秸秆还田对土壤有机碳不同活性组分储量及分配的影响

通过田间试验,研究了不同秸秆还田模式下土壤溶解性有机碳(DOC)、颗粒有机碳(POC)和矿物结合有机碳(MOC)储量及其在总有机碳(TOC)中的分配比例.结果表明: 相对于翻压还田(WR),小麦秸秆覆盖还田(WM)0～20 cm耕层TOC和MOC储量显著降低,降幅为4.1%和9.7%,DOC和POC储量显著提高,增幅为207.7%和11.9%;20～40 cm犁底层TOC和POC储量显著提高.玉米秸秆覆盖还田(MM)与MR相比,犁底层TOC和MOC储量显著提高,增幅为13.6%和14.6%.小麦-玉米秸秆均覆盖还田(WM-MM)相对于均翻压还田(WR-MR),耕层TOC和MOC储量显著降低,降幅为8.5%和10.3%.玉米秸秆还田耕层TOC和POC储量显著高于小麦秸秆还田.与对照(秸秆不还田)相比,6种还田模式耕层TOC储量增幅为5.2%～18.0%,差异达显著水平;除WM和MM模式外,犁底层TOC储量显著降低(降幅8.0%～11.5%).6种还田模式下土壤耕层DOC储量及DOC/TOC比值显著降低,在WM和WM-MM还田模式下耕层POC储量显著提高、POC/TOC比值增大,WR模式的耕层MOC储量显著提高、MOC/TOC比值增大,其余3种模式耕层POC和MOC储量均显著提高.秸秆覆盖还田有利于土壤有机碳活性组分积累,翻压还田有利于较稳定性有机碳组分积累.在提高关中地区农田TOC储量方面,玉米秸秆还田好于小麦秸秆还田、小麦-玉米秸秆翻压还田好于覆盖还田.     

Isolation and analysis of cell wall material from beeswing wheat bran (Triticum aestivum)

Cell wall material (CWM) isolated from beeswing wheat bran contains 66% carbohydrate, 12% Klason lignin, 6% protein and 4% ash. The relative proportions of sugars in the CWM are arabinose 34%, xylose 26%, galactose 2%, glucose 32% and uronic acid 6%. The uronic acid was shown to consist of glucuronic acid and its 4-O-Me analogue in the ratio 1.8:1. Partial acid hydrolysis of the CWM yielded neutral sugars and a uronic acid fraction. The latter was shown to contain Glc p A-(1→2)-Xyl p and Glc p A-(1→2)-O-Xyl p-(1→4)-Xyl p and their 4-O-Me substituted uronic acid analogues. Methylation analysis of the whole CWM and partially degraded methylated CWM revealed the nature of the constituent glycosidic linkages. From the combined evidence we infer that the major structural features of the non-cellulosic polysaccharides are a linear chain of xylopyranose units joined by (1→4)-linkages, and arabinofuranose, xylose, galactose (and uronic acid) end groups, which in at least some of the polysaccharides, are attached directly by (1→2)- and/or (1→3)-linkages to the xylan chain. The CWM has been fractionated by successive extractions with water at 80°, 0.2 M (NH₄)₂C₂O₄ at 80°, Na chlorite/HOAc at 70°, 0.2 M (NH₄)₂C₂O₄ at 80°, 1 M and 4 M KOH, and the neutral sugar composition of the fractions determined. It is concluded from these and other experiments that the CWM contains two main types of polysaccharides, the arabinoxylans and cellulosic polymers, and that phenolic ester linkages play a role in holding them together.     

A mixed finite element formulation for a non-linear,transversely isotropic material model for the cardiac tissue

In this paper we present a mixed finite element method for modeling the passive properties of the myocardium. The passive properties are described by a non-linear, transversely isotropic, hyperelastic material model, and the myocardium is assumed to be almost incompressible. Single-field, pure displacement-based formulations are known to cause numerical difficulties when applied to incompressible or slightly compressible material cases. This paper presents an alternative approach in the form of a mixed formulation, where a separately interpolated pressure field is introduced as a primary unknown in addition to the displacement field. Moreover, a constraint term is included in the formulation to enforce (almost) incompressibility. Numerical results presented in the paper demonstrate the difficulties related to employing a pure displacement-based method, applying a set of physically relevant material parameter values for the cardiac tissue. The same problems are not experienced for the proposed mixed method. We show that the mixed formulation provides reasonable numerical results for compressible as well as nearly incompressible cases, also in situations of large fiber stretches. There is good agreement between the numerical results and the underlying analytical models.     

黄酒酿造原料及生产工艺研究现状与展望

黄酒的质量取决于酿造原料、酒曲、加工工艺以及酿造环境,不同的酿造原料、酒曲、加工工艺和环境能赋予黄酒不同的品质与风味。本文在检索文献、比较分析新旧版黄酒国标的基础上,介绍了南北地区黄酒酿造原料的差异以及新型功能性黄酒原辅料研发现状,综述了浸米、蒸饭与发酵三个工艺关键环节的最新研究进展,旨在为黄酒技术的创新,功能性、饮料性、国际性黄酒新产品开发提供借鉴及参考。     

INTRACELLULAR DIMETHYLSULFOXIDE (DMSO) IN UNICELLULAR MARINE ALGAE: SPECULATIONS ON ITS ORIGIN AND POSSIBLE BIOLOGICAL ROLE

Recent studies have established that aqueous phase concentrations of dimethylsulfoxide (DMSO) often exceed those of dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS). Yet, in comparison to DMSP and DMS, DMSO remains a poorly understood component of the marine sulfur cycle. Much of what is known about the mechanisms for the formation and loss for DMSO is inferred from laboratory experiments, and no explanation exists to rationalize how a large pool of DMSO is maintained. One formation pathway that, until very recently, has been ignored involves the direct synthesis of DMSO by marine phytoplankton. This review examines some of the circumstantial evidence for DMSO in marine particulate material and recent reports containing preliminary data for particulate DMSO (DMSO_p) in the marine environment. Drawing on literature from a range of scientific disciplines, speculations on the possible origins and biological functions of intracellular DMSO are also made. On the basis of its physicochemical properties, intracellular DMSO could have a potential role as a cryoprotectant, a specialist cryo-osmoregulator in extreme environments, an intracellular electrolyte modifier, and a free-radical scavenger. The review also assesses the impact of DMSO_p at both the organism and the global level. Consideration is given to the marine biogeochemical cycling of sulfur and potential links to climate control.     

基于MFA的生态工业园区物质代谢研究方法探析

物质流分析(Material Flow Analysis,MFA)是国家尺度物质代谢研究的重要手段。首先对国内外不同地域尺度下MFA的研究现状进行了概述总结;在此基础上,从工业区内的企业及其所形成的工业共生网络(Industrial Symbiosis Networks,ISNs)物质核算入手,针对如何在生态工业园区(Eco-Industrial Parks,EIPs)尺度开展物质代谢研究进行了详细论述,并通过引入部门间实物型投入产出表(Physical Input-Output Table,PIOT)对该尺度MFA的核算方法进行了改进,最终构建了EIPs-MFA模型及指标体系。以期为生态工业园区实践中的规划与管理提供方法指导。     

可用于生物学参数检测的不同脉宽短脉冲激光器

本文介绍了一种可用于生物学参数检测的不同脉宽短脉冲激光器,可选用的脉冲宽度从20ns-200ns,激光输出能量从几十毫焦耳（mJ)到一百多毫焦耳（mJ),文中讨论了使用ARR调Q腔型及新型调Q材料Cr^4 ;YAG对激光输出能量稳定性及脉宽的影响情况。该激素器及其原理具有实用价值和学术价值。     

络合型含铁材料对砷胁迫下水稻生理生化特性及砷累积的影响

土壤重金属与农产品质量息息相关.本研究通过设置砷胁迫条件下水稻种植盆栽试验,分析络合型含铁材料不同施用时期和不同施用量对水稻SPAD值、抗氧化酶(SOD、POD、CAT)活性以及水稻砷吸收、累积的影响.结果表明,砷胁迫对水稻SOD、POD、CAT活性有着不同程度的抑制作用,添加络合型含铁材料可以降低水稻MDA含量,缓解砷对水稻光合作用和SOD、POD、CAT活性的抑制;同时能减少水稻对土壤砷的吸收和累积.与移栽前添加络合型含铁材料相比,选择水稻孕穗期前添加络合型含铁材料,水稻砷吸收的抑制效果较好;水稻植株地上部砷含量与络合型含铁材料的添加浓度呈显著负相关,孕穗期前添加0.2 g·kg-1络合型含铁材料对水稻植株砷的吸收抑制效果最好,水稻植株地上部砷含量降低59.22%.     

Material basis for inhibition of Dragon’s Blood on evoked discharges of wide dynamic range neurons in spinal dorsal horn of rats

In vivo experiments were designed to verify the analgesic effect of Dragon’s Blood and the material basis for this effect. Extracellular microelectrode recordings were used to observe the effects of Dragon’s Blood and various combinations of the three components (cochinchinenin A, cochinchinenin B, and loureirin B) extracted from Dragon’s Blood on the discharge activities of wide dynamic range (WDR) neurons in spinal dorsal horn (SDH) of intact male Wistar rats evoked by electric stimulation at sciatic nerve. When the Hill's coefficients describing the dose-response relations of drugs were dif-ferent, based on the concept of dose equivalence, the equations of additivity surfaces which can be applied to assess the interaction between three drugs were derived. Adopting the equations and Tal-larida's isobole equations used to assess the interaction between two drugs with dissimilar dose-response relations, the effects produced by various combinations of the three components in modulating the evoked discharge activities of WDR neurons were evaluated. Results showed that Dragon’s Blood and its three components could inhibit the evoked discharge frequencies of WDR neurons in a concentration-dependent way. The Hill's coefficients describing dose-response relations of three components were different. Only the combined effect of cochinchinenin A, cochinchinenin B and loureirin B was similar to that of Dragons Blood. Furthermore, the combined effect was synergistic. This investigation demonstrated that through the synergistic interaction of the three components Dragon’s Blood could interfere with the transmission and processing of pain signals in spinal dorsal horn. All these further proved that the combination of cochinchinenin A, cochinchinenin B, and loureirin B was the material basis for the analgesic effect of Dragon’s Blood.     

大型真菌分子生物学实验材料的保存方法介绍

介绍了几种保存大型真菌分子生物学实验材料的方法 ,用这几种方法所保存的材料提取的基因组核糖体脱氧核糖核酸 (DNA)质量适于系统生物学及其他分子生物学研究之用。