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A low-cost bromine-fixed additive enables a high capacity retention zinc-bromine batteries 被引量:3
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作者 Pengcheng Xu Tianyu Li +3 位作者 Qiong Zheng Huamin Zhang Yanbin Yin Xianfeng Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第2期89-93,共5页
In recent years,more and more efforts are devoting to clean energy,renewable energies in particular to achieving net zero carbon dioxide emissions[1].However,renewable energies,like solar power and wind power,are gene... In recent years,more and more efforts are devoting to clean energy,renewable energies in particular to achieving net zero carbon dioxide emissions[1].However,renewable energies,like solar power and wind power,are generally intermittent and random,hindering their wide application[2,3].To address this problem,there is an urgent need in effective and reliable energy storage device. 展开更多
关键词 Zinc-bromine battery Bromine-fixed additive capacity retention Tetraethylammonium bromide
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The Reductive Addition Reaction of Substituted 2-Chloromethyl-1,3,4-oxadiazole to Aldehydes and Ketones Promoted by Samarium Diiodide
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作者 Xiao Liang XU Wei Min ZHU Yong Min ZHANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第12期1566-1568,共3页
1-(β-Hydroxyalkyl)-l,3,4-oxadiazole derivatives were synthesized via reductive addition reactions of 2-chloromethyl-l,3,4-oxadiazole with carbonyl compounds under mild conditions promoted by SmI2.
关键词 Reductive addition samarium diiodide 1-(β-hydroxyalkyl)-1 3 4-oxadiazole deriva-tives SYNTHESIZE
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Effect of Pelletized Graphite Addition on Properties of Al_2O_3-SiC-C Castables
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作者 ZHAO Chenrui ZHANG Sanhua +2 位作者 WANG Guan WEI Yi YUAN Cong 《China's Refractories》 CAS 2015年第4期42-46,共5页
Al2O3 - SiC - C castables with pelletized graphite addition of 0. 2%, 4% or 6% (by mass, the same hereinafter ) were prepared using brown fused corundum (8 - 5, 5 - 3 and 3 - 1 mm ) , dense fused corundum ( ≤1 a... Al2O3 - SiC - C castables with pelletized graphite addition of 0. 2%, 4% or 6% (by mass, the same hereinafter ) were prepared using brown fused corundum (8 - 5, 5 - 3 and 3 - 1 mm ) , dense fused corundum ( ≤1 and 0. 045 mm) and SiC ( ≤1 and ≤0. 064 mm) its main starting materials with mass ratio of aggregate: matrix = 71: 29, 2% silicon powder and 0. 4% B4C as antioxidants, and pelletized graphite as carbon source, Effect of pelletized graphite addition on physical properties, oxidation resistance, slag resistance arid thermal shock resistance of Al2O3 -SiC- C eastables was researched. The results show that: with the in.crease of pelletized graphite addition, the required water amount of castables increases, the bulk density and strength reduce; with 4% pelletized graphite, the eastable performs the best oxidation resistance; the increase of graphite is beneficial to the improvement of slag penetration resistance and corrosion resistance; with 6% pelletized graphite, the thermal shock resistance is the best. 展开更多
关键词 pelletized graphite addition alumina - silicon carbide- carbon castable corrosion resistance
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Effect of TiO2 Addition on Slag Resistance of Lightweight Corundum-spinel Castables
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作者 MA Sanbao YAN Wen +1 位作者 LIN Xiaoli ZHOU Wenying 《China's Refractories》 CAS 2017年第4期44-49,共6页
Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel ( MgAl2O4 ) ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted u... Five lightweight castables containing different TiO2 additions were prepared by using porous corundum - spinel ( MgAl2O4 ) ceramics as aggregate. Corrosion of the lightweight cstables by ladle slag was conducted using a static crucible test. The effect of the TiO2 addition on the slag resistances of the lightweight corundum -spinel castables was investigated through SEM, EDS and Fact- Sage@ software, etc. h was found that TiO2 additi,ve t,vmoted the sintering degree of the castables, deereased the average pore .size, the apparent porosity, and the contact area between the casmbles and slag, and then en- hanced the corrosion resistance. However, TiO2 additive decreased the viscosity of the penetrated .slag simultane- ously, and then deteriorated the penetration resistance. 展开更多
关键词 lightweight eastables porous corundum - spinel aggregate titania addition microstructure slag ladle
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Pb-Ca合金板栅电池早期容量衰减的原因
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作者 谭晓波 李江 +3 位作者 王杜友 郭志刚 卢晓华 杨建芬 《电池》 CAS 北大核心 2024年第4期525-528,共4页
Pb-Ca合金在阀控式铅酸(VRLA)电池中应用广泛。针对Pb-Ca合金浇铸板栅电池的早期容量衰减问题进行研究。用同批次Pb-Ca合金极板,制作不同加酸化成工艺的电池,进行循环测试。充电电流小的电池发生了早期容量衰减,而大电流充电的电池循环... Pb-Ca合金在阀控式铅酸(VRLA)电池中应用广泛。针对Pb-Ca合金浇铸板栅电池的早期容量衰减问题进行研究。用同批次Pb-Ca合金极板,制作不同加酸化成工艺的电池,进行循环测试。充电电流小的电池发生了早期容量衰减,而大电流充电的电池循环性能正常。对发生早期容量衰减的电池进行分析,发现板栅腐蚀界面生成的硫酸铅晶体阻挡层是导致电池发生早期容量衰减的主要原因。提高电池的充电效率,如添加电解液添加剂、化成前对电池反充、增大充电电流等,可以使硫酸铅得以转化,能较好地避免电池发生早期容量衰减。 展开更多
关键词 阀控式铅酸(VRLA)电池 早期容量衰减 Pb-Ca合金 板栅 硫酸铅 电解液添加剂 循环性能
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Influence of Additives on the Solvothermal Synthesis in the Formation of Zn-MOF_5 被引量:1
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作者 LIN Xiaoying SU Ting +4 位作者 ZHONG Qinhua SHI Ronghui LIUMinyi LIU Yamin LU Dongfei 《Journal of Donghua University(English Edition)》 EI CAS 2018年第6期491-494,共4页
The influences of additives of NH_3,HCl,KOH and CH_3OH on the solvothermal synthesis of the Zn-based metal-organic frameworks(Zn-MOF_5s)were investigated.Powder X-ray diffraction(PXRD),thermal gravimetric analysis(TGA... The influences of additives of NH_3,HCl,KOH and CH_3OH on the solvothermal synthesis of the Zn-based metal-organic frameworks(Zn-MOF_5s)were investigated.Powder X-ray diffraction(PXRD),thermal gravimetric analysis(TGA),Fourier translation infrared spectroscope(FT-IR),N_2adsorption/desorption at 77 K and CO_2sorption measurements were used to characterize the as-prepared Zn-MOF_5s.The experimental results showthat additives of NH_3,CH_3OH,HCl and KOH in the synthesis of the Zn-MOF_5s do not change the underlying topology,but they are extremely sensitive to the pore textural properties,thus changing the CO_2adsorption capacity.Additives would lower the pore width and the surface area,and then lower the CO_2adsorption capacity of Zn-MOF_5s. 展开更多
关键词 Zn-MOF5s additIVES INFLUENCE CO2 adsorption capacity nanocrystal
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EFFECTS OF Pb COMPOUND ADDITIVES ON THE PROPERTIES OF YBa_2Cu_3O_(7-δ) 被引量:3
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作者 F.H.Li Z.G.Fan +3 位作者 J.Wang C.S.Liu D.W.Soh Y.J.Cho 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2005年第2期145-148,共4页
The melting temperature and critical transition temperature Tc of YBa2Cu3O7-δ with deferent content additives of PbO and BaPbO3 were studied. When PbO was doped in YBa2Cu3O7-δ, the melting temperature of YBa2Cu3O7-... The melting temperature and critical transition temperature Tc of YBa2Cu3O7-δ with deferent content additives of PbO and BaPbO3 were studied. When PbO was doped in YBa2Cu3O7-δ, the melting temperature of YBa2Cu3O7-δ was reduced, however its superconductivity was weakened. From the XRD pattern of the sintered mixture of YBa2Cu3O7-δ and PbO, it was known that there was a reaction between YBa2Cu3O7-δ and PbO, and the product was BaPbO3. Hence different contents of BaPbO3 (10mass%, 20mass% and 30mass%) were added in YBa2Cu3O7-δ. It was proved that there were no reactions between YBa2Cu3O7-δ and BaPbO3. And the superconductivity of the mixtures was much better than that of the samples with PbO additive. 展开更多
关键词 YBA2CU3O7-Δ PbO additive melting temperature SUPERCONDUCTIVITY
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基于XGBoost-SHAP的钢管混凝土柱轴向承载力预测模型 被引量:4
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作者 陈曦泽 贾俊峰 +2 位作者 白玉磊 郭彤 杜修力 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2023年第6期1061-1070,共10页
为了可靠、准确地预测钢管混凝土(CFST)柱的轴向承载力,建立和解释集成机器学习的CFST柱轴向承载力预测模型.使用马氏距离评估CFST柱数据库质量,通过极限梯度提升(XGBoost)算法建立CFST柱轴向承载力预测模型,使用K折交叉验证(K-Fold CV... 为了可靠、准确地预测钢管混凝土(CFST)柱的轴向承载力,建立和解释集成机器学习的CFST柱轴向承载力预测模型.使用马氏距离评估CFST柱数据库质量,通过极限梯度提升(XGBoost)算法建立CFST柱轴向承载力预测模型,使用K折交叉验证(K-Fold CV)和树结构概率密度估计(TPE)算法寻找模型的最优超参数组合.采用不同评价指标将优化后XGBoost模型的预测值与已有方法和未优化XGBoost模型的计算值比较.使用SHAP方法给出XGBoost模型预测结果的整体和局部的解释.结果表明,经过超参数调整优化的XGBoost模型的性能超越了相关规范和经验公式的性能,且SHAP方法能够有效地解释XGBoost模型的输出. 展开更多
关键词 钢管混凝土(CFST)柱 轴向承载力 极限梯度提升(XGBoost) 超参数优化 SHAP 可解释性
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Railroad capacity tools and methodologies in the U.S. and Europe 被引量:2
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作者 Hamed Pouryousef Pasi Lautala Thomas White 《Journal of Modern Transportation》 2015年第1期30-42,共13页
A growing demand for passenger and freight transportation, combined with limited capital to expand the United States (U.S.) rail infrastructure, is creating pressure for a more efficient use of the current line capa... A growing demand for passenger and freight transportation, combined with limited capital to expand the United States (U.S.) rail infrastructure, is creating pressure for a more efficient use of the current line capacity. This is further exacerbated by the fact that most passenger rail services operate on corridors that are shared with freight traffic. A capacity analysis is one alternative to address the situation and there are various approaches, tools, and methodologies available for application. As the U.S. continues to develop higher speed passenger services with similar characteristics to those in European shared-use lines, understanding the common methods and tools used on both continents grows in relevance. There has not as yet been a detailed investigation as to how each continent approaches capacity analysis, and whether any benefits could be gained from cross-pollination. This paper utilizes more than 50 past capacity studies from the U.S. and Europe to describe the different railroad capacity defini- tions and approaches, and then categorizes them, based on each approach. The capacity methods are commonly di- vided into analytical and simulation methods, but this paper also introduces a third, "combined simulation- analytical" category. The paper concludes that Europeanrail studies are more unified in terms of capacity, concepts, and techniques, while the U.S. studies represent a greater variation in methods, tools, and objectives. The majority of studies on both continents use either simulation or a combined simulation-analytical approach. However, due to the significant differences between operating philosophy and network characteristics of these two rail systems, European studies tend to use timetable-based simulation tools as opposed to the non-timetable-based tools commonly used in the U.S. rail networks. It was also found that validation of studies against actual operations was not typically completed or was limited to comparisons with a base model. 展开更多
关键词 Railroad capacity - Simulation - Railroadoperation ~ The U.S. and European railway characteristics
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Chloro-propylene Sulfite as Electrolyte Additive for Li/S Batteries
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作者 Guo Xiang XU Qi LU Lei WEN Ping HE 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第4期557-560,共4页
Chloro-propylene sulfite (CIPS) was employed as electrolyte additive of Li/S batteries for the first time. Linear potential sweep test showed that the CIPS keeps high electrochemical stability even under the voltage... Chloro-propylene sulfite (CIPS) was employed as electrolyte additive of Li/S batteries for the first time. Linear potential sweep test showed that the CIPS keeps high electrochemical stability even under the voltage of 5.0V. Being used as electrolyte additive in Li/S batteries, CIPS displayed an excellent property for self-discharge prohibition. With CIPS additive the Li/S cells initial discharge capacity was 856.2 mAh·g^-1 and 830.8 mAh·g^-1 at the current density of 15 mA.g and 30 mA·g^-1 , after 30 cycles the discharge capacities were contained at as high as 753.8 mAh.g and 715.6 mAh·g^-1. By means of infrared spectra, TG/DTA experiment and element conten analysis the speculated reason of CIPS's novel function as additive was proposed. 展开更多
关键词 Chloro-propylene sulfite Li/S battery additIVE SELF-DISCHARGE capacity cycle.
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Grain selection and growth orientation of prior-β phase for Ti-6-4 during additive manufacturing:insights from a modeling perspective
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作者 Wei-zhao Sun Fei-hu Shan +2 位作者 Nan-fu Zong Hong-biao Dong Tao Jing 《China Foundry》 SCIE CAS 2021年第2期83-93,共11页
The microstructure of Ti-6-4 components produced by additive manufacturing suffers from the coarse and elongated prior-β grain,which leads to a decrease of the tensile behavior and the occurrence of anisotropy.To und... The microstructure of Ti-6-4 components produced by additive manufacturing suffers from the coarse and elongated prior-β grain,which leads to a decrease of the tensile behavior and the occurrence of anisotropy.To understand and control the grain evolution,a multiscale simulation is applied to investigate the relationship between the grain selection,growth orientation,and the molten pool morphology with the different deposition layer numbers and processing parameters.The accuracy of the simulation is validated by experiments in both qualitative and quantitative ways.Results show that when the grain with unfavorable orientation loses the competitive growth with its neighbors,there will be a great chance that the blocked grain is eliminated in the following layer-and-layer deposition,which leads to the increase of the grain width.The size of the molten pool increases remarkably as the layer number increases,which lays a heavy burden on the stability of the molten pool.The analytical relationship between the molten pool morphology and the grain growth orientation is also deduced.The flat molten pool causes the grains with the <001> direction close to the building direction to have greater survival potential.Besides,decreasing the line power energy shows little effect on the stability of the molten pool and the grain growth orientation,especially when the deposited layer number is large.The revealing mechanisms will help in understanding and further controlling the grain evolution. 展开更多
关键词 additive manufacturing Ti-6-4 simulation grain selection grain growth
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Heat Capacities and Thermodynamic Properties of 3-(2,2-Dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic Acid
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作者 XUE Bin WANG Jian-ya +1 位作者 TAN Zhi-cheng WU Tong-hao 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2007年第4期460-464,共5页
The heat capacities of 3-( 2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid (a racemic mixture, molar ratio of cis-/trans-structure is 35/65) in a temperature range from 78 to 389 K were measured with ... The heat capacities of 3-( 2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylic acid (a racemic mixture, molar ratio of cis-/trans-structure is 35/65) in a temperature range from 78 to 389 K were measured with a precise automatic adiabatic calorimeter. The sample was prepared with a purity of 98.75% ( molar fraction). A solid-liquid fusion phase transition was observed in the experimental temperature range. The melting point, Tm, enthalpy and en- tropy of fusion, △fusHm, △fusSm, of the acid were determined to be (331.48±0.03 ) K, (16.321±0.031) kJ/mol, and (49.24±0.19) J/( K·mol), respectively. The thermodynamic functions of the sample, Ht-H298.15, Sr-S298.15 and Gr-G298.15, were reported at a temperature intervals of 5 K. The thermal decomposition of the sample was studied using thermogravimetric(TG) analytic technique, the thermal decomposition starts at ca. 418 K and ends at ca. 544 K, the maximum decomposition rate was obtained at 510 K. The order of reaction, preexponential factor and activation energy are n =0.23, A =7.3 ×10^7 min^-1 , E =70.64 kJ/mol, respectively. 展开更多
关键词 3-(2 2-Dichloroethenyl)-2 2-dimethylcyclopropanecarboxylic acid Adiabatic calorimetry Heat capacity Thermodynamic function Thermal decomposition
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Low-temperature heat capacities and standard molar enthalpy of formation of 4-(2-aminoethyl)-phenol (C_8H_(11)NO)
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作者 邸友莹 孔玉霞 +1 位作者 杨伟伟 谭志诚 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第9期3276-3283,共8页
This paper reports that low-temperature heat capacities of 4-(2-aminoethyl)-phenol (C8H11NO) are measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial eq... This paper reports that low-temperature heat capacities of 4-(2-aminoethyl)-phenol (C8H11NO) are measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of heat capacities as a function of the temperature was fitted by the least square method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15K were calculated and tabulated at the interval of 5K. The energy equivalent, εcalor, of the oxygen-bomb combustion calorimeter has been determined from 0.68g of NIST 39i benzoic acid to be εcalor=(14674.69±17.49)J·K^-1. The constant-volume energy of combustion of the compound at T=298.15 K was measured by a precision oxygen-bomb combustion calorimeter to be ΔcU=-(32374.25±12.93)J·g^-1. The standard molar enthalpy of combustion for the compound was calculated to be ΔcHm = -(4445.47 ± 1.77) kJ·mol^-1 according to the definition of enthalpy of combustion and other thermodynamic principles. Finally, the standard molar enthalpy of formation of the compound was derived to be ΔfHm(C8H11NO, s)=-(274.68 ±2.06) kJ·mol^-1, in accordance with Hess law. 展开更多
关键词 4-(2-aminoethyl)-phenol adiabatic calorimetry low-temperature heat capacity standard molar enthalpy of formation
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Molar heat capacities of La_2Mo_2O_9 and La_(1.9)Sr_(0.1)Mo_2O_(9-δ)
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作者 Baijun Yan Jianhua Liu Yunduo Dai Qifeng Shu Zhihua Ren 《Journal of University of Science and Technology Beijing》 CSCD 2007年第5期395-398,共4页
The molar heat capacities of La2Mo209 and La1.9Sr0.1MO209-δ were obtained using the differential scanning calorimetry (DSC) technique in a temperature range from 298 to 1473 K. The DSC curve of La2Mo209 showed an e... The molar heat capacities of La2Mo209 and La1.9Sr0.1MO209-δ were obtained using the differential scanning calorimetry (DSC) technique in a temperature range from 298 to 1473 K. The DSC curve of La2Mo209 showed an endothermal peak around 834 K corresponding to a first-order monoclinic-cubic phase transition, and the enthalpy change accompanying this phase transition is 5.99 kJ/mol. No evident endothermal peak existed in the DSC curve of La1.9Sr0.1MO209-δ, but a broad thermal anomaly existed in its heat capacity curve at around 832 K. In addition, the heat capacity values of La2Mo209 and La1.9Sr0.1MO209-δ began to decrease at 1196 and 1330 K, respectively. The non-transitional heat capacity values of La2Mo209 and La1.9Sr0.1MO209-δ were formulated using multiple regression analysis in two temperature ranges. 展开更多
关键词 heat capacity phase transition La2M0209 La1.9Sr0.1MO209-δ DSC
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中草药对产蛋后期坝上长尾鸡产蛋性能、蛋品质、血清抗氧化性、激素水平和免疫因子的影响 被引量:2
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作者 于禧凝 李琴 +5 位作者 张馨 闫婧较 赵志强 林向前 李杰峰 范春艳 《饲料研究》 CAS 北大核心 2024年第5期38-42,共5页
试验旨在研究中草药对产蛋后期坝上长尾鸡产蛋性能、蛋品质和血清指标的影响。试验选取240羽470日龄的坝上长尾鸡,随机分为4组,每组6个重复,每个重复10羽鸡。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加1.0%、1.5%和2.0%的中草药添... 试验旨在研究中草药对产蛋后期坝上长尾鸡产蛋性能、蛋品质和血清指标的影响。试验选取240羽470日龄的坝上长尾鸡,随机分为4组,每组6个重复,每个重复10羽鸡。对照组饲喂基础饲粮,试验组分别在基础饲粮中添加1.0%、1.5%和2.0%的中草药添加剂。预试期7 d,正式试验期56 d。结果显示,与对照组相比,1.5%剂量组产蛋率显著升高(P<0.05),1.0%、2.0%剂量组鸡蛋的平均蛋重显著升高(P<0.05);1.0%、1.5%剂量组鸡蛋的哈夫单位有升高趋势(P>0.05),1.5%剂量组鸡蛋的蛋壳厚度显著升高(P<0.05);1.5%剂量组血清中谷胱甘肽过氧化物歧化酶(GSH-Px)活性显著升高(P<0.05);试验各组血清中促黄体激素(LH)、雌二醇(E2)和孕酮(Prog)水平极显著升高(P<0.01),1.5%、2.0%剂量组血清中促卵泡激素(FSH)水平极显著升高(P<0.01);1.5%、2.0%剂量组血清中γ干扰素(IFN-γ)水平极显著升高(P<0.01),2.0%剂量组血清中白细胞介素-2 (IL-2)水平极显著升高(P<0.01)。研究表明,饲粮中添加中草药添加剂可提高产蛋后期坝上长尾鸡的产蛋率,改善蛋品质,增强机体抗氧化能力,促进生殖激素的分泌,提高了免疫功能,中草药适宜添加量为1.5%。 展开更多
关键词 中草药添加剂 坝上长尾鸡 产蛋性能 蛋品质 抗氧化能力 生殖激素 免疫因子
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酯交换法合成D-异抗坏血酸棕榈酸酯及其抗氧化性能 被引量:12
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作者 郑大贵 肖竹平 +3 位作者 叶红德 叶青 余泗莲 谢国豪 《精细化工》 EI CAS CSCD 北大核心 2004年第6期450-451,480,共3页
24℃下,2.9gD 异抗坏血酸和3.8g棕榈酸甲酯分别缓慢加入到14mL的浓硫酸中,搅拌反应24h。反应混合物加入到冰水中,用乙醚萃取,洗涤,除去乙醚,粗产品用甲苯重结晶,得到4.6gD 异抗坏血酸棕榈酸酯,产率79%。用FTIR对产品进行了表征。按国标(... 24℃下,2.9gD 异抗坏血酸和3.8g棕榈酸甲酯分别缓慢加入到14mL的浓硫酸中,搅拌反应24h。反应混合物加入到冰水中,用乙醚萃取,洗涤,除去乙醚,粗产品用甲苯重结晶,得到4.6gD 异抗坏血酸棕榈酸酯,产率79%。用FTIR对产品进行了表征。按国标(GB/T5009.37—1996)方法将产品用于新鲜茶籽油进行抗氧化性能实验,结果表明,D 异抗坏血酸棕榈酸酯是一种比L 抗坏血酸棕榈酸酯更好的油溶性抗氧化剂。 展开更多
关键词 D-异抗坏血酸 L-异抗坏血酸 棕榈酸甲酯 抗氧化性能 食品添加剂
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施氮对松嫩平原栽培羊草地生产性能和土壤养分的影响
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作者 王雪珊 孔晓蕾 +4 位作者 刘杰淋 张强 彭大庆 于利民 刘新鹏 《草业科学》 CAS CSCD 北大核心 2024年第7期1606-1613,共8页
为明确施氮对栽培草地生产性能及土壤养分的影响,本研究以栽培羊草(Leymus chinensis)地为研究对象,采用随机区组设计,设置不同施氮处理[N0(0 kg·hm^(-2))、N1 (42 kg·hm^(-2))、N2(84 kg·hm^(-2))、N3(126 kg·hm^(... 为明确施氮对栽培草地生产性能及土壤养分的影响,本研究以栽培羊草(Leymus chinensis)地为研究对象,采用随机区组设计,设置不同施氮处理[N0(0 kg·hm^(-2))、N1 (42 kg·hm^(-2))、N2(84 kg·hm^(-2))、N3(126 kg·hm^(-2))],通过连续两年(2018年、2019年)试验观测,分析不同施氮水平下栽培羊草地的株高、干物质产量及土壤p H、有机质、全氮、碱解氮、全磷和速效磷变化特征。结果表明,施氮后羊草的株高和干物质产量随施氮量的增加呈先增加后减小的变化趋势,在施氮量为84 kg·hm^(-2)(N2处理)时表现最好,随后呈下降趋势。2018年和2019年,在N2处理下羊草的干物质产量较N0分别提高了43.20%(P <0.05)和22.15%。与N0相比,N2处理显著提高了2019年0-10 cm土壤全氮和全磷含量,但对p H影响不显著。相关分析表明,羊草的株高、干物质产量与土壤全磷、速效磷和有机质含量呈显著正相关关系(P <0.05),与土壤p H呈极显著负相关关系(P <0.01)。综合分析,当氮肥施用量为84 kg·hm^(-2)时,对松嫩平原栽培羊草地的羊草生产和土壤肥力改善效果最好。 展开更多
关键词 羊草 氮添加 刈割 生产能力 土壤肥力 松嫩平原 退化草地
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基于灰色-马尔科夫残差预测模型的甘南草地载畜量预测 被引量:13
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作者 赵有益 林慧龙 +1 位作者 张定海 任继周 《农业工程学报》 EI CAS CSCD 北大核心 2012年第15期199-204,共6页
为了预测草地实际载畜量与理论载畜量,为草地畜牧业的可持续发展提供理论依据和决策支持基础,通过对甘南州4个县市1998-2009年的草地实际载畜量和理论载畜量数据分析,以灰色GM(1,1)模型和马尔科夫预测模型为基础,建立了优化改进的灰色... 为了预测草地实际载畜量与理论载畜量,为草地畜牧业的可持续发展提供理论依据和决策支持基础,通过对甘南州4个县市1998-2009年的草地实际载畜量和理论载畜量数据分析,以灰色GM(1,1)模型和马尔科夫预测模型为基础,建立了优化改进的灰色等维—马尔科夫残差预测模型,以甘南州合作市实际载畜量为实例进行验证,预测结果显著(p<0.01),预测误差低于7.06%,表明该预测模型精度较高,适用于对草地载畜量的预测研究。最后,利用该模型对2010-2014年甘南州4县市草地实际载畜量和理论载畜量进行预测分析,基本符合草地载畜量实际变化过程,为相关部门合理确定草地载畜量和进行科学草地管理提供参考。 展开更多
关键词 模型 预测 分析 灰色-马尔科夫残差模型 等维递补 载畜量 甘南草地
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离子强度对膨润土/木质素磺酸钠接枝丙烯酰胺-马来酸酐复合吸附树脂吸附Pb^(2+)/Cu^(2+)的影响 被引量:4
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作者 姚庆鑫 谢建军 +2 位作者 刘军霞 唐丽萍 刘元 《应用化学》 CAS CSCD 北大核心 2015年第8期940-947,共8页
为揭示外加电解质离子强度对重金属离子吸附的影响规律与内在机制,制备了膨润土/木质素磺酸钠接枝丙烯酰胺-马来酸酐复合吸附树脂(BLPAMA),研究了外加电解质离子强度对BLPAMA吸附单一和二元Pb2+/Cu2+的影响规律,以及有、无外加0.2 mol/L... 为揭示外加电解质离子强度对重金属离子吸附的影响规律与内在机制,制备了膨润土/木质素磺酸钠接枝丙烯酰胺-马来酸酐复合吸附树脂(BLPAMA),研究了外加电解质离子强度对BLPAMA吸附单一和二元Pb2+/Cu2+的影响规律,以及有、无外加0.2 mol/L Na NO3时BLPAMA对二元Pb2+/Cu2+的吸附等温线、吸附热力学及吸附动力学。结果表明,在单一Pb2+或Cu2+溶液中,随离子强度增加,Pb2+和Cu2+吸附量降低;在二元Pb2+/Cu2+溶液中,随离子强度增加,Pb2+吸附量降低而Cu2+吸附量提高。 展开更多
关键词 木质素 吸附 离子强度 外加电解质 重金属离子
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电弧增材制造T形件连接节点力学性能研究
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作者 张博 叶俊 +3 位作者 刘念武 林晓阳 王震 汤慧萍 《中国有色金属学报》 EI CAS CSCD 北大核心 2024年第4期1190-1200,共11页
电弧增材制造(WAAM)技术在结构工程领域有着广泛的应用前景,具有生产效率高、设备成本低、材料利用率高和环境可持续性等优点。为了探究WAAM碳钢T形件连接节点的力学性能,设计一系列共12组由WAAM碳钢T形件、高强钢(HSS)T形件和高强螺栓... 电弧增材制造(WAAM)技术在结构工程领域有着广泛的应用前景,具有生产效率高、设备成本低、材料利用率高和环境可持续性等优点。为了探究WAAM碳钢T形件连接节点的力学性能,设计一系列共12组由WAAM碳钢T形件、高强钢(HSS)T形件和高强螺栓组成的连接节点试件,通过试验研究螺栓线位置与螺栓排列方式对试件初始刚度、破坏模式及极限承载力的影响。采用三维激光扫描技术测量WAAM碳钢T形件相关几何参数,采用数字图像相关技术(DIC)辅助测量了T形件连接节点在加载过程中的位移响应。结果表明:WAAM碳钢T形件具有较好的力学性能,当螺栓线与腹板翼缘连接处距离减小时,试件的初始刚度与极限承载力均呈上升趋势,而失效模式均为预期的翼缘破坏,且螺栓未发生断裂。通过对比试验结果和现有设计规程计算结果,对相关计算方法的适用性与准确性进行评估,发现现有设计方法高估了试件的初始刚度,对破坏模式的预测较为准确,但对极限承载力的预测偏保守。最后,对已有计算模型进行修正,修正后的计算模型对连接节点极限承载力的预测效果较好。 展开更多
关键词 电弧增材制造 T形件 连接节点 初始刚度 破坏模式 极限承载力
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