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增材制造 3

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2R-1C模型；嵌入式系统；参数估计；非迭代方法；二次型 1

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Ductile extension of 3-D external circumferential cracks in pipe structures

Wuchao YANG, Xudong QIAN

《结构与土木工程前沿（英文）》 2011年第5卷第3期页码 294-303 doi: 10.1007/s11709-011-0115-9

摘要： This study investigates the ductile fracture resistance of 3-D external circumferential cracks in the wall of a steel pipe under remote tension, using a damage-mechanism model originally proposed by Gurson and Tvergaard. The ductile crack extension utilizes an element extinction technique implemented in the computational cell framework. The key parameter for the computational cell method, i.e., the initial porosity ratio , is calibrated using both the fracture resistance and the load-deformation responses obtained from fracture tests of multiple single-edge bend [SE(B)] specimens made of high-strength steel, HY80, which has a yield strength of 630 MPa. The fracture resistance along the 3-D semi-elliptical crack front is computed from the calibrated cell model. Based on the similarity concept in the near-tip stress-strain fields, this study demonstrates that an equivalent 2-D axi-symmetric model provides conservative estimations of the fracture resistance for 3-D circumferential cracks in pipes.

关键词： ductile fracture computational cell method G-T model J-R curve

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Purification of

PIETZSCH, J. ULRICH

《化学科学与工程前沿（英文）》 2013年第7卷第1期页码 37-42 doi: 10.1007/s11705-013-1303-z

摘要： Here a case study of -asparaginase II out of a recombinant is presented. The target protein was obtained by simple cell disintegration and acetone precipitation. The -asparaginase II has been crystallized in three different forms in the following microbatch crystallization. The rod-shaped crystals (~400 μm edge length) were obtained at either 8°C or 22°C after 17 h by addition of PEG . The rectangular-shaped crystals were obtained after further recrystallization of the rod-shaped crystals. The rhombic-shaped crystals formed at 8°C after 12 days when cold ethanol was used instead of PEG . All crystallizations were performed in tris-acetate buffer (50 mmol·L , pH 5.1). By crystallization, the specific activity of -asparaginase II has increased 5-fold. The protein content and the purity of the crystals were evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The more concentrated -asparaginase II out of an extract mixture and the presence of only less minor proteins after crystallization demonstrates that crystallization is an effective and mild method to purify the target protein. The single crystal X-ray diffraction pattern reveals that the crystals are proteins and the X-ray powder diffraction (XRPD) pattern shows clearly that the crystals forming in PEG and ethanol have different crystal structures.

关键词： protein crystallization L-asparaginase II purification

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Optimization of cellulase production using

Saravanan P, Muthuvelayudham R, Rajesh Kannan R, Viruthagiri T

《化学科学与工程前沿（英文）》 2012年第6卷第4期页码 443-452 doi: 10.1007/s11705-012-1225-1

摘要： The potential of for cellulase production using pineapple waste as substrate has been investigated. A maximum cellulase activity of 9.23 U/mL is obtained under the optimum experimental conditions: pH (5.5), temperature (37.5°C), initial substrate concentration (3%), inoculum concentration (6.6 × 10 ?CFU/mL), and culture time (6 days). Box-Behnken design (BBD) statistical tool and genetic algorithm (GA) are used to optimize the process parameters. The BBD study of linear and quadratic interactive effects of experimental variables on the desired response of cellulase activity showed that the second order polynomial is significant ( = 0.9414). The experimental cellulase activity under the optimal conditions identified by the BBD is 9.23 U/mL and that by GA is 6.98 U/mL. This result indicates that the BBD model gives better result than GA in the present case.

关键词： cellulase pineapple waste Trichoderma reesei Box-Behnken design genetic algorithm

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The <italic>rpoSitalic> deficiency suppresses acetate accumulation in glucose-enriched culture of <italic>Escherichia coliitalic> under an aerobic condition

Prayoga SURYADARMA, Yoshihiro OJIMA, Yuto FUKUDA, Naohiro AKAMATSU, Masahito TAYA

《化学科学与工程前沿（英文）》 2012年第6卷第2期页码 152-157 doi: 10.1007/s11705-012-1287-0

摘要： The role of on the central carbon metabolism was investigated through analyzing the deficiency of this regulon gene under aerobic and glucose-enriched culture conditions. The experimental results showed that while the wild type cells exhibited an overflow metabolism effect, the -deleting mutation alleviated this effect with the significant suppression of acetate accumulation under a high glucose condition. This gene deletion also induced the twofold upregulation of and one-tenth downregulation of , respectively. The overflow metabolism effect was confirmed to be recovered by re-introducing gene into the mutant. These results demonstrated changed the central carbon metabolism toward acetate overflow through dehydrogenation of pyruvate and reduction of TCA cycle activity.

关键词： Escherichia coli rpoS aerobic and glucose-enriched culture overflow metabolism

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Purification of artemisinin from quercetin by anti-solvent crystallization

Chandrakant R. MALWADE, Haiyan QU, Ben-Guang RONG, Lars P. CHRISTENSEN

《化学科学与工程前沿（英文）》 2013年第7卷第1期页码 72-78 doi: 10.1007/s11705-013-1305-x

摘要： In the present work, anti-solvent crystallization of artemisinin from four different organic solvents (methanol, ethanol, acetonitrile, and acetone) was studied. Water was used as anti-solvent. The effect of an impurity (quercetin) on the performance of anti-solvent crystallization of artemisinin was investigated. The fundamental process data such as solubility of artemisinin in pure organic solvents and their binary mixtures with varying composition water were measured at room temperature. The solubility of quercetin was measured only in pure organic solvents at room temperature. Anti-solvent crystallization experiments were designed based on the fundamental process data determined. Firstly, the anti-solvent crystallization of artemisinin without impurity was performed from all four organic solvents and then the experiments were repeated with addition of an impurity (quercetin) while keeping all other process parameters constant. Two different concentrations of impurity, i.e., 10% and 50% of its solubility, in the respective organic solvents at room temperature were used. The effect of impurity on performance of anti-solvent crystallization was evaluated by comparing the yield and purity of the artemisinin obtained with those in the absence of impurity. Results of the present work demonstrated that the presence of quercetin in the solution does not affect the final yield of artemisinin from the solution of each of four organic solvents used. However, the purity of artemisinin crystals were reduced when quercetin concentration was 50% of its solubility in all solvents studied.

关键词： anti-solvent crystallization artemisinin quercetin solubility Artemisia annua

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Synthesis of depsipeptides from

Hongfei CAO, Yakai FENG, Heyun WANG, Li ZHANG, Musammir KHAN, Jintang GUO

《化学科学与工程前沿（英文）》 2011年第5卷第4期页码 409-415 doi: 10.1007/s11705-011-1141-9

摘要： By using the corresponding -amino acid sodium as initiator, -caprolactone-depsipeptides CL-Ala and CL-Leu were prepared by the reactions of -caprolactone (CL) with -alanine and -leucine, respectively, and -dioxanone-depsipeptide (PDO-Leu) was prepared by the reaction of -dioxanone (PDO) with -leucine. Two poly( -caprolactone) oligomers (PCL-Ala and PCL-Leu) of different molecular weights with depsipeptide unit were synthesized by controlling the feed ratio of -amino acid sodium and CL. The presence of the depsipeptide structure in these obtained products was confirmed by H NMR spectra and the molecular weight of the poly( -caprolactone) oligomers was measured by gel permeation chromatography (GPC). These products contain a hydroxyl group and a carboxyl group in one molecule, which means they could act as bifunctional monomers for further polymerization to prepare high molecular weight polymers. By this way, the depsipeptide unit could be introduced into the polymers and the biodegradation rates of the novel polymers could be well controlled in vivo by the tailored molecular structures.

关键词： ?-caprolactone p-dioxanone L-alanine L-leucine depsipeptide

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Design and operational considerations for selective catalytic reduction technologies at coal-fired boilers

Jeremy J. SCHREIFELS, Shuxiao WANG, Jiming HAO

《能源前沿（英文）》 2012年第6卷第1期页码 98-105 doi: 10.1007/s11708-012-0171-4

摘要： By the end of 2010, China had approximately 650 GW of coal-fired electric generating capacity producing almost 75% of the country’s total electricity generation. As a result of the heavy reliance on coal for electricity generation, emissions of air pollutants, such as nitrogen oxides (NO ), are increasing. To address these growing emissions, the Ministry of Environmental Protection (MEP) has introduced new NO emission control policies to encourage the installation of selective catalytic reduction (SCR) technologies on a large number of coal-fired electric power plants. There is, however, limited experience with SCR in China. It is therefore useful to explore the lessons from the use of SCR technologies in other countries. This paper provides an overview of SCR technology performance at coal-fired electric power plants demonstrating emission removal rates between 65% and 92%. It also reviews the design and operational challenges that, if not addressed, can reduce the reliability, performance, and cost-effectiveness of SCR technologies. These challenges include heterogeneous flue gas conditions, catalyst degradation, ammonia slip, sulfur trioxide (SO ) formation, and fouling and corrosion of plant equipment. As China and the rest of the world work to reduce greenhouse gas emissions, carbon dioxide (CO ) emissions from parasitic load and urea-to-ammonia conversion may also become more important. If these challenges are properly addressed, SCR can reliably and effectively remove up to 90% of NO emissions at coal-fired power plants.

关键词： nitrogen oxides (NO_x) coal selective catalytic reduction (SCR) air pollution control

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Assessment of toxicity of two nitroaromatic compounds in the freshwater fish

Hongyan SHEN, Jixi GAO, Jinsheng WANG

《环境科学与工程前沿（英文）》 2012年第6卷第4期页码 518-523 doi: 10.1007/s11783-012-0427-6

摘要： This study was conducted to evaluate the toxicological response of -nitrotoluene and -nitroaniline to the key fish species, . A freshwater fish bioassay based on the 96 h was used to estimate the single and joint toxicity of the two chemicals. The toxicity of -nitrotoluene was greater than that of -nitroaniline based on 96 h values of 40.74 mg·L and 48.99 mg·L , respectively. Both compounds had moderate toxicity toward , and this toxicity increased with the exposure duration and concentration. Binary mixtures of the compounds were more toxic than the individual compounds at 96 h, and they acted upon partial addition. When the exposure time was longer, the toxicity increased for mixtures of compounds with the same concentration or toxicity. The results of this study suggest that exposure to a combination of these chemicals would result in a higher environmental risk in aquatic systems than exposure to either compound alone. Further research is needed to investigate the combined effects and sublethal toxicity of -nitrotoluene and -nitroaniline, since they are both still used in China.

关键词： joint toxicity Cyprinus carpio LC₅₀ p-nitrotoluene p-nitroaniline toxic unit

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Investigations on color variations of <italic>Morpho rhetenoritalic> butterfly wing scales

Guanglan LIAO, Haibo ZUO, Xuan JIANG, Xuefeng YANG, Tielin SHI

《机械工程前沿（英文）》 2012年第7卷第4期页码 394-400 doi: 10.1007/s11465-012-0347-y

摘要：

Experiments and simulations are carried out to investigate the optical properties of butterfly wing scales. The upper surface of a male butterfly wing presents a single-layer of scales, the microstructures of which are responsible for the brilliant blue color. The color varies from cyan blue to yellow green and soon afterwards returns back to cyan blue when some ethanol is dropped on the upper surface. At the start of the ethanol volatilization process, the reflection spectrum remains stable. As the ethanol further volatilizes, the peak reflectance decreases slightly, then increases dramatically. Meanwhile, the peak wavelength keeps approximately constant, then decreases, and keeps almost stable at the end of the process. Therefore, the optical properties depend strongly on the varying ambient conditions, including the refractive index and the thickness of the packing medium. Moreover, the possible causes for the scales in dark green region after several dropping ethanol experiments are clarified. This research benefits our understanding of the color variation mechanisms of the wing scales, and provides inspiration for further studies and applications.

关键词： Morpho rhetenor microstructures color variations ambient medium

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Administration with

Qi RUI, Qin LU, Dayong WANG

《医学前沿（英文）》 2009年第3卷第1期页码 76-90 doi: 10.1007/s11684-009-0002-0

摘要： During normal metabolism, oxidative byproducts will inevitably generate and damage molecules thereby impairing their biological functions, including the aging process. (补肾抗衰方, ) is a traditional Chinese medicine widely used for clinically treating premature ovarian failure. In the present study, administration at high concentrations significantly increased lifespan, slowed aging-related decline, and delayed accumulation of aging-related cellular damage in wild-type . administration could further largely alleviate the aging defects induced by UV and oxidative stresses, and administration at different concentrations could largely rescue the aging defects in mutant animals. The protective effects of administration on aging process were at least partially dependent on the Ins/IGF-like signaling pathway. Moreover, administration at different concentrations obviously altered the expression patterns of antioxidant genes and suppressed the severe stress responses induced by UV and oxidative stresses, suggesting that -induced tolerance to UV or oxidative stress might result from reactive oxygen species scavenging. administration during development was not necessarily a requirement for UV and oxidative stress resistance, and the concentrations of administrated examined were not toxic for nematodes. Therefore, administration could effectively retrieve the aging defects induced by UV irradiation and oxidative stress in .

关键词： Bushenkangshuai Tang UV irradiation oxidative stress tissue senescence lifespan Caenorhabditis elegans

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Mutagenesis and selective breeding of a high producing

Tian WANG, Shiru JIA, Zhilei TAN, Yujie DAI, Shuai SONG, Guoliang WANG

《化学科学与工程前沿（英文）》 2012年第6卷第2期页码 179-183 doi: 10.1007/s11705-012-1273-6

摘要： -Poly- -lysine ( -PL) is an -lysine linear homopolymer, which is produced by bacteria belonging to the family and by ergot fungi. However, the production of -PL by the wild bacteria strain is very low, which limits its utilization. In most bacteria including the genus, -lysine is a precursor of -PL and is biosynthesized by the -aspartate pathway. Aspartokinase (Ask) is the first key enzyme in this pathway and is subject to complex regulation such as the feedback inhibition by the end product amino acids. In addition, phosphoenolpyruvate carboxykinase is feedback-regulated by -aspartate. To reduce these feedback inhibitions and to improve -PL productivity, resistant mutants were produced using sulfaguanidine (SG) + glycine+ -lysine+ -3-hydroxynorvaline (AHV) as selective markers. Using the interaction between -PL and the charged dye in the solid culture medium, hundreds of colonies were simultaneously screened in a quick and effective manner. Finally, one -PL-producing strain, L9, was selected. The productivity of this strain during flask fermentation was 0.77 g/L, which was 15% higher than that of the original strain. Moreover, its fermentation performance and genetic characteristics were very stable.

关键词： ?-poly-L-lysine plasma AHV Streptomyces diastatochromogenes fermentation

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Biosorption of Cd

Fengyu ZAN, Shouliang HUO, Beidou XI, Xiulan ZHAO

《环境科学与工程前沿（英文）》 2012年第6卷第1期页码 51-58 doi: 10.1007/s11783-011-0206-9

摘要： The biosorption of Cd and Cu onto the immobilized ( ) was investigated in this study. Adsorption kinetics, isotherms and the effect of pH were studied. The results indicated that the biosorption of Cd and Cu on the immobilized was fast at initial stage and then became slow. The maximum biosorption of heavy metal ions on immobilized were observed at pH 4 for Cd and Cu . by the pseudo-second-order model described the sorption kinetic data well according to the high correlation coefficient ( ) obtained. The biosorption isotherm was fitted well by the Langmuir model, indicating possible mono-layer biosorption of Cd and Cu on the immobilized . Moreover, the immobilized after the sorption of Cd and Cu could be regenerated and reused.

关键词： Saccharomyces cerevisiae (S. cerevisiae) biosorption heavy metals immobilization desorption

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What can be taught in architectural design? —

Xing RUAN

《结构与土木工程前沿（英文）》 2010年第4卷第4期页码 450-455 doi: 10.1007/s11709-010-0098-y

摘要： This essay begins with a reflection on what has been taught in architectural design since the turn of the twentieth century. I shall trace back to the two disciplinary foundations of the French école des Beaux-Arts – and – in the education of an architect in the eighteenth and nineteenth centuries. I shall then attempt to superimpose and on a modern disciplinary framework, say that of mathematics, which leads to musings on a series of architectural problems that include pattern versus type, stability versus mobility, orthogonal versus oblique, confinement versus transparency, and aging versus metallic sheen. These paradoxes, I suggest, demand the education of an architect to address both the instrumental pattern of a building configuration and the ambient felt qualities of a room, rather than vision alone.

关键词： architectural design teaching parti and poché

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Highly effective extraction of oil from soybean by pretreatment of solid-state fermentation with fungi

Xiaojuan NIU, Shuyi QIU, Yuangen WU, Jie YUAN, Yingying XU

《化学科学与工程前沿（英文）》 2011年第5卷第1期页码 122-125 doi: 10.1007/s11705-010-0533-6

摘要： The solid-state prefermentation by (CICC 2377) and (CICC 40536) was employed to increase the oil extraction yield from soybean. The influence of incubation time on oil yield was investigated. The maximum oil yield extracted from the substrate prefermented by for 96 h was 23%, which increased by 47.4% compared with control (15.6%). In the same fermentation conditions, the maximum oil yield extracted from substrate prefermented by was 21.6%, which increased by 38.5% compared with control (15.6%). The quality of soybean oil was not changed obviously by the pretreatment of fermentation with fungi.

关键词： soybean Aspergillus niger Aspergillus flavus solid-state fermentation extraction of oil

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Spatial and seasonal variations in bacterial communities of the Yellow Sea by T-RFLP analysis

Hongyuan WANG, Xiaolu JIANG, Ya HE, Huashi GUAN

《环境科学与工程前沿（英文）》 2009年第3卷第2期页码 194-199 doi: 10.1007/s11783-009-0018-3

摘要： Four typical coastal sites (rocky shore, sandy shore, mud flat shore, and artificial harbor) at the Yellow Sea were chosen to investigate the spatial and seasonal variations in bacterial communities. This was accomplished by using terminal restriction fragment length polymorphism (T-RFLP) analysis of PCR amplified 16S rDNA fragments. Two kinds of tetrameric restriction enzymes, I and I, were used in the experiment to depict the bacterial community diversity in different marine environments. It was found that the community compositions digested by the two enzymes separately were different. However, the results of bacterial community diversity derived from them were similar. The MDA analysis results of T-RFLP profiles coming from I and I both exhibited a significant seasonal community shift for bacteria and a relatively low spatial variation among the four locations. With I as the sample, the pair wise -tests also revealed that variations were minor between each pair of marine environments, with ranging from 0.198 to 0.349. However, the bacterial community structure in the mud flat site depicted a larger difference than each of the other three sites ( ranging from 0.282 to 0.349).

关键词： terminal restriction fragment length polymorphism (T-RFLP) bacterial community structure marine microbial diversity HhaI MspI

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标题作者时间类型操作

Ductile extension of 3-D external circumferential cracks in pipe structures

Wuchao YANG, Xudong QIAN

期刊论文

Purification of

PIETZSCH, J. ULRICH

期刊论文

Optimization of cellulase production using

Saravanan P, Muthuvelayudham R, Rajesh Kannan R, Viruthagiri T

期刊论文

The <italic>rpoSitalic> deficiency suppresses acetate accumulation in glucose-enriched culture of <italic>Escherichia coliitalic> under an aerobic condition

Prayoga SURYADARMA, Yoshihiro OJIMA, Yuto FUKUDA, Naohiro AKAMATSU, Masahito TAYA

期刊论文

Purification of artemisinin from quercetin by anti-solvent crystallization

Chandrakant R. MALWADE, Haiyan QU, Ben-Guang RONG, Lars P. CHRISTENSEN

期刊论文

Synthesis of depsipeptides from

Hongfei CAO, Yakai FENG, Heyun WANG, Li ZHANG, Musammir KHAN, Jintang GUO

期刊论文

Design and operational considerations for selective catalytic reduction technologies at coal-fired boilers

Jeremy J. SCHREIFELS, Shuxiao WANG, Jiming HAO

期刊论文

Assessment of toxicity of two nitroaromatic compounds in the freshwater fish