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Nitrogen distribution in the products from the hydrothermal liquefaction of sp. and sp.

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 985-995 doi: 10.1007/s11705-021-2126-y

摘要: The high contents of nitrogen-containing organic compounds in biocrude obtained from hydrothermal liquefaction of microalgae are one of the most concerned issues on the applications and environment. In the project, Chlorella sp. and Spirulina sp. were selected as raw materials to investigate the influence of different reaction conditions (i.e., reaction temperature, residence time, solid loading rate) on the distribution of nitrogen in the oil phase and aqueous phase. Three main forms of nitrogen-containing organic compounds including nitrogen-heterocyclic compounds, amide, and amine were detected in biocrudes. The contents of nitrogen-heterocyclic compounds decreased with temperature while amide kept increasing. The effect of residence time on the components of nitrogen-containing organic compounds was similar with that of temperature. However, the influence of solid loading rate was insignificant. Moreover, it was also found that the differences of amino acids in the protein components in the two microalgae might affect the nitrogen distribution in products. For example, nitrogen in basic amino acids of Spirulina sp. preferred to go into the aqueous phase comparing with the nitrogen in neutral amino acids of Chlorella sp. In summary, a brief reaction map was proposed to describe the nitrogen pathway during microalgae hydrothermal liquefaction.

关键词: microalgae     hydrothermal liquefaction     biocrude     nitrogen distribution    

BORON:面向普适计算的超轻量低功耗加密设计 Article

Gaurav BANSOD,Narayan PISHAROTY,Abhijit PATIL

《信息与电子工程前沿(英文)》 2017年 第18卷 第3期   页码 317-331 doi: 10.1631/FITEE.1500415

摘要: BORON是一种替换、互换网络,运行于64位纯文本上,支持128位或80位密钥长度。与轻量加密LED相比,BORON具有更低的功耗水平;与现有SP网络加密相比,BORON具有更高的吞吐量。本文还展示了BORON的安全性分析及其作为超轻量紧凑型加密的性能。

关键词: 轻量密码;SP网络;分组密码;物联网;加密;嵌入式安全    

EXTRACTION AND EVALUATION OF EDIBLE OIL FROM SCHIZOCHYTRIUM SP. USING AN AQUEOUS ENZYMATIC METHOD

《农业科学与工程前沿(英文)》 2021年 第8卷 第4期   页码 623-634 doi: 10.15302/J-FASE -2021400

摘要:

Schizochytrium sp., a marine microalga, is a potential source of edible oil due to its short growth cycle and rapid lipid accumulation, especially of docosahexaenoic acid. An approach to isolate edible microalgal oil from Schizochytrium sp. using aqueous enzymatic extraction (AEE) was developed. Parameters were optimized by single-factor experiments followed by Box-Behnken design. Proteases were effective in extracting oil. The maximum free oil recovery (49.7%±0.58%) and total oil recovery (68.1%±0.94%) were obtained under optimum conditions of liquid-to-solid ratio of 4.8:1, a 2.5% enzyme concentration of papain and an extraction time of 2.2 h. There was a significant difference (P<0.05) in polyunsaturated fatty acid composition between microalgal oil obtained by AEE and by Soxhlet extraction, with the former having superior physiochemical properties and higher concentrations of bioactive components including total phenolic compounds and total tocopherols. These findings indicate a potential application of AEE for extraction of oil from Schizochytrium sp.

 

关键词: antioxidant activity / aqueous enzymatic extraction / edible microalgal oil / fatty acid composition / physicochemical properties    

Cultivation of sp. HQ in inland saline-alkaline water under different light qualities

《环境科学与工程前沿(英文)》 2022年 第16卷 第4期 doi: 10.1007/s11783-021-1479-2

摘要:

• Optimal growth of Chlorella in inland saline-alkaline water was achieved by blue LED.

关键词: Light quality     Chlorella     Inland saline-alkaline water     Fatty acid     Biodiesel property    

of cultivation strategies on the cultivation of Chlorella sp

Xiaoya Liu, Yu Hong, Peirui Liu, Jingjing Zhan, Ran Yan

《环境科学与工程前沿(英文)》 2019年 第13卷 第5期 doi: 10.1007/s11783-019-1162-z

摘要: Heterotrophic cultivation caused high level of ROS and high lipids accumulation. HMTC is the best culture strategy for improving the microalgal biomass. Chlorella sp. HQ had great nutrient removal capacity under five culture strategies. The effects of cultivation strategies (including autotrophic cultivation (AC), heterotrophic cultivation (HC), fed-batch cultivation (FC), heterotrophic+ autotrophic two-stage cultivation (HATC), and heterotrophic+ mixotrophic two-stage cultivation (HMTC)) on the growth and lipid accumulation of Chlorella sp. HQ and its total nitrogen (TN) and total phosphorus (TP) removal in secondary effluent were investigated in column photoreactors. The results showed that the TN and TP removal rates ranged between 93.72%–95.82% and 92.73%–100%, respectively, under the five different strategies. The microalgal growth potential evaluated by the maximal growth rate (Rmax) was in the order of HMTC>HC>FC>AC>HATC. The values of biomass, total lipid yield, triacylglycerols (TAGs) yield, and total lipid content of the microalga cultivated in the last 5 d increased significantly, but the TAGs productivities of the five strategies were lower than those in the first 7 d. Compared with all the other cultivation strategies, the TAGs productivity and yield after 12 d of cultivation under the heterotrophic condition reached the highest values accompanying the highest level of intracellular reactive oxygen species (ROS), in which the TAGs yield reached 40.81 mg/L at the end of the cultivation period. The peaks in TAGs yield and ROS level suggested that HC was beneficial for lipids accumulation via regulating the cellular redox status and exerting ROS stress on microalgal cells. In summary, HMTC was the best cultivation strategy for improving the microalgal biomass and HC was the best strategy for microalgal TAGs accumulation to produce biodiesel.

关键词: Chlorella sp. HQ     Cultivation strategy     lipids     Nitrogen removal     Phosphorus removal     Reactive oxygen species    

Comparison of growth and lipid accumulation properties of two oleaginous microalgae under different nutrient conditions

Qiao ZHANG,Yu HONG

《环境科学与工程前沿(英文)》 2014年 第8卷 第5期   页码 703-709 doi: 10.1007/s11783-014-0649-x

摘要: This study compared the growth and lipid accumulation properties of two oleaginous microalgae, namely, sp. LX1 and sp. HQ, under different nutrient conditions. Both algal species obtained the highest biomass, lipid content and lipid yield under low-nutrient conditions (mBG11 medium). The biomass, lipid content and lipid yield of sp. LX1 were 0.42 g·L , 22.5% and 93.8 mg·L , respectively. These values were relatively higher than those of sp. HQ (0.30 g·L , 17.1% and 51.3 mg·L , respectively). These algae were then cultivated in an SE medium that contained more nutrients; as a result, the biomass and lipid yield of sp. LX1 reduced more significantly than those of sp. HQ. Opposite results were observed in lipid and triacylglycerols (TAGs) contents. The cell sizes of both algal species under low-nutrient conditions were larger than those under high-nutrient conditions. sp. HQ cells did not aggregate, but sp. LX1 cells flocculated easily, particularly under low-nutrient conditions. In summary, low-nutrient conditions favour the growth and lipid production of both algae, but sp. LX1 outperforms sp. HQ.

关键词: Scenedesmus sp. LX1     Chlorella sp. HQ     growth rate     algal biomass     lipid accumulation     triacylglycerols (TAGs)    

Studies on culture condition of new marine bacterium sp. SY01

LAN Wenjian, MO Linfeng, LI Houjin, CAI Chuanghua, ZHOU Yipin, YAO Junhua

《化学科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 443-446 doi: 10.1007/s11705-008-0065-5

摘要: New marine bacterium sp. SY01, producer of prodigiosin, was isolated from the seawaters of Sanya Bay. The culture conditions of this bacterium were investigated. sp. SY01 was cultured in 2216E media which contained tryptophan, histidine, lactonic acid, camphor, limonene, casein, diphenyl guanidine, coumarin and 1,3-dinitrobenzene, respectively. After 5 days cultivation, the extracts of different culture broths were detected by direct infusion mass spectroscopy using positive ESI mode. As the results, tryptophan, histidine and casein didn’t show any observable influences on the biosynthesis of prodigiosin. Lactonic acid, camphor, limonene, diphenyl guanidine, coumarin could inhibit the bacterium growth and prodigiosin biosynthesis to a certain extent, slower the culture broth to turn red. However, 1, 3-dinitrobenzene inhibited the bacteria to produce prodigiosin completely. MS data suggested that various metabolites with chemodiversity were produced in different culture media. In particular, a series of high-molecular-weight compounds with high relative abundances were observed in the medium containing limonene. To further optimize the culture condition, more new prodigiosin analogues and lead compounds can be obtained and the goal of “one strain-many compounds” can be achieved.

关键词: producer     high-molecular-weight     relative     culture     different culture    

Effect of noble metal nanoparticle size on C–N bond cleavage performance in hydrodenitrogenation: a study of active sites

《化学科学与工程前沿(英文)》 2023年 第17卷 第12期   页码 1986-2000 doi: 10.1007/s11705-023-2337-5

摘要: Breakage of the C–N bond is a structure sensitive process, and the catalyst size significantly affects its activity. On the active metal nanoparticle scale, the role of catalyst size in C–N bond cleavage has not been clearly elucidated. So, Ru catalysts with variable nanoparticle sizes were obtained by modulating the reduction temperature, and the catalytic activity was evaluated using 1,2,3,4-tetrahydroquinoline and o-propylaniline with different C–N bond hybridization patterns as reactants. Results showed a 13 times higher reaction rate for sp3-hybridized C–N bond cleavage than sp2-hybridized C–N bond cleavage, while the reaction rate tended to increase first and then decrease as the catalyst nanoparticle size increased. Different concentrations of terrace, step, and corner sites were found in different sizes of Ru nanoparticles. The relationship between catalytic site variation and C–N bond cleavage activity was further investigated by calculating the turnover frequency values for each site. This analysis indicates that the variation of different sites on the catalyst is the intrinsic factor of the size dependence of C–N bond cleavage activity, and the step atoms are the active sites for the C–N bond cleavage. When Ru nanoparticles are smaller than 1.9 nm, they have a strong adsorption effect on the reactants, which will affect the catalytic performance of the Ru catalyst. Furthermore, these findings were also confirmed on other metallic Pd/Pt catalysts. The role of step sites in C–N bond cleavage was proposed using the density function theory calculations. The reactants have stronger adsorption energies on the step atoms, and step atoms have d-band center nearer to the Fermi level. In this case, the interaction with the reactant is stronger, which is beneficial for activating the C–N bond of the reactant.

关键词: sp3/sp2-hybridized C–N bond     noble metal nanoparticle     catalytic active site     turnover frequency     DFT    

Application of statistical design for the production of inulinase by

M. DILIPKUMAR, M. RAJASIMMAN, N. RAJAMOHAN

《化学科学与工程前沿(英文)》 2011年 第5卷 第4期   页码 463-470 doi: 10.1007/s11705-011-1112-1

摘要: A Plackett-Burman design was employed for screening 18 nutrient components for the production of inulinase using sp. and pressmud as the substrate via solid-state fermentation (SSF). From the experiments, three nutrients viz. yeast extract, FeSO ·7H O, and NH NO were found to be the most significant components. Hence these three components were selected and optimized using Response Surface Methodology (RSM). The optimum conditions are: yeast extract 0.00274 g/gds, FeSO ·7H O 0.00011 g/gds and NH NO 0.00772 g/gds. The effect of the substrate concentration and initial moisture content were also studied. A substrate concentration of 12 g and an initial moisture content of 65% are optimum for the maximum production of inulinase (89 U/gds).

关键词: inulinase     pressmud     Response Surface Methodology (RSM)     streptomyces sp    

Formation of disinfection byproducts from accumulated soluble products of oleaginous microalga after chlorination

Yu Liu, Qiao Zhang, Yu Hong

《环境科学与工程前沿(英文)》 2017年 第11卷 第6期 doi: 10.1007/s11783-017-0938-2

摘要: When microalgae are simultaneously applied for wastewater treatment and lipid production, soluble algal products (SAP) should be paid much attention, as they are important precursors for formation of disinfection byproducts (DBPs), which have potential risks for human health. sp. HQ is an oleaginous microalga that can generate SAP during growth, especially in the exponential phase. This study investigated the contribution of SAP from sp. HQ to DBP formation after chlorination. The predominant DBP precursors from SAP were identified with the 3D excitation-emission matrix fluorescence. After chlorination, a significant reduction was observed in the fluorescence intensity of five specific fluorescence regions, particularly aromatic proteins and soluble microbial by-product-like regions, accompanied with slight shifting of the peak. The produced DBPs were demonstrated to include trihalomethanes and haloacetic acids. As the algal cultivation time was extended in wastewater, the accumulated SAP strengthened the formation of DBPs. The trend for DBP formation was as follows: chloroform>dichloroacetic acid>trichloroacetic acid.

关键词: Chlorella sp. HQ     Chlorination     Disinfection byproducts     Fluorescence spectroscopy     Soluble algal products    

Effect of pH on biologic degradation of

Hongjing LI, Mengli HAO, Jingxian LIU, Chen CHEN, Zhengqiu FAN, Xiangrong WANG

《环境科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 224-230 doi: 10.1007/s11783-011-0314-6

摘要: In this paper, the effect of pH on biological degradation of by alga-lysing bacteria in laboratory-scale sequencing batch biofilm reactors (SBBRs) was investigated. After 10 d filming with waste activated sludge, the biological film could be formed, and the bioreactors in which laid polyolefin resin filler were used to treat algal culture. By comparing the removal efficiency of chlorophyll at different aerobic time, the optimum time was determined as 5 h. Under pH 6.5, 7.5, and 8.5 conditions, the removal rates of were respectively 75.9%, 83.6%, and 78.3% (in term of chlorophyll ), and that of Chemical Oxygen Demand (COD ) were 30.6%, 35.8%, and 33.5%. While the removal efficiencies of ammonia nitrogen ( ) were all 100%. It was observed that the sequence of the removal efficiencies of algae, and organic matter were pH 7.5>pH 8.5>pH 6.5. The results showed that the dominant alga-lysing bacteria in the SBBRs was strain HM-01, which was identified as sp. by Polymerase Chain Reaction (PCR) amplification of the 16S rRNA gene, Basic Local Alignment Search Tool (BLAST) analysis, and comparison with sequences in the GenBank nucleotide database. The algicidal activated substance which HM-01 strain excreted could withstand high temperature and pressure, also had better hydrophily and stronger polarity.

关键词: pH     biological degradation     alga-lysing bacteria     sequencing batch biofilm reactor (SBBR)     16S rRNA     Bacillus sp    

Determination of heterozygosity for avirulence/virulence loci through sexual hybridization of

Yuan TIAN,Gangming ZHAN,Xia LU,Jie ZHAO,Lili HUANG,Zhensheng KANG

《农业科学与工程前沿(英文)》 2017年 第4卷 第1期   页码 48-58 doi: 10.15302/J-FASE-2016114

摘要: Wheat stripe rust caused by f. sp. is one of the most devastating diseases of wheat worldwide and resistant cultivars are vital for its management. Therefore, investigating the heterozygosity of the pathogen is important because of rapid virulence changes in isolates heterozygous for avirulence/virulence. An isolate of f. sp. was selfed on to determine the heterozygosity for avirulence/virulence loci. One hundred and twenty progeny isolates obtained from this selfing were phenotyped using 25 lines of wheat containing genes and genotyped with 96 simple sequencing repeat markers, with 51 pathotypes and 55 multi-locus genotypes being identified. All of these were avirulent on lines with , , , and and virulent on lines with , and , indicating that the parental isolate was homozygously avirulent or homozygously virulent for these loci. Segregation was found for wheat lines with , , , , , , , , , , , , , , , and . The 17 cultivars to which the was identified as heterozygous with respect to virulence/avirulence should not be given priority in breeding programs to obtain new resistant cultivars.

关键词: Puccinia striiformis f. sp. tritici     selfing     heterozygosity     virulence inheritance    

Biosorption of mercury and lead by aqueous

Pratibha SANJENBAM, Kumar SAURAV, Krishnan KANNABIRAN

《化学科学与工程前沿(英文)》 2012年 第6卷 第2期   页码 198-202 doi: 10.1007/s11705-012-1285-2

摘要: Toxic heavy metals are increasingly accumulating in the environment worldwide and are considered to be life threatening contaminants. The biosorption of mercury and lead by marine actinomycetes isolated from marine sediment collected from the Bay of Bengal coast of Puducherry, India, was evaluated. The maximum tolerance concentration (MTC) of sp. was determined by a well diffusion method and a broth dilution method. The effects of the initial metal ion concentration, the pH and the biomass dosage on the biosorption of mercury and lead ions were investigated. The MTC of the isolate to metals was 200 mg·L for mercury and 1800 mg·L for lead. At neutral pH, the isolate had a maximum biosorption of metal ions of 200 mg·L and 150 mg·L for mercury and lead respectively. Fourier transform infrared (FTIR) absorption spectra showed the chemical interactions between the functional groups in the biomass such as hydroxyl (-OH), amine (-NH ), carboxyl (-COOH) and the metal ions. The isolate was further characterized by molecular taxonomy and identified as a member of the genus Based on the phenotypic and phylogenetic analysis, the strain was classified as a new species of the genus and designated as VITSVK9 sp. (HM137310). A blast search of the 16S rDNA sequence of the strain showed the most similarity (95%) with sp. A515 Ydz-FQ (EU384279). Based on the results, it can be concluded that this marine could be used as a biosorbent for the removal of heavy metal ions from aqueous environments.

关键词: mercury     lead     biosorption     maximum tolerance concentration     Streptomyces VITSVK9 sp.    

网络主权保障问题研究

邹鹏,何骏,邹红霞,刘韵洁

《中国工程科学》 2016年 第18卷 第6期   页码 8-12 doi: 10.15302/J-SSCAE-2016.06.002

摘要:

随着网络空间承载国家公共和私人利益的日益广泛,网络主权及其保障问题已引起了国际社会的高度重视。本文结合当前我国网络主权的现状,从网络独立权、网络平等权、网络自卫权和网络管辖权的角度分析了我国网络主权保障目前应当关注的主要问题,并给出了相应的对策建议,力求推动网络主权观的确立,增强我国在国际网络空间治理规则制定方面的话语权,提升维护国家网络空间安全利益的能力。

关键词: 网络主权     网络独立权     网络平等权     网络自卫权     网络管辖权     网络边防    

网络系统行为效用计算——概念与原理 Article

胡昌振

《工程(英文)》 2018年 第4卷 第1期   页码 78-84 doi: 10.1016/j.eng.2018.02.010

摘要:
网络的服务与应用是一个面向业务与任务的行为过程,其度量与评估目前尚处于粗略比较状态。本文把网络行为场景刻画为微分流形,根据光滑微分流形的同胚变换,给出了网络行为的数学定义,提出了网络行为路径及行为效用的数学描述。基于微分几何原理,提出了网络行为效用的计算原理与方法,并构建了基于行为效用的网络攻防对抗评估计算框架,从而奠定了网络行为定量度量和评估的数学基础。

关键词: 网络度量评估     微分流形     网络行为效用     网络攻防对抗    

标题 作者 时间 类型 操作

Nitrogen distribution in the products from the hydrothermal liquefaction of sp. and sp.

期刊论文

BORON:面向普适计算的超轻量低功耗加密设计

Gaurav BANSOD,Narayan PISHAROTY,Abhijit PATIL

期刊论文

EXTRACTION AND EVALUATION OF EDIBLE OIL FROM SCHIZOCHYTRIUM SP. USING AN AQUEOUS ENZYMATIC METHOD

期刊论文

Cultivation of sp. HQ in inland saline-alkaline water under different light qualities

期刊论文

of cultivation strategies on the cultivation of Chlorella sp

Xiaoya Liu, Yu Hong, Peirui Liu, Jingjing Zhan, Ran Yan

期刊论文

Comparison of growth and lipid accumulation properties of two oleaginous microalgae under different nutrient conditions

Qiao ZHANG,Yu HONG

期刊论文

Studies on culture condition of new marine bacterium sp. SY01

LAN Wenjian, MO Linfeng, LI Houjin, CAI Chuanghua, ZHOU Yipin, YAO Junhua

期刊论文

Effect of noble metal nanoparticle size on C–N bond cleavage performance in hydrodenitrogenation: a study of active sites

期刊论文

Application of statistical design for the production of inulinase by

M. DILIPKUMAR, M. RAJASIMMAN, N. RAJAMOHAN

期刊论文

Formation of disinfection byproducts from accumulated soluble products of oleaginous microalga after chlorination

Yu Liu, Qiao Zhang, Yu Hong

期刊论文

Effect of pH on biologic degradation of

Hongjing LI, Mengli HAO, Jingxian LIU, Chen CHEN, Zhengqiu FAN, Xiangrong WANG

期刊论文

Determination of heterozygosity for avirulence/virulence loci through sexual hybridization of

Yuan TIAN,Gangming ZHAN,Xia LU,Jie ZHAO,Lili HUANG,Zhensheng KANG

期刊论文

Biosorption of mercury and lead by aqueous

Pratibha SANJENBAM, Kumar SAURAV, Krishnan KANNABIRAN

期刊论文

网络主权保障问题研究

邹鹏,何骏,邹红霞,刘韵洁

期刊论文

网络系统行为效用计算——概念与原理

胡昌振

期刊论文