste, and natural peach flavour.  相似文献   
997.
The aim of this research was to evaluate acute toxicity of the essential oil of leaves of Chinese chives, Allium tuberosum Rottler ex Spreng (Asparagales: Alliaceae) and its major constituents against Apolygus lucorum Meyer-Dür (Hemiptera: Miridae). The essential oil of A. tuberosum leaves was obtained by hydrodistillation and analyzed by gas chromatography and gas chromatography-mass spectrometry. The major constituents of the oil were sulfur-containing compounds, including allyl methyl trisulfide (36.24%), diallyl disulfide (27.26%), diallyl trisulfide (18.68%), and dimethyl trisulfide (9.23%). The essential oil of A. tuberosum leaves exhibited acute toxicity against Ap. lucorum with an LD50 value of 20.03 μg per adult. Among the main compounds, diallyl trisulfide (LD50 = 10.13 μg per adult) showed stronger acute toxicity than allyl methyl trisulfide (LD50 = 21.10 μg per adult) and dimethyl trisulfide (LD50 = 21.65 μg per adult). The LD50 value of diallyl disulfide against Ap. lucorum was 28.10 μg per adult. The results indicated that the essential oil of A. tuberosum and its major constituents may have a potential to be developed as botanical insecticides against Ap. lucorum.  相似文献   
998.
The red imported fire ant (RIFA) Solenopsis invicta Buren causes severe damage to humans and animals as well as the environment. Chemical treatment is the main strategy of RIFA management, which also is potentially toxic to the environment. Plant essential oils (EOs) are considered as potential substance that can be used to control insects. This study aimed to identify the chemical composition of camphor EO and investigate the insecticidal activity on RIFAs. The chemical composition of the EO was analyzed by gas chromatography/mass spectrometry and gas chromatography with flame ionization detection. Results revealed that 36.61% camphor and 30.05% cineole were the major components. The insecticidal activity of camphor EO was assessed against RIFA workers by conducting two different bioassays: fumigant toxicity and repellence. Fumigant toxicity assay results showed that the lethal dose (LC50) of the EO at 24 h was 1.67 and 4.28 μg/ml for minor and major workers, respectively; knockdown time (KT50) was 10.82 and 14.73 h. At 2.55 μg/ml, the highest average mortality of the ants was 84.89% after 72 h. Camphor EO exhibited fumigant toxicity against minor and major workers as indicated by the effects on attacking, feeding, and climbing behaviors. This EO was also strongly repellent to the two size workers of the colony as observed in their behavior against Tenebrio molitor treated with 5 µl EO. The fumigant toxicity and repellence of camphor EO against RIFA indicated that this substance could be a potential alternative for the development of eco-friendly products used to control pests.  相似文献   
999.
Essential fatty acids should be included in the diet to ensure adequate fish growth. Despite the great number of studies on fatty acid nutrition of fish, there are still several unknowns. The aim of the present study was to investigate fatty acid nutrition of jundiá, a Latin American freshwater catfish. Four diets were formulated containing (i) coconut oil (?C, negative control), (ii) coconut oil + high‐docosahexaenoic‐acid‐fish oil (+C, positive control) and coconut + sunflower + linseed oils at different ratios, producing either (iii) a diet rich in linoleic acid (LA) (HighLA) or 4) a diet low in LA (LowLA). All diets contained significant amounts of saturated fatty acids (at least 57.5% total fatty acids in HighLA) and monounsaturated fatty acids (at least 19.1% total fatty acids in ?C). Diets were fed to jundiá fingerlings (1.5 g) for 70 days; growth, body composition and liver histology were evaluated. The ?C diet, without essential fatty acids, promoted significantly lower fish growth, body fat accumulation and hepatic lipidosis. Fish fed HighLA and LowLA diets presented similar growth as fish fed +C diet. These findings suggest that diet formulations for jundiá catfish fingerlings can include only plant oils without negative effect on growth, survival, body composition, fish health or parameters of feed utilization (ingestion rate and protein utilization).  相似文献   
1000.
To investigate the effect of low light (LL, 50% natural light) during grain filling (GF) stage on rice transamination, amino acid (AA) accumulation, nutritional value, and cooking quality in three different rice genotypes, transaminase activities and AA levels in grains during GF stage and the traits that significantly affected rice quality (physical appearance, cooking quality, and nutritional value) were analyzed. LL did not disturb transamination in rice grains during GF stage, as minimal impact was found on alanine and aspartate transaminase activities. Nevertheless, most AAs in caryopses, including lysine and threonine, increased in response to LL, except for sulfur-containing AAs. These results suggest that AA metabolism and accumulation in rice grains were rarely suppressed by LL during GF stage. Rice nutritional ingredients at harvest, such as major protein components including glutelin and most important essential amino acids (EAAs) including lysine and threonine, increased significantly in response to LL, whereas most protein and EAA ratios were rarely affected. However, LL markedly affected physical appearance of rice grains by reducing brown rice rate, milled rice rate, and 1000-grain weight and increasing the chalkiness rate. In addition, cooking qualities decreased in response to LL, while breakdown values and amylose levels decreased and setback values increased. We concluded that LL during GF stage decreased the cooking quality of rice, but could potentially improve the nutritional value of rice.  相似文献   
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