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Analysis on the Temporal and Spatial Change of Grain Production of China in Recent Years and Its Adaptation Strategies 被引量:2
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作者 周巧富 吴绍洪 +2 位作者 戴尔阜 潘韬 陈曦炜 《Agricultural Science & Technology》 CAS 2010年第9期164-167,共4页
A comprehensive analysis on the change of the total grain production and the temporal and spatial change of three main crops production(including wheat,maize and rice),as well as the transfer trace of the center gra... A comprehensive analysis on the change of the total grain production and the temporal and spatial change of three main crops production(including wheat,maize and rice),as well as the transfer trace of the center gravity of grain production in China were analyzed to reveal the overall developing trend of the grain production,explore the reasons and finally propose the corresponding suggestions and strategies to cope with the situation. 展开更多
关键词 Grain production Temporal and spatial change Adaptation strategies
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水泥磨钢球窜仓原因分析及处理
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作者 张美娟 崔继中 李中兴 《科技创新与应用》 2022年第31期123-126,共4页
该文通过对公司水泥1号磨在运行过程中发生的钢球窜仓故障(二仓小球进入到一仓),再结合运行过程中经常发生的饱磨、堵塞篦缝的现象及质量数据的分析判断等,在2022年1月份检修期间,对该故障现象进行现场确认、综合判断,采取剔篦缝、修复... 该文通过对公司水泥1号磨在运行过程中发生的钢球窜仓故障(二仓小球进入到一仓),再结合运行过程中经常发生的饱磨、堵塞篦缝的现象及质量数据的分析判断等,在2022年1月份检修期间,对该故障现象进行现场确认、综合判断,采取剔篦缝、修复中间筛网、更换一仓衬板和调整级配等方案,在2月份试生产过程中运行正常,后期正常生产中,再从操作等方面进行完善调整,保证系统的正常稳定运行。 展开更多
关键词 水泥磨 篦缝堵塞 饱磨 级配 时产
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Uniform asymptotics for finite-time ruin probability in some dependent compound risk models with constant interest rate 被引量:1
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作者 杨洋 刘伟 +1 位作者 林金官 张玉林 《Journal of Southeast University(English Edition)》 EI CAS 2014年第1期118-121,共4页
Consider two dependent renewal risk models with constant interest rate. By using some methods in the risk theory, uniform asymptotics for finite-time ruin probability is derived in a non-compound risk model, where cla... Consider two dependent renewal risk models with constant interest rate. By using some methods in the risk theory, uniform asymptotics for finite-time ruin probability is derived in a non-compound risk model, where claim sizes are upper tail asymptotically independent random variables with dominatedly varying tails, claim inter-arrival times follow the widely lower orthant dependent structure, and the total amount of premiums is a nonnegative stochastic process. Based on the obtained result, using the method of analysis for the tail probability of random sums, a similar result in a more complex and reasonable compound risk model is also obtained, where individual claim sizes are specialized to be extended negatively dependent and accident inter-arrival times are still widely lower orthant dependent, and both the claim sizes and the claim number have dominatedly varying tails. 展开更多
关键词 compound and non-compound risk models finite-time ruin probability dominatedly varying tail uniformasymptotics random sums dependence structure
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Evaluation on Solar Radiation Resource and Photosynthetic and Thermal Potential Productivity in Shandong Province 被引量:6
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作者 王建源 赵玉金 +1 位作者 陈艳春 冯建设 《Agricultural Science & Technology》 CAS 2010年第2期150-154,共5页
To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,... To evaluate scientifically the change of photosynthetic and thermal potential productivity caused by climate variation,based on comparison with mean of previous 30 years(1971-2000),the change of total solar radiation,sunshine hours,photosynthetic active radiation,photosynthetic and thermal potential productivity since 2001 were analyzed through data of radiation,sunshine and temperature in Shandong Province from 1971 to 2007,and the change trend was also tested by Mann-Kendall non-parametric statistical met... 展开更多
关键词 Solar radiation Duration of sunshine Photosynthetic and thermal potential productivity EVALUATION Shandong Province
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Effects of Water and Nitrogen Application on Photosynthetic Characteristics of Flag Leaves and Grain Yield of Wheat 被引量:2
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作者 姚战军 李保利 +1 位作者 陈若英 郭天财 《Agricultural Science & Technology》 CAS 2011年第2期258-261,共4页
[Objective] The aim was to provide a scientific and rational water,nitrogen model for achieving high yield,high quality of wheat and water and fertilizer saving.[Method] Under the field conditions,the effects of irrig... [Objective] The aim was to provide a scientific and rational water,nitrogen model for achieving high yield,high quality of wheat and water and fertilizer saving.[Method] Under the field conditions,the effects of irrigation frequencies and N application times on net photosynthetic rate(Pn),chlorophyll fluorescence parameters of flag leaf and yield of wheat was studied.[Result] The differences on Pn,chlorophyll fluorescence parameters Fv/Fo,Fv/Fm,qP,qN of flag leaves and yield of wheat among different irrigation times had reached a significant level,and the difference between treatment without irrigation and irrigation treatments were relatively large;the difference on Pn,Fv/Fo,Fv/Fm,qP and qN between treatments of basal application of N fertilizer and N application(40%)in returning green stage was not significant,however,the photosynthetic parameters and yield of two treatments were obviously lower than that of N application(40%)in jointing stage or booting stage.[Conclusion] The effects of irrigation frequencies and N application times showed significant interaction effects on photosynthetic characteristics of wheat flag leaves and yield,in which W2N4 treatment combination was best. 展开更多
关键词 WHEAT Irrigation frequency N application time Photosynthetic traits Yield
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Effects of Different Application Times of Tillering Fertilizer on Grain Yield and Population Development of Double-cropping Rice Transplanted by Machine
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作者 商庆银 吕伟生 +5 位作者 曾勇军 黄山 杨秀霞 谭雪明 石庆华 潘晓华 《Agricultural Science & Technology》 CAS 2015年第9期1860-1864,1868,共6页
The application of tillering fertilizer plays an important role in promoting rice tillering and improving rice yield. However, under the condition of mechanical transplanting, the optimal application time of tillering... The application of tillering fertilizer plays an important role in promoting rice tillering and improving rice yield. However, under the condition of mechanical transplanting, the optimal application time of tillering fertilizer is still unclear. In this study, the early rice cultivar Zhongjiazao 17 and late rice cultivar H You 518 were used as materials, and the effects of different application times of tillering fertilizer on yield and population development of double-cropping rice transplanted by machine were investigated. The tillering fertilizer was applied 7(D07), 10(D10) and 13(D13) d after the transplanting, respectively. The results showed that compared with those in the D07 treatment groups, the yield of early rice in the D10 and D13 treatment groups were reduced by 9.4% and 3.8%, respectively, and the yield of late rice in the D10 and D13 treatment groups were reduced by 4.5% and 12.6%,respectively. However, there were no significant differences in rice yield among the treatment groups. The application time of tillering fertilizer showed significant effects on grain number per panicle and seed setting rate of early rice. The grain number per panicle in the D10 treatment group was significantly lower than that in the D07 treatment group, and the seed setting rate of the D13 treatment group was significantly lower than that in the D07 treatment group(P〈0.05). For the late rice, the effect of application time of tillering fertilizer on effective tiller number was most obvious, and the effective tiller number in the D13 treatment group was significantly lower than that in the D07 treatment group(P〈0.05). Compared with those in the D07 treatment group, the effective tiller numbers, leaf area indexes and biomasses in the D10 and D13 treatment groups were all trended to be decreased. Therefore,to improve the quality of population and fulfill the high-yielding potential of double-cropping rice transplanted by machine, the tillering fertilizer should be applied as early as possible after rice seedlings turn green. 展开更多
关键词 Double-cropping rice Mechanical transplanting Tillering fertilizer Application time YIELD Population development
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Spatio-temporal distribution of net primary productivity along the northeast China transect and its response to climatic change 被引量:9
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作者 朱文泉 潘耀忠 +1 位作者 刘鑫 王爱玲 《Journal of Forestry Research》 SCIE CAS CSCD 2006年第2期93-98,共6页
An improved Carnegie Ames Stanford Approach model (CASA model) was used to estimate the net primary productivity (NPP) of the Northeast China Transect (NECT) every month from 1982 to 2000. The spatial-temporal d... An improved Carnegie Ames Stanford Approach model (CASA model) was used to estimate the net primary productivity (NPP) of the Northeast China Transect (NECT) every month from 1982 to 2000. The spatial-temporal distribution of NPP along NECT and its response to climatic change were also analyzed. Results showed that the change tendency of NPP spatial distribution in NECT is quite similar to that of precipitation and their spatial correlation coefficient is up to 0.84 (P 〈 0.01). The inter-annual variation of NPP in NECT is mainly affected by the change of the aestival NPP every year, which accounts for 67.6% of the inter-annual increase in NPP and their spatial correlation coefficient is 0.95 (P 〈 0.01). The NPP in NECT is mainly cumulated between May and September, which accounts for 89.8% of the annual NPP. The NPP in summer (June to August) accounts for 65.9% of the annual NPP and is the lowest in winter. Recent climate changes have enhanced plant growth in NECT. The mean NPP increased 14.3% from 1980s to 1990s. The inter-annual linear trend of NPP is 4.6 gC·m^-2·a^-1, and the relative trend is 1.17%, which owns mainly to the increasing temperature. 展开更多
关键词 China Transect Remote sensing Net primary productivity (NPP) Climatic change Spatio-temporal distribution
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Spatial-Temporal Distribution Characteristics and Limiting Factors of Medium-low Yield Farmland in Tianjin
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作者 潘洁 吕雄杰 +1 位作者 肖辉 陆文龙 《Agricultural Science & Technology》 CAS 2015年第3期578-582,共5页
[Objective] This paper aimed to understand the area change and distribu- tion of medium-low yield farmland, and offered basis to the improvement of mediumlow farmland and its increase of grain production in Tianjin. [... [Objective] This paper aimed to understand the area change and distribu- tion of medium-low yield farmland, and offered basis to the improvement of mediumlow farmland and its increase of grain production in Tianjin. [Method] Based on the statistical date of Tianjin and its relevant counties and districts, the yield standard was set up to classify high-yield, medium-yield and low-yield farmland in Tianjin. The author analyzed area change of medium-low yield farmland in six agricultural counties and districts (including Jixian County, Wuqing District, Baodi District, Ninghe County, Jinghai County and Dagang district of Binghai New Area) from 1980 to 2010. [Result] The results showed that the average yield of grain rose from 2 445 kg/hm^2 in 1980 to 5 130 kg/hm^2 in 2010, increasing 109.82%. The area of mediumlow yield farmland was reduced from 291 250.13 hm^2 in 1985 to 76 489.87 hm^2 in 2010, coming down 74%. In Tianjin, the area of medium-low yield farmland of 2010 accounted for 19% of the total farmland, of which the ratios of medium-low yield farmland of Jinghai County, Jixian County, Dagang district of Binghai New Area, Wuqing District, Baodi District and Ninghe County were 43.12%, 18.59%, 17.23%, 14.01%, 7.05% and 0, respectively. Low soil nutrient content, drought and water shortage, as well as soil salinization were the main yield limiting factors to mediumlow yield farmland in Tianjin in 2010. [Conclusion] The countermeasures to improve the medium-low yield farmland were proposed, involving enhancing the investment of the government, strengthening the construction of water conservancy infrastructure, further improving the soil fertility, as well as saline and alkaline land, optimizing the farming system and planting drought and salt tolerance crops, etc. 展开更多
关键词 Medium-low yield farmland Spatial-temporal distribution Limiting factors TIANJIN
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OPTIMAL PERFORMANCE OF THERMOELECTRIC REFRIGERATION SYSTEM USING ENTROPY GENERATION MINIMIZATION METHOD 被引量:2
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作者 曹业玲 夏文庆 余莉 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第4期339-343,共5页
With the entropy generation minimization (EGM) method, the thermodynamical performance optimization in a thermoelectric refrigeration system is studied. The optimization is affected by the irreversibility of heat tr... With the entropy generation minimization (EGM) method, the thermodynamical performance optimization in a thermoelectric refrigeration system is studied. The optimization is affected by the irreversibility of heat transfer caused by finite temperature differences, the heat leak between external heat reservoirs and the internal dissipation of working fluids. EGM is taken as an objective function for the optimization. The objective function and design parameters are obtained. Optimal performance curves are presented by thermal and electronic parameters. Effects of these parameters on general and optimal performances are investigated. Results are helpful in determining optimal design conditions in real thermoelectric refrigeration systems. 展开更多
关键词 thermoelectric refrigeration system entropy generation minimization finite-time thermodynamics
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有理的谢老汉为何打输了赔偿官司
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作者 王玉信 《今日法坛》 2000年第3期22-23,共2页
关键词 民事诉讼案 诉讼时产 人身损害赔偿
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Effects of Low Temperature on Freezing Injury of Various Winter Wheat Cultivars at Different Sowing Time 被引量:1
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作者 张向前 黄国勤 +2 位作者 黄正来 卞新民 江学海 《Agricultural Science & Technology》 CAS 2012年第11期2332-2337,共6页
Freezing injury is one of the major disasters for the production of winter wheat in the North China Plain, which leads to a significant decrease of wheat yield. This study was conducted to investigate the impact of su... Freezing injury is one of the major disasters for the production of winter wheat in the North China Plain, which leads to a significant decrease of wheat yield. This study was conducted to investigate the impact of subfreezing temperature on freezing injury of various winter wheat cultivars at different sowing time. Three wheat cultivars, including Zhengmai 9023, Wanmai 48 and Wanmai 50, were sowed on 25 September and 5 October, respectively. Plant anatomy was applied to investi- gate the impact of subfreezing temperature on cells of three wheat cultivars, results showed that severe plasmolysis occurred in wheat sowed earlier suddenly encoun- tered subfreezing temperature without cold acclimation, compared with wheat sowed at proper sowing time. The degree of plasmolysis of different cultivars and tissues of wheat had significant differences and showed positive correlation with subfreezing temperature. Wanmai 50 had the highest cold resistance compared with Zhengmai 9023 and Wanmai 48, and there was no significant difference between Zhengmai 9023 and Wanmai 48. This study concluded that wheat cold resistance may be im- proved by adopting proper cultivars and sowing dates. 展开更多
关键词 CELL Cold acclimation PLASMOLYSIS Plant anatomy Subfreezing temper-ature
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Just-in-time learning based integrated MPC-ILC control for batch processes 被引量:4
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作者 Li Jia Wendan Tan 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第8期1713-1720,共8页
Considering the two-dimension(2 D) characteristic and the unknown optimal trajectory problem of the batch processes, an integrated model predictive control-iterative learning control(MPC-ILC) for batch processes is pr... Considering the two-dimension(2 D) characteristic and the unknown optimal trajectory problem of the batch processes, an integrated model predictive control-iterative learning control(MPC-ILC) for batch processes is proposed in this paper. Firstly, the batch-axis information and time-axis information are combined into one quadratic performance index. It implies the integration of ILC and MPC algorithm idea, which leads to superior tracking performance and better robustness against disturbance and uncertainty. To address the problem of the unknown optimal trajectory, both time-varying prediction horizon and end product quality control are employed. Moreover, an integrated 2 D just-in-time learning(JITL) model is used to improve the predictive accuracy. Furthermore, rigorous description and proof are presented to prove the convergence and tracking performance of the proposed MPC-ILC strategy. The simulation results show the effectiveness of the proposed method. 展开更多
关键词 Model predictive control Batch process Just-in-time learning (JITL) model
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Safety Assessment for a Side-by-side Offloading Mooring System 被引量:6
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作者 Liping Sun Qiang He Shangmao Ai 《Journal of Marine Science and Application》 2011年第3期315-320,共6页
In order to improve the safety properties of an offloading system with side-by-side (SBS) mooring in which the FPSO is moored by a yoke system in the field of BZ25-1, it is necessary to analyze those properties. Acc... In order to improve the safety properties of an offloading system with side-by-side (SBS) mooring in which the FPSO is moored by a yoke system in the field of BZ25-1, it is necessary to analyze those properties. According to the experience of similar projects, tow strategies of different offioading arrangements were discussed by using the 3-D radiation/diffraction theory and quasi-static time domain method to assess their respective safety properties. Through the safety assessment analysis of different arrangement comparisons, various ways to improve the safety properties of off'loading systems with side-by-side mooring were verified by analyzing the tension in the mooring lines and the fender deflection. Through comparison it can be concluded that by enlarging the key factors properly, including the size of the fenders and the hawsers as well as the number of hawsers, a better safety performance can be achieved. 展开更多
关键词 hydrodynamic interaction damping lids yoke system quasi static time domain mooring system
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Age and sex specific timing, frequency, and spatial distribution of horseshoe crab spawning in Delaware Bay:Insights from a large-scale radio telemetry array 被引量:4
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作者 David R.SMITH Lorne J.BROUSSEAU +1 位作者 Mary T. MANDT Michael J.MILLARD 《Current Zoology》 SCIE CAS CSCD 北大核心 2010年第5期563-574,共12页
To study horseshoe crab Limulus polyphemus spawning behavior and migration over a large-spatial extent (〉100 km), we arrayed fixed station radio receivers throughout Delaware Bay and deployed radio transmitters and... To study horseshoe crab Limulus polyphemus spawning behavior and migration over a large-spatial extent (〉100 km), we arrayed fixed station radio receivers throughout Delaware Bay and deployed radio transmitters and archival tags on adult horseshoe crabs prior to their spawning season. We tagged and released 160 females and 60 males in 2004 and 217 females in 2005. The array covered approximately 140 km of shoreline. Recapture rates were 〉70% with multi-year recaptures. We categorized adult age by carapace wear. Older females tended to spawn earlier in the season and more frequently than young females, but those tendencies were more apparent in 2004 when spawning overall occurred earlier than in 2005 when spawning was delayed possibly due to decreased water temperatures. Timing of initial spawning within a year was correlated with water temperature. After adjusting for day of first spring tide, the day of In'st spawning was 4 days earlier for every 1 degree (℃) rise in mean daily water temperature in May. Seventy nine % of spawning occurred during nighttime high tides. Fifty five % of spawning occurred within 3 d of a spring tide, which was slightly higher than the 47% expected if spawning was uniformly distributed regardless of tidal cycle. Within the same spawning season, males and females were observed spawning or intertidally resting at more than one beach separated by 〉5 kin. Between years, most (77%) did not return to spawn at the same beach. Probability of stranding was strongly age dependent for males and females with older adults experiencing higher stranding rates. Horseshoe crabs staging in the shallow waters east of the channel spawned exclusively along the eastern (N J) shoreline, but those staging west of the channel spawned throughout the bay. Overall, several insights emerged from the use of radio telemetry, which advances our understanding of horseshoe crab ecology and will be useful in conserving the Delaware Bay horseshoe crab population and habitats 展开更多
关键词 Spawning behavior Marine arthropod Xiphosurid Limulus polyphemus Delaware Bay Radio telemetry
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Spectral Characterization of Colored Dissolved Organic Matter for Productive Inland Waters and Its Source Analysis 被引量:5
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作者 SONG Kaishan LI Lin +3 位作者 Lenore TEDESCO Nicolas CLERCIN LI Linhai SHI Kun 《Chinese Geographical Science》 SCIE CSCD 2015年第3期295-308,共14页
This study examined the spatiotemporal dynamics of colored dissolved organic matter (CDOM) and spectral slope (S), and further to analyze its sources in three productive water supplies (Eagle Creek, Geist and Mor... This study examined the spatiotemporal dynamics of colored dissolved organic matter (CDOM) and spectral slope (S), and further to analyze its sources in three productive water supplies (Eagle Creek, Geist and Morse reservoirs) from Indiana, USA. The re- sults showed that he absorption coefficient aCDOM(440) ranged from 0.37 m-1 to 3.93 m-1 with an average of 1.89 ± 0.76 m-1 (±SD) for the aggregated dataset, and S varied from 0.0048 nm -1 to 0.0239 nm-1 with an average of 0.0108 ±0.0040 nmI. A significant relation- ship between S and aCDOM(440) can be fitted with a power equation (S = 0.013 × aCDOM(440)-0.42, R2 = 0.612), excluding data from Geist Reservoir during high flow (12 April 2010) and the Morse Reservoir on 25 June 2010 due to a T-storm achieves even higher determina- tion coefficient (R2 = 0.842). Correlation analysis indicated that aCDOM(440) has strong association with inorganic suspended matter (ISM) concentration (0.231 〈 R2 〈 0.786) for each of the field surveys, and this trend followed the aggregated datasets (R2 = 0.447, p 〈 0.001). In contrast, chlorophyll-a was only correlated with aCDOM(440) in summer and autumn (0.081 〈 R2 〈 0.763), indicating that CDOM is mainly from terrigenous sources in early spring and that phytoplankton contributed during the algal blooming season. The S value was used to characterize CDOM origin. The results indicate that the CDOM source is mainly controlled by hydrological varia- tions, while phytoplankton originated organic matter also closely linked with CDOM dynamics in three productive reservoirs. 展开更多
关键词 absorption coefficient colored dissolved organic matter (CDOM) CHLOROPHYLL-A spectral slope (S) inorganic suspendedmatter (ISM)
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Production of microbial oils co-fermented by Trichoderma.koningii and Trichosporon cutaneum with Daqu distiller's grains 被引量:2
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作者 李新社 陆步诗 唐伟 《Journal of Central South University》 SCIE EI CAS 2011年第5期1738-1743,共6页
Abstract: Daqu distiller's grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The singl... Abstract: Daqu distiller's grains were co-fermented as raw materials by Trichoderma.koningii and Trichosporon cutaneum to produce microbial oils, which can provide raw materials for bio-diesel development. The single factor tests were used to investigate the effects of ratio of strains, inoculum size, culture temperature and culture time on the production of microbial oils. The best processing conditions were obtained by orthogonal test through measuring the content of microbial oils in product. The result shows that the microbial oils content of the co-fermented product under the ratio of Trichoderma.koningii to Trichosporon cutaneum of 1:1, the inoculum size of strains of 11% at 28 ℃ for 6 d is 7.15 g/L. It is shown that the production of microbial oils co-fermented by Trichoderma.koningii and Trichosporon cutaneum with Daqu distiller's grains is possible. The research provides a new idea for the reuse of Daqu distiller's grains and also provides a new way for the development of microbial oils. 展开更多
关键词 Daqu distiller's grains Trichoderma.koningii Trichosporon cutaneum CO-FERMENTATION microbial oils
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Inventory control model based on external and interior reverse logistics 被引量:1
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作者 董景峰 王刚 +1 位作者 吕民 高国安 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第5期717-722,共6页
To improve the inventory control strategy for enterprise and optimize inventory control parameters of existing external and interior reverse logistics, a multi-resource inventory control model is proposed to better si... To improve the inventory control strategy for enterprise and optimize inventory control parameters of existing external and interior reverse logistics, a multi-resource inventory control model is proposed to better simulate the logistics fact, which is aimed at periodic inventory checking and pull mode of inventory control strategy, based on the return product arrival time obeying Poisson distribution, the return product employing lotsize process and the nonzero lead time of manufaeturinge/remanufacturing. The rational cost function with multiple constraints is employed to describe the inventory model. The genetic algorithm is employed to solve the inventory cost function to obtain the optimal solution of inventory checking periods, safe inventory point, product lot-sizes and process lot-sizes of return product. An example is presented to prove the feasibility and validity of the proposed method. Moreover, the influence of manufacturing/remanufacturing lead time and reuse rate of return production on the inventory control strategy of enterprise is analyzed. 展开更多
关键词 reverse logistics inventory control periodic checking lead time
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Lipid Oxidation and Histamine Production in Atlantic Mackerel(Scomber scombrus) Versus Time and Mode of Conservation 被引量:1
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作者 Hanane Oucif Smail Ali-Mehidi Sidi-Mohamed El-Amine Abi-Ayad 《Journal of Life Sciences》 2012年第7期713-720,共8页
Lipids oxidation, histamine production and quality loss were studied according to storage time and temperature (ambient temperature (Tamb) 26 ℃, 4 ℃ and -18℃) in Atlantic mackerel (Scomber scombrus). Muscle p... Lipids oxidation, histamine production and quality loss were studied according to storage time and temperature (ambient temperature (Tamb) 26 ℃, 4 ℃ and -18℃) in Atlantic mackerel (Scomber scombrus). Muscle pH, hydrolysis of phospholipids, content of primary (hydroperoxides), secondary lipid oxidation products (TBARS) and histamine were determined and compared with a sensory assessment. Atlantic mackerel is sensory acceptable, less than 24 hours at Tamb, for up to 3 days at 4 ℃ and 3 months at-18 ℃. Evolution of biochemical parameters with storage time and temperature showed significant differences (P 〈 0.05). Muscle pH increased from 5.99 to 6.13 at Tamb, to 6.23 at 4 ℃ and to 6.04 at -18 ℃. The highest content of TBARS is associated with a decrease in phospholipids and hydroperoxides contents and highest levels of sensory alteration. Histamine content exceeded the limit recommended by the Trade Algerian Ministry (10 mg/100g), after 24 hours at Tamb, 5 days of storage at 4 ~C only. Therefore, freezing storage has a preserving effect on lipid damage and histamine production and seems the best means of storage; if these species are not consumed during the two days following capture. Moreover, monitoring histamine production is more useful as sanitary index rather than spoilage parameter and the strategy used for measuring kinetic of lipid oxidation appear pertinent for determining the degree of oxidation. 展开更多
关键词 CONSERVATION HISTAMINE HYDROPEROXIDES PHOSPHOLIPIDS temperature TBARS Scomber scombrus.
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Biogas by two-stage microbial anaerobic and semi-continuous digestion of Chinese cabbage waste 被引量:1
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作者 Xiaoying Dong Lijie Shao +3 位作者 Yan Wang Wei Kou Yanxin Cao Dalei Zhang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第5期847-852,共6页
Anaerobic digestion of Chinese cabbage waste was investigated through a pilot-scale two-stage digester at a mesophilic temperature of 37 ℃. In the acidification digester, the main product was acetic acid, with the ma... Anaerobic digestion of Chinese cabbage waste was investigated through a pilot-scale two-stage digester at a mesophilic temperature of 37 ℃. In the acidification digester, the main product was acetic acid, with the maxi- mum concentration of 4289 mg·L^-1 on the fourth day, accounting for 50.32% of total volatile fatty acids. The oxidation reduction potential (ORP) and NH^+-N level decreased gradually with hydraulic retention time (HRT) of acidification. In the second digestion phase, the maximum methanogenic bacterial concentration reached 9.6 × 10^10ml^-1 at the organic loading rate (OLR) of 3.5-4 kg VS·m^-3, with corresponding HRT of 12-16 days. Accordingly, the optimal biogas production was 0.62 m^3· (kg VS)^-1, with methane content of 65%-68%;. ORP and NH4^+-N levels in the methanizer remained between -500 and -560 mV and 2000-4500mg· L^-1, respec- tively. Methanococcus and Methanosarcina served as the main methanogens in the anaerobic digester. 展开更多
关键词 Anaerobic digestion Semi-continuous Two-stage Biogas Chinese cabbage waste Microbial ecology
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Formation and removal of active oxygen species for the non-catalytic CO oxidation on Au/TiO_2 catalysts
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作者 Daniel Widmann R.Jurgen Behm 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2016年第10期1684-1693,共10页
Applying quantitative temporal analysis of products reactor measurements, we studied the reactive removal of active oxygen present on Au/TiO2 catalysts after calcination at elevated temperatures (400 &#176;C) by CO... Applying quantitative temporal analysis of products reactor measurements, we studied the reactive removal of active oxygen present on Au/TiO2 catalysts after calcination at elevated temperatures (400 &#176;C) by CO pulses and its replenishment by O2 pulses at 80 &#176;C, focusing on the nature of the active oxygen species. In contrast to previous studies, which mainly focused on and clarified the nature of the active oxygen species for the catalytic CO oxidation, which is reversibly formed and replenished under typical reaction conditions, this study demonstrates that directly after calcina‐tion an additional oxygen species is present. This species is also active for the CO oxidation, but it is not or only very little formed under typical reaction conditions. Implications of these results on the mechanistic understanding of the CO oxidation on Au/TiO2, in particular on the role of different active oxygen species, will be discussed. 展开更多
关键词 Titanium dioxide Gold catalysis Carbon monoxide oxidation Reaction mechanism Active oxygen Temporal analysis of products
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