Remote sensing for agricultural applications

<正>Agricultural geospatial information is critical for agricultural policy formulation and decision making,land use monitoring,agricultural sustainability,crop acreage and yield estimation,disaster assessment,bioenergy crop inventory,food security policy,environmental assessment,carbon accounting,and other research topics that are of vital importance to agriculture and economy.Remote sensing technology enables us     

Chemiluminescence of anodized and etched silicon: evidence for a luminescent siloxene-like layer on porous silicon

Treatment of anodized or chemically etched silicon ("porous silicon") with dilute nitric acid or persulfate solution results in weak chemiluminescence in the visible region. Concentrated nitric acid reacts violently with porous Si produced by anodization with a bright flash of light. The fact that similar reactions occur with siloxene (Si(6)H(6)O(3)) prepared from CaSi(2) suggests that the visible emission seen with porous Si can be attributed to this substance.     

阿霉素-多孔磷酸三钙陶瓷缓释体的研制及体内释药试验

目的；研制阿霉素－多孔磷酸三钙陶１缓释体并为骨肿瘤保肢治疗术后肌缺损的修复提供新方法。材料与方法：制备ＰＴＣＰ陶瓷，将阿霉素载入其中制得Ａ－ＰＴＣＰ。实验动物分成Ａ，Ｂ两组，Ａ组右股骨粗隆中植入Ａ－ＰＴＣＰ，Ｂ组静脉注射阿霉素。不同时期取粗隆部位的肌肉及血浆标本，用高效液相色谱法测定肌肉及血浆中阿霉素的浓度。     

New methods of drug delivery

Conventional forms of drug administration generally rely on pills, eye drops, ointments, and intravenous solutions. Recently, a number of novel drug delivery approaches have been developed. These approaches include drug modification by chemical means, drug entrapment in small vesicles that are injected into the bloodstream, and drug entrapment within pumps or polymeric materials that are placed in desired bodily compartments (for example, the eye or beneath the skin). These techniques have already led to delivery systems that improve human health, and continued research may revolutionize the way many drugs are delivered.     

Chemical modification of the photoluminescence quenching of porous silicon

The photoluminescence of porous silicon can be quenched by adsorbates, and the degree of quenching can be tuned by chemical derivatization of the porous silicon surface. Thus, as-prepared porous silicon has a hydrophobic, hydrogen-terminated surface, and the photoluminescence is strongly quenched by ethanol and weakly quenched by water. Mild chemical oxidation (iodine followed by hydrolysis) produces a hydrophilic porous silicon surface. Photoluminescence from this hydrophilic material is quenched to a lesser extent by ethanol and to a greater extent by water, relative to the original surface. This demonstrates that the visible luminescence from porous silicon is highly surface-sensitive, and the surface interactions can be tuned by specific chemical transformations.     

Agricultural remote sensing big data: Management and applications

Big data with its vast volume and complexity is increasingly concerned, developed and used for all professions and trades. Remote sensing, as one of the sources for big data, is generating earth-observation data and analysis results daily from the platforms of satellites, manned/unmanned aircrafts, and ground-based structures. Agricultural remote sensing is one of the backbone technologies for precision agriculture, which considers within-field variability for site-specific management instead of uniform management as in traditional agriculture. The key of agricultural remote sensing is, with global positioning data and geographic information, to produce spatially-varied data for subsequent precision agricultural operations. Agricultural remote sensing data, as general remote sensing data, have all characteristics of big data. The acquisition, processing, storage, analysis and visualization of agricultural remote sensing big data are critical to the success of precision agriculture. This paper overviews available remote sensing data resources, recent development of technologies for remote sensing big data management, and remote sensing data processing and management for precision agriculture. A five-layer-fifteen-level (FLFL) satellite remote sensing data management structure is described and adapted to create a more appropriate four-layer-twelve-level (FLTL) remote sensing data management structure for management and applications of agricultural remote sensing big data for precision agriculture where the sensors are typically on high-resolution satellites, manned aircrafts, unmanned aerial vehicles and ground-based structures. The FLTL structure is the management and application framework of agricultural remote sensing big data for precision agriculture and local farm studies, which outlooks the future coordination of remote sensing big data management and applications at local regional and farm scale.     

Research advances of SAR remote sensing for agriculture applications: A review

Synthetic aperture radar (SAR) is an effective and important technique in monitoring crop and other agricultural targets because its quality does not depend on weather conditions. SAR is sensitive to the geometrical structures and dielectric properties of the targets and has a certain penetration ability to some agricultural targets. The capabilities of SAR for agriculture applications can be organized into three main categories: crop identification and crop planting area statistics, crop and cropland parameter extraction, and crop yield estimation. According to the above concepts, this paper systematically analyses the recent progresses, existing problems and future directions in SAR agricultural remote sensing. In recent years, with the remarkable progresses in SAR remote sensing systems, the available SAR data sources have been greatly enriched. The accuracies of the crop classification and parameter extraction by SAR data have been improved progressively. But the development of modern agriculture has put forwarded higher requirements for SAR remote sensing. For instance, the spatial resolution and revisiting cycle of the SAR sensors, the accuracy of crop classification, the whole phenological period monitoring of crop growth status, the soil moisture inversion under the condition of high vegetation coverage, the integrations of SAR remote sensing retrieval information with hydrological models and/or crop growth models, and so on, still need to be improved. In the future, the joint use of optical and SAR remote sensing data, the application of multi-band multi-dimensional SAR, the precise and high efficient modeling of electromagnetic scattering and parameter extraction of crop and farmland composite scene, the development of light and small SAR systems like those onboard unmanned aerial vehicles and their applications will be active research areas in agriculture remote sensing. This paper concludes that SAR remote sensing has great potential and will play a more significant role in the various fields of agricultural remote sensing.     

肺泡表面活性物质气管内注入方式改进后的临床效果观察

目的 探讨肺泡表面活性物质安全、有效的给药方式.方法 将80例确诊为新生儿呼吸窘迫综合征的早产儿随机分为试验组和对照组.试验组40例,采用55号头皮针直接从气管导管外壁刺入注药.对照组40例,按传统方法,分开气管导管与呼吸囊,分3个体位将药物直接从气管导管内注入.比较两组早产儿用药过程中的血氧饱和度(SpO2)、心率、口周发绀、药物反流、机械通气时间等情况.结果 试验组的SpO2、心率、口周发绀、药物反流等情况好于对照组(P＜0.01).结论 改进后的注药方式更有利于药物的有效利用,减少药物浪费,利于患儿生命体征的稳定,缩短机械通气时间.     

Receptor-mediated drug delivery to macrophages in chemotherapy of leishmaniasis

Methotrexate coupled to maleylated bovine serum albumin was taken up efficiently through the "scavenger" receptors present on macrophages and led to selective killing of intracellular Leishmania mexicana amazonensis amastigotes in cultured hamster peritoneal macrophages. The drug conjugate was nearly 100 times as effective as free methotrexate in eliminating the intracellular parasites. Furthermore, in a model of experimental cutaneous leishmaniasis in hamsters, the drug conjugate brought about more than 90% reduction in the size of footpad lesions within 11 days. In contrast, the free drug at a similar concentration did not significantly affect lesion size. These studies demonstrate the potential of receptor-mediated drug delivery in the therapy of macrophage-associated diseases.     

遥感技术在森林生态系统中的应用概述

从森林生物量估测、森林动态变化监测以及森林生态环境评价等方面较为系统地介绍了遥感技术在森林生态系统中的应用实例,为进一步发展遥感技术和研究森林生态系统的结构与功能提供了一定的参考依据。     

木质素三甲基季铵盐为模板剂制备多孔氧化硅材料

为了探索以小质素为模板剂制备无机多孔材料的方法,提高木质素产品附加值,以小质素三甲 铵盐为模板剂、正硅酸乙酯为硅源,采用溶胶凝胶法和焙烧脱模法制备多孔氧化硅材料。结果表明：小质素三甲基事铵盐行在于煅烧前的复合物中,煅烧后得到的多孔氧化硅材料中木质素三甲基季铵盐吸收峰消失,但具有SiO2特征吸收峰;多扎氧化硅材料孔隙发达...     

国外从事药物释放系统(DDS)研究的主要机构及其技术平台和产品

 

通过对全球10家杰出的从事药物释放系统研究的制药公司，包括公司主要技术平台、专利技

术、已上市药物和研发中的新药等进行分析，总结国外DDS的研究现状及研究开发热点。

     

磷硅肥配施抑制华南地区水稻籽粒砷积累的效果

选取华南地区广泛种植的杂交水稻品种"培杂泰丰",利用外源添加砷(50 mg·kg~(-1))的土壤盆栽试验,研究不同施用量的磷硅肥对水稻生长特性和砷积累的影响。结果表明,施用磷硅肥的处理,水稻糙米中砷含量为0.504~0.586 mg·kg~(-1),低于农业部颁布的粮食中砷限量标准(NY 861—2004)中大米砷限值。相关性分析表明,水稻糙米砷含量与水稻植株的生物量、稻谷千粒重和秸秆中硅/砷摩尔比呈显著负相关,与秸秆中磷/砷摩尔比呈极显著负相关;糙米的砷含量随磷、硅肥的施加而降低。综合分析表明,在华南地区同类中度砷污染土壤中可有效控制砷向水稻籽粒运输累积的磷、硅肥最优施加量及配比为40 mg P·kg~(-1)土、50 mg Si·kg~(-1)土。     

Predicting plant available phosphorus using infrared spectroscopy with consideration for future mobile sensing applications in precision farming

Phosphorus (P) fertilisation recommendations rely primarily on soil content of plant available P (P_avl) that vary spatially within farm fields. Spatially optimized P fertilisation for precision farming requires reliable, rapid and non-invasive P_avl determination. This laboratory study aimed to test and to compare visible-near infrared (Vis–NIR) and mid-infrared (MIR) spectroscopy for P_avl prediction with emphasis on future application in precision agriculture. After calibration with the conventional calcium acetate lactate (CAL) extraction method, limitations of Vis–NIRS and MIRS to predict P_avl were evaluated in loess topsoil samples from different fields at six localities. Overall calibration with 477 (Vis–NIRS) and 586 (MIRS) samples yielded satisfactory model performance (R² 0.70 and 0.72; RPD 1.8 and 1.9, respectively). Local Vis–NIRS models yielded better results with R² up to 0.93 and RPD up to 3.8. For MIRS, results were comparable. However, an overall model to predict P_avl on independent test data partly failed. Sampling date, pre-crop harvest residues and fertilising regime affected model transferability. Varying transferability could partly be explained after deriving the cellulose absorption index from the Vis–NIR spectra. In 62 (Vis–NIRS) and 67% (MIRS) of all samples, prediction matched the correct P_avl content class. Rapid discrimination between high, optimal and low P classes could be carried out on many samples from single fields thus marking an improvement over the common practice. However, P_avl determination by means of IR spectroscopy is not yet satisfactory for determination of precision fertilizer dosage. For introduction into agricultural practice, a standardized sampling protocol is recommended to help achieve reliable spectroscopic P_avl prediction.

     

卫星遥感在海洋渔业资源开发、管理与保护中的应用

海洋渔业资源的开发、管理与保护需要大量的海洋环境数据。由于卫星遥感能大面积、长时间、近实时地获取海洋环境数据,其在海洋渔业资源开发、管理与保护中的作用越来越大。本文回顾了卫星遥感数据在海洋渔业资源评估、渔情预报、鱼类栖息地分类与保护、渔船监测、渔业安全、渔具渔法等方面的应用,探讨了在这些应用中可能存在的问题,并对其未来的发展进行了展望,为相关学者了解卫星遥感在海洋渔业资源的开发、管理与保护中的作用提供参考。     

高空间分辨率遥感的单木树冠自动提取方法与应用

用高空间分辨率遥感影像对单木树冠进行自动提取和轮廓描绘,是获取森林信息的一种快速有效的方法。也是近年来林业遥感领域研究的热点。详细介绍了目前高分辨率遥感单木树冠信息自动提取的各种方法．包括局部最大值法、模板匹配法、谷地跟踪法、多尺度法、种子区域生长法、分水岭分割法、局部射线法．并对单木树冠提取在林业上的应用进行了探讨,最后结合国内外研究现状,对单木树冠自动提取的未来作了展望。参51