Table of Content

29 April 2015, Volume 21 Issue 2

Previous Issue    Next Issue

Metallurgical Materials

Relationship between PWR primary water chemistry and material degradation

WU Xin-qiang1,2,3, LIU Xia-he1,2,3, HAN En-hou1,2,3, KE Wei1,2,3

2015, 21(2):  141-151.  doi:10.3969/j.issn.1007-2861.2014.04.015

Asbtract ( 1047 )   PDF (18769KB) ( 428 )  

References | Related Articles | Metrics

Optimization of primary water chemistry is one of the most effective ways to minimize radiation field, mitigate material degradation and maintain fuel performance in pressurized water reactor (PWR) nuclear power plants. It improves characteristics of oxide scales formed on the materials of equipment due to interactions between water chemistry and materials. This article reviews the current status and related problems of the relationship between water chemistry of primary coolant and material degradation in PWR nuclear power plants. Fundamental research progress achieved in recent years on Zn-injected water
chemistry (ZWC) into primary coolants of PWR is introduced.

Feasibility and benefits of applying grain boundary engineering to fuel cladding materials of liquid metal cooled fast breeder reactor

XIA Shuang, ZHOU Bang-xin

2015, 21(2):  152-159.  doi:10.3969/j.issn.1007-2861.2014.05.012

Asbtract ( 1570 )   PDF (4573KB) ( 646 )  

References | Related Articles | Metrics

Feasibility and benefits of applying grain boundary engineering (GBE) to the fuel cladding material 316 or 15-15Ti austenitic stainless steels of sodium-cooled-fastreactor for reducing void swelling and creep is discussed. GBE can be used to greatly enhance the proportion of low  coincidence site lattice (CSL) grain boundaries that are mainly of annealing twins and its variants. The cladding tubes are normally subjected to 20% cold working after solution annealing before using, which by virtue of providing a dislocation strewn matrix microstructure, contributes to the annihilations of irradiationinduced point defects. If the proportion of low CSL grain boundaries are greatly enhanced prior to the cold working, transfer of slip across the special-structured grain boundaries or pile-up against them during deformation may alter the distribution of dislocations of the microstructure, which may accommodate more defects generated during being irradiated.

Corrosion resistance of Zr-0.70Sn-0.35Nb-0.30Fe-xS alloy in lithiated water at 360 C

GAO Chang-yuan1,2, YAO Mei-yi1,2, XU Qi-di1,2,HUANG Jiao1,2, ZHANG Jin-long1,2, ZHOU Bang-xin1,2

2015, 21(2):  160-169.  doi:10.3969/j.issn.1007-2861.2014.05.011

Asbtract ( 1096 )   PDF (11898KB) ( 296 )  

References | Related Articles | Metrics

The effect of adding dilute S on the corrosion resistance of Zr-0.70Sn-0.35Nb-0.30Fe alloy was investigated in lithiated water with 0.01 mol/L LiOH at 360 C/18.6 MPa by autoclave tests. The microstructures of the alloys and the oxide layers formed on the alloys were investigated by transmission electron microscope (TEM) and scanning electron microscope (SEM). Results showed that adding 5570 μg/g S degraded the corrosion resistance of Zr-0.70Sn-0.35Nb-0.30Fe alloy and the higher the S content was, the worse corrosion resistance was. Surface segregation of S and the precipitation of coarse Zr₉S₂ and Zr₃Fe second phase particles accelerated the evolution of pores and micro-cracks formed by diffusion of defects in oxide layer, which leads to the bad corrosion resistance of Zr-0.70Sn-0.35Nb-0.30Fe-S alloy.

Effects of different cover rate of shop peening on residual stress and stress corrosion cracking of 800 alloy tube

CAI Zhi-gang1, WANG Yong-dong2, SU Cheng1, CAO Ping1

2015, 21(2):  170-176.  doi:10.3969/j.issn.1007-2861.2014.04.020

Asbtract ( 1115 )   PDF (7364KB) ( 450 )  

References | Related Articles | Metrics

Shot peening is conducted on the outside surface of an 800 alloy heat-exchanging tube in a nuclear steam generator using a shot-peening machine. The effects on the 800 alloy tube surface micrograph, residual stress and stress corrosion cracking (SCC) in the 10%NaOH solution at high temperature and high pressure have been studied. The result shows that the shot peening can change the surface micrograph and residual stress of the 800 alloy tube. As the cover rate of shot peening is creases, the residual stress of the 800 alloy tube gradually decreases, and SCC resistance is significantly improved.

Uneven nodular corrosion resistance of Zr-4 alloy

CHEN Chuan-ming, ZHOU Bang-xin, HUANG Jiao,GOU Shao-qiu, YAO Mei-yi, ZHANG Jin-long

2015, 21(2):  177-181.  doi:10.3969/j.issn.1007-2861.2014.04.018

Asbtract ( 968 )   PDF (4612KB) ( 427 )  

References | Related Articles | Metrics

Some bright stripes with several millimeters in width and several tens of millimeters in length appeared on the surface of Zr-4 plates in certain batches of the products. Autoclave corrosion tests, composition analysis by energy dispersive spectrometer (EDS), and texture measurement were used to investigate the essentials of bright stripes and their effect on the nodular corrosion resistance. The results showed that the contents of Fe and Cr alloying elements were somewhat higher, and (0001) texture factor (fN) is larger in bright stripe area than that in the surrounding area. Nodular corrosion resistance on the bright stripe area was much better than the surrounding area after corrosion test at 500 C/10.3 MPa in superheated steam after 3 h exposure. The uneven distribution of Fe
and Cr alloying elements and the difference of texture factor between the bright stripes and their surrounding area were contributed to the different nodular corrosion resistance.The uneven component of the ingot was the main reason.

Effect of adding dilute Si on corrosion resistance of zirconium alloys

SUN Feng-tao1,2, YAO Mei-yi1,2, XU Long1,2, HUANG Jiao1,2,ZHANG Jin-long1,2, ZHOU Bang-xin1,2

2015, 21(2):  182-189.  doi:10.3969/j.issn.1007-2861.2014.05.008

Asbtract ( 1110 )   PDF (4716KB) ( 402 )  

References | Related Articles | Metrics

The effect of adding dilute Si(0.02%) on the corrosion resistance of Zr-1Nb and Zr-1Nb-0.8Sn-0.38Fe-0.1Cr alloys was investigated in super-heated steam at 400 C/ 10.3 MPa and in lithiated water with 0.01 mol/L LiOH at 360℃/18.6 MPa by autoclave tests. The microstructure of the alloys was investigated with transmission electron microscope (TEM) and energy dispersive spectrometer (EDS). No obvious difference was found in the corrosion resistance of the Zr-1Nb and Zr-1Nb-0.02Si alloys in the two corrosion conditions, respectively. In the case of Zr-1Nb-0.8Sn-0.38Fe-0.1Cr alloy, the corrosion resistance decreased due to the addition of Si in super-heated steam at 400 C. However,addition of Si had little effect on corrosion resistance in lithiated water with 0.01 mol/L LiOH at 360 ℃/18.6 MPa. It meant that the influence of Si addition on the corrosion resistance was related to the compositions of alloys and water chemistries. Zr5Si4 second phase particles (SPPs) were observed in Zr-1Nb-0.02Si alloy, while Zr(Nb,Fe,Cr,Si)₂ SPPs were observed in Zr-1Nb-0.8Sn-0.38Fe-0.1Cr-0.02Si alloy. Compared to SPPs in Zr-1Nb and Zr-1Nb-0.8Sn-0.38Fe-0.1Cr alloys, Zr5Si4 and Zr(Nb,Fe,Cr,Si)₂ SPPs are coarse. Different effects of Si addition on the corrosion resistance of the alloys are related to the SPPs.

Steganographic algorithm with histogram-preserving property

SHEN Wen-feng, LI Feng-yong, ZHANG Xin-peng, YANG Qian-xing

2015, 21(2):  190-196.  doi:10.3969/j.issn.1007-2861.2013.07.046

Asbtract ( 1088 )   PDF (5103KB) ( 499 )  

References | Related Articles | Metrics

To enhance security of steganography, the characteristics of the image should be kept as far as possible. This paper proposes a steganography algorithm with histogrampreserving property. Firstly, the histogram of pixel values is grouped. By calculating the maximum payload under a given distortion, the modification rate for each pixel is found and the location of pixels is got that need to be changed by syndrome trellis codes (STC). Then embedding is performed by changing those pixels using adaptive intra-group and/or inter-group adjustments. The difference in histogram between the cover and the stegoimages is very small. Experimental results show that the proposed method makes less histogram change and gives better visual quality than existing methods under the same
embedding rate.

Self-adaptive fast mode decision algorithm for depth map intra coding

SI Xiao-hua, WANG Guo-zhong, ZHAO Hai-wu, LI Guo-ping, TENG Guo-wei

2015, 21(2):  197-205.  doi:10.3969/j.issn.1007-2861.2014.03.015

Asbtract ( 1262 )   PDF (1385KB) ( 805 )  

References | Related Articles | Metrics

In the high efficiency video code (HEVC) based depth video coding in 3D video coding, depth modeling mode (DMM) and a region boundary chain (RBC) mode
are introduced. DMM traverses all Wedgelet patterns in the current coding unit (CU) to get the best prediction pattern. Encoding efficiency is improved significantly by these added technologies. Computation complexity is increased significantly, hindering its practical application. To reduce computation complexity, a fast depth mode decision algorithm is proposed for depth video coding based on correlation between the most probable mode and DMM and RBC mode. The proposed method divides coding blocks into flat blocks, directional blocks and texture-complicated blocks. Redundant DMM and RBC mode are
skipped for flat blocks. Explicit Wedgelet search patterns are skipped for directional blocks based on directivity of non-flat blocks. Experimental results show that the proposed algorithm can reduce computational complexity of depth coding by 75.4% for all-intra test case, with BD-rate increase of only 0.4% after decoder-side view synthesis.

Dispersion characteristic of symmetric slab waveguide with chiral negative refractive medium

XU Xiao-xue, XIAO Zhong-yin, MA Quan-wen, MA Xiao-long,LIU De-jun, WANG Zi-hua

2015, 21(2):  206-212.  doi:10.3969/j.issn.1007-2861.2014.03.018

Asbtract ( 1055 )   PDF (2260KB) ( 390 )  

References | Related Articles | Metrics

According to the Maxwell equations and constitutive relations in chiral medium, the paper studies the dispersion characteristic of a symmetric slab waveguide with a chiral negative refractive medium. With the normalized frequency and propagation factor, dispersion equations expressed with normalized parameters are derived in a slab waveguide with a chiral negative refractive medium. Numerical results show that the chiral parameter has great influence on the dispersion characteristic of a slab waveguide. When the relative chiral parameter is 0.047 7, the zero order mode of a left-handed polarized wave disappears. When it is greater than 1, the core becomes a chiral negative refractive medium and the zero-order mode exists. In addition, the tendency of dispersion curves in slab wave-guide is compared with a chiral negative refractive medium and that with a general chiral medium.

Design of a bandpass filter with independently tunable dual-band

JIAN Hao, LI Guo-hui, WANG Huan-ying, LI Wei

2015, 21(2):  213-219.  doi:10.3969/j.issn.1007-2861.2014.03.017

Asbtract ( 1232 )   PDF (7028KB) ( 924 )  

References | Related Articles | Metrics

A dual bandpass filter (BPF) with two center frequencies tuned asynchronously and independently is presented. The proposed filter consists of a stepped-impedance resonator (SIR) with two-terminal shorted stubs and a dual-mode open-loop resonator. To generate additional transmission zeros and improve frequency selectivity, the common input and output coupling lines are used for these two structures. Using the odd-even mode analysis method, resonant frequencies of odd-even mode are electrically tuned due to the loaded varactors at the end of transmission line. The measured performance shows that
the first passband can be tuned in a frequency range of 1.93~2.20 GHz, whereas the second passband varies from 2.78 to 3.10 GHz. Comparisons of simulated and measured results show effectiveness of the method.

Optimizing extraction technology of total flavonoids in Cynanchum wilfordii and its antioxidant effects

YANG Shen-ming1,2, WANG Ying-shun1,2, WANG Zhen-ji1,2

2015, 21(2):  220-228.  doi:10.3969/j.issn.1007-2861.2014.03.001

Asbtract ( 1079 )   PDF (1147KB) ( 353 )  

References | Related Articles | Metrics

Total flavonoids in Cynanchum wilfordii were extracted using an ethanol refluxing method, and the extraction procedure was optimized with orthogonal experiments. The antioxidant effects of the obtained total flavonoids on active oxygen radicals were studied. The results show the following optimum extraction parameters. The volume fraction of ethanol as extractant is 60%, the extraction temperature is 75℃, the extraction time is 60 min, and the ratio of solid to liquid is 1∶30 (g/mL). Under these conditions, the average extraction rate of total flavonoids reaches 10.79%, the average recovery rate of the added sample is 98.78%, and the scavenging effects of total flavonoids on ·OH and O⁻₂ · are 29.2% and 36.7%, respectively, implying that the material has good ability to scavenge ·OH and O⁻₂ ·.

Identification of protopectinase-producing strain X4 and optimization of medium

ZHAO Zhi-qiang, LIU Zhan-min, YAO Li-feng

2015, 21(2):  229-236.  doi:10.3969/j.issn.1007-2861.2014.01.035

Asbtract ( 1144 )   PDF (1725KB) ( 510 )  

References | Related Articles | Metrics

The purpose of the experiment was to identify protopectinase-producing bacteria X4 by molecular biology methods. To improve productivity of protopectinase, the X4 medium was optimized using a response surface method with enzyme activity as the index. The final result of X4 was Bacillus polyfermenticus. Starch, yeast extract and tryptone were found to be the main influencing factors. The optimal formula of the medium was determined: starch 3.45 g/L, yeast extract 3.29 g/L, and tryptone 5.68 g/L. The final activity of protopectinase was 51.35 U/mL, which was 2.74 times before optimization.

Effect of RNA interference targeting SEMA3A on proliferation and metastasis of glioma cell line U251

2015, 21(2):  237-244.  doi:10.3969/j.issn.1007-2861.2014.03.007

Asbtract ( 1041 )   PDF (10318KB) ( 337 )  

References | Related Articles | Metrics

This paper explores the effect of knockdown SEMA3A gene on the migration and invasion of glioma cell line U251. Preliminary discussion of the potential in treatment of glioma was carried out. The highest knockdown efficiency plasmid packaged by a lentivirus packaging vector system was constructed, which contained a pFH-GFP-L vector and a short hairpin RNA (shRNA) sequence targeting the human SEMA3A gene. U251 cells were infected with a modified lentivirus vector. The infection efficiency of shRNA targeting SEMA3A gene was observed by fluorescence microscope. Real-time PCR reaction and
Western-blot were used to investigate the expression of mRNA and protein of SEMA3A. The results show that the lentivirus containing SEMA3A target shRNA are efficient in silencing SEMA3A expression (P < 0.01). Knockdown SEMA3A gene expression could significantly inhibit the proliferation and metastasis of U251 cells (P < 0.05). In addition,a large number of U251 cells are arrested in G2/M phase, promoting apoptosis (P < 0.05).

Implementation and improvement of SD11 decoder

WANG Zhi-heng, JIN Yi, OUYANG Shan

2015, 21(2):  245-256.  doi:10.3969/j.issn.1007-2861.2013.07.053

Asbtract ( 1083 )   PDF (12627KB) ( 1380 )  

References | Related Articles | Metrics

This paper describes the decoder of a ternary optical computer’s applied research systems, SD11. Hardware of the decoder includes four cameras, an embedded system, and an adapter plate connecting the cameras with the embedded system. With this adapter plate, works of the four cameras is time-shared controlled by a program in the embedded system. Some modules such as data storage, threshold decision and three alues data generation used in the decoder are contributed by the existing research. Having integrated these into the system, an available core program of the decoder is formed. Since the software is independent of the particular process of picture taking, the core part of the program may be used in the future commercial ternary optical computer. The contribution of this work is to study the ternary optical decoder’s functionality and adaptability to environmental change via a series of test. Through the experiments, the problem of image quality degradation is solved when the signal carrying wire is longer than 1.2 m. This makes the decoder meet the requirements for the SD11’s practical uses, and promotes the development of ternary optical computer.

Acute and subchronic toxicity of farnesol, tributyltin and vinclozolin to marine crustacean Acartia tonsa

HAO Ying, CAO Tie-hua, ZHANG Wen-jie

2015, 21(2):  257-266.  doi:10.3969/j.issn.1007-2861.2014.04.017

Asbtract ( 1115 )   PDF (5735KB) ( 405 )  

References | Related Articles | Metrics

Tests on acute and subchronic toxicity toward a marine crustacean Acartia tonsa were conducted from 3 endocrine disrupting chemials farnesol, tributyltin and vinclozolin. Toxicity of tributyltin and vinclozolin to second generation of larval development were also investigated. The 48-h-LC10 and 48-h-LC50 values from acute tests with farnesol and tributyltin were 2.16 and 6.11 mg/L, and that with tributyltin were 0.39 and 2.33 μg/L, respectively. The 96-h-LC50 value from acute test with vinclozolin is 7.89 mg/L. The 5-d-EC10 and 5-d-EC50 values obtained in the subchronice toxicity tests with larval development were 113, 150 ng/L for tributyltin and 0.3, 2.7 mg/L for vinclozolin, respectively. The 3 chemicals affectedl larval development at a lower concentration than those for hatching success and larval survival. The results showed that all 3 chemical compounds displayed acute toxicity at a certain concentration. Eggs of Acartia tonsa can stand relatively higher toxicity of those chemicals. However, once hatched, the development of larval is more sensitive to those chemicals than larval survival, suggesting that Acartia tonsa can survive with the exposure of the chemicals, but their growth was serverely inhibited by the tested chemicals. The second generation of larval development tests are conducted with tributyltin and vinclozolin with eggs from the treated adult Acartia tonsa by exposed to tributyltin and vinclozlolin through the entire lifetime. The results suggest that the second generation of Acartia tonsa is no more vulnerable to tributyltin than the first generation, i.e., the second generation of Acartia tonsa is less sensitive to vinclozolin than the first generation.

Vendor selection of service outsourcing based on fuzzy quality function deployment

DONG You-de, LI Qin-zhu

2015, 21(2):  267-274.  doi:10.3969/j.issn.1007-2861.2014.02.018

Asbtract ( 911 )   PDF (625KB) ( 460 )  

References | Related Articles | Metrics

Service outsourcing is advantageous to adjust the industrial structure and increase market competitiveness, and vendor selection is a critical link from service outsourcing. This paper establishes a model of vendor selection in service outsourcing based on the method of fuzzy quality function deployment (QFD). According to the practical demand of the service outsourcer, an evaluating indicator system of service outsourcing vendor is built up. Representatives of the outsourcer give the fuzzy weights to those evaluating indicators. The relevance of vendors and indicators is graded by external experts. Further, the vendors of service outsourcing are ranked using a method of integrating fuzzy weighted average and fuzzy expected value operator to help the outsourcer make a selection
decision. An empirical case is presented to show feasibility and practicability of the model.