期刊文献+
共找到240篇文章
< 1 2 12 >
每页显示 20 50 100
Investigation of gas content of organic-rich shale:A case study from Lower Permian shale in southern North China Basin,central China 被引量:19
1
作者 Wei Dang Jin-Chuan Zhang +5 位作者 Xuan Tang Xiao-Liang Wei Zhong-Ming Li Cheng-Hu Wang Qian Chen Chong Liu 《Geoscience Frontiers》 SCIE CAS CSCD 2018年第2期559-575,共17页
Measuring gas content is an essential step in estimating the commerciality of gas reserves. In this study,eight shale core samples from the Mouye-1 well were measured using a homemade patented gas desorption apparatus... Measuring gas content is an essential step in estimating the commerciality of gas reserves. In this study,eight shale core samples from the Mouye-1 well were measured using a homemade patented gas desorption apparatus to determine their gas contents. Due to the air contamination that is introduced into the desorption canister, a mathematical method was devised to correct the gas quantity and quality.Compared to the chemical compositions of desorbed gas, the chemical compositions of residual gas are somewhat different. In residual gas, carbon dioxide and nitrogen record a slight increase, and propane is first observed. This phenomenon may be related to the exposure time during the transportation of shale samples from the drilling site to the laboratory, as well as the differences in the mass, size and adsorptivity of different gas molecules. In addition to a series of conventional methods, including the USBM direct method and the Amoco Curve Fit(ACF) method, which were used here for lost gas content estimation, a Modified Curve Fit(MCF) method, based on the 'bidisperse' diffusion model, was established to estimate lost gas content. By fitting the ACF and MCF models to gas desorption data, we determined that the MCF method could reasonably describe the gas desorption data over the entire time period, whereas the ACF method failed. The failure of the ACF method to describe the gas desorption process may be related to its restrictive assumption of a single pore size within shale samples. In comparison to the indirect method, this study demonstrates that none of the three methods studied in this investigation(USBM, ACF and MCF) could individually estimate the lost gas contents of all shale samples and that the proportion of free gas relative to total gas has a significant effect on the estimation accuracy of the selected method. When the ratio of free gas to total gas is lower than 45%, the USBM method is the best for estimating the lost gas content, whereas when the ratio ranges from 45% to 75% or is more than 75%, the ACF and MCF methods, are the best options respectively. 展开更多
关键词 Organic-rich SHALE GAS content Air contamination Modified curve fit method Lost GAS content estimation
下载PDF
Effects of dietary fiber content and different fiber-rich ingredients on endogenous loss of fat and fatty acids in growing pigs 被引量:3
2
作者 Yifan Chen Zhenyu Wang +5 位作者 Jian Ding Dongxu Ming Wenhui Wang Zhaoning Jiang Ling Liu Fenglai Wang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2019年第3期745-758,共14页
Background: Determination of the endogenous loss of fat(ELF) is used to adjust for the estimation of true total tract digestibility(TTTD) of fat in diets and ingredients.Any factor which affected ELF may further affec... Background: Determination of the endogenous loss of fat(ELF) is used to adjust for the estimation of true total tract digestibility(TTTD) of fat in diets and ingredients.Any factor which affected ELF may further affect the digestibility of fat,including sources and concentrations of fat and fiber in the diet.There are some reports of determining the ELF using regression methods based on different levels of fat intake,while reports on effects of dietary fiber content and different fiber-rich ingredients in pig diets on ELF are very limited.Therefore,the objective of this study was to determine the effects of dietary fiber content and different fiber-rich ingredients on endogenous losses of fat and fatty acids at the end of ileum and throughout the entire intestinal tract in growing pigs.Methods: In Exp.1,the effect of fiber content on endogenous loss of fat was determined using six growing pigs(Duroc × Landrace × Yorkshire;27.6 ± 2.4 kg),fitted with a T-cannula at the end of ileum.The experimental design was a 6 × 6 complete Latin square design with six periods of feeding and six diets.The six experimental fat-free diets were formulated to include graded levels of neutral detergent fiber(NDF)(0,40,80,120,160 and 200 g/kg) and soybean hull(SH) was the only fiber source,providing 0,75,150,225,300 and 375 g/kg,respectively.Chromic oxide was included at4 g/kg in all diets as an indigestible marker.In Exp.2,six crossbred growing barrows(27.6 ± 1.6 kg) were used and the experimental design was the same as for Exp.1.The six fat-free diets were formulated to include six common fiber-rich ingredients and the concentration of NDF was 100 g/kg.The six fiber-rich ingredients were defatted rice bran(DRB),sugar beet pulp(SBP),rice hull(RH),corn germ meal(CGM),SH and wheat bran(WB) and they were fed at represented250,270,145,250,170 and 280 g/kg in the diet,respectively.Results: In Exp.1,the endogenous loss of fatty acids profile did not change as dietary NDF increased in growing pigs.The endogenous losses of fat,C16:0,C18:0,C18:1,C18:2,total unsaturated fatty acids(UFA) and total saturated fatty acids(SFA) in growing pigs at the end of ileum and throughout the entire intestinal tract increased linearly as NDF content of diets increased.The endogenous losses of fat,as well as C16:0 and C18:0 throughout the entire intestinal tract also increased quadratically as NDF content of diets increased.The ELF increased from 0.71 to 3.14 g/kg of dry matter intake(DMI) and 0.56 to 8.21 g/kg DMI at the end of ileum and throughout the entire intestinal tract in growing pigs,respectively.The ELF occurred in the hindgut except for the growing pigs fed 0 and 4% NDF in their diets.The endogenous losses of C16:0 and UFA occurred primarily in the upper regions of the gut and the greatest endogenous losses of C18:0 occurred in the hindgut.The endogenous losses of fat,individual SFA and total SFA throughout the entire intestinal tract were much greater than that at the end of ileum.However,the endogenous losses of individual UFA and total UFA were less throughout the intestinal tract than at the end of ileum.In Exp.2,the endogenous losses of fat at the end of ileum were greater in growing pigs fed CGM or WB diets.The endogenous loss of fatty acids profile changed to a slight degree at the end of ileum that the endogenous loss of UFA(particularly C18:1 and C18:2) in growing pigs fed CGM or WB diets were greater(P < 0.01) than that for the other four diets.The greatest(P < 0.01) endogenous loss of SFA(particularly C18:0) was in growing pigs fed the RH diet.The endogenous losses of fat,C16:0,C18:0 and SFA over the entire intestinal tract were much greater in growing pigs fed CGM or WB diets,whereas the lowest values were in growing pigs fed DRB diet.The ELF at the end of ileum in growing pigs fed CGM or WB diets were 3.50 or 4.17 g/kg DMI,respectively,and the ELF over the entire intestinal tract was 7.23 or 7.38 g/kg DMI.The contribution in percentage of ELF in the upper gut was greater than that in the hindgut of growing pigs fed DRB and RH diets,while the ELF in the upper gut and hindgut were equal in growing pigs fed SBP,CGM and WB diets.On the whole,the endogenous losses of C18:1 and C18:2 throughout the entire intestinal tract in growing pigs fed the six fiber-rich ingredients diets were less than losses at the end of ileum,whereas the endogenous loss of fat,C16:0,C18:0 and SFA were greater throughout the intestinal tract than at the end of ileum.Conclusion: The profile of loss in endogenous fatty acids did not change as dietary NDF increased in growing pigs and the endogenous losses of fatty acids(C16:0,C18:0,C18:1 and C18:2) fat,UFA and SFA increased linearly as NDF content increased in the diets of pigs.The endogenous losses of fat or fatty acids at the end of ileum were greater in growing pigs fed RH,CGM or WB diets.The endogenous losses of fat,fatty acids(C16:0 and C18:0) and SFA were greater over the entire intestinal tract in pigs fed CGM or WB diet,while these values were the lowest in growing pigs fed the DRB diet.The contribution in percentage losses of fat in the upper gut were greater than in the hindgut of growing pigs fed DRB and RH diets,while the contribution of losses of fat in the upper gut and hindgut were equal in growing pigs fed SBP,CGM and WB diets.In addition,the endogenous loss of individual or total UFA was less over the entire intestinal tract of growing pigs fed fiber diets than that at the end of ileum,and the greatest endogenous losses of fat,individual or total SFA were over the entire intestinal tract.Therefore,differences in fiber content and the nature of fiber-rich ingredients in diets of pigs have different effects to the endogenous losses of fat or fatty acids.Considering the requirement of fat or fatty acids of pigs,careful attention must be paid that the endogenous losses of fat and fatty acids when fiber ingredients are used in diets of pigs. 展开更多
关键词 ENDOGENOUS LOSS FAT Fatty acids FIBER content Fiber-rich INGREDIENTS Growing pigs
下载PDF
Agglomeration Mechanism of Rich Hematite Sinter with Lowering SiO_2 Content
3
《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2000年第4期256-260,共5页
关键词 SIO rich Agglomeration Mechanism of rich Hematite Sinter with Lowering SiO2 content
下载PDF
论黄爵滋的古文观与古文成就
4
作者 胡迎建 《老区建设》 2024年第7期83-96,共14页
黄爵滋持古文通变观。为治国安邦计而作的奏疏,富有文采,或骈散相间,条分缕析,严谨细密;论政、论教文警辟深刻,章法严谨;序跋见识宏博,情辞并茂;杂记盘曲绵邈,恣肆峻奇;游记生动有趣,文笔洗炼;书信真诚恳切;传记、诔文以典型事例动人。... 黄爵滋持古文通变观。为治国安邦计而作的奏疏,富有文采,或骈散相间,条分缕析,严谨细密;论政、论教文警辟深刻,章法严谨;序跋见识宏博,情辞并茂;杂记盘曲绵邈,恣肆峻奇;游记生动有趣,文笔洗炼;书信真诚恳切;传记、诔文以典型事例动人。内容丰茂浑厚,各种文体运用自如,文笔简炼雅洁。叙事记人,剪裁得体;写景状物,生动逼真。 展开更多
关键词 古文观 通变 内容丰厚 文笔雅洁
下载PDF
福建富硒红壤区土壤硒含量特征及作物对硒的吸收
5
作者 张青 孔庆波 +1 位作者 栗方亮 罗涛 《肥料与健康》 CAS 2024年第4期12-16,25,共6页
在调查我国南方红壤区土壤及农产品中硒含量状况的基础上,分析了富硒红壤中硒的分布特征及其所产农产品中硒含量的变化规律。结果表明:我国南方富硒红壤面积较大,但在地理空间分布上具有一定破碎度;土壤中的硒虽伴生一定量的重金属和稀... 在调查我国南方红壤区土壤及农产品中硒含量状况的基础上,分析了富硒红壤中硒的分布特征及其所产农产品中硒含量的变化规律。结果表明:我国南方富硒红壤面积较大,但在地理空间分布上具有一定破碎度;土壤中的硒虽伴生一定量的重金属和稀土等元素,但与重金属或稀土元素的相关性不大;在富硒土壤上生产的农作物总体表现为可食部位的硒含量低于非可食部位的,并且农作物中的硒含量与土壤有效态硒含量相关性显著。依据我国南方富硒红壤区土壤自身特性,可以通过调控富硒红壤区农田土壤的酸碱度、水分含量、施肥种类、施用调理剂等来提高土壤硒的有效性,达到农产品中硒含量增加的目的;同时,对外源补硒的技术和相应农产品硒的健康效应,需进一步研究与规范。 展开更多
关键词 红壤 富硒农产品 含量特征 食品安全 建议
下载PDF
Fe、Ni元素微合金化对Al-11Si铝合金微观组织及力学性能的影响
6
作者 刘清 王若超 +2 位作者 晁延吉 齐志峰 刘洪涛 《轻金属》 2024年第4期44-49,共6页
本研究利用扫描电子显微镜(SEM)、能量散射X射线光谱(EDS)和拉伸试验机,研究了Ni(1.2及1.6wt.%)和Fe(0.6及0.8wt.%)含量对Al-11Si铝合金的微观组织及不同温度下的力学性能的影响。实验结果表明,适量的Ni元素对于Al-11Si合金中富含Fe相... 本研究利用扫描电子显微镜(SEM)、能量散射X射线光谱(EDS)和拉伸试验机,研究了Ni(1.2及1.6wt.%)和Fe(0.6及0.8wt.%)含量对Al-11Si铝合金的微观组织及不同温度下的力学性能的影响。实验结果表明,适量的Ni元素对于Al-11Si合金中富含Fe相的类型、形态和分布具有积极作用。在Al-11Si铝合金中添加1.2wt.%Ni和0.6wt.%Fe可以生成一种类似“汉字状”的富Fe强化相。当进一步增加到1.6wt.%Ni和0.8wt.%Fe后,富Fe相变为了长针状,对Al基体产生严重的割裂作用,降低了合金力学性能。由于含有1.2wt.%Ni和0.6wt.%Fe的Al-11Si铝合金中生成了“汉字状”富Fe强化相,合金的高温拉伸性能得到了显著改善。在350℃的测试温度下,Al-11Si铝合金的抗拉强度(UTS)达到了139 MPa。 展开更多
关键词 Al-11Si铝合金 Ni含量 Fe含量 富Fe相 力学性能
下载PDF
富钼专用保水剂对东北典型土壤保墒性能及大豆幼苗生长的影响 被引量:1
7
作者 张玉斌 景泉 +3 位作者 崔金虎 陈贵娟 赵雪来 侯利园 《中国水土保持科学》 CSCD 北大核心 2024年第1期63-69,共7页
在东北集约化种植体系中,苗期水肥供应强度直接影响作物生长状况,并最终导致产量变异。富钼大豆专用保水剂是基于高分子材料合成与钼肥技术的耦合。针对东北2种典型土壤类型开展温室盆栽试验,通过二因子五水平的试验设计,研究土壤类型... 在东北集约化种植体系中,苗期水肥供应强度直接影响作物生长状况,并最终导致产量变异。富钼大豆专用保水剂是基于高分子材料合成与钼肥技术的耦合。针对东北2种典型土壤类型开展温室盆栽试验,通过二因子五水平的试验设计,研究土壤类型、保水剂类型及施用量对大豆苗期土壤水分利用效率及幼苗生长的影响。结果表明:1)施用不同剂量普通保水剂(H 2020)和富钼专用保水剂(GH 2021)均可在不同程度上提高土壤保水性能,并促进苗期大豆生长及地上部植株干质量;2)土壤含水率和大豆幼苗株高均随用量的增大而增加,且用量为0.5%的GH 2021显著促进大豆幼苗的生长,在黑土和风沙土条件下增幅分别可达68.0%和44.9%;3)0.5%剂量的GH 2021使风沙土土壤含水率提高343.1%,相较于施用H 2020保水性能提升33.6%;4)与H 2020相比,施用量为0.5%的GH 2021使风沙土条件下苗期大豆株高和地上部干质量分别提高16.3%和34.0%。综上,富钼专用保水剂在东北大豆种植区最佳应用范围为:2种土壤条件下,保水剂理论田间推荐用量为0.5%,其对风沙土的保墒性能优于黑土。该保水剂可用于提升干旱区土壤保水性能,改善苗期大豆生长环境和营养状况,最大限度激发东北大豆的增产潜力。 展开更多
关键词 富钼专用保水剂 黑土 风沙土 大豆 土壤含水率 苗期大豆生长
下载PDF
微波消解-氢化物原子荧光光谱法测定胡萝卜硒含量
8
作者 张美琦 苏丹 +2 位作者 张嘉璇 张珍岩 铁梅 《科技创新与应用》 2024年第32期71-74,共4页
硒是人体内各种含硒酶及含硒蛋白的合成过程中必不可少的一种微量元素,能提高身体的免疫功能。硒对人体有一定的防癌作用,硒不但对肿瘤有抑制作用而且还能影响致癌物质的新陈代谢,素有“防癌之王”之称。采用人工栽培方式生产的富硒胡... 硒是人体内各种含硒酶及含硒蛋白的合成过程中必不可少的一种微量元素,能提高身体的免疫功能。硒对人体有一定的防癌作用,硒不但对肿瘤有抑制作用而且还能影响致癌物质的新陈代谢,素有“防癌之王”之称。采用人工栽培方式生产的富硒胡萝卜是一种较为理想的富硒型蔬菜。该文以胡萝卜为研究对象,利用微波消解-氢化物原子荧光光谱法测定胡萝卜中总硒的含量,探讨不同微波消解溶剂和消解条件对含硒胡萝卜消解效果的影响,并优化氢化物原子荧光光谱法测定条件。结果表明,最佳消解体系为HNO_(3)-H_(2)O_(2)体系(5 mL∶2 mL);最佳微波消解条件为,第一工步为2 min、0.2 MPa;第二工步为6 min、0.5 MPa和6 min、0.7 MPa;第三工步为5 min、1 MPa;在最优条件下,测硒的线性范围为0~50μg/L。对样品空白荧光值进行10次测定,RSD=2.24%,最低检出限为0.90μg/kg。土壤中施硒能够显著提高胡萝卜中总硒的含量,较空白对照组提高6.50%(地上)和10.30%(地下),可食用(地下)部位的最高硒含量为445.90μg/kg。 展开更多
关键词 微波消解 氢化物原子荧光光谱法 富硒 胡萝卜 含量
下载PDF
富硒啤酒酵母的选育及有机硒含量的测定 被引量:2
9
作者 汪锡武 冯婉婷 +7 位作者 方旭娟 程子杨 钱森和 王洲 徐康 张杰 赵文豪 张圣伟 《食品与发酵工业》 CAS CSCD 北大核心 2024年第10期48-54,共7页
为了进一步研究微生物富硒的能力,得到富硒能力较强的啤酒酵母,以啤酒酵母WX-01为出发菌,通过高浓度亚硒酸钠初筛,再经过常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变处理以及亚硒酸钠抗性平板筛选,观察菌株的... 为了进一步研究微生物富硒的能力,得到富硒能力较强的啤酒酵母,以啤酒酵母WX-01为出发菌,通过高浓度亚硒酸钠初筛,再经过常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变处理以及亚硒酸钠抗性平板筛选,观察菌株的生长状况结合对其生物量与硒含量的测定,选育出一株富硒优势啤酒酵母。通过培养条件为添加质量浓度35 mg/L,加硒时间8 h,培养时间36 h,得到的酵母WX-1的生物量提高到(5192±36)mg/L,较原始菌株WX-01提高了201%,硒含量达到(1475±33)μg/g,较原始菌株提高了330%,其有机硒产量和转化率分别为7658μg/L和97.1%。扫描电镜分析酵母菌富集后表面有少量单质硒析出。另外红外光谱在特定区域出现不同强度的吸收峰表明酵母细胞参与了硒蛋白的合成。 展开更多
关键词 富硒 啤酒酵母 常压室温等离子体诱变 富集优化 硒含量 表征
下载PDF
RICH教改中教师观念转变内容探析 被引量:9
10
作者 郑志恋 《浙江师范大学学报(社会科学版)》 2004年第1期84-86,共3页
通过近八年的教学改革实践,浙江师范大学外国语学院RICH教改组部分教师的教学观念逐渐发生了变化。本文主要从教师对教学对象的看法转变、教师对教学内容的看法转变、教师对教学评估的看法转变三个方面进行探讨。
关键词 教师观念 教学内容 教学评估 rich教学 学生
下载PDF
基于AI的消息业务内容安全治理解决方案及关键技术
11
作者 赵晨斌 陈浩然 +1 位作者 李善诗 李蔚然 《邮电设计技术》 2024年第8期8-12,共5页
调研了消息业务内容安全治理现状以及基于AI的消息业务内容安全治理的关键技术,并根据当前技术短板,提出了优化建议。根据消息业务网络架构特征,对短信和5G消息2种消息业务提出了不良消息治理的方案。通过AI辅助垃圾短信策略生成、异常... 调研了消息业务内容安全治理现状以及基于AI的消息业务内容安全治理的关键技术,并根据当前技术短板,提出了优化建议。根据消息业务网络架构特征,对短信和5G消息2种消息业务提出了不良消息治理的方案。通过AI辅助垃圾短信策略生成、异常电子信息提取、AI稽核拦截明细,赋能短信业务治理,通过构建AI能力基座,利用深度学习赋能5G消息治理。 展开更多
关键词 短消息业务 富媒体消息业务 5G消息 内容安全治理
下载PDF
Fe含量对再生铝硅合金组织和性能的影响
12
作者 于明轩 范超 +3 位作者 张骏 王太子 魏巍 唐清春 《热加工工艺》 北大核心 2024年第14期108-113,117,共7页
利用金相显微镜、X射线衍射仪、万能拉伸试验机等研究了Fe含量对再生铝硅合金组织和性能的影响,并对该合金中富铁相形态进行了定量分析。结果表明:当Fe含量从0.796%增加到1.301%时,合金组织中二次枝晶臂间距先减小再增大再减小;富铁相... 利用金相显微镜、X射线衍射仪、万能拉伸试验机等研究了Fe含量对再生铝硅合金组织和性能的影响,并对该合金中富铁相形态进行了定量分析。结果表明:当Fe含量从0.796%增加到1.301%时,合金组织中二次枝晶臂间距先减小再增大再减小;富铁相形貌的演变过程为紧密汉字状→汉字状+鱼骨状→汉字状+鱼骨状+针状→针状+汉字状→针状;合金中的富铁相面积分数逐渐上涨,富铁相长度不断增长,尤其当Fe含量从1.022%上升到1.301%,针状β-Fe相长度显著增长,平均长度最长可达119.5μm;β-Fe相的出现导致合金力学性能的显著下降,当Fe含量增至1.301%时,合金抗拉强度和伸长率相比0.796%Fe时分别下降26.26%和52.58%。 展开更多
关键词 Fe含量 再生铝硅合金 富铁相 力学性能
下载PDF
Rich GetRicher——图像检索中的一种自适应的相关反馈方法 被引量:3
13
作者 段立娟 高文 马继勇 《计算机研究与发展》 EI CSCD 北大核心 2001年第8期960-965,共6页
早期的基于内容的图像检索系统以图像处理技术为核心 ,研究重点集中在视觉特征的选择和提取方面 ,而没有充分利用人们在视觉方面的主观性和人类所广泛使用的高层次概念和低层次视觉特征之间的相关性 .为解决上述问题 ,近年来相关反馈在... 早期的基于内容的图像检索系统以图像处理技术为核心 ,研究重点集中在视觉特征的选择和提取方面 ,而没有充分利用人们在视觉方面的主观性和人类所广泛使用的高层次概念和低层次视觉特征之间的相关性 .为解决上述问题 ,近年来相关反馈在基于内容的图像检索中受到重视 .提出了一种新的相关反馈方法 ,使得高层次语义特征能够逐步嵌入到基于低层次特征的图像检索中 ,该方法不仅能够记忆以前的交互信息 ,而且能够记忆相应的交互信息给系统带来的影响 ,实验结果表明该方法准确率高。 展开更多
关键词 图像检索 自适应 图像处理 计算机
下载PDF
盛荚期喷施亚硒酸钠对大豆籽粒硒含量及单株产量的影响
14
作者 亢江飞 晏云 +4 位作者 李林 方社法 陈颖民 李晓慧 郭建秋 《陕西农业科学》 2024年第4期90-95,共6页
为了研究喷施亚硒酸钠对大豆籽粒硒含量及单株产量的影响,采用裂区设计,主区为盛荚期喷施不同用量的亚硒酸钠,共5个处理(CK(清水):0 g/hm^(2),C1:30 g/hm^(2),C2:60 g/hm^(2),C3:90 g/hm^(2),C4:120 g/hm^(2)),副区为8个大豆品种。分析... 为了研究喷施亚硒酸钠对大豆籽粒硒含量及单株产量的影响,采用裂区设计,主区为盛荚期喷施不同用量的亚硒酸钠,共5个处理(CK(清水):0 g/hm^(2),C1:30 g/hm^(2),C2:60 g/hm^(2),C3:90 g/hm^(2),C4:120 g/hm^(2)),副区为8个大豆品种。分析8个大豆品种在喷施5种用量亚硒酸钠处理中籽粒硒含量及单株产量变化规律。结果表明,试验地土壤达到富硒水平,在CK处理中,不同大豆品种籽粒硒含量均未达到富硒大豆标准,需要额外喷施硒肥。随着喷施亚硒酸钠用量的增加,8个大豆品种籽粒中硒含量均呈增加趋势,亚硒酸钠用量与大豆籽粒硒含量呈显著或者极显著正相关。8个大豆品种籽粒硒含量均值随亚硒酸钠用量的增加呈上升趋势,与CK相比,C1~C4处理均能极显著提高8个大豆品种籽粒硒含量均值,提高了571.186%~2489.831%。亚硒酸钠用量对大豆籽粒硒含量的影响大于大豆品种对大豆籽粒硒含量的影响。喷施亚硒酸钠用量(X)与每种用量下8个大豆籽粒硒含量均值(Y_(均))的直线回归方程为Y_(均)=0.012X+0.003,r=0.986,达到极显著正相关。根据该方程,当大豆籽粒硒含量达到富硒大豆标准(0.1~1 mg/kg),喷施亚硒酸钠用量的范围为8.08~83.08 g/hm^(2)。分析喷施亚硒酸钠用量与大豆籽粒硒含量的回归方程发现,郑9525的回归方程斜率最大,C4处理中籽粒硒含量达到最大值1.997 mg/kg,籽粒富集硒能力最强;齐黄34斜率最小,C4处理中籽粒硒含量达到最小值1.133 mg/kg,籽粒富集硒能力最弱。在本试验条件下,喷施亚硒酸钠对大豆单株产量没有显著影响。大豆品种对单株产量的影响大于亚硒酸钠用量对单株产量的影响。 展开更多
关键词 亚硒酸钠 大豆 硒含量 富硒能力 单株产量
下载PDF
含水排土场蠕变特性及长期强度研究
15
作者 常剑 郭霁 +2 位作者 苏强 王浩然 孙鸿昌 《科技和产业》 2024年第5期280-285,共6页
为揭示排土场岩土体蠕变特性及长期强度,采用ZLB-1型三联蠕变直剪蠕变仪,以分级加载形式开展一系列试验,研究不同含水率和固结压力下,岩土体蠕变特性及长期强度变化规律。试验结果表明:15%~39.2%(饱和)含水率范围内,排土场岩土体显示为... 为揭示排土场岩土体蠕变特性及长期强度,采用ZLB-1型三联蠕变直剪蠕变仪,以分级加载形式开展一系列试验,研究不同含水率和固结压力下,岩土体蠕变特性及长期强度变化规律。试验结果表明:15%~39.2%(饱和)含水率范围内,排土场岩土体显示为非线性蠕变,且随着剪应力增加,蠕变曲线分别呈现衰减蠕变、非稳定蠕变及加速蠕变,直至试样发生破坏;施加剪应力瞬间发生较大瞬时应变,并随剪应力增加而变大;长期强度指标与含水率呈现指数递减趋势;对比15%含水率试样,饱和含水率下排土场岩土体长期强度指标中黏聚力降低66%,内摩擦角降低69%,其变化规律满足指数拟合公式。研究成果可为同类型含水排土场稳定性计算提供基础数据。 展开更多
关键词 富水排土场 分级加载 含水率 蠕变 长期强度
下载PDF
新型少水型相变吸收剂的筛选及其含水量影响分析
16
作者 张达光 钱新凤 +2 位作者 侯大伟 汪鑫 慕晓炜 《高校化学工程学报》 EI CAS CSCD 北大核心 2024年第5期831-838,共8页
为克服水型吸收剂能耗高、腐蚀性强的缺点,提出一种基于混合胺的新型少水型相变吸收剂。开展溶剂效应对吸收剂的吸收、分相、富相黏度等性能的影响实验,研究含水量与吸收剂性能的关系,为优化吸收剂的含水量提供理论依据。实验结果表明,... 为克服水型吸收剂能耗高、腐蚀性强的缺点,提出一种基于混合胺的新型少水型相变吸收剂。开展溶剂效应对吸收剂的吸收、分相、富相黏度等性能的影响实验,研究含水量与吸收剂性能的关系,为优化吸收剂的含水量提供理论依据。实验结果表明,增加吸收剂的含水量可以提高吸收剂对CO_(2)的吸收性能、加速相分离和降低富相黏度,水与二甲基亚砜最佳的质量比为4:6,与质量分数为30%的乙醇胺相比,新型吸收剂的循环容量提高了27%,同时具备相变和少水的特性,有效降低了能耗和腐蚀性。 展开更多
关键词 二氧化碳 少水型两相吸收剂 含水量 相分离 富相黏度
下载PDF
叶面喷施富硒水溶肥对水稻产量及稻米含硒量的影响
17
作者 范晓伦 孙燕华 《农业技术与装备》 2024年第5期141-142,145,共3页
为探究叶面喷施富硒水溶肥对水稻产量及稻米含硒量的影响,以鄄城县引马镇为试验地,探讨了叶面喷施富硒水溶肥的不同方案对水稻产量及稻米含硒量的影响。结果表明,叶面喷施富硒水溶肥可显著提高水稻生长状况,包括株高、穗长、分蘖数、穗... 为探究叶面喷施富硒水溶肥对水稻产量及稻米含硒量的影响,以鄄城县引马镇为试验地,探讨了叶面喷施富硒水溶肥的不同方案对水稻产量及稻米含硒量的影响。结果表明,叶面喷施富硒水溶肥可显著提高水稻生长状况,包括株高、穗长、分蘖数、穗粒数和结实率,分别提高11.96%、9.11%、7.16%、6.27%和5.98%,为提高水稻产量提供了有效支持;同时,叶面喷施富硒水溶肥还显著提高了水稻的产量和稻米硒含量,处理组D在百粒质量和产量方面表现最佳,增幅分别为15.41%和22.84%。叶面喷施富硒水溶肥在水稻生产中具有明显促进作用,为农业生产提供了一种可行的施肥方式,具有广阔的应用前景。 展开更多
关键词 水稻 富硒水溶肥 产量 稻米含硒量
下载PDF
小麦富锌育种的发展现状及研究趋势
18
作者 张诗琦 刘含章 +1 位作者 胡能兵 朱守晶 《安徽农学通报》 2024年第17期1-5,共5页
本文总结分析了农田土壤锌含量分布现状、锌对小麦籽粒营养品质的影响、小麦对锌的吸收积累特性以及小麦籽粒锌营养强化途径等。土壤中锌含量的分布特征与地形地貌、地质构造和生态环境等密切相关,部分小麦主产区的土壤中锌含量较低。... 本文总结分析了农田土壤锌含量分布现状、锌对小麦籽粒营养品质的影响、小麦对锌的吸收积累特性以及小麦籽粒锌营养强化途径等。土壤中锌含量的分布特征与地形地貌、地质构造和生态环境等密切相关,部分小麦主产区的土壤中锌含量较低。锌是一种重要的微量元素,对小麦籽粒淀粉和蛋白质含量均有影响,一般被植物根系吸收后,在根部压力或蒸腾作用下被输送到地上部,或者被横向输送到韧皮部,由韧皮部进行向上或向下的运输,再被运输到各组织和器官中。小麦锌强化途径包括遗传改良育种、农艺改良和生物技术应用等。研究结果为小麦富锌育种提供了一些新的思路。 展开更多
关键词 小麦 土壤锌含量 锌分布和积累 锌强化 富锌育种
下载PDF
Expression of a Lysine-rich Gene in Bacillus subtilis 168 被引量:1
19
作者 Li Xue-lin Liu Xiao-fei +3 位作者 Gao Xue-jun Qiao Bin Pan Hong-bao Ao Jin-xia 《Journal of Northeast Agricultural University(English Edition)》 CAS 2013年第1期43-48,共6页
Lysine-rich protein gene (lys) was cloned from winged bean (Psophocarpus tetragonolobus (L.) DC), and cloned into prokaryotie expression vector pHT43, the recombinant plasmid pHT43/lys were constructed and then ... Lysine-rich protein gene (lys) was cloned from winged bean (Psophocarpus tetragonolobus (L.) DC), and cloned into prokaryotie expression vector pHT43, the recombinant plasmid pHT43/lys were constructed and then transferred into Bacillus subtilis168, upon IPTG induction, the recombinant protein was expressed, and the content of lysine was detected by HPLC. The result showed that lysine content increased by 9.85%. It was suggested that introducing lys gene into Bacillus subtilis 168 was an effective way to improve its nutrition quality. 展开更多
关键词 lysine-rich protein gene Bacillus subtilis 168 lysine content HPLC
下载PDF
Preliminary Study on the Standard of Selenium Content in Agricultural Products 被引量:2
20
作者 ZHANG Zhi-yuan YOU Yong +2 位作者 GUO Qing-quan WANG Yong-hong DENG Shi-lin 《Asian Agricultural Research》 2012年第10期83-85,共3页
With the improvement of living standards, people pay more attention to the agricultural products with health protection function, and the selenium-rich agricultural products attract more and more consumers. The main b... With the improvement of living standards, people pay more attention to the agricultural products with health protection function, and the selenium-rich agricultural products attract more and more consumers. The main biological role of selenium is to resist oxidation and inflammatory response, mainly focusing on resisting aging, preventing cardiovascular disease, protecting eyesight, counteracting or destroying the toxic properties, preventing cancer and thyroid disease. In most areas of China, there is a widespread shortage of selenium, thus producing selenium-rich agricultural products to provide natural selenium-rich health food to the areas in need of selenium, has gradually become a new hot spot of China's health food industry, but high content of selenium in food is detrimental to human body, even leads to selenium intoxication, and artificially adding inorganic selenium is difficult to guarantee that the selenium content of agricultural products is not exceeded. According to human body's daily demand for selenium in dietetics and the content of selenium in agricultural products in the Chinese food composition table, we put forward the recommendations on the standard of selenium in agricultural products, in order to provide the basis for China to formulate the health standard of selenium content in selenium-rich agricultural products. 展开更多
关键词 SELENIUM Selenium-rich AGRICULTURAL PRODUCTS SELEN
下载PDF
上一页 1 2 12 下一页 到第
使用帮助 返回顶部