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Effects of characteristic inhomogeneity of bamboo culm nodes on mechanical properties of bamboo fiber reinforced composite

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Journal of forestry Research 2015年第4期26卷 1057-1060页

作者： Jinqiu Qi Jiulong Xie Wenji Yu Simin Chen College of forestry Sichuan Agricultural University Research institute of Wood Industry Chinese Academy of Forestry

Dendrocalamus farinosus and Phyllostachys heterocycla bamboo logs were subjected to a novel treat- ment process for the preparation of bamboo fiber mats （BFMs）, and the obtained BFM were used to fabricate bamboo fiber reinforced composite （BFRC）. We studied the mechanical properties of the BFRCs manufactured from the mats with and without bamboo nodes. The pres- ence of nodes in BFM greatly reduced tensile strength, compressive strength, modulus of elasticity, and modulus of rupture of the BFRCs, while the BFRCs fabricated from BFMs with nodes possessed higher horizontal shear strength. Therefore, the nodes in bamboo culms were an important factor in the uniform distribution of mechanical properties, and BFMs should be homogeneously arranged to reduce the impact of nodes on the mechanical strengths of BFRCs.

关键词： Bamboo fiber reinforced composite - Culmnode Mechanical properties

Fecundity and egg hatchability of Dastarcus helophoroides adults fed on different types of artificial diets

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Journal of forestry Research 2015年第1期26卷 219-224页

作者： Xiao-juan Li Guang-ping Dong Li Yang Wan-lin Guo institute of Forest Protection Anhui Provincial Academy of Forestry

Both fecundities and egg hatchabilities were compared among three populations of Dastarcus helophoroides Fairmaire adults（Coleoptera： Bothrideridae） fed on three types of artificial diets（Diet of formula 1 composed of silkworm pupa powder, dried yeast powder,sucrose, peptone, egg yolk powder and poplar branch powder. Diet of formula 2 composed of silkworm pupa powder, dried yeast powder, sucrose, egg yolk powder,poplar branch powder, cricket powder, benzoic acid and distilled water. Diet of formula 3 composed of pine bark powder and Monochamus alternatus larva powder）. for90 days. The three diets showed no significant difference regarding the average number of eggs deposited by all D. helophoroides females（16622.3–23874.7）; the average number of eggs per female（1278.6–1836.5）; and the average number of eggs per female per day（14.2–20.4）.The number of eggs one cluster contained mainly（82.06–82.66 %） lied in 1–100 eggs, and the average number of eggs per cluster ranged from 61.7 to 63.1. In the first 10-day period, the number of eggs deposited by all females fed on formula 1 was significantly larger than that on formula 3. The eggs deposited in the last four 10-day periods were more than in the former five 10-day periods,on formula 3. There were no significant differences in hatchability of total eggs among the three artificial diets,and the average corrected egg hatchability ranged from82.85 to 84.78 %. No significant differences in the adult mortality and mean weight gain of D. helophoroides were found after feeding on three artificial diets. Our results suggest that D. helophoroides adults were not specialized on the diet, and the diet types might have little effect on fecundity and egg hatchability in D. helophoroides, as long as sufficient nutrition was supplied.

关键词： Dastarcus helophoroides Fecundity Egg hatchability Artificial diet

N_2O emission from nitrogen removal via nitrite in oxic-anoxic granular sludge sequencing batch reactor

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Journal of Environmental Sciences 2014年第3期26卷 537-541页

作者： Hong Liang Jiaoling Yang Dawen Gao School of forestry Northeast Forestry University State Key Laboratory of Urban Water Resource and Environment Harbin Institute of Technology

Bionitrification is considered to be a potential source of nitrous oxide （N2O） emissions, which are produced as a by-product during the nitrogen removal process. To investigate the production of N2O during the process of nitrogen removal via nitrite, a granular sludge was studied using a labscale sequence batch reactor operated with real-time control. The total production of N2O generated during the nitrification and denitrification processes were 1.724 mg/L and 0.125 mg/L, respectively, demonstrating that N2O is produced during both processes, with the nitrification phase generating larger amount. In addition, due to the NEO-N mass/oxidized ammonia mass ratio, it can be concluded that nitrite accumulation has a positive influence on N2O emissions. Results obtained from PCRDGGE analysis demonstrate that a specific Nitrosomonas microorganism is related to N2O emission.

关键词： nitrous oxidenitrite accumulation nitrification and denitrification biological nitrogen removalwastewater treatment

Synthesis and Crystal Structure of a Degraded Dehydroabietylamine Thiophene Imine

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Chinese Journal of Structural Chemistry 2008年第7期27卷 884-887页

作者：饶小平宋湛谦伍勇贾卫红商士斌 institute of Chemical Industry of Forest Products Chinese Academy of Forestry

A degraded dehydroabietylamine thiophene imine （C24H30NS, Mr = 364.55） has been synthesized from dehydroabietic acid, and its structure was characterized by IR, IH NMR spectroscopy and single-crystal X-ray diffraction. White crystals of the title compound crystallize in the monoclinic system, space group P21 with a = 5.9490（12）, b = 16.337（3）, c = 10.780（2）A, β = 92.21（3）°, V = 1046.9（3）A^3, Z = 2, Dc = 1.156 g/cm^3, λ= 0.71073A,μ = 0.162 mm^-1, F（000） = 394, the final R = 0.0443 and wR = 0.0805 for 1325 observed reflections with I 〉 2σ（I）. The imine group was directly attached to the chiral carbon atom of tricyclo hydrophenthenrane structure with a trans configuration. The dihedral angle between two aromatic rings is 88.3°.

关键词： degraded dehydroabietylamine thiophene imine synthesis crystal structure

Evaluation of Mechanical Properties of Cross-Laminated Timber with Different Lay-ups Using Japanese Larch

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Journal of Renewable Materials 2019年第10期7卷 941-956页

作者： Yingchun Gong Fenglu Liu Zhaopeng Tian Guofang Wu Haiqing Ren Cheng Guan Research institute of forestry New Technology Chinese Academy of ForestryBeijing100091China School of Technology Beijing Forestry UniversityBeijing10083China

Japanese larch is one of the main plantation tree species in China.A lack of engineered wood products made by Japanese larch,however,limits its application in wood *** this study,based on optimum process parameters,such as pressure(12 MPa),adhesive spread rate(200 g/m^(2))and adhesive(one-component polyurethane),the mechanical properties of Japanese larch-made cross-laminated timber(CLT)with different lay-ups were evaluated by means of the static *** of this study showed that variations in lay-ups significantly affected the mechanical properties of *** strength and modulus of bending and parallel compression for CLT increased with the thickness of lumber,while that of bending,parallel compression and rolling shear all decreased with the number of ***,layup orientation and the number of layers all had an impact on the strength of *** modes obtained from numerical simulation were basically the same as those of experimental *** was also strong alignment between theoretical value and test value for effective bending stifness and shear ***,the shear analogy method can be used to predict the mechanical properties of CLT *** study proved great potential in using Japanese larch wood for manufacturing CLT due to its good mechanical properties.

关键词： Cross-laminated timber mechanical properties lay-ups failure mode shear analogy

Switching and Fano resonance via exciton–plasmon interaction

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Chinese Physics B 2014年第6期23卷 489-492页

作者：李建波贺梦冬王新军彭小芳陈丽群 institute of Mathematics and Physics Central South University of Forestry and Technology

We fnrther study theoretically the properties of switching and Fano resonance in a hybrid nanosystem consisting of two quantum dots （QDs） and a metal nanowire via exciton-plasmon interaction. The transmission of the single plasmon can be switched on or off in a wide-frequency region by adjusting the transition frequencies of the QDs and the phase of the propagating plasmon. Specifically, the dynamical mechanism of Fano-type transmission is further revealed and analyzed in detail.

关键词： surface plasmon quantum dots quantum computation optical waveguides and couplers

No consistent daily variation in DNA methylation detected in Populus nigra leaves by methylation-sensitive amplification polymorphism analysis

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Journal of forestry Research 2017年第4期28卷 653-660页

作者： Shu Diao Yanbo Wang Changjun Ding Yingying Chang Lixiong Liang Yanan Gao Bingyu Zhang Xiaohua Su State Key Laboratory of Tree Genetics and Breeding Research Institute of ForestryChinese Academy of ForestryBeijing 100091People’s Republic of China Key Laboratory of Tree Breeding and Cultivation of State forestry Administration Research Institute of ForestryChinese Academy of ForestryBeijing 100091People’s Republic of China

DNA methylation, an epigenetic mechanism used by cells to control gene expression, has an important biological role in plant development and environmental fitness. Since plant DNA methylation is closely related to environmental conditions, variation during the day is expected. Here, in genetically identical plants of Populus nigra clone N46, DNA methylation changes in leaves over a 24 h period were detected using the methylation-sensitive amplification polymorphism method. The results showed different DNA methylation patterns in mature poplar leaves: not only in individuals at the same time, but also in samples at each of the six time during the day. In addition, night samples had a higher percentage of methylation than in morning samples. However, no statistically significant differences were found among the samples gathered at different times. Similar results were obtained for three other P. nigra clones with different genetic backgrounds. Real time qPCR showed that the DNA methyltransferase genes Pt-MET1 and Pt-SOM1 involved in CG DNA methylation in poplar were stable over a 24 h period in leaves of P. nigra N46 compared with circadian-controlled genes. That could be part of the reason that methylation of CCGG sites is stable in those leaves. That DNA methylation differed even in genetically identical plants indicates the specificity of DNA methylation changes in their genomes. No statistically significant differences in methylation changes were found between day and night, suggesting that DNA methylation is more stable than expected and is unlikely to be involved in circadian regulation in plants.

关键词： Cytosine methylation Epigenetic Populus nigra Methylation-sensitive amplification polymorphism (MSAP) Variation

Comparison of three processing methods for laminated bamboo timber production

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Journal of forestry Research 2019年第1期30卷 363-369页

作者： Edi Suhaimi Bakar Muhammad Nadzim Mohd Nazip Rogerson Anokye Lee Seng Hua Faculty of forestry Universiti Putra Malaysia institute of Tropical forestry and Forest Products (INTROP) Universiti Putra Malaysia

Three processing techniques, split-squaring(SS),V-grooving(VG), and split-edging(SE), were evaluated and compared in terms of their processing time and recovery. Semantan bamboo(Gigantochloa scortechinii Gamble) was used as a raw material and the results showed that the VG-method required the longest processing time(32.1 min), followed by the SS-method(18.2 min), and the SE-method(17.9 min). However, the VG-method showed the highest recovery(82.0%) compared to the SS-method and SE-method, 31.0 and 49.4%, respectively. When both processing time and recovery factors were combined with the same weighing factor, the highest value was recorded with the VG-method(49.1), while the SE-method had values of 31.1 and the SS-method 12.8. The results suggest that the VG-method is the best option. However, the V-grooving machine is still a prototype and therefore the SE-method could be an alternative option until the improved V-grooving machine is available.

关键词： Bamboo culm Laminated bamboo timber Vgrooving method Split-squaring method Split-edging method

Torrential flood prevention in the Kolubara river basin

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Journal of Mountain Science 2017年第11期14卷 2230-2245页

作者： KOSTADINOV Stanimir DRAGI?EVI? Slavoljub STEFANOVI? Tomislav NOVKOVI? Ivan PETROVI? M.Ana University of Belgrade Faculty of Forestry University of Belgrade Faculty of Geography institute of forestry Serbian Academy of Sciences and Arts Geographical institute "J. Cviji?"

One of the most vulnerable parts to natural hazards in Serbia is Kolubara river basin. In the past, during the period from 1929 to 2013, 121 torrential flood events in the Kolubara river basin were recorded which show that this territory is extremely vulnerable to the torrential floods. The extreme event which occurred in May 2014 causing the catastrophic material damages and casualties was the latest and historical flood. The analysis of natural conditions in the Kolubara basin uniformly showed that this area is predisposed to a greater number of torrential floods due to its geomorphological, hydrological and land use properties. Torrential floods are closely related to the intensity and spatial distribution of erosive processes in the upper part of the Kolubara basin. The estimation of soil erosion potential is generally achieved by Erosion Potential Model(EPM). For the purposes of determining the degree of torrential properties in various water streams in the Kolubara basin, the calculation ofsusceptibility to torrential floods was assessed by Flash Flood Potential Index(FFPI). More than half of the basin area(57.2%) is located within the category of very weak and weak erosion(Z_(sr) = 0.35), but the category of medium erosion is geospatially very common. Such a distribution of medium erosion category provides conditions for generating, i.e. production of sediment which would boost torrential properties of water streams. After the classification of the obtained FFPI values it was determined that 25% of the Kolubara basin is very susceptible to torrents and this data should be seriously taken into consideration. Based on the analyses, the best and most successful manner of defence is prevention which consists of the integrated river basin management system(integrated torrent control system) so that technical works in hydrographic networks of torrents and biological and biotechnical works on the slope of the basin would be the best solution. Permanent control of er

关键词： Soil erosion Torrential floods Erosioncontrol works Integrated river basin management