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Effect of Sodium Ion Concentration on Hydrogen Production from Sucrose by Anaerobic Hydrogen-producing Granular Sludge 被引量:11
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作者 郝小龙 周明华 +2 位作者 俞汉青 沈琴琴 雷乐成 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2006年第4期511-517,共7页
This work evaluated the effects of sodium ion concentration, ranging from 0 to 16000mg·L^-1(Na^+), on the conversion of sucrose to hydrogen by a high-activity anaerobic hydrogen-producing granular sludge. At ... This work evaluated the effects of sodium ion concentration, ranging from 0 to 16000mg·L^-1(Na^+), on the conversion of sucrose to hydrogen by a high-activity anaerobic hydrogen-producing granular sludge. At the optimum sodium ion concentration [1000-2000mg·L^-1(Na^+)] for hydrogen production at 37℃, the maximum sucrose degradation rate, the specific hydrogen production yield and the specific hydrogen production rate were 393.6-413.1mg·L^-1.h^-1, 28.04-28.97ml·g^-1, 7.52-7.83ml·g^-1.h^-1, respectively. The specific production yields of propionate, butyrate and valerate decreased with increasing sodium ion concentration, whereas the specific acetate production yield increased, meanwhile the specific production yields of ethanol and caproate were less than 55.3 and 12.6mg·g^-1, respectively. The hybrid fermentation composition gradually developed from acetate, propionate and butyrate to acetate with the increase in sodium ion concentration. 展开更多
关键词 sodium ion concentration anaerobic fermentation hydrogen production SUCROSE volatile fatty acids up-flow anaerobic sludge blanket (UASB) reactor
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Biogenic silica concentration as a marine primary productivity proxy in the Holsteinsborg Dyb, West Greenland, during the last millennium 被引量:1
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作者 Longbin Sha Dongling Li +5 位作者 Yanguang Liu Bin Wu Yanni Wu Karen Luise Knudsen Zhongqiao Li Hao Xu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2020年第9期78-85,共8页
We analyzed the biogenic silica(BSi)content and produced a diatom-based summer sea-surface temperature(SST)reconstruction for sediment core GC4 from the Holsteinsborg Dyb,West Greenland.Our aim was to reconstruct mari... We analyzed the biogenic silica(BSi)content and produced a diatom-based summer sea-surface temperature(SST)reconstruction for sediment core GC4 from the Holsteinsborg Dyb,West Greenland.Our aim was to reconstruct marine productivity and climatic fluctuations during the last millennium.Increased BSi content and diatom abundance suggest relatively high marine productively during the interval of AD 1000–1400,corresponding in time to the Medieval Warm Period(MWP).The summer SST reconstruction indicates relatively warm conditions during AD 900–1100,followed by cooling after AD 1100.An extended cooling period during AD 1400–1900 is characterized by prolonged low in reconstructed SST and high sea-ice concentration.The BSi values fluctuated during this period,suggesting varying marine productivity during the Little Ice Age(LIA).There is no significant correlation between the BSi content and SST during the last millennium,suggesting that the summer SST has little influence on marine productively in the Holsteinsborg Dyb.A good correspondence between the BSi content and the element Ti counts in core GC4 suggests that silicate-rich meltwater from the Greenland ice sheet was likely responsible for changes in marine productively in the Holsteinsborg Dyb. 展开更多
关键词 biogenic silica marine productivity sea-surface temperature sea-ice concentration
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Effect of initial substrate and biomass concentrations on anaerobic fermentative hydrogen production in batch reactors
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作者 昌盛 李建政 +1 位作者 刘枫 王淑静 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2011年第6期11-15,共5页
The effects of initial substrate (5-60 g /L) and biomass concentration (0.5-3 g /L) on fermentative hydrogen production by mixed cultures were investigated in batch tests using glucose as substrate.The experimental re... The effects of initial substrate (5-60 g /L) and biomass concentration (0.5-3 g /L) on fermentative hydrogen production by mixed cultures were investigated in batch tests using glucose as substrate.The experimental results showed that the hydrogen production increases as the initial substrate concentration increases from 0 to 25 g /L.It indicated that the shift in the metabolic pathway or in the composition of the bacterial flora occurs.The maximum hydrogen yield of 1.78 mol /mol-glucose is obtained at the substrate concentration of 15 g /L.This study also shows that initial biomass concentration affects the hydrogen yield as the cumulative hydrogen production has been increased with the increase of initial cell concentration up to 1.5 g /L and reached the highest level.The maximum hydrogen yield is obtained at the cell concentration of 1.5 g /L.It indicated that the optimum biomass /substrate ratio,maximizing the hydrogen yield and the hydrogen production rate,is determined to be 0.1 g biomass /g glucose. 展开更多
关键词 fermentative hydrogen production hydrogen yield substrate concentration biomass concentration modified Gompertz model
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Effect of Sodium Ion Concentration on Hydrogen Production from Sucrose by Anaerobic Hydrogen-producing Granular Sludge
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作者 郝小龙 周明华 +2 位作者 俞汉青 沈琴琴 雷乐成 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2006年第4X期511-517,共7页
This work evaluated the effects of sodium ion concentration, ranging from 0 to 16000mg·L-1(Na+), on the conversion of sucrose to hydrogen by a high-activity anaerobic hydrogen-producing granular sludge. At the op... This work evaluated the effects of sodium ion concentration, ranging from 0 to 16000mg·L-1(Na+), on the conversion of sucrose to hydrogen by a high-activity anaerobic hydrogen-producing granular sludge. At the opti- mum sodium ion concentration [1000—2000mg·L-1(Na+)] for hydrogen production at 37℃, the maximum sucrose degradation rate, the specific hydrogen production yield and the specific hydrogen production rate were 393.6— 413.1mg·L-1·h-1, 28.04—28.97ml·g-1, 7.52—7.83ml·g-1·h-1, respectively. The specific production yields of propionate, butyrate and valerate decreased with increasing sodium ion concentration, whereas the specific acetate production yield increased, meanwhile the specific production yields of ethanol and caproate were less than 55.3 and 12.6mg·g-1, respectively. The hybrid fermentation composition gradually developed from acetate, propionate and butyrate to acetate with the increase in sodium ion concentration. 展开更多
关键词 sodium ion concentration anaerobic fermentation hydrogen production SUCROSE volatile fatty acids up-flow anaerobic sludge blanket (UASB) reactor
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Concentration of mixed acid by electrodialysis for the intensification of absorption process in acrylic acid production
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作者 Hanxiao Du Lixin Xie +1 位作者 Jie Liu Shichang Xu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第8期10-18,共9页
The absorption process in acrylic acid production was water-intensive.The concentration of acrylic acid before distillation process was low,which induced to large amount of wastewater and enormous energy consumption.I... The absorption process in acrylic acid production was water-intensive.The concentration of acrylic acid before distillation process was low,which induced to large amount of wastewater and enormous energy consumption.In this work,a new method was proposed to concentrate the side stream of absorption column and thus increase the concentration in bottom product by electrodialysis.The influence of operating conditions on concentration rate and specific energy consumption were investigated by a laboratory-scale device.When the voltage drop was 1 V·cP^(-1)(1 cP=10^(-3) Pa·s),flow velocity was 3 cm·s^(-1) and the temperature was 35℃,the concentration rates of acrylic acid and acetic acid could be 203.3%and 156.6%in the continual-ED process.Based on the experimental data,the absorption process combined with ED was simulated,in which the diluted solution from ED process was used as spray water and the concentrated solution was feed back to the absorption column.The results shown that the flow rate of spray water was decreased by 37.1%,and the acrylic acid concentration at the bottom of the tower was increased by 4.56%.The ions exchange membranes before and after use 1200 h were tested by membrane surface morphology(scanning electron microscope),membrane chemical groups(infrared spectra),ion exchange capacity,and membrane area resistance,which indicated the membrane were stable in the acid system.This method provides new method for energy conservation and emission reduction in the traditional chemical industry. 展开更多
关键词 Acrylic acid production ELECTRODIALYSIS concentration Membranes ABSORPTION Mixtures
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Influence of water vapor concentration on discharge dynamics and reaction products of underwater discharge within a He/H2O-filled bubble at atmospheric pressure
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作者 Shengran MA Wen YAN +3 位作者 Zhenhua BI Hongzhi WANG Ying SONG Dezhen WANG 《Plasma Science and Technology》 SCIE EI CAS CSCD 2020年第8期129-136,共8页
In this study,a two-dimensional fluid model is proposed to simulate the underwater discharge in a He/H2O-filled bubble at atmospheric pressure.The molar fraction of water vapor is varied in the range of 0.01%-1%to inv... In this study,a two-dimensional fluid model is proposed to simulate the underwater discharge in a He/H2O-filled bubble at atmospheric pressure.The molar fraction of water vapor is varied in the range of 0.01%-1%to investigate the dependence of discharge dynamics and reaction products on water vapor concentration(WVC).The numerical results show that most properties of the discharge sensitively depend on the WVC.The increase of WVC leads to an increase in the electron density and discharge propagation velocity,which is attributed to Penning ionization between He*and H2O.The main positive ion switches from He+to H2O+,while the WVC increases from 0.01%to 1%.The dominant reactive oxygen species is OH,whose peak density is about two orders of magnitude higher than that of O.Besides,the densities of OH and O radicals increase with the increasing WVC.It is shown that the formation mechanism of O radicals is significantly affected by the WVC.The dominant reaction creating O radicals changes from the charge exchange between He2+and H2O to the electron impact dissociation of H2O as the WVC increases from 0.01%to 1%.This study is helpful for better understanding the application of non-thermal plasmas discharges in water,such as biomedical,environmental engineering. 展开更多
关键词 UNDERWATER discharge water vapor concentration production and loss mechanisms fluid simulation
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The Influence of Selection for Plasma very Low Density Lipoprotein Concentration upon Production Performance in Layer Type Chickens
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作者 Li Hui, Yang Shan (Northeast Agricultural University, Harbin, 150030 PRC) 《Journal of Northeast Agricultural University(English Edition)》 CAS 1997年第2期95-102,共8页
The chickens studied were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasima very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experi... The chickens studied were from a pure line of brown shell egg-type (YAFA) female grandparents of 17-week-old. Plasima very low density lipoprotein (VLDL) concentration was measured with turbidimetric assay. The experiment results showed that the phenotypic correlations between 29-week or 50-week plasma VLDL concentration and egg production (EP) were positive in the early stage of laying period, but those in the latter stage were negative. Selection for low plasma VLDL concentration will decrease the EP in the early stage of laying period but increase the one in the latter stage. There was a significant negative phenotypic correlation between the age at first egg (AFE) and 18-week body weight (BW). The phenotypic correlation between 29-week plasma VLDL concentration and the AFE was negative. AFE was influenced by BW and body fatness as well. There was significant positive phenotypic correlation between plasima VLDL concentration and body weights (BWs) at the same stage in laying period and the phenotypic correlation was also positive between 29-week plasma VLDL concentration and the BW at middle stage of laying period, indicating that selection for low plasma VLDL concentration would reduce BWs at various stages to different degree. 展开更多
关键词 layer type chicken plasma VLDL concentration production performance
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Modelling of heat transfer for progressive freeze concentration process by spiral finned crystallizer
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作者 Shafirah Samsuri Nurul Aini Amran Mazura Jusoh 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第5期970-975,共6页
This study presents a novel design for a spiral finned crystallizer which is the primary element of progressive freeze concentration(PFC) system, which simplifies the setup of the conventional system. After the crysta... This study presents a novel design for a spiral finned crystallizer which is the primary element of progressive freeze concentration(PFC) system, which simplifies the setup of the conventional system. After the crystallizer has been designed, the research experiments have been conducted and evaluated through a thorough analysis of its performance by developing a mathematical model that can be used to predict the productivity of ice crystal at a range of coolant temperature. The model is developed based on the basic heat transfer equation, and by considering the solution's and the coolant's convective heat transfer coefficient(h) under the forced flow condition.The model's accuracy is verified by making comparison between the ice crystal mass' experimental value and the values predicted by the model. Consequently, the study found that the model helps in enhancing the PFC system. 展开更多
关键词 Heat transfer model Progressive freeze concentration Ice crystal Spiral finned crystallizer Ice production
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Effects of Crude Protein Level of Concentrate Supplement on Production Performance and Serum Biochemical Parameters in Post-fattening Hainan Yellow Cattle
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作者 Liu Quanwei Wei Limin +6 位作者 Zheng Xinli Sun Ruiping Chao Zhe Liu Hailong Huang Lili Fu Liang Wang Feng 《Animal Husbandry and Feed Science》 CAS 2020年第1期31-35,共5页
[Objective]The paper was to investigate the effects of crude protein level of concentrate supplement on production performance and serum biochemical parameters of post-fattening Hainan Yellow Cattle.[Method]Twelve Hai... [Objective]The paper was to investigate the effects of crude protein level of concentrate supplement on production performance and serum biochemical parameters of post-fattening Hainan Yellow Cattle.[Method]Twelve Hainan Yellow Cattles with the same genetic backgrounds and similar initial weight of(168.13±0.55)kg were randomly divided into three treatments.Cattle were fed with concentrate supplement containing different levels of crude protein.The trial lasted 60 d.[Result]The daily gain of 17.56%crude protein group was significantly higher than those of 15.55%and 13.56%crude protein groups(P<0.05),and the gross profit of 17.56%crude protein group was markedly higher than that of 13.56%crude protein group(P<0.05),but the feed gain ratio of 17.56%crude protein group was significantly lower than that of 13.56%crude protein group(P<0.05).Compared with 15.55%and 13.56%crude protein groups,the serum total protein content markedly increased(P<0.05),but the urea nitrogen level significantly decreased(P<0.05).[Conclusion]When crude protein level of concentrate supplement was 17.56%,post-fattening Hainan Yellow Cattle could obtain better production performance. 展开更多
关键词 Protein level concentrATE supplement HAINAN YELLOW CATTLE production performance SERUM biochemical parameters
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Analysis of Raw Materials Components of Dry Composite Mixes for Production Food Concentrates
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作者 Tatyana Samuylenko 《Journal of Food Science and Engineering》 2019年第9期355-361,共7页
Background:The simplest and most convenient food technology is the using of dry composite mixtures.They have a lot of advantages.Dry composite mixtures,which would completely be the basis for the production of persona... Background:The simplest and most convenient food technology is the using of dry composite mixtures.They have a lot of advantages.Dry composite mixtures,which would completely be the basis for the production of personalized food concentrates,are not represented.The development of such dry composite mixtures is actual and of scientific and practical interest.The purpose of this research is the selection and justification of local import-substituting raw materials components for dry composite mixtures used as the basis for the production of food concentrates.As the objects of research,the raw materials components of the starch,fruit and vegetable,industry were selected.The work uses currently accepted standard research methods for organoleptic and physic-chemical parameters of raw materials components.The research was carried out within of the project“Theoretical Substantiation of Production Technology and the Development of Import-Substituting Food Products of Functional Purpose Based on Dry Composite Mixtures”,funded by the Belarusian Republican Foundation for Basic Research.Based on the researches,it was found out that in the composition of dry composite mixtures for the production of food concentrates it is expedient to use the following raw materials:potato starch,extruded corn starch,dried carrots,dried beets,dried topinambur and dried apples in chopped form. 展开更多
关键词 Dry composite mixtures food concentrates raw materials components starches processed products of the fruit and vegetable industry
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Effect of Pelleted Total Mixed Ration with Different Concentrate-roughage Ratios on Production Performance and Serum Biochemical Parameters of Fattening Hainan Black Goats
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作者 Liu Quanwei Wang Feng +5 位作者 Wei Limin Tan Shuyi Sun Ruiping Huang Lili Xing Manping Zheng Xinli 《Animal Husbandry and Feed Science》 CAS 2019年第1期4-8,共5页
[Objective] This paper was to study effects of pelleted total mixed ration with different concentrate-roughage ratios on production performance and serum biochemical parameters of fattening Hainan black goats.[Method]... [Objective] This paper was to study effects of pelleted total mixed ration with different concentrate-roughage ratios on production performance and serum biochemical parameters of fattening Hainan black goats.[Method] Thirty-six fattening Hainan black goats with the same genetic background and similar initial weight of(14.08±0.13) kg were randomly assigned into three treatments. Goats were fed with Juncao + concentrate(control group), pelleted total mixed ration I(concentrate: roughage 50 ∶50, group Ⅰ) and Ⅱ(concentrate: roughage 45∶55, group Ⅱ), respectively. The test lasted 45 d.[Result] The final weight, daily gain and feed intake of rams in experimental group Ⅰ were significantly higher than those of control group and experimental group Ⅱ(P<0.05);the final weight and daily gain of rams in experimental group Ⅰ were also markedly higher than those of experimental group Ⅱ(P<0.05);the feed/gain of rams in experimental group Ⅰ was significantly lower than those in control group and experimental group Ⅱ(P<0.05). The feed gain cost of rams in experimental group Ⅰ was markedly lower than that in experimental group Ⅱ( P<0.05), but was significantly higher than that in experimental group Ⅰ(P<0.05);the gross profit of rams in experimental group Ⅰ was significantly higher than those in control group and experimental group Ⅱ(P<0.05). Compared with control group and experimental group Ⅱ, the serum total protein and glucose lev-els in experimental group Ⅱ increased significantly(P<0.05), but the urea nitrogen content reduced(P>0.05).[Conclusion] When the concentrateroughage ratio of pelleted total mixed ration was 50∶50, the fattening effect of Hainan black goat was better, and the serum total protein and glucose levels were evidently improved. 展开更多
关键词 FATTENING HAINAN black GOAT Pelleted total mixed ration concentrate-roughage ratio production performance SERUM BIOCHEMICAL parameters
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孔内空气间隔对有/无金属罩聚能装药定向侵彻效果的影响
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作者 蔡静静 徐轩 +1 位作者 陈占扬 杨军 《含能材料》 EI CAS CSCD 北大核心 2024年第7期726-736,共11页
为了探究孔内径向空气间隔对有/无金属罩聚能装药定向侵彻效果和炸药爆轰能量传递过程的影响,采用ANSYS/LS-DYNA软件,开展孔内装药空气间隔为6,8,10,12,14 cm时的数值模拟研究,分析了聚能装药中有药型罩形成EFP和无药型罩形成聚能气流... 为了探究孔内径向空气间隔对有/无金属罩聚能装药定向侵彻效果和炸药爆轰能量传递过程的影响,采用ANSYS/LS-DYNA软件,开展孔内装药空气间隔为6,8,10,12,14 cm时的数值模拟研究,分析了聚能装药中有药型罩形成EFP和无药型罩形成聚能气流的能量集中释放过程,以及对孔壁的定向侵彻深度。结果表明空气间隔小于10 cm时,聚能气流对孔壁的侵彻深度相对于EFP平均侵深分别提高了53%(6 cm)和29%(8 cm)。空气间隔大于10 cm时,EFP平均侵彻深度相比于聚能气流均增加了26%(12 cm和14 cm)。计算聚能轴线上EFP和聚能气流单位面积通过孔壁的动能,发现空气间隔较小时,聚能气流在空气中衰减耗散的能量小于EFP塑性变形耗能,此时聚能气流对孔壁的侵彻效果较优;空气间隔较大时,爆轰产物空间膨胀造成聚能气流轴线处的密度和动能显著降低,而EFP由于具有高密度和不可压缩性,能量分散小,动能衰减缓慢,此时EFP对孔壁的侵彻效果优于聚能气流。 展开更多
关键词 聚能装药 空气间隔 聚能气流 爆炸能量 定向控制
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铅冶炼渣基生态胶凝材料的研发及重金属固化
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作者 刘文欢 胡静 +4 位作者 赵忠忠 杜任豪 万永峰 雷繁 李辉 《材料导报》 EI CAS CSCD 北大核心 2024年第6期139-146,共8页
铅冶炼渣(LSS)是一种含有重金属(Cr、Ni、Cu、Zn、As和Pb)的危险废物,其不当处置会对生态系统造成不可挽回的危害。本工作采用化灰渣(LAS)、水氯镁石(BF)、矿粉(SP)及适量水泥(CM)协同激发铅冶炼渣制备生态胶凝材料。通过正交试验得到... 铅冶炼渣(LSS)是一种含有重金属(Cr、Ni、Cu、Zn、As和Pb)的危险废物,其不当处置会对生态系统造成不可挽回的危害。本工作采用化灰渣(LAS)、水氯镁石(BF)、矿粉(SP)及适量水泥(CM)协同激发铅冶炼渣制备生态胶凝材料。通过正交试验得到胶凝材料的最优配比,阐述了不同因素对生态胶凝材料抗压强度的影响;采用XRD、SEM、FTIR、硫酸和硝酸法等方法分析了胶凝材料水化产物的特性及重金属浸出规律。研究结果表明:当铅冶炼渣和水泥的质量比为3∶1,化灰渣、水氯镁石、矿粉的外掺量分别为铅冶炼渣和水泥质量总量的20%、10%、10%时,制备出的生态胶凝材料抗压强度最优,28 d抗压强度达到40.9 MPa,且矿粉掺量为影响其抗压强度的第一要素。微观分析表明,胶凝材料的水化产物主要为弗里德尔盐、方解石、C-S-H和C-A-S-H,它们相互连接形成致密的空间网络结构,这不但有助于提高胶凝材料的力学性能,还能实现对重金属元素的物理固封和离子交换吸附固化。胶凝材料对主要重金属的胶结固化率大于83%,重金属浸出液浓度符合生活饮用水卫生标准(GB5749-2006)的要求。 展开更多
关键词 铅冶炼渣 生态胶凝材料 抗压强度 水化产物 重金属 浸出液浓度
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冠脉支架集中采购政策对医用耗材产业影响的实证研究
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作者 刘欣 王成 +1 位作者 董继伟 骆希青 《中国医疗管理科学》 2024年第2期12-18,共7页
目的以北京市某三级甲等医院执行国家冠脉支架集中采购政策前后产品使用情况的真实数据,结合上市中标企业公开年报信息,分析集中采购政策对医用耗材产业的影响。方法2019年1月至2020年12月为集中采购政策执行前,2021年1月至2022年12月... 目的以北京市某三级甲等医院执行国家冠脉支架集中采购政策前后产品使用情况的真实数据,结合上市中标企业公开年报信息,分析集中采购政策对医用耗材产业的影响。方法2019年1月至2020年12月为集中采购政策执行前,2021年1月至2022年12月为集中采购政策执行后,利用赫芬达尔—赫希曼指数(Herfindahl-Hirschman Index,HHI)分析集中采购政策对市场集中度的影响;对比国产和进口企业冠脉支架产品使用量占有率及价格均值变化,比较上市中标企业在心血管介入产品线的产品范围、企业营业收入及研发费用;以企业类别、企业类型及价格降幅为影响因素,利用灰色关联分析确定影响产品使用量占有率的最相关因素。结果实施冠脉支架集中采购提高了市场集中度;国内和进口冠脉支架产品价格均值在集中采购前有显著差异(P<0.01),集中采购后无差异(P>0.05),进口企业冠脉支架使用量增幅高,心血管介入产品种类丰富;企业类型是影响使用量占有率的最相关因素。结论加强产品研发、丰富产品线、拓宽业务领域可以提高企业竞争力;构建多层次的医用耗材产业融资制度,为产业提供必要的资金支持;深化国际合作,实行全球化经营,帮助企业分散风险,促进产业可持续发展。 展开更多
关键词 冠脉支架 集中采购 市场集中度 灰色关联分析 产品创新
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反刍动物日粮精粗比和非纤维性碳水化合物/中性洗涤纤维的研究进展 被引量:1
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作者 郭训雨 孙磊 +1 位作者 董晓玲 张微 《中国畜牧杂志》 CAS CSCD 北大核心 2024年第6期1-6,共6页
反刍动物的生长发育受日粮精料水平的影响。日粮精粗比和非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)是反映日粮精料水平的2个常用指标。适宜的精粗比和NFC/NDF可以提高反刍动物的生产性能,维持瘤胃健康,提高经济效益。本文主要综述日粮... 反刍动物的生长发育受日粮精料水平的影响。日粮精粗比和非纤维性碳水化合物/中性洗涤纤维(NFC/NDF)是反映日粮精料水平的2个常用指标。适宜的精粗比和NFC/NDF可以提高反刍动物的生产性能,维持瘤胃健康,提高经济效益。本文主要综述日粮精粗比和NFC/NDF对反刍动物生产性能、消化代谢和产品品质的影响,以期为反刍动物的日粮配制及健康生产提供参考。 展开更多
关键词 反刍动物 精粗比 NFC/NDF 生产性能 消化代谢 产品品质
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日粮精粗比对舍饲育肥牦牛瘤胃菌群结构、挥发性脂肪酸及其转运载体表达量的影响 被引量:2
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作者 徐俊杰 王莹 +7 位作者 丁宁 马向花 刘塔 周天赐 李涛 袁朝海 张威 蔡亚非 《南京农业大学学报》 CAS CSCD 北大核心 2024年第1期133-141,共9页
[目的]本试验以舍饲育肥牦牛为研究对象,探究日粮精粗比对舍饲育肥牦牛瘤胃代谢的影响,期望为青海牦牛规模化、产业化和现代化养殖过程中日粮精粗比调控提供参考。[方法]对15头试验牛群进行分组,分别饲喂精粗(质量)比为3∶7(A组)、5∶5(... [目的]本试验以舍饲育肥牦牛为研究对象,探究日粮精粗比对舍饲育肥牦牛瘤胃代谢的影响,期望为青海牦牛规模化、产业化和现代化养殖过程中日粮精粗比调控提供参考。[方法]对15头试验牛群进行分组,分别饲喂精粗(质量)比为3∶7(A组)、5∶5(B组)、7∶3(C组)的全混合日粮(total mixed ration,TMR)。饲喂90 d后于凌晨空腹屠宰,采集瘤胃液和瘤胃上皮组织,通过16S核糖体RNA(16S ribosomal RNA,16S rRNA)高通量测序、气相色谱、RT-qPCR以及Western blot试验方法,探究不同精粗比日粮饲喂下,舍饲育肥牦牛瘤胃细菌菌群结构、瘤胃发酵参数以及瘤胃上皮中挥发性脂肪酸(VFA)转运载体表达量的变化。[结果]日粮精粗比显著影响瘤胃细菌菌群结构,随着精料占比升高,在门水平上,拟杆菌门(Bacteroidetes)、螺旋体门(Spirochaetes)和黏胶球形菌门(Lentisphaerae)相对丰度显著上升(P<0.05),厚壁菌门(Firmicutes)和软壁菌门(Tenericutes)相对丰度显著下降(P<0.05);属水平上,随着精料比例提高,理研菌科RC9肠道群(Rikenellaceae RC9 gut group)、克里斯腾森菌科R7群(Christensenellaceae R7 group)、Saccharofermentans、产琥珀酸菌属(Succiniclasticum)和Lachnoclostridium相对丰度显著升高(P<0.05),C组牦牛瘤胃球菌属(Ruminococcus)和拟杆菌属(Bacteroides)相对丰度显著低于A组(P<0.05),B组和C组牦牛普氏菌属(Prevotella)、假丁酸弧菌(Pseudobutyrivibrio)和密螺旋体属(Treponema)相对丰度显著高于A组(P<0.05)。日粮精粗比对瘤胃pH值及VFA产量影响显著,精粗比上升显著下调瘤胃内容物pH值(P<0.05),乙酸浓度、乙酸浓度/丙酸浓度显著降低(P<0.05),丙酸、戊酸和总VFA浓度显著升高(P<0.05),与A、B组相比,C组丁酸和异丁酸浓度显著升高(P<0.05)。日粮精粗比对瘤胃上皮VFA转运载体表达量影响显著。随着日粮精料比例升高,腺瘤下调蛋白基因(DRA)、假定阴离子转运载体1基因(PAT1)、单羧酸转运载体1基因(MCT1)和单羧酸转运载体4基因(MCT4)在mRNA水平的相对表达量显著升高(P<0.05),而阴离子交换蛋白2基因(AE2)在mRNA水平和蛋白水平的相对表达量则显著下降(P<0.05),上述基因的蛋白表达趋势与mRNA的一致。随着日粮精粗比例升高,牦牛的生产性能,即平均日增重、饲料转化率、屠宰率也随之提高,且具有显著差异(P<0.05)。[结论]饲喂高精料日粮可提升牦牛瘤胃中非纤维素降解菌的相对丰度,使大量能量饲料和蛋白饲料快速转化为VFA,为机体供能。激活瘤胃上皮细胞中VFA转运载体,提高其表达量,加快VFA转运入血的速度,以提高脂肪代谢底物,最终达到快速育肥的效果。 展开更多
关键词 舍饲牦牛 日粮精粗比 瘤胃细菌菌群 挥发性性脂肪酸 挥发性性脂肪酸转运载体 生产性能
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大气CO_(2)浓度升高背景下优化施氮对淹水稻田CH4排放的影响
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作者 黄薇 王圆媛 +3 位作者 刘超 伍翥嵘 李琪 胡正华 《农业环境科学学报》 CAS CSCD 北大核心 2024年第7期1666-1676,共11页
为探讨未来气候变化条件下,合理管理氮肥以充分协调水稻产量与温室气体排放量之间的矛盾,实现低碳排放并保持水稻产量,本研究探讨了大气CO_(2)浓度升高120μmol·mol^(-1)与氮肥减施40%对淹水稻田水稻生产及CH4排放的影响及机理。... 为探讨未来气候变化条件下,合理管理氮肥以充分协调水稻产量与温室气体排放量之间的矛盾,实现低碳排放并保持水稻产量,本研究探讨了大气CO_(2)浓度升高120μmol·mol^(-1)与氮肥减施40%对淹水稻田水稻生产及CH4排放的影响及机理。利用开顶式气室(OTC)组成的CO_(2)浓度自动调控平台设置4个处理,即环境CO_(2)浓度+施氮250 kg·hm^(-2)(CK)、大气CO_(2)浓度升高120μmol·mol^(-1)+施氮250 kg·hm^(-2)(C+)、环境CO_(2)浓度+施氮150 kg·hm^(-2)(N-)、大气CO_(2)浓度升高120μmol·mol^(-1)+施氮150 kg·hm^(-2)(C+N-),分析了稻田CH4累积排放量(CAC)、水稻生物量及产量、土壤理化性质及酶活性等指标。结果表明:与CK处理相比,C+处理使CAC/产量显著提高了16.93%,N-处理使CAC/产量显著降低了13.33%,C+N-处理使CAC/产量降低了7.89%,但不显著;N-处理在一定程度上削弱了C+处理对CAC、CAC/产量、水稻生物量、土壤可溶性有机碳含量的促进作用;逐步回归分析表明,基于可溶性有机碳和硝态氮含量及土壤脲酶活性的线性模型,可解释稻田CH4累积排放64%的变异。综上,在大气CO_(2)浓度升高条件下,氮肥减施可通过影响土壤碳、氮基质及土壤脲酶活性来调节稻田CH4排放。 展开更多
关键词 大气CO_(2)浓度升高 氮肥减施 CH4排放 水稻生产
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选矿厂智能化建设目标与实施路径 被引量:1
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作者 赵奕 张维国 +1 位作者 尤腾胜 张海胜 《有色设备》 2024年第1期1-7,共7页
选矿厂的智能化升级转型是建设现代矿山企业的必然选择,其建设目标及实施路径与广义智能工厂建设有着显著差异。本文结合选矿厂智能化建设背景、面临的问题,探讨了选矿厂智能化的建设目标,提出了智能选矿厂的建设路径:智能装备与智能感... 选矿厂的智能化升级转型是建设现代矿山企业的必然选择,其建设目标及实施路径与广义智能工厂建设有着显著差异。本文结合选矿厂智能化建设背景、面临的问题,探讨了选矿厂智能化的建设目标,提出了智能选矿厂的建设路径:智能装备与智能感知、过程自动化稳定运行、工艺优化控制、信息化生产管理以及与之匹配的生产组织管理体系,最后给出了选矿厂智能化建设的实施步骤建议。 展开更多
关键词 智能化选矿厂 智能装备与仪表 工艺优化控制 组织管理体系 智慧决策 矿山
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反刍动物饲粮精粗比应用研究进展
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作者 张犇 郭宪 《饲料研究》 CAS 北大核心 2024年第15期146-150,共5页
饲粮精粗比是科学饲喂反刍动物的基础,直接影响反刍动物的营养摄入、消化吸收和健康状况。合理的饲粮精粗比能够稳定反刍动物瘤胃内环境,改善瘤胃发酵,预防酸中毒,提高屠宰性能和泌乳性能,增加养殖经济效益。文章综述了不同精粗比饲粮... 饲粮精粗比是科学饲喂反刍动物的基础,直接影响反刍动物的营养摄入、消化吸收和健康状况。合理的饲粮精粗比能够稳定反刍动物瘤胃内环境,改善瘤胃发酵,预防酸中毒,提高屠宰性能和泌乳性能,增加养殖经济效益。文章综述了不同精粗比饲粮对反刍动物的生长、血液等各项指标的影响,为选择适宜的反刍动物饲粮精粗比提供参考。 展开更多
关键词 反刍动物 精料 粗饲料 生产性能 血液指标 瘤胃发酵
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典型自然源气溶胶沉降引起的海洋初级生产响应
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作者 刘畅 毛志华 +1 位作者 陈焕焕 王云涛 《海洋与湖沼》 CAS CSCD 北大核心 2024年第2期363-374,共12页
大气沉降是陆源物质向海洋输入营养盐的重要方式,沙尘、野火和火山喷发均能够产生气溶胶,这些典型的自然源气溶胶在风场的作用下,能够进行远距离的输运,期间由于沉降作用进入海洋,为上层海洋提供限制性营养盐促进海洋浮游植物生长,提升... 大气沉降是陆源物质向海洋输入营养盐的重要方式,沙尘、野火和火山喷发均能够产生气溶胶,这些典型的自然源气溶胶在风场的作用下,能够进行远距离的输运,期间由于沉降作用进入海洋,为上层海洋提供限制性营养盐促进海洋浮游植物生长,提升海洋的初级生产力,促进碳循环过程。以海表叶绿素浓度作为海洋初级生产力的重要指标,通过海表叶绿素浓度的响应,探究沙尘、野火和火山这三种典型自然源气溶胶的传输路径及其沉降对海洋初级生产的影响。结果显示,海洋初级生产对气溶胶沉降的响应不仅与气溶胶排放类型有关,也与温度、动力过程、光合有效辐射等海域初级生产影响因素有关,体现了海洋初级生产对自然源气溶胶的敏感性,自然源气溶胶沉降所驱动的海洋初级生产在全球碳循环中具有重要的潜在影响。 展开更多
关键词 自然源气溶胶 传输与沉降 营养盐 海表叶绿素浓度 海洋初级生产力
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