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141.
The relationships between bending properties, compressive strength, tracheid length, microfibril angle, and ring characteristics
of 20-year-old Taiwania (Taiwania cryptomerioides Hay.) trees were examined. The trees came from different thinning and pruning treatments, but the practices showed no significant
effect on the investigated properties. The results showed that based on comparison with the literature, plantation-grown immature
Taiwania have noticeably lower average strength properties than mature trees of the same species. Wood density and bending
and compressive strengths were not related to either tracheid length or microfibril angle in young Taiwania. There were positive
relationships between bending strength and compressive strength. The wood density, ring width, earlywood width, earlywood
density, and latewood percentage were the most important predictors of strength by simple linear regressions. The wood density
and ring width/earlywood width may be considered as indicators for assessing the bending strength, while wood density and
latewood percentage were the best predictors of compressive strength by multiple linear regressions. 相似文献
142.
Chen-Wei Chiu Tomonori Kume Hikaru Komatsu Han Tseng Tsong-Huei Wey Kyoichi Otsuki 《Journal of Forest Research》2016,21(4):151-160
Stand transpiration (E) estimated using the sap flux methods is affected by the azimuthal, radial, and tree-to-tree variations of sap flux. Although several studies have examined the relative importance of the three variations in estimating E, the seasonality of the three variations remains unknown. In the current study, we attempted to clarify whether the relative importance of these three variations could show seasonal changes. Using sap flux data measured in a subtropical cloud forest from August 2010 to July 2011, we calculated the differences resulting from omitting the three variations in estimating E. The effects of the three variations in estimating E showed seasonality. The azimuthal and tree-to-tree variations were more pronounced during winter, whereas the radial variation was more pronounced during summer. However, the effect of tree-to-tree variation was consistently much larger than the other two variations throughout the study period. The tree-to-tree variation is more important in estimating E monthly, seasonally and annually than both the azimuthal and radial variations, although all three variations have shown seasonality. In addition, the sensor allocation for summer would be acceptable for the practical estimation of E if aiming at the long time scale. 相似文献
143.
Studies on samples of 20 hard-grained wheat cultivars and a commercial flour that varied in starch and protein quality showed that both characteristics influenced the texture of Japanese alkaline noodles (ramen). Flour swelling volume (FSV) and flour pasting characteristics (peak viscosity and breakdown) determined with a Rapid-Visco Analyser (RVA) assessed independently of α-amylase effects, were negatively correlated with total texture score. Protein quality, as indicated by farinograph stability, was positively correlated with total texture score. RVA pasting characteristics were substantially affected by small levels of α-amylase, and inactivation by means of 1 mM AgNO3 was a critical requirement in characterizing the quality of the starch component of flour. 相似文献
144.
In this study, catch and effort data of southern bluefin tuna (SBT) from Taiwan longliners operating in the Central Indian Ocean (CIO) during 1982 to 2003 were compiled and their catch per unit effort (CPUE) was standardized using the generalized linear model (GLM). The GLM includes factors such as year, season, by-catch, latitude, sea surface temperature (SST) and the interactive effects among factors. The standardized CPUE and its relationship with SST fluctuation were then analyzed to understand the effects of fishing ground SST variations on CPUE of SBT, as well as their connection to El Niño-Southern Oscillation (ENSO) events. The standardized CPUE in the CIO seemed to oscillate with the sea surface temperature anomalies (SSTA) between 30 and 50°S where SSTA fluctuations were prolonged and slower than the ENSO cycle. It is then very likely that fishing conditions at the CIO fishing ground were influenced by the expansion of the cold water mass from the Southern Ocean, and the colder SST is beneficial to increasing SBT catch rate. 相似文献
145.
Jiunn-Yih Lee Kuo-Wei Lu Chang-Mou Wu Ching-Ti Chiu Ching-Iuan Su 《Fibers and Polymers》2017,18(5):882-890
In this study, polyacrylonitrile was used as the nanofiber membrane material. Through A two-stage continuous process, namely, oxidation process and carbonization and activation process, an activated nanofiber membrane material was fabricated. Subsequently, the membrane underwent high-temperature heat treatment (1100-1500 °C) to explore the effect of temperature on its properties. Charge/discharge rate was employed to determine the capacitance retention ratio to evaluate the applicability of the fabricated membrane in high-power super capacitor electrodes. The results revealed that in the treated membrane, the lattice size increased from 1.24 nm to between 3.20 and 4.72 nm. In addition, the volume resistivity was reduced from 6 Ω-cm to between 9.70E-2 and 3.85E-2 Ω-cm, substantially improving the electric conductivity. The activated carbon nanofiber membrane treated with high temperature at 1100 °C exhibited the highest capacitance of 704 F/g at a scan rate of 5 mV/s. 相似文献
146.
在编写“浙江植物志”的过程中,作者最近从事浙江产的荚蒾属(Viburnum Linn.)的研究。本文包括23种,1变种及2变型,分隶于:(1)锥序组Sect,Thyrsosma (Rafin.)Rehd.—3种,(2)荚蒾组Sect.Viburnum—4种及1变型,(3)合轴组Sect.Pseudotinus C.B.Clarke—1种,(4)球核组Sect.Tinus(Borkh.)Maxim.—种,(5)蝶花组Sect.Pseudopulus(Dipp.)Rehd.—1种及1变型,(6)齿叶组Sect.Odontotinus Rehd.—12种及1变种,以及(7)裂叶组Sect.Opulus A.DC.—1种。其中尚有归并为同物异名者1种及1个新组合的亚种。 作为分类学研究成果,本文提供了对主要器官及附属物的特征,分组及分种的检索表,对每一分类群的地理分布、生态条件等作了系统的论述和列举。 本文中所被研究的大量标本均藏于杭州植物园标本室、杭州大学生物系标本室及浙江博物馆标本室。 相似文献
147.
苦楝油防治桔全爪螨的研究 总被引:4,自引:0,他引:4
本文认为苦楝(Melia azedarach L.)油对桔全爪螨Panonychus Citri(McG.)的毒杀作用,可能是因油剂堵塞螨的气门造成窒息而死亡。用电镜扫描的方法比较了桔全爪螨和捕食螨的气门结构,指出气门结构的差异是产生选择毒性的主要原因。本文提出了乳化苦楝油的经济、简易、有效的配方和方法。室内测定,苦楝油对桔全爪螨LC_(50)为0.27%;大田防治试验的效果达93.7%,是一种优良的高效杀螨剂。利用植物油防治柑桔叶螨具有广阔的前途。 相似文献
148.
杀虫剂田间毒理研究的新进展 总被引:3,自引:0,他引:3
本文扼要地介绍了杀虫剂田间毒理的观点及近年来的进展,指出杀虫剂田间毒理的主要观点是:在化学药剂、环境条件及害虫三者互相联系、互相制约的基础上,研究在田间生态条件下如何提高药剂对害虫个体及群体的防治效果,最大限度地发挥化学防治在害虫综合治理(IPM)中的作用。主要进展有:1.以生态学为基础,用田间毒理观点为指导,系统地研究了荔蝽的自然抗药性现象,包括自然抗药性机理、实际防治措施及施药技术等,为有效地解决生产实际问题提供了理论依据。2.通过对植物质杀虫剂及昆虫生长发育调节剂的研究,为综合治理提供了新型药剂。3.利用“累积虫日”等参数,改进了田间药效的评价方法。这些观点和研究进展将进一步推动我国昆虫毒理学及害虫防治技术的发展。 相似文献
149.
紫背金盘提取物对四种鳞翅目害虫作用活性的初步研究 总被引:23,自引:0,他引:23
紫背金盘(A(?)(?)(Makine))提取物对菜青虫(P(?)(?)(L.))小菜蛾(P(?)xylostella(L.))斜纹夜蛾(Prode(?)ia Iit(?)(Fabricius))和粘虫(M(?) aeparola (Walker))的幼虫均有显著的抑制生长发育和拒食作用,甲醇提取物及其氯仿提取物对五龄菜青虫的拒食中浓度(AFC_(50))分别为0.31%和0.12%;抑制生长发育有效中量(ED_(50))分别为1.36mg/g和0.34mg/g.氯仿萃取物对3—4龄小菜蛾的AFC_(50)为0.23%,EC_(50)=为0.29%(饲喂法)和0.22%(点滴法)。杀虫活性成分是易溶于氯仿的弱极性物质,分离提纯工作仍在进行中。 相似文献
150.
Y-S Lai H-C Chiu S Murali I-C Guo S-C Chen K Fang & C-Y Chang 《Journal of fish diseases》2001,24(4):237-244
Mouse monoclonal antibodies (MAbs) were produced by using yellow grouper nervous necrosis virus (YGNNV) as an immunogen, isolated from infected yellow grouper, Epinephelus awoara (Temminck & Schlegel), and propagated in GB cells. In enzyme linked immunosorbent assay (ELISA), 43 hybridoma clones secreting MAbs strongly reacted with the purified virus. Ten of them showed a higher neutralization index (NI) value between 6.5 and 4.5 (log10 NI) than the other 33 MAbs against YGNNV infection in cell culture. All 10 MAbs belonged to the IgG isotype with a κ light chain and recognized the 42 kDa coat protein of YGNNV by Western blot analysis. Immunohistochemical results demonstrated that the viral signals co-located with pathological lesions observed in retina, brain and spinal cord. These results indicate that the MAbs are useful for confirmative diagnosis of YGNNV infection. 相似文献