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Yue K.,Nanjing University of Technology | Cheng X.,Nanjing Institute of Product Quality Inspection | Xia J.,Nanjing University of Technology | Lu W.,Nanjing University of Technology | And 3 more authors.
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2015

The mechanical performance of common wood plastic composites was poor and couldnot be used as structural member. Structural wood-plastic laminated timber was prepared with domestic fast-growing poplar wood veneer and thermoplastic plastic alloy by the flat-pressed method. The plastic alloy was composed with polyethylene and polypropylene film with the weight ratio of 1:1 and acting as adhesive in laminated timber. The hot pressing temperature, ranging from the melting temperature of plastic alloy measured by differential scanning calorimeter to the pyrolysis temperature of wood materials, could be determined preliminarily. Secondly the effects of the hot pressing temperature, the wood-plastic ratio and the concentration of maleic anhydride on the bonding strength of wood-plastic laminated timber were studied. Then the tests on the effects of the above 3 factors on the bending behavior of wood-plastic laminated timber were carried out. The results showed that, the interfacial damage mode of wood-plastic laminated timber with coupling agent under tension and shear forces was wood failure, while that of controlled specimens was interfacial delamination between wood and plastic. Compared with controlled specimens, the bonding strength of wood-plastic laminated timber pretreated with coupling agent was the highest, and increased by 16.7% at 180℃, wood-plastic ratio of 3/2 and maleic anhydride concentration of 4%. Wood-plastic laminated timber exhibited better mechanical properties with the flat pressing preparation method, and could be used as a structural wooden member. Bending strength was negatively correlated with modulus of elasticity for wood-plastic laminated timber. In the experiment, bending strength of wood-plastic laminated timber increased with the increasing of the wood density and the ratio of wood to plastic at the density of 0.6 and 0.8 g/cm3, while modulus of elasticity decreased, and the microstructure of wood kept integrated. Compared with the densities of 0.6 and 0.8 g/cm3, wood-plastic laminated timber was stronger at a density of 1.0 g/cm3. Bending strength decreased with the increasing of wood-plastic ratio at the density of 1.0 g/cm3. The resistance of wood-plastic laminated timber increased with the density and the wood-plastic ratio. There was much discontinuous crack at the direction of cross grain of wood veneer, so the structural integrity of wood decreased at a wood-plastic ratio of 3/3. The bending properties of wood-plastic laminated timber met the demands and reached the 100E level according to the national standard of China when the hot-pressing temperature was 190℃, the wood-plastic ratio was 3/2 and 3/3, the concentration of maleic anhydride was 4%, and the density was 0.8 g/cm3. The study may provide valuable information for the structural applications of wood-plastic laminated timber. © 2015, Chinese Society of Agricultural Engineering. All right reserved.


Wang R.-H.,Nanjing Forestry University | Wang R.-H.,CAS Nanjing Institute of Soil Science | Zhu X.-F.,Nanjing Forestry University | Zhu X.-F.,Nanjing Institute of Product Quality Inspection | And 5 more authors.
Environmental Science and Pollution Research | Year: 2016

Batch experiments were conducted to investigate cadmium(II) (Cd(II)) adsorption by two variable-charge soils (an Oxisol and an Ultisol) as influenced by the presence of pectin. When pectin dosage was less than 30 g kg−1, the increase in Cd(II) adsorption with the increasing dose of pectin was greater than that when the pectin dosage was >30 g kg−1. Although both Langmuir and Freundlich equations fitted the adsorption isotherms of Cd(II) and electrostatic adsorption data of Cd(II) by the two soils well, the Langmuir equation showed a better fit. The increase in the maximum total adsorption of Cd(II) induced by pectin was almost equal in both the soils, whereas the increase in the maximum electrostatic adsorption of Cd(II) was greater in the Oxisol than in the Ultisol because the former contained greater amounts of free Fe/Al oxides than the latter, which, in turn, led to a greater increase in the negative charge on the Oxisol. Therefore, the presence of pectin induced the increase in Cd(II) adsorption by the variable-charge soils mainly through the electrostatic mechanism. Pectin increased the adsorption of Cd(II) by the variable-charge soils and thus decreased the activity and mobility of Cd(II) in these soils. © 2016 Springer-Verlag Berlin Heidelberg


PubMed | CAS Nanjing Institute of Soil Science, Nanjing Institute of Product Quality Inspection and Nanjing Forestry University
Type: Journal Article | Journal: Environmental science and pollution research international | Year: 2016

Batch experiments were conducted to investigate cadmium(II) (Cd(II)) adsorption by two variable-charge soils (an Oxisol and an Ultisol) as influenced by the presence of pectin. When pectin dosage was less than 30gkg(-1), the increase in Cd(II) adsorption with the increasing dose of pectin was greater than that when the pectin dosage was >30gkg(-1). Although both Langmuir and Freundlich equations fitted the adsorption isotherms of Cd(II) and electrostatic adsorption data of Cd(II) by the two soils well, the Langmuir equation showed a better fit. The increase in the maximum total adsorption of Cd(II) induced by pectin was almost equal in both the soils, whereas the increase in the maximum electrostatic adsorption of Cd(II) was greater in the Oxisol than in the Ultisol because the former contained greater amounts of free Fe/Al oxides than the latter, which, in turn, led to a greater increase in the negative charge on the Oxisol. Therefore, the presence of pectin induced the increase in Cd(II) adsorption by the variable-charge soils mainly through the electrostatic mechanism. Pectin increased the adsorption of Cd(II) by the variable-charge soils and thus decreased the activity and mobility of Cd(II) in these soils.


Zhang C.,Nanjing University | Zhang C.,Nanjing Southeast University | Zhang C.,Nanjing Institute of Product Quality Inspection | Fang X.,Nanjing Institute of Product Quality Inspection | And 2 more authors.
Journal of AOAC International | Year: 2015

Real-time PCR amplification of mitochondria gene could not be used for DNA quantification, and that of single copy DNA did not allow an ideal sensitivity. Moreover, cross-reactions among similar species were commonly observed in the published methods amplifying repetitive sequence, which hindered their further application. The purpose of this study was to establish a short interspersed nuclear element (SINE)-based real-time PCR approach having high specificity for species detection that could be used in DNA quantification. After massive screening of candidate Sus scrofa SINEs, one optimal combination of primers and probe was selected, which had no cross-reaction with other common meat species. LOD of the method was 44 fg DNA/reaction. Further, quantification tests showed this approach was practical in DNA estimation without tissue variance. Thus, this study provided a new tool for qualitative detection of porcine component, which could be promising in the QC of meat products.


PubMed | Nanjing Institute of Product Quality Inspection and Nanjing Southeast University
Type: | Journal: Food chemistry | Year: 2015

Using murine meat to substitute mutton has been identified as a new type of meat fraud in China, yet no detection method for murine species has been reported. Here, three kinds of rodent were used as target species to establish a murine-specific real-time PCR method of detection. The mitochondrial cytochrome b gene (cytb) of each target was sequenced and a TaqMan probe was designed based on the cytb. Simultaneously, an internal positive control (IPC) plasmid along with its respective probe were designed to monitor the PCR reaction. As a result, the duplex real-time PCR system was verified to be specific. The limit of detection (LOD) was lower than 1 pg of DNA per reaction and 0.1% murine contamination in meat mixtures. Standard curves were generated for a quantitative analysis. Thus, this study provided a new tool to control the quality of meat products for official and third-party laboratories.


Ma X.,Nanjing Institute of Product Quality Inspection | Ma X.,Nanjing University | Wang N.,Nanjing Institute of Product Quality Inspection | Wang N.,Nanjing University | And 5 more authors.
Proceedings - 2016 IEEE International Conference on Software Quality, Reliability and Security-Companion, QRS-C 2016 | Year: 2016

With the growing popularity and complexity of mobile apps, quality assurance becomes more and more important in mobile app development. Unfortunately, Android is also suffering from the notorious fragmentation problem. To tackle these problems, we introduce an automated testing platform, BugRocket. BugRocket combines a distributed testing system with automated testing techniques equipped on mobile devices. In this paper, we developed a toolset for automated testing, and set up such a testing platform with 40 of the most popular Android devices. An case study is conducted and the results show that BugRocket can work for functional testing and compatibility testing. Besides, BugRocket can record a failed run as long as annotated GUI model and system logs to alleviate locating bugs and bug fixing. © 2016 IEEE.


Gao R.,Nanjing Institute of Product Quality Inspection | Gao R.,Nanjing University | Chen Z.,Nanjing University | Fang C.,Nanjing Institute of Product Quality Inspection | And 5 more authors.
Proceedings - 2016 IEEE International Conference on Software Quality, Reliability and Security-Companion, QRS-C 2016 | Year: 2016

With the development of online education, more and more people learn knowledge about software engineering through online courses. Scoring homework has become a burden on both teachers and teaching assistants. In order to alleviate such burden, some courses provide a platform that can run students' codes automatically. However, most platforms pay attention to programming with specific languages. Few platforms can score homework about performance testing and evaluate test scripts automatically. In this paper, a new approach, based on weighted arithmetic mean, is proposed to evaluate performance test scripts automatically. A preliminary set of evaluation items and their weights are proposed in the approach and an experiment is conducted among hundreds of students from Coursera. The results show that our approach can perform even better than peer-review evaluation. Our approach can avoid students' lack of experience and the possibility of cheating. The score through our approach can indicate the correctness of scripts and whether the design of scripts is good or not. © 2016 IEEE.


Gao R.,Nanjing Normal University | Gao R.,Nanjing Institute of Product Quality Inspection | Zhang N.,Nanjing Normal University
Atomic Spectroscopy | Year: 2015

A different analytical line pair is required when the Pd 340.45-nm line, as recommended by ISO regulation 11495:2008, is not available on an inductively coupled plasma optical emission spectrometer (ICP-OES) for the determination of Pd in palladium jewellery alloys. This work selected Pd 342.124 nm and Y 371.030 nm as the optimal analytical line pair from 21 spectral lines of palladium and 7 spectral lines of yttrium based on recoveries, relative standard deviations (RSD), spectral interferences, simultaneous detection principle of the analyte and the internal standard signals. The recoveries of the line pair were in the range of 101.6∼101.9% and the RSD was 0.2% (n=10). This method is complementary to the ISO 11495:2008 regulation.


Gao R.-F.,Nanjing Normal University | Gao R.-F.,Nanjing Institute of Product Quality Inspection | Gao M.-C.,Nanjing Institute for Food and Drug Control | Ling R.,Nanjing Institute for Food and Drug Control | Zhang N.,Nanjing Normal University
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2016

The measurement uncertainty is a non-negative parameter associated with the result of a measurement that characterizes the dispersion of the quantity values that could reasonably be attributed to the measurand. In the present study measurement uncertainty is estimated using the GUM (ISO/IEC Guide 98: 1993 Guide to the expression of uncertainty in measurement) bottom-up approach. The steps were followed: specifying the measurand; identifying all the associated sources of uncertainty; quantifying the uncertainty components; combining the uncertainty components; determining the extended combined standard uncertainty; reviewing the estimates and reporting the measurement uncertainty. In this process, the major uncertainty components with greater impact were identified; try to eliminate or to reduce the impact of these components can improve measurement methods. Examples were the determination of aluminum in starch and bread crumbs by inductively coupled plasma-mass spectrometry (ICP-MS). The uncertainties of aluminum contents were from measurement repeatability, variability of calibration curve, standard stock solution, dilution, solution volume and sample weighing. The data indicated that the major contributions to the uncertainty budget originating from urel(cAl)1 (the relative standard uncertainty of aluminum content derived from linear least squares calibration), urel(cAl)3 (the relative standard uncertainty of aluminum content derived from the dilution of the standard stock solutions) and urel(rep) (the relative standard uncertainty derived from the repeatability). Based on the analysis of the main individual contributions of each uncertainty source to the total uncertainty value, several modifications were proposed. Firstly helium collision mode was replaced by no gas mode to improve the sensitivity of mass spectrometry. Secondly the number of measurements was increased. Thirdly let the mean of data points in the calibration closer the measurand. Finally the relative error smaller gauges were used. After these modifications, urel(cAl)1, urel(cAl)3 and urel(rep) were from (0.0358, 0.0132, 0.0085) down to (0.0060, 0.0105, 0.0033), respectively; the combined relative standard uncertainty of aluminum was from 0.039 down to 0.013; the expanded uncertainty from 1.8 down to 0.4 mg·kg-1 (coverage factor k=2). The improvement effect was significant. © 2016, Peking University Press. All right reserved.


Zhou J.,Nanjing Institute of Product Quality Inspection | Zhang Z.,State Key Laboratory for Novel Software Technology | Xie P.,Nanjing Institute of Product Quality Inspection | Wang J.,Nanjing Institute of Product Quality Inspection
Proceedings - 2015 IEEE International Conference on Software Quality, Reliability and Security-Companion, QRS-C 2015 | Year: 2015

Since automotive software contains many control flows, symbolic execution is an effective approach to generate test data for it. However, symbolic execution is cost expensive, so it is difficult to apply it directly. Moreover, parameters in automotive software are usually closely related to implement the same function, thus the constraints are dependent on other constraints in the entire path constraint set, which results in traditional optimization techniques, such as constraint independence optimization, could not be used for symbolic execution of automotive software. In this paper, we present a new test data generation approach for automotive software. In our approach, we combine symbolic execution and minimum cut to generate test data for automotive software. We firstly use minimum cut technique to divide the entire path constraint set into two constraint subsets. Then we solve the smaller subset and reuse the solution when solving the entire path constraint set. We believe this approach can not only be faster than solving the entire constraint set directly, but also increase the probability of hitting the cache. © 2015 IEEE.

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