Structural and optical properties of cellulose nanocrystals isolated from the fruit shell of <Emphasis Type="Italic">Camellia oleifera</Emphasis> Abel     

Jin Yao  Haibo Huang  Long Mao  Zhihan Li  Heping Zhu  Yuejun Liu 《Fibers and Polymers》2017,18(11):2118-2124

Cellulose nanocrystals (CNC) with high aspect ratio of 80 have been readily prepared from the inexpensive fruit shell of Camellia oleifera Abel (SCOA) for the first time. In this study, SOCA was consecutively subjected to alkali extraction, hydrogen peroxide bleaching and acid hydrolysis to remove non-cellulosic components and release CNC. The derived CNC possesses a needle-shaped structure that in average diameter and length of 6±2 nm and 500±100 nm, respectively. The crystallinity index of CNC increased to 72 % and the initial decomposition temperature raised to 230 oC. The obtained CNC was formed to nanopaper by vacuum filtration showing high visible light transmittance over 90 %. Thus SOCA derived CNC is of great practical potential to apply in the field of biomedicine, energy, packing, etc. Overall, this study is anticipated to offer new possibility for the CNC production from the inexpensive but abundant agricultural wastes.  相似文献   

Water and dye-free coloration of wool     

Guangming Cai  Zhenglin Xu  Bin Tang  Xungai Wang 《Fibers and Polymers》2017,18(1):102-109

A water and dye-free heat treatment method was used to color wool fibers. The heat effect changed wool fibers to different colors from white in a nitrogen atmosphere. The influences of heating temperature and time on the colors of wool were investigated and the mechanical property of colored wool fibers was evaluated. The color strength of wool fibers increased as heat treatment temperature and time increased. The tensile strength retention rate of wool fiber was relatively high (≥90 %) when the heat temperature was below 200 °C. The surface morphologies of wool fibers scarcely changed during the heat treatment. The carbon content of fibers was found to reduce by heat treatment, indicating oxidization of components in the wool fibers in the process of coloration. Heat treatment may provide a water and dye-free approach to color wool and other textile fibers, albeit within a limited color range.  相似文献   

Optimization of curing process for polymer-matrix composites based on orthogonal experimental method     

Tengfei Chang  Lihua Zhan  Wei Tan  Shujian Li 《Fibers and Polymers》2017,18(1):148-154

In this paper, the orthogonal experimental method was carried out to optimize the curing process of aeronautical composite X850/T800 in autoclave process. Four important curing parameters including curing pressure, heating rate, curing temperature and heat preservation time were taken into account, and sixteen samples were fabricated to study the effects of the four parameters mentioned above on the curing quality by interlaminar properties test and microstructure analysis. The interlaminar properties and the interfacial bonding quality of these samples were studied by the short-beam three points bending test and scanning electron microscopy, respectively. Results revealed that the optimal curing process of X850/T800 composite laminate should be as follows: curing pressure of 0.6 MPa, heating rate of 1.5 °C/min, curing temperature of 160 °C, and heat preservation time of 120 min.  相似文献   

Effect of hybrid post treatments on the structural property and water flux of polysulfone hollow fiber membrane     

Reza Saghafi 《Fibers and Polymers》2017,18(1):41-49

The application of post treatments in preparation of high flux membranes is expanding rapidly. In this work, several hybrid post treatments have been introduced and used for change in the water flux of polysulfone (PSf) hollow fiber membranes. Dry wet spinning method was employed for fabrication of PSf hollow fiber membrane from spinning dope in mass ratio of 15:5:80 of PSf/PVP-K90/NMP. The simultaneous effects of single and hybrid post treatments containing traditional hypochlorite; high pressure injection technique (HPI) of hypochlorite, hot air and hot water treatments on the morphology and water flux of fabricated hollow fibers has been investigated. AFM analysis and image processing of SEM microphotographs of hollow fibers were used for structural studies. The mechanical properties of hollow fibers as well as strain at break and strength also were studied. It was found that the pores size and surface roughness parameter of hollow fiber membranes have been increased after traditional hypochlorite, HPI technique and hot water treatments while decreased when heat treated in air. In general all the employed hybrid post treatments caused to increase in the pores size of hollow fibers although the pores size increase rate in the membranes treated by the hybrid post treatments involving hot air was much lower than the others. The mechanical properties of hollow fibers have been decreased after hybrid and single post treatments containing traditional hypochlorite, HPI technique and hot water treatment while slightly increased after post treatments containing hot air. It was stated that the fabricated PSf hollow fibers were considerably affected by the employed hybrid post treatments. This can be attributed to the combine effects of used post treatments.  相似文献   

Effect of nitrogen root zone fertilization on rice yield,uptake and utilization of macronutrient in lower reaches of Yangtze River,China   总被引：1，自引：0，他引：1  

Xiaowei Liu  Huoyan Wang  Jianmin Zhou  Zhaoming Chen  Dianjun Lu  Dejin Zhu  Pingliang Deng 《Paddy and Water Environment》2017,15(3):625-638

Improper application of nitrogen (N) has led to high N losses and low N use efficiency in the lower reaches of Yangtze River in China. An effective method to solve such problems is the deep fertilized N in root zone (RZF). Limited information is available on the effect of RZF on the uptake of macronutrients (N, P and K) and rice yield. Field experiments, conducted from 2014 to 2015, compared the farmer fertilizer practice (FFP, with 225 kg ha^?1 of N, split into three doses) and RZF using the same rate but placing N 5 cm away from rice roots in holes 10 cm deep (RZF10) or 5 cm deep (RZF5) as a single application. The highest mean yield (10.0 t ha^?1) was obtained in RZF10, which was 19.5% more than that in FFP. Root zone fertilization of urea (whether 10 cm deep or 5 cm deep) resulted in greater accumulation of N, P and K in stem, leaf sheaths, leaf blades and grains compared to that in FFP in sandy and in loam soils. The uptake of N, P and K was the highest in RZF10 (average at 176.7, 66.2 and 179.1 kg ha^?1, respectively), higher than that in FFP by 45.0, 17.0 and 22.6%, respectively. N apparent recovery efficiency was markedly higher in RZF10 (53.1%) than in FFP (27.5%). RZF10 significantly increased the N, P, K uptake compared with FFP under different N rates in both sandy and loam soils. These results suggest that the N, P and K input amount should be re-determined under RZF.  相似文献   

Drainage and irrigation performance of hybrid ditches in converted paddy fields under winter wheat cultivation in Hokkaido     

Yasutaka Tsukamoto  Iwao Kitagawa  Ryuuich Nakamura 《Paddy and Water Environment》2017,15(3):681-691

Paddy fields converted into winter wheat fields in Hokkaido, Japan, receive extremely high snowfall, creating a risk of flood damage to crops in spring due to waterlogging of snowmelt runoff and poor drainage. Meanwhile, in June there is relatively little rainfall, and a lack of moisture inhibits winter wheat growth. Therefore, we developed a method involving a series of 30-cm-deep ditches in agricultural fields to be used for drainage during the flood-prone period and for furrow irrigation during the dry period using water drawn from the canals that feed the paddy fields. The ditches are called ‘hybrid ditches’ as they are able to perform both drainage and irrigation functions. In this study, we investigated the optimal construction timing and spacing for hybrid ditches. We also evaluated their ability to improve the drainage and irrigation of winter wheat. We found that the optimal timing for digging hybrid ditches is immediately after sowing, and the inter-ditch spacing for irrigation should be 15 m or less. The hybrid ditches promoted increased soil temperature and healthy development of wheat plants by improving drainage during the flood-prone period. In addition, water was successfully supplied via the hybrid ditches to irrigate the fields in June. Under experimental conditions in which rainfall was excluded, grain yield was 10% higher and percent protein content was more than 1% point greater in the irrigated plot compared with the non-irrigated plot. Grain yield was also observed to increase by 3–29% in demonstration tests conducted at local farms. From these results, we conclude that hybrid ditches are capable of improving the growth and yield of winter wheat by improving drainage and providing irrigation in converted paddy fields in Hokkaido.  相似文献   

Agronomic fortification of rice grains with secondary and micronutrients under differing crop management and soil moisture regimes in the north Indian Plains     

Anchal Dass  Subhash Chandra  Norman Uphoff  Anil K. Choudhary  Ranjan Bhattacharyya  K. S. Rana 《Paddy and Water Environment》2017,15(4):745-760

Although the System of Rice Intensification (SRI) has been reported to produce higher paddy (Oryza sativa L.) yields with better-quality grains, little research has addressed the latter claim. This study investigated the interactive effects of rice cultivation methods with different irrigation schedules and plant density on the uptake and concentration of sulfur (S), zinc (Zn), iron (Fe), manganese (Mn) and copper (Cu) in the grain and straw of two rice cultivars during two rainy seasons in the northern plains of India. As the two seasons differed in amounts of rainfall, there were impacts of soil moisture differences on nutrient uptake. Plots with SRI cultivation methods enhanced the grain uptake and concentrations of S, Zn, Fe, Mn and Cu by 36, 32, 28, 32 and 63%, respectively, compared to conventional transplanting (CT). Under SRI management, the highest concentrations of S, Zn and Cu in the grain and straw occurred with irrigation intervals scheduled at 3 days after disappearance of ponded water (DADPW; 3_D), whereas Fe and Mn concentrations in the grain and straw were higher with irrigation at 1 DADPW (1 _D ) compared with plots under 3 _D or 5 DADPW (5 _D ). The higher nutrient uptakes were also manifested in higher grain yield in 1 _D and 3 _D plots (by 9 and 6%, respectively) compared with 5 _D . Wider spacing (25 × 25 cm) compared with closer spacing (20 × 20 cm) significantly increased yield and the uptake and concentrations of all the said nutrients in the grains. When comparing the performance of two cultivars, the total uptakes of Zn, Fe, Mn and Cu in both grain and straw were significantly more in Hybrid 6444 than the improved variety Pant Dhan 4. Overall, SRI crop management compared to CT practices led to more biological fortification of rice grains with respect to S and the four micronutrients studied, giving a concomitant yield advantage of about 17% on average in this region.  相似文献   

Modeling the water and nitrogen transports in a soil–paddy–atmosphere system using HYDRUS-1D and lysimeter experiment     

Ranjeet K. Jha  Bhabagrahi Sahoo  Rabindra K. Panda 《Paddy and Water Environment》2017,15(4):831-846

Efficient water and fertilizer use is of paramount importance both in rain-fed and irrigated rice cultivation systems to tread off between the crop water demand during the dry spell and the fertilizer leaching. This lysimeter study on paddy in a lateritic sandy loam soil of the eastern India, to simulate the water and solute transports using the HYDRUS-1D model, reveals that this model could very well simulate the soil depth-specific variations of water pressure heads and nitrogen (N) concentrations with the efficiency of >86 and 89%, respectively. The change in the level of water ponding depth did not have a significant effect on the time to peak and the temporal variability of N concentration in the bottom soil layer. The lysimeter-scale water balance analysis indicated that the average deep percolation loss and crop water use were 35.01 ± 2.03 and 39.74 ± 1.49% of the total water applied during the crop growth period, respectively. Similarly, the amount of N stored in the plant and lost through soil storage, deep percolation, and other losses (mineralization, denitrification, and gaseous N loss to the atmosphere through plant leaves) were 1.60 ± 0.16, 0.17 ± 0.04, 12.00 ± 0.48, and 86.23 ± 0.41% of the total applied nitrogen, respectively. The simulation results reveal that a constant ponding depth of 3 cm could be maintained in paddy fields to reduce the N leaching loss to 7.5 kgN/ha.  相似文献   

Influence of crop establishment methods on yield,economics and water productivity of rice cultivars under upland and lowland production ecologies of Eastern Indo-Gangetic Plains     

Rishi Raj  Anil Kumar  I. S. Solanki  Shiva Dhar  Anchal Dass  Ashish Kumar Gupta  Vikash Kumar  C. B. Singh  R. K. Jat  U. C. Pandey 《Paddy and Water Environment》2017,15(4):861-877

A field study on assessment of crop establishment methods on yield, economics and water productivity of rice cultivars under upland and lowland production ecologies was conducted during wet seasons (June–November) of 2012 and 2013 in Eastern Indo-Gangetic Plains of India. The experiment was laid-out in a split-plot design (SPD) and replicated four times. The main-plot treatments included three crop establishment methods, viz. dry direct-seeded rice (DSR), system of rice intensification (SRI) and puddled transplanted rice (PTR). In sub-plots, five rice cultivars of different groups like aromatic (Improved Pusa Basmati 1 and Pusa Sugandh 5), inbreds (PNR 381 and Pusa 834) and hybrid (Arize 6444) were taken for their evaluations. These two sets of treatments were laid-out simultaneously in two production ecologies, upland and lowland during both years. In general, lowland ecology was found favourable for rice growth and yield and resulted in 13.2% higher grain yield as compared to upland ecology. Rice grown with SRI method produced 19.4 and 7.0% higher grain yield in 2012 and 20.6 and 7.1% higher in 2013, over DSR and PTR. However, PTR yielded 13.1 and 14.5% higher grain over DSR during 2012 and 2013, respectively. On an average, Arize 6444 produced 26.4, 26.9, 28.9 and 54.7% higher grain yield as compared to PS 5, P 834, PNR 381 and IPB1, respectively. Further, the interaction of production ecologies × crop establishment methods revealed that, in upland ecology, SRI recorded significantly higher grain yield as compared to PTR and DSR, but in lowland, grain yield resulting from SRI was similar to the yield obtained with PTR and significantly higher than DSR. The latter two methods (PTR and DSR) yielded alike in lowland ecology in both study years. The production ecologies × crop establishment methods × cultivars interaction on grain yield showed that the growing of Arize 6444 cultivar using SRI method in upland ecology resulted in the higher grain yield (8.87 t/ha). But the cost of production was also highest in SRI followed by PTR and DSR across production ecologies and cultivars. Cultivation of hybrid (Arize 6444) involved higher cost of production than all other cultivars. Irrespective of crop establishment methods and cultivars, gross returns, net returns and B:C ratio were significantly higher in lowland compared to upland ecology. Owing to higher grain yield, SRI method fetched significantly higher gross returns and net returns over PTR and DSR. Average increase in net return with Arize 6444 was 68.8, 41.0, 37.7 and 33.1% over IPB 1, PNR 381, P 834 and PS 5, respectively. There was a saving of 30.7% water in SRI and 19.9% in DSR over PTR under upland ecology. Similarly in lowland ecology, water saving of 30.2% was observed in SRI and 21.2% in DSR over PTR. Due to higher yield and saving on water, SRI returned significantly higher total water productivity (TWP) (5.9 kg/ha-mm) as compared to DSR (3.5 kg/ha-mm) and PTR (3.6 kg/ha-mm) under upland ecology. In lowland ecology, also SRI (6.2 kg/ha-mm) resulted in higher TWP as compared to other two methods. However, DSR gave significantly higher TWP as compared to PTR. Among cultivars, hybrid Arize 6444 recorded the highest TWP in both upland and lowland production ecologies across crop establishment methods. Hence, growing of hybrid Arize 6444 with SRI method can enhance rice productivity and water-use efficiency in lowland and upland production ecologies of Eastern Indo-Gangetic Plains and in other similar regions.  相似文献   

Predicting adoption of double cropping in paddy fields of northern Iran: a comparison of statistical methods     

Solmaz Nadaf Fahmideh  Mohammad Sadegh Allahyari  Christos A. Damalas  Zahara Daghighi Masouleh  Mona Ghazi 《Paddy and Water Environment》2017,15(4):907-917

Factors affecting the adoption of double cropping were explored in rice farms of Fouman County of Guilan Province in northern Iran using artificial neural networks (ANNs), linear discriminant analysis (LDA), and logistic regression (LGR). Eleven factors (age, education, occupation, family size, type of farm ownership, distance to the agricultural service center, attending agricultural extension courses, use of financial resources and bank loans, number of domestic animals, area under cultivation, and social participation) were examined. An additional objective was to compare the ability of the three models in predicting the adoption of double cropping. ANNs showed an overall predictive power of 89.8%. LDA showed an overall predictive power of 83.2%, with seven of the eleven independent variables being effective on the adoption of double cropping. LGR indicated an overall predictive power of 87.6%, with eight of the eleven independent variables being effective on the adoption of double-rice cropping. ANNs showed higher power than LGR and LDA in predicting the adoption of double cropping. Based on all three methods used for analysis, the most important independent variables were social participation and area under cultivation (positive factors) as well as distance to the agricultural service center and family members (negative factors). Establishment of cooperatives or other kinds of farmers’ associations to foster social participation could motivate adoption of double cropping, particularly among small-scale farmers. To increase agricultural services, more local centers should be created in rural areas. The government should promote double cropping through effective incentives and technology transfer to small-scale farmers.  相似文献