Contents of Indigestible Fraction,Water Solubility,and Color of Pyrodextrins Made from Waxy Sorghum Starch

To investigate the effect of prethinning of starch by acid before pyrolysis on the formation of indigestible fraction (IF) in pyrodextrins, native and prethinned (50°C for 1, 4, and 24 hr) waxy sorghum starches were heated at 120–160°C with 20–60 μL of 9% HCl/g of starch. Pyrodextrin containing 14.6% IF, measured as total dietary fiber by enzymatic‐gravimetric method, was produced at 120°C with 20 μL of HCl from native waxy sorghum starch. Prethinning before pyrolysis increased IF content by 0–68%, depending on the conditions for pyrolysis, compared with that of the native starch. Reduction in the molecular size of starch by prethinning might cause greater mobility during pyroconversion reaction and thus generate higher IF contents. Increasing temperature and acid concentration during pyroconversion also increased IF content of pyrodextrins. Pyrodextrin of 44.9% IF was produced at 160°C with 60 μL of HCl from prethinned starch (50°C for 24 hr). Solubility of pyrodextrins was inversely proportional to IF content (r = ‐0.87) and had a range of 62.7–98.3%. Color of pyrodextrins became brownish with more severe pyroconversion conditions.     

基于ARSIS策略的SAR影像与多光谱遥感小波融合

针对南方多云多雨、光学遥感数据不易获取的特点,在江苏省宝应县设置了区域试验,探索了ENVISAT/SAR影像与HJ-1A星多光谱遥感融合的模式与效果。基于ARSIS策略,利用Mallat小波变换和波段间交互构造模型IBSM,对SAR影像和HJ-1A/CCD影像进行小波分解与低频、高频系数重构,然后通过小波逆变换得到信息融合影像。针对低频与高频影像的不同区域特征使用不同的融合规则,以增强融合过程的自适应性。对融合影像进行了主观与相应的定量评价,并与PCA变换、IHS变换等传统方法进行比较。最后,利用GPS矢量样点提取了小波融合前后影像的波段值与NDVI信息,对融合效果做了进一步的分析与说明。结果表明,小波融合、IHS变换、PCA变换影像光谱扭曲度平均值分别为0.1016、0.3261、1.2772,其中小波融合方法的值最小。三者的信息熵平均值分别为14.7015、11.8993和13.2293,以小波融合方法的值最高。说明小波融合方法在提高空间分别率的同时,较好的增强了光谱保持能力,信息解译效果明显优于PCA变换和IHS变换2种方法。     

Effect of seedling transplanting date on methane emission from rice paddy soil during cultivation

In most temperate mono-rice cultivation systems like Korea, the local recommended transplanting date of rice (Oryza sativa L.) seedlings is proposed by the government agency considering climate, rice cultivar, rice productivity and quality, etc. Recently the transplanting of rice seedlings earlier than the recommended transplanting date (RTD) has been adopted by the local farmers to get high yield and to harvest earlier for higher market value. Earlier transplanting than RTD might influence methane (CH₄) emission due to the prolonged cultivation period, but its effect was not evaluated well so far. In this study, the effects of seedling transplanting date on CH₄ emission and rice productivity were investigated for two years in a general paddy soil. The 30-day old seedlings were transplanted on the local RTD (every June 15) as the control, and at 30 and 15 days before and 15 days after the RTD for comparison. There was no difference on CH₄ flux pattern among the treatments, but the earlier transplanting before the RTD significantly (P ?≤?0.05) increased total CH₄ emissions during rice cultivation due to the extended soil flooding period and improved plant growth. Rice grain yield was increased by earlier transplanting, but the values were not significantly different from those of transplanting practices on RTD and 15 days before RTD. Therefore, among all the treatments, the lowest total CH₄ emission per grain yield was observed in the RTD treatment. Conclusively, rice transplanting following the RTD, rather than early or late transplanting, could be more effective to minimize CH₄ emission without significantly decreasing the rice productivity.     

Energy-absorbing Properties and Crushing Flow Stress Equation of Lightweight Foamed Concrete

Lightweight foamed concrete is a new arresting material for arresting overrun aircraft. To reveal its compression properties and mechanism of deformation and destruction, a study on lightweight foamed concrete with different density, 0.21 and 0.31 g/cm 3 respectively, has been carried out. Experiment system include CSS4410 electronic universal testing machine and Dynatup9250 drop-hammer testing machine and VHS8800 high strain rate system. Then, extrusion strength under different indenter area is predicted with a theoretical model, and a crushing flow stress constitutive equation is proposed. The results show that it is characterized by the movement of crushing driving interface during the process of deformation, crush to compaction of the material, and the deformation is notably in local. The compression strength is relevant to density and impact velocity. Moreover, theoretical model can predict the extrusion strength under different indenter area exactly, and the crushing flow stress equation can describe mechanic properties of compression well.     

兴隆热带植物园旅游开发管理经验

通过对兴隆热带植物园旅游开发过程中形成的企业文化,目标、制度、人性化、培训、营销管理等经验进行总结,以期为兴隆热带植物园的可持续发展提供支持。     

Repellent and attractive effects of herbs on insects in pear orchards intercropped with aromatic plants

There is increasing interest in the use of vegetation such as aromatic plants as intercrops to biologically control insect pests in agroecosystems and orchard ecosystems. Understanding the mechanisms underlying the repellent effects of aromatic plants on orchard pests (e.g., scarabaeid pests) can lead to improved application of intercropping cultivation practices in orchards. We tested eight intercropping treatments, each containing a different species of aromatic plant, in a pear orchard, along with a natural grass treatment and a clean tillage (control) treatment. The results showed that intercropping reduced the annual cumulative number and abundance of scarab beetles relative to the control. The annual dynamics of scarab populations were also significantly altered where intercrops were used. However, with the exception of Ichneunmonidae, the natural parasites of scarabs showed no preference for the aromatic plants. A correlation analysis indicated that the reduction in some of the scarab beetle species was related to the abundance of certain specific natural enemy species. In addition, the diversity, evenness and degree of dominance of natural enemy species may have contributed to the decrease in scarab populations. This study shows that intercropped aromatic plants can be applied to control the scarab beetles in orchard ecosystems, but that effects vary across aromatic plant species.     

休闲渔船拖网标准化改造前后渔获物中游泳动物群落结构分析

为了解休闲渔船体验式拖网标准化改造对乐清湾游泳动物群落结构的影响,分别在2016年网具改造前和2017年网具改造后的春、夏季于乐清湾海域进行游泳动物底拖网调查。结合相对重要性指数、种类更替率、生态多样性指数和多元统计分析等方法,对网具标准化改造前后渔获物中游泳动物的组成进行分析。结果表明：网具标准化改造前后游泳动物群落组成发生了一定的变化,2年春季共有优势种为三疣梭子蟹（Portunus trituberculatus）、小黄鱼（Larimichthys polyactis）,夏季共有优势种为三疣梭子蟹、小黄鱼、龙头鱼（Harpodon nehereus）和刀鲚（Coilia nasus）。网具标准化改造后：春季渔获物中游泳动物的平均丰度由5.91×10⁴ ind./km²降低至2.72×10⁴ ind./km²,夏季平均丰度由9.76×10⁴ ind./km²降低到3.45×10⁴ ind./km²;春季平均生物量由310.87 kg/km²提高至356.07 kg/km²,夏季由444.90 kg/km²提高到515.90 kg/km²;渔获物中的小黄鱼、花鲈（Lateolabrax japonicus）和刀鲚等重要经济种的平均体长显著大于改造前,部分站位的三疣梭子蟹的甲宽和小黄鱼的体长显著增大;重要经济种的幼体比例降低,小型饵料生物种类的优势度有所下降。综上所述,休闲渔船体验式拖网标准化改造对重要经济种类的幼体和饵料生物有一定的保护效果,有利于对乐清湾渔业资源的可持续利用和生境保护,但渔获物中幼体数量仍占有较高的比例,说明网具规格需要进一步改进。该结果可为休闲渔船的管理提供参考。     

Effect of alkyl chain length on thermochromism of novel nitro compounds

A series of novel nitro compounds containing different alkyl chain length (x=2∼5), 1,5-bis(hydroxyalkylamino)-2,4-dinitrobenzene (BDBx), are synthesized and their thermochromic behavior is investigated by using differential scanning calorimetry and optical microscopy. All the BDBx crystals synthesized show yellow color at room temperature. BDBx (x=2∼4) samples display orange color even in the solid when heated above respective thermochromic transition temperature, while the yellow color of BDB5 changes to orange with melting. The orange color of BDBx crystals returns to yellow when cooled down to room temperature, indicating that the thermochromic behavior of BDBx is reversible. The thermochromic transition temperatures of BDBx crystals are found to be decreased with increasing the alkyl chain length, exhibiting evenodd fluctuation.