A portable NMR sensor for moisture monitoring of wooden works of art, particularly of paintings on wood     

L. Senni  C. Casieri  A. Bovino  M. C. Gaetani  F. De Luca 《Wood Science and Technology》2009,43(1-2):167-180

It is proposed the use of a mobile device based on a NMR single-sided sensor for in situ non-invasive determination of the moisture content (MC) of wood items, especially items of Cultural Heritage interest. The MC is obtained through the moisture volume fraction, which is an appropriate quantity for the sensor and corresponds to the fraction of its measurements sensitive volume occupied by water. The device has been used here to track changes in MC of wood specimens caused by changes over time of the environmental relative humidity. The kinetics of water adsorption has been related to results obtained with the gravimetric method. Measurements on an old painting, the Pietà (1516–1517), oil on a poplar wood panel by Sebastiano del Piombo (1485 Venice, 1547 Rome), Civic Museum, Viterbo, Italy, have shown, conclusively, the good sensitivity of the sensor and its capability to behave as a non-invasive and in situ utilizable device. Results of in situ painting measurements show that the NMR sensor can track moisture fluctuations that are outside the sensitivity range and precision of electro-hygrometric approach.  相似文献   

Establishment and analysis of dynamic mathematical model for coal gasifier     

YANG Chen  KONG De feng 《保鲜与加工》2009,(8):864-868

Based on the analysis of flowing combustion, gasification reaction, and lumped parameter, a three region model is established to predict the temperature and gas components of Texaco coal gasifier. Using mass balance and energy balance equations to each zone, the model takes account of gas solid two phase flow, coal pyrolysis, radiation heat transfer, and heterogeneous and homogeneous kinetic chemical reactions. Based on the model, a program is developed for dynamic and static simulation. After parameterization and simulation analysis, some important trends and conclusions are attained. Because the model can accurately predict the temperature and gas components in jet region, it has widespread engineering application value.  相似文献   

Design and optimization of drawing surface and FE analysis forthe front side panel of autobody     

ZHOU Jie  YANG De sen  HUA Jun jie  YI Zong hua  YANG Ming 《保鲜与加工》2009,(12):1392-1397

The drawing process of the front side panel of autobody is simulated by using the finite element software, Dynaform. The drawing surface is designed, focusing on the optimization of the addendum and the drawbead layout. By comparing the stress/strain conditions and the FLD in two types of addendum (stepped and slope) and three types of drawbead layout (closed, discontinuous and oblique drawbead), the slope addendum is chosen as the optimized addendum and the oblique drawbead is chosen as the optimized drawbead layout. The simulation results show the material flow in the corner and the quality of the part can be improved effectively with the optimized drawing surface. The optimized parameters are employed in production and acceptable quality parts are produced. Therefore, the optimized drawing surface is verified to be effective.  相似文献   

Design of compatible processing and analyzing system for nuclear signals     

REN Yong  WEI Biao  FENG Peng  TANG Yue lin  MI De ling 《保鲜与加工》2009,(9):1054-1058

To on line detect, store and process nuclear signals with multiple forms and multiple frequencies, a compatible processing and analyzing system for nuclear signals based on ultrahigh speed data acquisition card was constructed. When the source signal is at pulse form, the system records signal with the mode of time digital converting. When source signal is at continuous form, the system records signal with the mode of analog digital converting. The processing procedures and algorithms were designed for various signal forms. The results for nuclear random process such as correlation function and power spectrum were effectively obtained.  相似文献   

Fourteen years of applying zero and conventional tillage,crop rotation and residue management systems and its effect on physical and chemical soil quality     

Mariela Fuentes  Bram Govaerts  Fernando De León  Claudia Hidalgo  Luc Dendooven  Ken D. Sayre  Jorge Etchevers 《European Journal of Agronomy》2009,30(3):228-237

Soil management systems may negatively affect the quality of the soil. Policymakers and farmers need scientific information to make appropriate land management decisions. Conventional (CT) and zero tillage (ZT) are two common soil management systems. Comparative field studies under controlled conditions are required to determine the impact of these systems on soil quality and yields. The research presented studied plant and soil physical and chemical characteristics as affected by different agricultural management practices, i.e. ZT and CT, cropped with continuous wheat or maize in monoculture (M) or in a yearly rotation (R) of these two crops, either with residue retention (+r) or without residues retention (?r), in an experimental field in the Transvolcanic Belt of Mexico after 14 years. The dominant factors defining soil quality were organic C, total N, moisture, aggregate stability, mechanical resistance, pH and EC. The principal component combining the variables organic C, total N, aggregate stability and moisture content showed the highest correlations with final yield (R = 0.85 for wheat and 0.87 for maize).After 14 years of continuous practice, ZTM + r and ZTR + r had the best soil quality and produced the highest wheat and maize yields of average 2001–2004 (6683 and 7672 kg ha^?1 and 5085 and 5667 kg ha^?1, respectively). Removing the residues, i.e. treatments ZTM ? r with maize (average 2001–2004: 1388 kg ha^?1) and ZTR ? r and CTR ? r with wheat (average 2001–2004: 3949 and 5121 kg ha^?1), gave the lowest yields and less favourable soil physical and chemical characteristics compared to the other practices. It was found that zero tillage with residue retention is a feasible management technology for farmers producing maize and wheat in the agro-ecological zone studied, resulting in a better soil quality and higher yields than with the conventional farmer practice (maize monoculture, conventional tillage and residue removal).  相似文献   

The use of <Emphasis Type="Italic">Vp1</Emphasis> in real time RT-PCR to select for pre-harvest sprouting tolerance in triticale   总被引：1，自引：0，他引：1  

Sarah De Laethauwer  Dirk Reheul  Jan De Riek  Geert Haesaert 《Euphytica》2009,168(3):379-384

In spite of the availability of laboratory and field tests there is still a major problem to select pre-harvest sprouting (PHS) tolerant triticale varieties in a reliable, field-independent way. One approach to minimize the influence of environmental conditions and physio-morphological traits on PHS detection is using molecular genetic tools. The ‘viviparous’ Vp1 gene has been repeatedly described to play an important role in dormancy in wheat. A quantitative RT-PCR assay based on the expression of the Vp1 gene has been developed. Specific primers were designed for detecting Vp1 in both wheat and triticale. The expression levels of Vp1 were normalized using reference genes and relatively quantified with the comparative C_t-method. However, the first results indicate that the achieved Vp1 expression levels at 50 days post anthesis are not useful to select for PHS tolerance, both in wheat and triticale. This negative outcome so far is possibly due to the existence of several splicing events or to the late assaying moment in the kernel development, when Vp1 expression is found to be low.  相似文献   

Genetic stability at nuclear and plastid DNA level in regenerated plants of <Emphasis Type="Italic">Solanum</Emphasis> species and hybrids     

Riccardo Aversano  Salvatore Savarese  Jose Maria De Nova  Luigi Frusciante  Maria Punzo  Domenico Carputo 《Euphytica》2009,165(2):353-361

In this work we detected the extent of variability at nuclear and cytoplasmic DNA level of regenerated plants belonging to Solanum genotypes with a different genetic background and somatic chromosome number. As for the nuclear characterization, a total of 66 (18.5%) polymorphic bands were scored using 13 ISSR primers on 45 randomly selected regenerants. Our results show that the regenerants obtained from clone cmm 1T and, at lower level, those from cph 1C are unstable under in vitro conditions or rather more prone to in vitro-induced stress leading to somaclonal variation than the other genotypes used. Two types of changes were observed: disappearance of parental ISSR fragments, termed “loss”; appearance of novel ISSR fragments, termed “gain”. The most frequent event occurring in the regenerants was the loss of fragments (41 bands). Regenerated plants were analyzed with seven plastid universal primers to determine the cytoplasmic composition at chloroplast level. All cpDNA primer pairs tested produced amplicons of the same size in all genotypes analyzed and no polymorphic fragments were observed with any universal primers used. Our results show that under in vitro culture conditions genotype affects the integrity of the genome. In addition, the absence of polymorphism at plastid level confirms the greater genetic stability of cytoplasmic DNA.  相似文献   

基于GIS的瓦房店市耕地资源管理信息系统的建立     

贾树海  白静  李秀凤  周德  孟维军  张琦 《湖北农业科学》2009,48(3)

以辽宁省瓦房店市为例,采用MapInfo作为技术平台,运用MapBasic语言编程,建立了涵盖气候、水文、地形地貌、土壤、农业基础设施建设和土地利用现状等信息的县域耕地资源管理信息系统.该系统以1:10 000的土地利用现状图为工作底图,具体包括基础地理信息、土壤环境信息、土壤属性信息、专项评价信息、信息查询服务和施肥专家咨询6部分信息,实现了对瓦房店市耕地资源高效、系统的管理.  相似文献   

荷叶离褶伞菌丝最佳生长条件研究   总被引：2，自引：0，他引：2  

李永红  柴红梅  何德  赵永昌 《西南农业学报》2009,22(2)

本文研究了菌丝生长所需要的碳源、氮源、无机盐、pH值以及离褶伞子实体浸出液对荷叶离褶伞菌丝生长的影响。结果表明,荷叶离褶伞菌丝生长最适碳源是葡萄糖,最适氮源是蛋白胨,每1000mL培养基中加入1g磷酸二氢钾或1g氯化钙能促进菌丝生长;菌丝在pH值5—9都能生长,但在酸性环境下生长较好;加入离褶伞子实体漫出液对荷叶离褶伞菌丝生长促进作用明显。  相似文献   

Effects of C:N ratio and substrate integration on periphyton biomass, microbial dynamics and growth of Penaeus monodon juveniles     

P. S. Shyne Anand  Sujeet Kumar  A. Panigrahi  T. K. Ghoshal  J. Syama Dayal  G. Biswas  J. K. Sundaray  D. De  R. Ananda Raja  A. D. Deo  S. M. Pillai  P. Ravichandran 《Aquaculture International》2013,21(2):511-524

An outdoor growth trial was conducted for 75 days to investigate the effect of C:N ratio and bamboo substrate (S) in brackish water shrimp culture. Penaeus monodon juveniles (0.35 ± 0.03 g) were stocked in experimental tanks with and without bamboo substrate. C:N ratio of 10 and 20 was manipulated with shrimp feed containing 32 % crude protein and rice flour as carbohydrate source. Addition of substrate and higher C:N ratio (CN20+S) significantly reduced (p < 0.01) inorganic nitrogen NH₃–N by 48.2 %, NO₃–N by 41.6 %, NO₂–N by 42.7 % compared with CN10. Substrate addition significantly (p < 0.05) reduced the turbidity by 22.4 % (CN10+S against CN10) and 20.7 % (CN20+S against CN20). Periphyton biomass and total heterotrophic bacterial load were significantly higher (p < 0.05) in CN20+S in comparison with CN10+S treatment. The autotrophic index increased from 123.4 ± 0.62 to 158.9 ± 3.8 for CN10+S and, 121.8 ± 1.6 to 228 ± 9.11 for CN20+S system. Provision of substrate and carbohydrate addition resulted in the highest body weight, 4.87 ± 0.12 g in CN20+S against 3.66 ± 0.07 g in CN20 and 2.90 ± 0.12 g in CN10 through provision of natural food in the form of periphytic algae and heterotrophic bacterial community. Treatment with substrates showed a higher survival rate by 7 % in comparison with without substrate treatments as it acted as shelter to shrimp during molting and there by reduced cannibalism. Thus, our results demonstrated that high C:N ratio and substrate addition improved growth, reduced FCR and better water quality conditions.  相似文献