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901.
Xiaolin Huang Jun Xu Shuning Wang 《Journal of Optimization Theory and Applications》2012,155(1):145-164
Utilizing compact representations for continuous piecewise linear functions, this paper discusses some theoretical properties for nonseparable continuous piecewise linear programming. The existence of exact penalty for continuous piecewise linear programming is proved, which allows us to concentrate on unconstrained problems. For unconstrained problems, we give a sufficient and necessary local optimality condition, which is based on a model with universal representation capability and hence applicable to arbitrary continuous piecewise linear programming. From the gained optimality condition, an algorithm is proposed and evaluated by numerical experiments, where the theoretical properties are illustrated as well. 相似文献
902.
通过对筛选的3种纳滤膜结构及对低聚壳聚糖、氨基葡萄糖和NaAc溶液的截留性能和纯化过程研究发现,3种纳滤膜的膜面粗糙度大小依次为:DL>DK>NTR-7450,均能对低聚壳聚糖100%截留,但只能部分截留氨基葡萄糖和NaAc,其截留率大小为:DK>DL>NTR-7450。从低聚壳聚糖的纯化工艺要求和抗污染能力方面考虑,NTR-7450纳滤膜更具有工业应用价值。此外,纳滤膜对溶质的分离效果主要由空间位阻和静电效应决定,综合作用结果导致了低聚壳聚糖体系中的各种主要阳离子在纳滤过程中存在竞争透过,截留次序依次为:高分子低聚壳聚糖>氨基葡萄糖>Na+>H+。在Donnan效应和电离平衡的影响下,体系中Ac-在纳滤过程中也被脱出。纳滤纯化低聚壳聚糖制备液在技术上可行。 相似文献
903.
Xiaolin Pei Qiuyan Wang Xiaofeng Qiu Longbin Ying Junhua Tao Tian Xie 《Applied biochemistry and biotechnology》2010,162(5):1423-1434
2-Deoxyribose-5-phosphate aldolase (DERA) catalyzes a sequential aldol reaction useful in synthetic chemistry. In this work,
the effect of a feeding strategy on the production of a thermophilic DERA was investigated in fed-batch cultures of recombinant
Escherichia coli BL21 (pET303-DERA008). The predetermined specific growth rate (μ
set) was evaluated at 0.20, 0.15, and 0.10 h−1, respectively. The DERA concentration and volumetric productivity were associated with μ
set. The cells synthesized the enzyme most efficiently at μ
set = 0.15 h−1. The maximum enzyme concentration (5.12 g/L) and total volumetric productivity (0.256 g L−1 h−1) obtained were over 10 and five times higher than that from traditional batch cultures. Furthermore, the acetate concentration
remained at a relatively low level, less than 0.4 g/L, under this condition which would not inhibit cell growth and target
protein expression. Thus, a specific growth rate control strategy has been successfully applied to induce fed-batch cultures
for the maximal production of the thermophilic 2-deoxyribose-5-phosphate aldolase. 相似文献
904.
Danqun Huo Limin Yang Changjun Hou Huanbao Fa Xiaogang Luo Yi Lu Xiaolin Zheng Jun Yang Li Yang 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,74(2):336-343
The molecular interactions of monosulfonate tetraphenylporphyrin (TPPS1) and meso-tetra(4-sulfonatophenyl)porphyrin (TPPS) with dimethyl methylphosphonate (DMMP) have been investigated by UV–vis and fluorescence spectroscopies. The association constants and interaction stoichiometries of the bindings were obtained through Benesi–Hildebrand (B–H) method. Particularly, both linear and nonlinear fitting procedures were performed to evaluate the possible 1:2 interactions. Experimental results showed that hydrogen-bonding interactions existed in both of the two systems, resulting in regular changes in the absorbance and fluorescence characteristics of the porphyrins. The association constants and stoichiometries determined from absorbance and fluorescence studies were in excellent agreement. Using a nonlinear fitting method, we demonstrated that the one-step 1:2 interaction took place in the TPPS1–DMMP system, and the association constants were determined to be 71.4 M−1 by absorbance measurements and 70.92 M−1 by fluorescence measurements. The interaction stoichiometry of the TPPS–DMMP system was 1:1, and the association constants were determined to be 16.06 M−1 by absorbance measurements and 16.03 M−1 by fluorescence measurements. It was concluded that the interaction between TPPS1 and DMMP was stronger than that between TPPS and DMMP. 相似文献
905.
The boundary node method (BNM) exploits the dimensionality of the boundary integral equation (BIE) and the meshless attribute of the moving least-square (MLS) approximations. However, since MLS shape functions lack the property of a delta function, it is difficult to exactly satisfy boundary conditions in BNM. Besides, the system matrices of BNM are non-symmetric. 相似文献
906.
Xiaolin Xue Weigang Zhang Limei Yin Shilei Wei Shecheng Gao Pengcheng Geng Juan Ruan 《Optics Communications》2012,285(19):3935-3938
We report a novel all-fiber narrow-bandwidth intermodal Mach–Zehnder interferometer (MZI) based on a long-period fiber grating (LPFG) combined with a fiber bitaper, and the MZI has no special limit for the resonant wavelength of the LPFG. Its responses to temperature and axial strain are studied theoretically and experimentally. Experimental results indicate that the temperature sensitivity is 0.0585 nm/°C within the temperature range from 30 °C to 90 °C and the axial strain sensitivity of 0.00013 nm/με can be neglected. Furthermore, as only the common single-mode fiber (SMF) is required during the fabrication process, the proposed device is cost effective and has good practicability in the optical sensing systems. 相似文献
907.
A new architecture for generating pure azimuthally and radially polarized beams is presented. It involves coherent polarization beam combination of two orthogonally polarized LP(11) fiber modes. Experimental results reveal that high purely polarized (polarization purity of 95% or better) azimuthal and radial beams can be generated. 相似文献
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