Located along the southern part of the West Qinling orogenic belt,the Yangshan gold deposit is one of the largest in China.The major gold ores of Yangshan are disseminated in metasedimentary host rocks with minor nati...Located along the southern part of the West Qinling orogenic belt,the Yangshan gold deposit is one of the largest in China.The major gold ores of Yangshan are disseminated in metasedimentary host rocks with minor native gold amounts in stibnite-gold quartz veins.Pyrite and arsenopyrite are the major Au-bearing minerals.Hydrothermal muscovite from gold-bearing quartz veins was dated using the in situ Rb-Sr method to determine the formation age of the Yangshan gold deposit.The Rb-Sr isochron date of the muscovite yielded 210.1±5.6 Ma(MSWD=1.2).This date is near the lower end of the period of the mineralized granitic dykes(210.49-213.10 Ma).Two stages of gold enriching process are recognized in the gold-bearing pyrite:the first is incorporated with the Co,Cu,As,Ni enrichment;and the second is accompanied by Bi,Co,Ni,Pb,Cu,Sb concentration.The in-situ sulfur isotopic values of pyrites show a restrictedΔ34s range of-1.43‰to 2.86‰with a mean value of 0.43‰.Trace-element mapping and in-situ sulfur isotopic analysis of pyrite suggest that the sulfur deposits are likely derived from a magmatic source and likely assimilated by sulfur from the sedimentary bedrock.Thus,magmatism plays a critical role in the formation of the Yangshan gold deposit.展开更多
Global gridded daily mean data from the NCEP/NCAR Reanalysis(1948-2012) are used to obtain the onset date,retreat date and duration time series of the South China Sea summer monsoon(SCSSM) for the past 65 years.The su...Global gridded daily mean data from the NCEP/NCAR Reanalysis(1948-2012) are used to obtain the onset date,retreat date and duration time series of the South China Sea summer monsoon(SCSSM) for the past 65 years.The summer monsoon onset(retreat) date is defined as the time when the mean zonal wind at 850 hPa shifts steadily from easterly(westerly) to westerly(easterly) and the pseudo-equivalent potential temperature at the same level remains steady at greater than 335 K(less than 335 K) in the South China Sea area[110-120°E(10-20°N)].The clockwise vortex of the equatorial Indian Ocean region,together with the cross-equatorial flow and the subtropical high,plays a decisive role in the burst of the SCSSM.The onset date of the SCSSM is closely related to its intensity.With late(early) onset of the summer monsoon,its intensity is relatively strong(weak),and the zonal wind undergoes an early(late) abrupt change in the upper troposphere.Climate warming significantly affects the onset and retreat dates of the SCSSM and its intensity.With climate warming,the number of early-onset(-retreat) years of the SCSSM is clearly greater(less),and the SCSSM is clearly weakened.展开更多
This study aimed to formulate a nutritive diet enriched with protein, iron and energy for under-five children. It was conducted in Elhosh rural area, Gezira State, Sudan, 2010. The diet was formulated and blended usin...This study aimed to formulate a nutritive diet enriched with protein, iron and energy for under-five children. It was conducted in Elhosh rural area, Gezira State, Sudan, 2010. The diet was formulated and blended using locally available foods, produced at home level, by a twin-roller drum dryer and in biscuit form. The raw materials included pigeon pea (Cajanus cajan) sesame (Sesamum indicum) and dates (Phoenix dactylifera). The three products were evaluated for their proximate composition, energy value, iron content and acceptability after storage at (4℃ - 6℃) and at room temperature for 5 months. The protein content of the products was (14.0 - 14.1 g/100g);the energy value ranged from 382 to 390 Kcal/100g, both in-line with many recommendations for children aged under five. The iron content was found in the range of 14.6 - 14.8 mg/100g, in agreement with the codex recommendation. Yeast, mold and salmonella were not detected while other microbes were found within acceptable values. Studied products were found nutritious and remained acceptable after storage for five months. Legumes, sesame seeds and dates can be effectively used in wheat-based baby foods as a source of protein and mineral supplement.展开更多
Global warming has become a topic of widespread attention. The climate change will affect the change of agricultural climate resource,thereby affecting the agricultural planting structure,the grain yield,etc. Based on...Global warming has become a topic of widespread attention. The climate change will affect the change of agricultural climate resource,thereby affecting the agricultural planting structure,the grain yield,etc. Based on the daily temperature of Zhangjiakou from 1960 to 2011,the temporal changes of ≥0 ℃ and ≥10 ℃ accumulated temperatures were analyzed by using the methods of linear trend estimation and M-K mutation test. The results indicated that(1) the annual average temperature showed an increasing trend with the linear warming rate of 0. 42 ℃ /10 a in the past 52 years. In 1982,the annual average temperature had abrupt change,especially after 1983,the warming trend increased significantly.(2) In the past 52 years,≥0 ℃ accumulated temperature showed an increasing trend with the warming rate of 89. 4 ℃ /10 a. Mutation point of ≥0 ℃ accumulated temperature appeared in 1983,and after 1985,≥0 ℃ accumulated temperature increased sharply. At the same time,the ≥10 ℃ accumulated temperature had abrupt change in 1983,especially from 1987 to 1995 and after 1986,the warming trend increased sharply.(3) The initial date of ≥0 ℃ presented significant advancing trend,and that of ≥10 ℃ had little change,while their terminal dates presented delaying trend,so the sustained days of ≥0 ℃ and ≥10 ℃ increased significantly.(4) In the past 52 years,the delay of the terminal dates of ≥0 ℃ and ≥10 ℃ was greater than the advancing of the initial dates,and ≥0 ℃ accumulated temperature had a greater increase than ≥10 ℃ accumulated temperature.展开更多
The melt onset dates(MOD)over Arctic sea ice plays an important role in the seasonal cycle of sea ice surface properties,which impacts Arctic surface solar radiation absorbed by the ice-ocean system.Monitoring interan...The melt onset dates(MOD)over Arctic sea ice plays an important role in the seasonal cycle of sea ice surface properties,which impacts Arctic surface solar radiation absorbed by the ice-ocean system.Monitoring interannual variations in MOD is valuable for understanding climate change.In this study,we investigated the spatio-temporal variability of MOD over Arctic sea ice and 14 Arctic sub-regions in the period of 1979 to 2017 from passive microwave satellite data.A set of mathematical and statistical methods,including the Sen’s slope and Mann-Kendall mutation tests,were used to comprehensively assess the variation trend and abrupt points of MOD during the past 39 years for different Arctic sub-regions.Additionally,the correlation between Arctic Oscillation(AO)and MOD was analyzed.The results indicate that:(1)all Arctic sub-regions show a trend toward earlier MOD except the Bering Sea and St.Lawrence Gulf.The East Siberian Sea exhibits a significantly earlier trend,with the highest rate of-9.45 d/decade;(2)the temporal variability and statistical significance of MOD trend exhibit large interannual differences with different time windows for most regions in the Arctic;(3)during the past 39 years,the MOD changed abruptly in different years for different sub-regions;(4)the seasonal AO has more influence on MOD than monthly AO.The findings in this study can improve our knowledge of MOD changes and are beneficial for further Arctic climate change study.展开更多
The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, ...The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, overrun%, rheological and melting properties during storage period up to 60 days at -18°C was studied. It was noticed that there are higher mean of viscosity values (cp) when using “Al-khalas” dates paste 5% and 10% followed by samples with “sokary” paste then samples with molasses in ice cream samples compared to those with added date’s pieces of either “Sokary” or “Al-khalas”. There are significant differences of overrun values between all treatments and samples with the added date paste of either “sokary” or “Al-khalas” which recorded the lowest values. Increased melting resistance and good qualities as heat shock and melting properties were significantly better for the samples with added dates pieces or paste unlike the molasses. The storage effect is obvious decline, especially when using dates molasses.展开更多
Peral millet being drought tolerant has substantial potential to contribute in food security ensuring the food, fodder and nutritional value in different Asian and African countries. Susceptibility to abiotic and biot...Peral millet being drought tolerant has substantial potential to contribute in food security ensuring the food, fodder and nutritional value in different Asian and African countries. Susceptibility to abiotic and biotic factors and low productivity are the main reasons for decreasing productivity and area of millets. In this context, evaluation of the effect of weed control practices and varying sowing dates on grain yield of kharif season grown pearl millet (Pennisetum americanum L.) was demonstrated at post graduate agriculture research station, University of Agriculture, Faisalabad during 2015. Forage pearl millet was sown at three different sowing dates i.e. mid-June, end of June and mid-July and four weed control practices viz. weedy check (no weeding), twice hoeing at 15 and 30 days after sowing (DAS), weed control using herbicides i.e. application of Atrazine (Awax 38 SC) @330 g a.i. ha-1 at 15 DAS, and twice foliar applications of 10% Sorghum water extract (Sorgaab) (at 15 and 30 DAS). The experiment was laid out in randomized complete block design (RCBD) under split plot arrangement, comprising of three replications. The treatments with varying sowing dates were randomized in main plots and weed control practices were in subplots. Results showed that the highest plant height (279.51 cm), leaf area (2777.80 cm2), fresh weight of leaves per plant (155.57 g), maximum number of grains per head (3162.0) and grain yield (3419.7 kg·ha-1) were obtained in the treatment combination of 30th June sowing × twice weed hoeing (at 15 and 30 DAS) while, maximum 1000-grain weight (8.45 g) was observed in treatments where weeds were controlled by hoeing (at 15 and 30 DAS). Moreover, cultural weed control practices reduce significantly weed density, fresh and dry Wight of weeds. In sum, it is concluded that to reduce the weed-crop competition and to gain higher productivity of pearl millet, field should be weed free 20 - 45 days after sowing.展开更多
The objective of this study is the valorization of downgraded dates from a high Algerian date variety <span style="font-family:Verdana;"><i></i></span><i><i><span style...The objective of this study is the valorization of downgraded dates from a high Algerian date variety <span style="font-family:Verdana;"><i></i></span><i><i><span style="font-family:Verdana;">Deglet Nour</span></i><i><span style="font-family:Verdana;"></span></i></i><span style="font-family:;" "=""><span style="font-family:Verdana;">, locally called “</span><span style="font-family:Verdana;">h’chef</span><span style="font-family:Verdana;">”. The work starts with the implementation of a food formulation of semi-candied dat</span></span><span style="font-family:Verdana;">es in syrup extracted from dates. This formulation was based on dehydration-impregnation by immersion (D.I.I.). The downgraded dates were cleaned, cut, blanched, and then immersed in date syrups with increasing differential</span><span style="font-family:Verdana;"> concentrations in Brix degrees: 65</span><span style="font-family:Verdana;">°</span><span style="font-family:Verdana;">, 70</span><span style="font-family:Verdana;">°</span><span style="font-family:;" "=""> <span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> 75</span></span><span style="font-family:Verdana;">°</span><span style="font-family:;" "=""><span style="font-family:Verdana;">. The chosen date/syrup immersion ratio is 1:2 (w/w). The obtained semi-candied dates were the subject of physicochemical and sensory analyses. The characterization of the downgraded dates before immersion showed high sugar content with a rate </span><span style="font-family:Verdana;">52.67</span><span style="font-family:Verdana;"> g% g of dry matter and low water content (14%) which favors their use in semi-candied products. The </span><span style="font-family:Verdana;">physico-chemical</span> <span style="font-family:Verdana;">analyses</span><span style="font-family:Verdana;"> results of the three semi-candied dates products show an increase in their final sugar content, </span></span><span style="font-family:Verdana;"><i></i></span><i><i><span style="font-family:Verdana;">i.e.</span></i><i><span style="font-family:Verdana;"></span></i></i><span style="font-family:Verdana;"> from 53.55% to 60.78% and in ashes between 1</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">76 p.cent and 1</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">94 p.cent. On the other hand, sensory analysis results confirm that the semi-candied dates with a syrup of 75</span><span style="font-family:Verdana;">°</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> Brix present the most appreciated and preferable organoleptic characteristics than the other variables. Finally, following appertisation, the stability test </span><span style="font-family:Verdana;">reveal</span></span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> good microbiological quality (100</span><span style="font-family:Verdana;">°</span><span style="font-family:Verdana;">C for 20 minutes) of the three (3) semi-candied formulations of dates.</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> Thus, the valorization of the “</span><span style="font-family:Verdana;">h’chef</span><span style="font-family:Verdana;">” as sorting gap <i></i></span><i><i><span style="font-family:Verdana;">Deglet Nour</span></i></i></span><span style="font-family:Verdana;"> date allowed its transformation into semi-candied dates, stable, appreciable on the organoleptic side. This new formulation could constitute a value-added product if eventually manufactured on an industrial scale, mainly in southern Algeria.</span>展开更多
Colza is a relatively new crop for North Kazakhstan. The increase of colza seeds production is restricted by its cultivation technology imperfection. Empiric model of colza for seeds cultivation is designed, allowing ...Colza is a relatively new crop for North Kazakhstan. The increase of colza seeds production is restricted by its cultivation technology imperfection. Empiric model of colza for seeds cultivation is designed, allowing using its maximum potential. It was found out that correct preceding crops selection, optimization of norms and dates of colza seeding provide seeds heavy weight crops, reducing crops production cost and increasing cost efficiency at 62% average.展开更多
Agricultural sector in Jordan is facing serious challenges in meeting the<span style="font-family:;" "=""> growing needs of food security because of its low water availability. Maintaini...Agricultural sector in Jordan is facing serious challenges in meeting the<span style="font-family:;" "=""> growing needs of food security because of its low water availability. Maintaining <span>and enhancing agricultural water productivity under such prevailing</span> environmental constraints are hard to achieve. Potatoes water productively in Jordan Valley was modeled using Decision Support System for Agrotechnology Transfer (DSSAT) under six nitrogen applications (0, 60, 80, 100, 120 and 140 kg/ha) and twelve planting dates every two weeks from October 1 to March 15 scenarios. The potatoes yield increased from 0% to 100% nitrogen treatment and then no considerable increase occurred. The potatoes</span><span style="font-family:;" "="">’</span><span style="font-family:;" "=""> crop yield increased from October 1<sup>st</sup> to January 15 and then decreased after which until the last day of planting date. The seasonal cumulative crop evapotranspiration for potatoes about doubled from 0% to 60% nitrogen treatment and then kept increasing gradually until the last treatment. The growing season cumulative crop evapotranspiration for potatoes increased gradually from October 1 to March 1. The water productivity increased from 0% nitrogen treatment to 100% and then decreased. The potatoes</span><span style="font-family:;" "="">’</span><span style="font-family:;" "=""> water productivity increased from October 1 until November 15 and then decreased to the end. From these results, we recommend that 100% of nitrogen requirements should be applied. The best window for potatoes</span><span style="font-family:;" "="">’</span><span style="font-family:;" "=""> planting date is the last two weeks in November.</span>展开更多
The production of citric acid from dates of the date palm Phoenix dactilifera was studied using a full factorial design with two design variables;Aspergillus niger strain, and starter juice treatment. Analyses of data...The production of citric acid from dates of the date palm Phoenix dactilifera was studied using a full factorial design with two design variables;Aspergillus niger strain, and starter juice treatment. Analyses of data have shown that mould type and the interaction between Aspergillus niger strain + juice treatment had significant effect (P ≥ 0.05) on the final total acidity. It was also found that all design variables and the interaction between them had significant effect (P ≥ 0.05) on the final pH and Total Soluble Solids. The highest total acidity expressed as citric acid was achieved with a commercial strain of Aspergillus niger, and filtered and centrifuged date juice.展开更多
The Kingdom of Saudi Arabia produces over one million metric tons annually, which returns a 20% of wasted dates annually. Lactic acid and its derivatives are widely used in food, pharmaceutical and textile industries....The Kingdom of Saudi Arabia produces over one million metric tons annually, which returns a 20% of wasted dates annually. Lactic acid and its derivatives are widely used in food, pharmaceutical and textile industries. There has been an increase in lactic acid production because it is used as a raw material to produce polylactic acid, a polymer that is used as a special medical and environmental friendly biodegradable plastic. This study aimed to use wasted dates to produce lactic acid by single culture Lactobacillus casei (ATCC 393), Lactobacillus acidophilus (CICC 6088) and the mixed culture using batch fermentation. The investigation results showed that the maximum concentration of lactic acid for ATCC 393, CICC 6088 and the mixed culture are 87, 84 and 84 g/l respectively. For single CICC 6088 and the mixed culture, the total percentage of glucose and fructose utilized was found to be 100%;76%, respectively, whereas in the case of the single culture ATCC 393, the total percentage of glucose and fructose were 100% and 72%, respectively. With regard to lactic acid concentration, and sugar consumption, the results revealed that the single culture ATCC 393 produced the optimum lactic acid of 87 g/l for 48 hr with initial sugar concentration of 90 g/l.展开更多
Big dates abound in Henan Province. Henan big dates are of big size, thick flesh, fine texture and sweet taste. They are renowned at home and abroad, and are an exported dry fruit variety of Henan Province. Big dates ...Big dates abound in Henan Province. Henan big dates are of big size, thick flesh, fine texture and sweet taste. They are renowned at home and abroad, and are an exported dry fruit variety of Henan Province. Big dates have abundant nourishment, their fruit contains protein, sugar, organic acid, various kinds of vitamins and such trace elements as calcium,展开更多
The single machine scheduling problem which involves uncertain job due dates is one of the most important issues in the real make-to-order environment. To deal with the uncertainty, this paper establishes a robust opt...The single machine scheduling problem which involves uncertain job due dates is one of the most important issues in the real make-to-order environment. To deal with the uncertainty, this paper establishes a robust optimization model by minimizing the maximum tardiness in the worst case scenario over all jobs. Unlike the traditional stochastic programming model which requires exact distributions, our model only needs the information of due date intervals. The worst case scenario for a given sequence that belongs to a set containing only n scenarios is proved, where n is the number of jobs. Then, the model is simplified and reformulated as an equivalent mixed 0-1 integer linear programming(MILP) problem. To solve the MILP problems efficiently, a heuristic approach is proposed based on a robust dominance rule. The experimental results show that the proposed method has the advantages of robustness and high calculating efficiency, and it is feasible for large-scale problems.展开更多
In order to determine the optimal sowing date of ratoon rice in South Henan's rice-growing areas,this paper performs a comparative analysis of rice growth process,seedling quality and yield of first season rice an...In order to determine the optimal sowing date of ratoon rice in South Henan's rice-growing areas,this paper performs a comparative analysis of rice growth process,seedling quality and yield of first season rice and ratoon rice under different sowing date treatments. The results show that under climatic conditions( 2014),by using dry seedling cultivation in a small plastic shed,the growth of seedling sown on February21 was affected,while the sowing treatments from March 1 to April 11 can breed normal seedlings,and in this period,the maturity period of first season rice was delayed with prolonged sowing date,and ratoon rice yield declined with prolonged sowing date( total production of rice sown on 11 March reaching a peak). Thus,it is considered that the optimal sowing date of ratoon rice in South Henan's rice-growing areas is mid-March.展开更多
Seed shattering is a common problem in early soybean production system (ESPS) in the Midsouth, which mainly uses maturity group (MG) IV soybeans. Many studies have been conducted on the genetics of soybean shattering ...Seed shattering is a common problem in early soybean production system (ESPS) in the Midsouth, which mainly uses maturity group (MG) IV soybeans. Many studies have been conducted on the genetics of soybean shattering resistance for individual varieties;however, information on the physiology of soybean shattering pattern under specific environmental conditions, which is often critical to soybean growers, is very limited. Field experiments were conducted at Stoneville MS from 2007 to 2009 to investigate the shattering patterns of 80-132 MG IV soybean varieties each year. Results from 2007 and 2008 indicated that, when April-planted MG IV soybeans matured in mid- to late August, pods of most soybean varieties did not shatter within the first three weeks after maturity (WAM) and there was no significant shattering effect on final yields. However, differences in pod shattering among the varieties became apparent in the fourth WAM. Late-planted MG IV soybeans, which matured in early September, had a low shattering rate and could hold seeds up to 6 WAM before reaching a critical shattering point. Most soybean varieties planted in April 2009 did not show significant pod shattering by the end of the fourth WAM. The critical point of shattering was not reached until 6 - 7 WAM. Relatively lower temperatures and abundant rainfall during the late growing season in 2009 may be the main reasons causing delayed shattering in April-planted MG IV soybeans. Results from the May-planting of 2007 and the April-planting of 2009 indicated that soybeans maturing after September have much less problematic shattering. Different weather patterns, especially temperature and rainfall in each year could be essential factors affecting seed shattering patterns.展开更多
Dating of fracture-filling calcitewith U-Pb geochronology is becoming a rapidly adopted technique for determining the absolute timing of brittle deformation in the upper crust.Slickenfibre calcite is a desirable targe...Dating of fracture-filling calcitewith U-Pb geochronology is becoming a rapidly adopted technique for determining the absolute timing of brittle deformation in the upper crust.Slickenfibre calcite is a desirable target,as it precipitates between individual fault slip displacement events,and provides additional kinematic information.Here we present a case study of slickenfibres formed on the Očkov thrust in the Lower Palaezoic Prague Basin,Bohemian Massif,utilising a combination of petrographic and in situ methods.We demonstrate that slickenfibre external textures can be preserved,whilst internally primary textures are removed by fluid infiltration and recrystallization,leading to variable U and Pb mobilisation.One slickenfibre yielded a date of ca.250 Ma,which we interpret as recording fault slip along the Očkov thrust.Another cross-cutting slickenfibre yielded more scattered U-Pb data,with an imprecise apparent age around ca.95 Ma.This slickenfibre is recrystallised,destroying the primary textures,and exhibits element mobility.The meaning of this younger apparent age is therefore questionable;whereas it likely reflects Cretaceous U and Pb mobility assisted by fluid-flow along the fault plane,it may not reflect a period of fault slip.Our results demonstrate that slickenfibre-based U-Pb dates do not unequivocally relate to fault motion,and that petrographic and elemental analyses are important requirements for interpreting calcite U-Pb data.展开更多
Guar is a drought and salt tolerant summer annual legume, which could be a potential alternative crop in the semi-arid Southern High Plains. Increased use of guar gum in oil industries has increased the demand of guar...Guar is a drought and salt tolerant summer annual legume, which could be a potential alternative crop in the semi-arid Southern High Plains. Increased use of guar gum in oil industries has increased the demand of guar globally. Planting date effects on stand establishment, physiological parameters, and yield formation of guar genotypes were investigated at the New Mexico State University’s Agricultural Science Center at Clovis, NM for two seasons (2014 and 2015). Four guar genotypes (HES 1123, Kinman, Lewis, and Matador) were tested under three planting dates (June 18, July 7, and July 22 in 2014;and June 18, July 6, and July 20 in 2015). Higher temperature and rainfall were recorded under mid-June planting than early-July and late-July plantings. Guar planted under mid-June had better stand establishment as shown by the higher number of plants m<sup>-2</sup>, better physiology as revealed by higher photosynthetic rate (P<sub>n</sub>), transpiration rate (T<sub>r</sub>), leaf area index (LAI), and SPAD values than early-July and late-July plantings. Guar planted under mid-June resulted in taller plants, and therefore, produced higher plant biomass than both of the July plantings. Yield attributing characteristics including clusters plant<sup>-1</sup>, pods plant<sup>-1</sup>, seeds plant<sup>-1</sup>, seed spod<sup>-1</sup>, 1000 seed weight, and harvest index (HI) were highest under mid-June planting followed by the early-July and late-July plantings, respectively. The mid-June planting increased seed yield by 26% and 55% over early-July and late-July (1399 vs. 1111 and 903 kg·ha<sup>-1</sup>) plantings, respectively in 2014;while the same increase in 2015 was 51% and 243% (1308 vs. 868 and 381 kg·ha<sup>-1</sup>), respectively. These results indicate that delaying planting beyond mid-June is detrimental to guar productivity. However, genotypes did not show any significant variation in their performance. Overall, warmer growing conditions and more precipitation under mid-June planting caused better growth and yield formation of guar genotypes.展开更多
[Objectives]This study was conducted to clarify the appropriate nitrogen fertilizer amount and transplanting density that should be selected for different transplanting dates.[Methods]The effects of nitrogen fertilize...[Objectives]This study was conducted to clarify the appropriate nitrogen fertilizer amount and transplanting density that should be selected for different transplanting dates.[Methods]The effects of nitrogen fertilizer rate and transplanting density on the traits and yield of late japonica rice in the Jianghuai rice-wheat cropping area under different transplanting dates(transplanting at an appropriate time and delayed transplanting)were studied.[Results]The transplanting date significantly affected the heading,maturity and whole growth period of rice,and when the transplanting date of early-maturing late japonica rice was delayed by 15 d,the growth period was shortened by about 10 d.Nitrogen and density interaction obviously affected the dry matter accumulation and effective tillers of rice,and the dry matter production and effective tiller number of rice treated with B_(1)N_(2) were greater than other treatments.Under the timely transplanting date,the best nitrogen and density combination was 225-300 kg/hm^(2) and 250500 holes/hm^(2),and the nitrogen use efficiency was ideal.It suggests that under the condition of transplanting rice in a timely manner,applying nitrogen fertilizer at an appropriate rate while ensuring a reasonable population density is conducive to the coordination of the number of stems and tillers,the number of grains per panicle,etc.,thereby ensuring the best formation of yield factors in the middle and late stages of rice growth.[Conclusions]This study provides technical support and theoretical reference for reasonable nitrogen and density interaction of rice.展开更多
基金financially supported by China Geological Survey Project(Grant No.DD20220971)。
文摘Located along the southern part of the West Qinling orogenic belt,the Yangshan gold deposit is one of the largest in China.The major gold ores of Yangshan are disseminated in metasedimentary host rocks with minor native gold amounts in stibnite-gold quartz veins.Pyrite and arsenopyrite are the major Au-bearing minerals.Hydrothermal muscovite from gold-bearing quartz veins was dated using the in situ Rb-Sr method to determine the formation age of the Yangshan gold deposit.The Rb-Sr isochron date of the muscovite yielded 210.1±5.6 Ma(MSWD=1.2).This date is near the lower end of the period of the mineralized granitic dykes(210.49-213.10 Ma).Two stages of gold enriching process are recognized in the gold-bearing pyrite:the first is incorporated with the Co,Cu,As,Ni enrichment;and the second is accompanied by Bi,Co,Ni,Pb,Cu,Sb concentration.The in-situ sulfur isotopic values of pyrites show a restrictedΔ34s range of-1.43‰to 2.86‰with a mean value of 0.43‰.Trace-element mapping and in-situ sulfur isotopic analysis of pyrite suggest that the sulfur deposits are likely derived from a magmatic source and likely assimilated by sulfur from the sedimentary bedrock.Thus,magmatism plays a critical role in the formation of the Yangshan gold deposit.
基金National Key Basic Research and Development Planning Program of China(Program 973)(2013CB430202)Basic Research Program of Jiangsu Province,China(BK20130997)+1 种基金National Natural Science Fund of China(91337109)Project Funded by the Priority Academic program Development of Jiangsu Higher Education Institutions(PAPD)
文摘Global gridded daily mean data from the NCEP/NCAR Reanalysis(1948-2012) are used to obtain the onset date,retreat date and duration time series of the South China Sea summer monsoon(SCSSM) for the past 65 years.The summer monsoon onset(retreat) date is defined as the time when the mean zonal wind at 850 hPa shifts steadily from easterly(westerly) to westerly(easterly) and the pseudo-equivalent potential temperature at the same level remains steady at greater than 335 K(less than 335 K) in the South China Sea area[110-120°E(10-20°N)].The clockwise vortex of the equatorial Indian Ocean region,together with the cross-equatorial flow and the subtropical high,plays a decisive role in the burst of the SCSSM.The onset date of the SCSSM is closely related to its intensity.With late(early) onset of the summer monsoon,its intensity is relatively strong(weak),and the zonal wind undergoes an early(late) abrupt change in the upper troposphere.Climate warming significantly affects the onset and retreat dates of the SCSSM and its intensity.With climate warming,the number of early-onset(-retreat) years of the SCSSM is clearly greater(less),and the SCSSM is clearly weakened.
文摘This study aimed to formulate a nutritive diet enriched with protein, iron and energy for under-five children. It was conducted in Elhosh rural area, Gezira State, Sudan, 2010. The diet was formulated and blended using locally available foods, produced at home level, by a twin-roller drum dryer and in biscuit form. The raw materials included pigeon pea (Cajanus cajan) sesame (Sesamum indicum) and dates (Phoenix dactylifera). The three products were evaluated for their proximate composition, energy value, iron content and acceptability after storage at (4℃ - 6℃) and at room temperature for 5 months. The protein content of the products was (14.0 - 14.1 g/100g);the energy value ranged from 382 to 390 Kcal/100g, both in-line with many recommendations for children aged under five. The iron content was found in the range of 14.6 - 14.8 mg/100g, in agreement with the codex recommendation. Yeast, mold and salmonella were not detected while other microbes were found within acceptable values. Studied products were found nutritious and remained acceptable after storage for five months. Legumes, sesame seeds and dates can be effectively used in wheat-based baby foods as a source of protein and mineral supplement.
文摘Global warming has become a topic of widespread attention. The climate change will affect the change of agricultural climate resource,thereby affecting the agricultural planting structure,the grain yield,etc. Based on the daily temperature of Zhangjiakou from 1960 to 2011,the temporal changes of ≥0 ℃ and ≥10 ℃ accumulated temperatures were analyzed by using the methods of linear trend estimation and M-K mutation test. The results indicated that(1) the annual average temperature showed an increasing trend with the linear warming rate of 0. 42 ℃ /10 a in the past 52 years. In 1982,the annual average temperature had abrupt change,especially after 1983,the warming trend increased significantly.(2) In the past 52 years,≥0 ℃ accumulated temperature showed an increasing trend with the warming rate of 89. 4 ℃ /10 a. Mutation point of ≥0 ℃ accumulated temperature appeared in 1983,and after 1985,≥0 ℃ accumulated temperature increased sharply. At the same time,the ≥10 ℃ accumulated temperature had abrupt change in 1983,especially from 1987 to 1995 and after 1986,the warming trend increased sharply.(3) The initial date of ≥0 ℃ presented significant advancing trend,and that of ≥10 ℃ had little change,while their terminal dates presented delaying trend,so the sustained days of ≥0 ℃ and ≥10 ℃ increased significantly.(4) In the past 52 years,the delay of the terminal dates of ≥0 ℃ and ≥10 ℃ was greater than the advancing of the initial dates,and ≥0 ℃ accumulated temperature had a greater increase than ≥10 ℃ accumulated temperature.
基金The National Key Research and Development Program of China under contract No.2018YFA0605403the National Natural Science Foundation of China under contract No.42071084Jiangyuan Zeng was supported by the Youth Innovation Promotion Association CAS under contract No.2018082。
文摘The melt onset dates(MOD)over Arctic sea ice plays an important role in the seasonal cycle of sea ice surface properties,which impacts Arctic surface solar radiation absorbed by the ice-ocean system.Monitoring interannual variations in MOD is valuable for understanding climate change.In this study,we investigated the spatio-temporal variability of MOD over Arctic sea ice and 14 Arctic sub-regions in the period of 1979 to 2017 from passive microwave satellite data.A set of mathematical and statistical methods,including the Sen’s slope and Mann-Kendall mutation tests,were used to comprehensively assess the variation trend and abrupt points of MOD during the past 39 years for different Arctic sub-regions.Additionally,the correlation between Arctic Oscillation(AO)and MOD was analyzed.The results indicate that:(1)all Arctic sub-regions show a trend toward earlier MOD except the Bering Sea and St.Lawrence Gulf.The East Siberian Sea exhibits a significantly earlier trend,with the highest rate of-9.45 d/decade;(2)the temporal variability and statistical significance of MOD trend exhibit large interannual differences with different time windows for most regions in the Arctic;(3)during the past 39 years,the MOD changed abruptly in different years for different sub-regions;(4)the seasonal AO has more influence on MOD than monthly AO.The findings in this study can improve our knowledge of MOD changes and are beneficial for further Arctic climate change study.
文摘The effect of using camel milk with 2 dates types (Sokary & Al-Khalas), in 3 forms (paste, pieces, and molasses), with 2 different concentrations (5% & 10%) in the manufacturing of ice cream on its viscosity, overrun%, rheological and melting properties during storage period up to 60 days at -18°C was studied. It was noticed that there are higher mean of viscosity values (cp) when using “Al-khalas” dates paste 5% and 10% followed by samples with “sokary” paste then samples with molasses in ice cream samples compared to those with added date’s pieces of either “Sokary” or “Al-khalas”. There are significant differences of overrun values between all treatments and samples with the added date paste of either “sokary” or “Al-khalas” which recorded the lowest values. Increased melting resistance and good qualities as heat shock and melting properties were significantly better for the samples with added dates pieces or paste unlike the molasses. The storage effect is obvious decline, especially when using dates molasses.
文摘Peral millet being drought tolerant has substantial potential to contribute in food security ensuring the food, fodder and nutritional value in different Asian and African countries. Susceptibility to abiotic and biotic factors and low productivity are the main reasons for decreasing productivity and area of millets. In this context, evaluation of the effect of weed control practices and varying sowing dates on grain yield of kharif season grown pearl millet (Pennisetum americanum L.) was demonstrated at post graduate agriculture research station, University of Agriculture, Faisalabad during 2015. Forage pearl millet was sown at three different sowing dates i.e. mid-June, end of June and mid-July and four weed control practices viz. weedy check (no weeding), twice hoeing at 15 and 30 days after sowing (DAS), weed control using herbicides i.e. application of Atrazine (Awax 38 SC) @330 g a.i. ha-1 at 15 DAS, and twice foliar applications of 10% Sorghum water extract (Sorgaab) (at 15 and 30 DAS). The experiment was laid out in randomized complete block design (RCBD) under split plot arrangement, comprising of three replications. The treatments with varying sowing dates were randomized in main plots and weed control practices were in subplots. Results showed that the highest plant height (279.51 cm), leaf area (2777.80 cm2), fresh weight of leaves per plant (155.57 g), maximum number of grains per head (3162.0) and grain yield (3419.7 kg·ha-1) were obtained in the treatment combination of 30th June sowing × twice weed hoeing (at 15 and 30 DAS) while, maximum 1000-grain weight (8.45 g) was observed in treatments where weeds were controlled by hoeing (at 15 and 30 DAS). Moreover, cultural weed control practices reduce significantly weed density, fresh and dry Wight of weeds. In sum, it is concluded that to reduce the weed-crop competition and to gain higher productivity of pearl millet, field should be weed free 20 - 45 days after sowing.
文摘The objective of this study is the valorization of downgraded dates from a high Algerian date variety <span style="font-family:Verdana;"><i></i></span><i><i><span style="font-family:Verdana;">Deglet Nour</span></i><i><span style="font-family:Verdana;"></span></i></i><span style="font-family:;" "=""><span style="font-family:Verdana;">, locally called “</span><span style="font-family:Verdana;">h’chef</span><span style="font-family:Verdana;">”. The work starts with the implementation of a food formulation of semi-candied dat</span></span><span style="font-family:Verdana;">es in syrup extracted from dates. This formulation was based on dehydration-impregnation by immersion (D.I.I.). The downgraded dates were cleaned, cut, blanched, and then immersed in date syrups with increasing differential</span><span style="font-family:Verdana;"> concentrations in Brix degrees: 65</span><span style="font-family:Verdana;">°</span><span style="font-family:Verdana;">, 70</span><span style="font-family:Verdana;">°</span><span style="font-family:;" "=""> <span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> 75</span></span><span style="font-family:Verdana;">°</span><span style="font-family:;" "=""><span style="font-family:Verdana;">. The chosen date/syrup immersion ratio is 1:2 (w/w). The obtained semi-candied dates were the subject of physicochemical and sensory analyses. The characterization of the downgraded dates before immersion showed high sugar content with a rate </span><span style="font-family:Verdana;">52.67</span><span style="font-family:Verdana;"> g% g of dry matter and low water content (14%) which favors their use in semi-candied products. The </span><span style="font-family:Verdana;">physico-chemical</span> <span style="font-family:Verdana;">analyses</span><span style="font-family:Verdana;"> results of the three semi-candied dates products show an increase in their final sugar content, </span></span><span style="font-family:Verdana;"><i></i></span><i><i><span style="font-family:Verdana;">i.e.</span></i><i><span style="font-family:Verdana;"></span></i></i><span style="font-family:Verdana;"> from 53.55% to 60.78% and in ashes between 1</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">76 p.cent and 1</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;">94 p.cent. On the other hand, sensory analysis results confirm that the semi-candied dates with a syrup of 75</span><span style="font-family:Verdana;">°</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> Brix present the most appreciated and preferable organoleptic characteristics than the other variables. Finally, following appertisation, the stability test </span><span style="font-family:Verdana;">reveal</span></span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> good microbiological quality (100</span><span style="font-family:Verdana;">°</span><span style="font-family:Verdana;">C for 20 minutes) of the three (3) semi-candied formulations of dates.</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> Thus, the valorization of the “</span><span style="font-family:Verdana;">h’chef</span><span style="font-family:Verdana;">” as sorting gap <i></i></span><i><i><span style="font-family:Verdana;">Deglet Nour</span></i></i></span><span style="font-family:Verdana;"> date allowed its transformation into semi-candied dates, stable, appreciable on the organoleptic side. This new formulation could constitute a value-added product if eventually manufactured on an industrial scale, mainly in southern Algeria.</span>
文摘Colza is a relatively new crop for North Kazakhstan. The increase of colza seeds production is restricted by its cultivation technology imperfection. Empiric model of colza for seeds cultivation is designed, allowing using its maximum potential. It was found out that correct preceding crops selection, optimization of norms and dates of colza seeding provide seeds heavy weight crops, reducing crops production cost and increasing cost efficiency at 62% average.
文摘Agricultural sector in Jordan is facing serious challenges in meeting the<span style="font-family:;" "=""> growing needs of food security because of its low water availability. Maintaining <span>and enhancing agricultural water productivity under such prevailing</span> environmental constraints are hard to achieve. Potatoes water productively in Jordan Valley was modeled using Decision Support System for Agrotechnology Transfer (DSSAT) under six nitrogen applications (0, 60, 80, 100, 120 and 140 kg/ha) and twelve planting dates every two weeks from October 1 to March 15 scenarios. The potatoes yield increased from 0% to 100% nitrogen treatment and then no considerable increase occurred. The potatoes</span><span style="font-family:;" "="">’</span><span style="font-family:;" "=""> crop yield increased from October 1<sup>st</sup> to January 15 and then decreased after which until the last day of planting date. The seasonal cumulative crop evapotranspiration for potatoes about doubled from 0% to 60% nitrogen treatment and then kept increasing gradually until the last treatment. The growing season cumulative crop evapotranspiration for potatoes increased gradually from October 1 to March 1. The water productivity increased from 0% nitrogen treatment to 100% and then decreased. The potatoes</span><span style="font-family:;" "="">’</span><span style="font-family:;" "=""> water productivity increased from October 1 until November 15 and then decreased to the end. From these results, we recommend that 100% of nitrogen requirements should be applied. The best window for potatoes</span><span style="font-family:;" "="">’</span><span style="font-family:;" "=""> planting date is the last two weeks in November.</span>
文摘The production of citric acid from dates of the date palm Phoenix dactilifera was studied using a full factorial design with two design variables;Aspergillus niger strain, and starter juice treatment. Analyses of data have shown that mould type and the interaction between Aspergillus niger strain + juice treatment had significant effect (P ≥ 0.05) on the final total acidity. It was also found that all design variables and the interaction between them had significant effect (P ≥ 0.05) on the final pH and Total Soluble Solids. The highest total acidity expressed as citric acid was achieved with a commercial strain of Aspergillus niger, and filtered and centrifuged date juice.
文摘The Kingdom of Saudi Arabia produces over one million metric tons annually, which returns a 20% of wasted dates annually. Lactic acid and its derivatives are widely used in food, pharmaceutical and textile industries. There has been an increase in lactic acid production because it is used as a raw material to produce polylactic acid, a polymer that is used as a special medical and environmental friendly biodegradable plastic. This study aimed to use wasted dates to produce lactic acid by single culture Lactobacillus casei (ATCC 393), Lactobacillus acidophilus (CICC 6088) and the mixed culture using batch fermentation. The investigation results showed that the maximum concentration of lactic acid for ATCC 393, CICC 6088 and the mixed culture are 87, 84 and 84 g/l respectively. For single CICC 6088 and the mixed culture, the total percentage of glucose and fructose utilized was found to be 100%;76%, respectively, whereas in the case of the single culture ATCC 393, the total percentage of glucose and fructose were 100% and 72%, respectively. With regard to lactic acid concentration, and sugar consumption, the results revealed that the single culture ATCC 393 produced the optimum lactic acid of 87 g/l for 48 hr with initial sugar concentration of 90 g/l.
文摘Big dates abound in Henan Province. Henan big dates are of big size, thick flesh, fine texture and sweet taste. They are renowned at home and abroad, and are an exported dry fruit variety of Henan Province. Big dates have abundant nourishment, their fruit contains protein, sugar, organic acid, various kinds of vitamins and such trace elements as calcium,
基金supported by the National Natural Science Foundation of China(61503211,U1660202)。
文摘The single machine scheduling problem which involves uncertain job due dates is one of the most important issues in the real make-to-order environment. To deal with the uncertainty, this paper establishes a robust optimization model by minimizing the maximum tardiness in the worst case scenario over all jobs. Unlike the traditional stochastic programming model which requires exact distributions, our model only needs the information of due date intervals. The worst case scenario for a given sequence that belongs to a set containing only n scenarios is proved, where n is the number of jobs. Then, the model is simplified and reformulated as an equivalent mixed 0-1 integer linear programming(MILP) problem. To solve the MILP problems efficiently, a heuristic approach is proposed based on a robust dominance rule. The experimental results show that the proposed method has the advantages of robustness and high calculating efficiency, and it is feasible for large-scale problems.
基金Supported by Modern Agricultural Industry Technology System in Henan Province(S2015-04-04)Key Scientific and Technological Project in Henan Province(132102110023)
文摘In order to determine the optimal sowing date of ratoon rice in South Henan's rice-growing areas,this paper performs a comparative analysis of rice growth process,seedling quality and yield of first season rice and ratoon rice under different sowing date treatments. The results show that under climatic conditions( 2014),by using dry seedling cultivation in a small plastic shed,the growth of seedling sown on February21 was affected,while the sowing treatments from March 1 to April 11 can breed normal seedlings,and in this period,the maturity period of first season rice was delayed with prolonged sowing date,and ratoon rice yield declined with prolonged sowing date( total production of rice sown on 11 March reaching a peak). Thus,it is considered that the optimal sowing date of ratoon rice in South Henan's rice-growing areas is mid-March.
文摘Seed shattering is a common problem in early soybean production system (ESPS) in the Midsouth, which mainly uses maturity group (MG) IV soybeans. Many studies have been conducted on the genetics of soybean shattering resistance for individual varieties;however, information on the physiology of soybean shattering pattern under specific environmental conditions, which is often critical to soybean growers, is very limited. Field experiments were conducted at Stoneville MS from 2007 to 2009 to investigate the shattering patterns of 80-132 MG IV soybean varieties each year. Results from 2007 and 2008 indicated that, when April-planted MG IV soybeans matured in mid- to late August, pods of most soybean varieties did not shatter within the first three weeks after maturity (WAM) and there was no significant shattering effect on final yields. However, differences in pod shattering among the varieties became apparent in the fourth WAM. Late-planted MG IV soybeans, which matured in early September, had a low shattering rate and could hold seeds up to 6 WAM before reaching a critical shattering point. Most soybean varieties planted in April 2009 did not show significant pod shattering by the end of the fourth WAM. The critical point of shattering was not reached until 6 - 7 WAM. Relatively lower temperatures and abundant rainfall during the late growing season in 2009 may be the main reasons causing delayed shattering in April-planted MG IV soybeans. Results from the May-planting of 2007 and the April-planting of 2009 indicated that soybeans maturing after September have much less problematic shattering. Different weather patterns, especially temperature and rainfall in each year could be essential factors affecting seed shattering patterns.
基金by the Czech Science Foundation through Grant No.16-11500S(to JiříŽák)by the Charles University through Centre for Geosphere Dynamics(UNCE/SCI/006)project PROGRES Q45.Wealso acknowledge financial support from theMinistry of Culture of the Czech Republic through project DKRVO 2019–2023/1.IV.b(National Museum,00023272).
文摘Dating of fracture-filling calcitewith U-Pb geochronology is becoming a rapidly adopted technique for determining the absolute timing of brittle deformation in the upper crust.Slickenfibre calcite is a desirable target,as it precipitates between individual fault slip displacement events,and provides additional kinematic information.Here we present a case study of slickenfibres formed on the Očkov thrust in the Lower Palaezoic Prague Basin,Bohemian Massif,utilising a combination of petrographic and in situ methods.We demonstrate that slickenfibre external textures can be preserved,whilst internally primary textures are removed by fluid infiltration and recrystallization,leading to variable U and Pb mobilisation.One slickenfibre yielded a date of ca.250 Ma,which we interpret as recording fault slip along the Očkov thrust.Another cross-cutting slickenfibre yielded more scattered U-Pb data,with an imprecise apparent age around ca.95 Ma.This slickenfibre is recrystallised,destroying the primary textures,and exhibits element mobility.The meaning of this younger apparent age is therefore questionable;whereas it likely reflects Cretaceous U and Pb mobility assisted by fluid-flow along the fault plane,it may not reflect a period of fault slip.Our results demonstrate that slickenfibre-based U-Pb dates do not unequivocally relate to fault motion,and that petrographic and elemental analyses are important requirements for interpreting calcite U-Pb data.
文摘Guar is a drought and salt tolerant summer annual legume, which could be a potential alternative crop in the semi-arid Southern High Plains. Increased use of guar gum in oil industries has increased the demand of guar globally. Planting date effects on stand establishment, physiological parameters, and yield formation of guar genotypes were investigated at the New Mexico State University’s Agricultural Science Center at Clovis, NM for two seasons (2014 and 2015). Four guar genotypes (HES 1123, Kinman, Lewis, and Matador) were tested under three planting dates (June 18, July 7, and July 22 in 2014;and June 18, July 6, and July 20 in 2015). Higher temperature and rainfall were recorded under mid-June planting than early-July and late-July plantings. Guar planted under mid-June had better stand establishment as shown by the higher number of plants m<sup>-2</sup>, better physiology as revealed by higher photosynthetic rate (P<sub>n</sub>), transpiration rate (T<sub>r</sub>), leaf area index (LAI), and SPAD values than early-July and late-July plantings. Guar planted under mid-June resulted in taller plants, and therefore, produced higher plant biomass than both of the July plantings. Yield attributing characteristics including clusters plant<sup>-1</sup>, pods plant<sup>-1</sup>, seeds plant<sup>-1</sup>, seed spod<sup>-1</sup>, 1000 seed weight, and harvest index (HI) were highest under mid-June planting followed by the early-July and late-July plantings, respectively. The mid-June planting increased seed yield by 26% and 55% over early-July and late-July (1399 vs. 1111 and 903 kg·ha<sup>-1</sup>) plantings, respectively in 2014;while the same increase in 2015 was 51% and 243% (1308 vs. 868 and 381 kg·ha<sup>-1</sup>), respectively. These results indicate that delaying planting beyond mid-June is detrimental to guar productivity. However, genotypes did not show any significant variation in their performance. Overall, warmer growing conditions and more precipitation under mid-June planting caused better growth and yield formation of guar genotypes.
基金Supported by Major National Research and Development Program(2016YFD0300206-2)。
文摘[Objectives]This study was conducted to clarify the appropriate nitrogen fertilizer amount and transplanting density that should be selected for different transplanting dates.[Methods]The effects of nitrogen fertilizer rate and transplanting density on the traits and yield of late japonica rice in the Jianghuai rice-wheat cropping area under different transplanting dates(transplanting at an appropriate time and delayed transplanting)were studied.[Results]The transplanting date significantly affected the heading,maturity and whole growth period of rice,and when the transplanting date of early-maturing late japonica rice was delayed by 15 d,the growth period was shortened by about 10 d.Nitrogen and density interaction obviously affected the dry matter accumulation and effective tillers of rice,and the dry matter production and effective tiller number of rice treated with B_(1)N_(2) were greater than other treatments.Under the timely transplanting date,the best nitrogen and density combination was 225-300 kg/hm^(2) and 250500 holes/hm^(2),and the nitrogen use efficiency was ideal.It suggests that under the condition of transplanting rice in a timely manner,applying nitrogen fertilizer at an appropriate rate while ensuring a reasonable population density is conducive to the coordination of the number of stems and tillers,the number of grains per panicle,etc.,thereby ensuring the best formation of yield factors in the middle and late stages of rice growth.[Conclusions]This study provides technical support and theoretical reference for reasonable nitrogen and density interaction of rice.