C_4作物FACE(free-air CO_2 enrichment)研究进展

持续迅速上升的大气二氧化碳浓度([CO2])是全球变暖最大的驱动因子,但其作为光合作用底物直接增加了作物的生产力。相比C3作物,人们对未来高浓度CO2情形下C4作物的响应规律认识较少。与封闭或半封闭气室研究相比,FACE(free-airCO2 enrichment)试验在空气自由流动的大田条件下对作物表现进行研究,它提供了对未来作物生长环境的真实模拟,因此提供了评估CO2肥料效应以及揭示植物响应机制的最好机会。作为人类重要的粮食和饲料来源,高粱和玉米是最重要的C4作物。在简介美国玉米和高粱FACE系统的基础上,综述了FACE情形下高浓度CO2(模拟本世纪中叶大气CO2浓度,即550μmol/mol)对两大作物生理、生长和产量以及土壤特性等方面的影响,同时比较了与气室研究结果的异同点。(1)FACE使干旱条件下两作物光合作用显著增强,但湿润条件下没有影响;FACE条件下高粱出现光合适应现象,而玉米没有;(2)FACE使两作物气孔导度大幅下降,导致叶温升高、蒸腾速率下降、蒸发蒸腾总量减少或没有变化、叶片总水势和水分利用效率增加或没有变化;(3)FACE对两作物物候期和化学组分影响很少;(4)FACE使干旱条件下两作物生长和产量略有增加,但湿润条件下没有影响;(5)FACE使高粱田土壤丛枝状菌根真菌的长度和易提取胶状物质浓度显著增加,导致水稳性土壤团聚体增加;FACE对高粱田N2O或含氮气体(N2O+N2)的排放没有影响;(6)高浓度CO2对两作物气孔导度的影响FACE试验明显大于气室试验,而对生长和产量的影响呈相反趋势。阐明CO2与基因型、土壤湿度和大气温度间的互作效应及其机制是下一轮C4作物FACE研究优先考虑的方向,技术的不断进步已为利用大型FACE系统来研究这些互作效应提供了可能。

翻堆频率对中药渣堆肥过程及其理化性质的影响

为了研究翻堆频率对中药渣堆肥过程及其理化性质的影响,采用中试规模的条垛式堆肥系统,研究了中药渣堆肥过程中温度、全碳、全氮、全磷、全钾、C/N、pH、GI及表观特征变化和堆肥产品的质量特征。试验设6个处理,分别为:不翻堆(A1)、每5天翻一次(A2)、每10天翻一次(A3)、每15天翻一次(A4)、每20天翻一次(A5)、每25天翻一次(A6)。结果表明:高温(≥50℃)持续时间以A3最长,达44天;与A1相比,A4、A5和A6的全碳含量分别减少了0.35%、1.73%和1.61%;A2、A3、A4和A6的全氮含量分别减少了5.32%、8.40%、5.25%和1.44%;A2、A3、A4、A5和A6的全磷含量且分别增加了4.82%、9.64%、6.83%、8.03%和2.01%;A2、A3、A4、A5和A6的全钾含量分别增加了6.18%、5.38%、2.96%、8.33%和4.03%;GI分别提高了35.15%、33.23%、31.30%、28.89%和17.01%,而C/N和pH差异不大。成熟中药渣中的C含量为36.0%,N含量比猪粪、鸡粪、羊粪、鸭粪及鹅粪分别高25.97%、17.12%、28.81%、41.20%和41.91%。综合分析各影响因素后认为,在中试规模的条垛式堆肥系统中进行中药渣堆肥时,以每10天翻堆一次较为适宜。

中药渣堆肥与化肥配合施用对当归产量与品质的影响

目的采用田间试验,研究氮、磷、钾等量条件下,中药渣堆肥与无机肥配合施用对当归产量和品质的影响。方法试验设6个处理,即:T1(不施肥)、T2(单施化肥,每公顷施N 90 kg、P2O590 kg、K2O 60 kg)、T3(每公顷施堆肥1 350 kg+86-84-52 N-P2O5-K2O kg)、T4(每公顷施堆肥2 250 kg+83-81-47 N-P2O5-K2O kg)、T5(每公顷施堆肥3 150 kg+82-77-42 N-P2O5-K2O kg)及T6(每公顷单施堆肥4 500 kg,其N量等同T2)。结果单施中药渣堆肥能降低当归早期抽薹率,增强当归生长期净光合速率和蒸腾速率,提高当归阿魏酸和藁本内酯含量,比对照(T1)分别提高57.69%和1.78%;堆肥与化肥配合施用能促进生长后期当归根系的伸长及增粗,增加当归产量。结论综合考虑产量构成因素、品质指标及对化肥土壤环境的影响等因素,以T3(每公顷施用堆肥1 350 kg+86-84-52 N-P2O5-K2O kg)可作为岷县当归产区推荐施肥量。

黄鳝血清白蛋白的纯化及抗体制备

通过阴离子交换层析和凝胶过滤层析,从黄鳝血清中得到其血清白蛋白,命名为MAA-serum,分子量为67kDa,为单链非糖蛋白,其N末端氨基酸序列为GHKKW。用0.5mg/只MAA-serum作为免疫源免疫大白兔,经3次免疫后,抽取大白兔血液,分离血清,饱和硫酸氨沉淀,获得抗MAA-serum的多克隆抗体。经ELISA方法测定该抗体与黄鳝血清白蛋白的免疫反应,抗体滴度为1∶100000。经初步研究发现黄鳝皮肤中也有大量血清白蛋白分布,该抗体为进一步研究MAA-serum在皮肤中的分布及生物学功能打下基础。

黄鳝皮肤白蛋白的纯化及性质

通过阴离子交换层析和凝胶过滤层析,从黄鳝(Monopterus albus)皮肤中得到其白蛋白,命名为MAA-skin。该蛋白为单链蛋白质,相对分子质量为67×103,经Schiff’s试剂鉴定为非糖蛋白,其N-末端氨基酸序列为GHVKW。用纯化的黄鳝血清白蛋白(MAA-serum)为免疫原免疫大白兔,制备抗MAA-serum的多克隆抗体。经ELISA检测,该抗体与MAA-skin有强烈的免疫反应,抗体滴度为1∶10000。Western blot检测,该抗体与MAA-skin也发生阳性反应,强度与MAA-serum相似。这说明黄鳝皮肤中分布有大量白蛋白,推测其在黄鳝皮肤的水盐代谢、渗透压维持、吸收,转运外界环境的物质等方面具有重要作用。

基于铁基载氧体的污泥化学结构热解分子动力学模拟

市政污泥的低碳资源化利用,是“无废城市”建设、应对全球气候变化的重要保障。化学链燃烧/气化技术是通过载氧体在污泥燃料和空气之间的循环反应实现污泥热解继而燃烧和碳捕集。采用廉价易得的铁基载氧体开展市政污泥化学链燃烧研究,为探究市政污泥基于铁基载氧体的化学链燃烧初始阶段的热解机理,采用X射线光电子能谱、^(13)C固体核磁等表征手段结合工业分析、元素分析,确定了典型市政污泥所含元素种类、化学价态以及成键方式,从而确定其分子团化学结构;以AlFeO_(3)的载氧体形式,构建了污泥独立热解和载氧体表面热解2种结构模型。通过反应力场分子动力学模拟(ReaxFF MD),主要针对升温速率和热解温度2个影响因素进行模拟。结果表明:不同升温速率下,污泥独立热解的产物主要为有机气体,升温速率过高不利于污泥分子团热解,选取16 K/ps较为合适;热解温度的升高和载氧体的存在均促进了污泥化学结构的热解,减少了焦油生成;无载氧体作用时,N元素在不同升温速率下,主要迁移至重质焦油中参与后续的燃烧反应;热解温度对含氮产物的生成影响不大。而载氧体的存在促使含氮活性基团的生成,进而产生NO并部分还原为N_(2);S元素主要迁移至小分子量碎片中,或以H_(2) S形式析出。因此,铁基载氧体提升了固体燃料的热解速率,可减少焦油产生,降低了NO_(x)生成,但对SO_(2)排放影响不大。

花狭口蛙海南亚种皮肤分泌物的溶血活性研究

[目的]观察花狭口蛙海南亚种皮肤分泌物溶血活性并探讨不同因素对其溶血活性的影响。[方法]采用花狭口蛙皮肤分泌物对健康小鼠红细胞进行溶血试验,并分析了渗透性保护剂、糖类、金属离子以及抗氧化剂等不同因素对其溶血活性的影响。[结果]渗透保护剂明显抑制花狭口蛙皮肤分泌物的溶血活性,而糖类、抗氧化剂和金属离子等几乎都无抑制作用。[结论]花狭口蛙海南亚种皮肤分泌物通过在细胞膜表面形成孔道而发挥溶血活性。

液相芯片法联合检测乙肝血清标志物HBsAb/HBcAb方法的建立

乙肝血清标志物（HBV—M）对于乙肝筛查、诊断、分期、疗效监测及预后判断等具有重要价值。目前，检测乙肝血清标志物主要是采用酶联免疫吸附试验（ELISA），该方法仅能单独检测，不能满足临床中多指标检测分析的要求。液相芯片法是一种新型生物芯片技术平台，其最大优势在于可同时对同一样本中多达100种不同目的分子进行分析。

Advances in reduction of NO_x and N_2O emission formation in an oxy-fired fluidized bed boiler

Fossil fuel combustion is one of the major means to meet the mounting global energy demand. However, the increasing NO_x and N_2 O emissions arising from fossil fuel combustion process have hazardous effects. Thus, mitigating these gases is vital to attain a sustainable environment. Interestingly, oxy-fuel combustion in fluidized bed for carbon capture and minimized NO_x emissions is strongly sustainable compare to the other approaches. It was assessed that NO_x formation and fuel-N conversion have significant limitation under oxy-fluidized bed compared to air mode and the mechanism of NO_x formation is still deficient and requires further development. In addition, this review paper discussed the potential of primary measure as low emission process with others supplementary techniques for feasible NO_x reduction. The influences of combustion mode, operating parameters, and reduction techniques such as flue gas recirculation, oxygen staging, biomass co-firing, catalyst, influence of fluidized bed design and structure, decoupling combustion and their merges are respectively evaluated. Findings show that significant minimization of NO_x emission can be achieved through combination of primary and secondary reduction techniques.

射频/微波及ATE系统的应用、挑战与解决方案(英文)

射频/微波自动测试系统中仪器信号的传输依靠的是信号路由和分布式系统,例如从频谱分析仪和频率合成器到待测设备。系统的设计人员总是背负着系统交付的压力,因此,他们需要尽可能快的设计周期。同时,系统往往规格和要求多样,非常复杂。许多情况下,系统设计需要使用RF界面单元(RFIU)来引导并判定从测试仪器到待测设备的信号,包括衰减、过滤、开关等。然而,一个测试系统通常的需求是要对很多测试单位进行测试,单一信号的RFIU设计并不能满足需要。近年来,商用的设计工具已经进入仪器市场,这些工具集合了诸如:LXI(LAN extensions for Instrumentation)、LVI(Interchangeable Virtual Instrument)等工业标准,为RFIU提供基于商业现成可用(COTS)的基础构架,可以降低定制需求。文章介绍了不同行业的应用案例,自动测试系统(ATE)、射频/微波自动测试系统在其中可用作核心测试界面。文章进一步介绍了一些系统设计人员在系统应用时所面临的的挑战与问题。最后,介绍了如何利用基于LXI的RFIUs,将工业标准系统水平的驱动用于解决所遇到的这些问题,并优化应用性能。最后文章讨论了两个特定案例,一个关于航空电子链路可替代设备测试,另一个关于消费电子产品测试环境。

Weak central coherence in patients with Alzheimer’s disease

Central coherence refers to the ability to interpret details of information into a whole. To date, the concept of central coherence is mainly used in research of autism, Asperger＇s syndrome and recently in the research on eating disorders. The main purpose of the present study was to examine central coherence in patients with Alzheimer＇s disease. Nine Alzheimer＇s disease patients and ten age- and gender-matched control subjects, who differed significantly in neurological assessment, were shown a picture of a fire. Compared to control subjects, the Alzheimer＇s disease patients described the picture in a fragmented way by mentioning details and separate objects without perceiving the context of the fire. In conclusion, patients with Alzheimer＇s disease are at the weak end of central coherence, and hence suffer from a fragmented view of their surroundings. The findings have important clinical implications for the understanding of patients with Alzheimer＇s diseaseand also for the possibility of caregivers to meet the Alzheimer＇s disease individual in an appropriate way in the everyday care.

MEMS传感器市场面临空前机遇

随着我国汽车电子、新型数字消费电子和医疗电子等产业的快速发展,对MEMs传感器的各种新需求和基于该技术的创新不断涌现,为此专业科技市场分析机构北京华兴万邦管理咨询有限公司走访了总部位于欧洲芬兰的老牌微机电系统(MEMS)传感器制造商VTI科技(VTI Technologies).

Influence of Road Wetness on Tire-Pavement Rolling Resistance

Rolling resistance of tires is one of the most important factors influencing energy consumption of road vehicles, especially on rural roads. For practical reasons, most of rolling resistance measurements are usually performed for dry road conditions. Based on the fact that roads are wet during a considerable time over the year and as part of the projects MIR/AM, ROLRES and ROSANNE, the TUG （Technical University of Gdafisk） in Poland and VTI （Swedish National Road and Transport Research Institute） in Sweden carried out trailer rolling resistance measurements on wet road surfaces to investigate water film influence on rolling resistance on different pavements. A specially-designed trailer to measure rolling resistance has been used. The test sections were both rural roads and an abandoned airfield equipped with water film sensors mounted in the pavement. Results indicate strong influence of test speed and water film depth, as well as influence of surface texture. The increase of rolling resistance on wet surfaces is caused by both hydrodynamic phenomena and cooling effect of water that decreases tire temperature thus increasing rolling resistance.

Support Systems Designed for Older Drivers to Achieve Safe and Comfortable Driving

Background: The number of older people is increasing. Many of them expect to maintain a rich social life and to continue driving at an older age. Objective: The present study investigates the mechanisms behind self-regulation and driving cessation in order to suggest development of support systems to prolong older drivers’ safe mobility. Method: Three focus groups were conducted with 19 older active drivers aged 65+ who were divided according to annual mileage driven. Results: A content analysis revealed broad self-regulatory behaviour as already reported in the literature, e.g., avoiding driving at rush hour and at night. The participants also reported difficulty in finding the way to their final destination and an increasing need to plan their travelling. Co-piloting was a behaviour applied by couples to cope with difficulties encountered in traffic. A large part of the discussion was focused on emerging feelings of stress, anxiety and fear when driving in recent years, a feeling induced by external factors e.g., other road users’ behaviour, traffic density or high speed. Apart from health problems, high levels of stress could explain driving cessation, especially for women. An increased feeling of safety and comfort could be achieved by an increased use of support systems specifically designed to respond to older drivers’ needs. Conclusion: Support systems for older drivers should increase comfort and decrease their stress levels. New systems, such as co-pilot function and more developed Global Positioning System (GPS) supporting of the entire travel from door to door, should be developed to respond to the market needs.

Genetic variation of Norway spruce clones regarding their natural durability, physical and chemical properties

Genetic variation of ten Norway spruce (Picea abies (L.) Karst.) clones regarding their decay resistance against brown rot fungi, as well as physical and chemical properties of clones were investigated. 31- year-old spruce clones: 26, 31, A10, A15, A7, B10, B15, B6, V7, V9 were selected across Latvia. The stem diameters of spruce clones varied between 13.0 and 20.9 cm. The wood density of clones ranged from 361 to 443 kg/m3. Klason lignin content, depending on the clone, was between 27.0%-28.9%. Cellular UV microspectrophotometry of the non-infected tracheids displayed the typical lignin distribution with highest absorbance values in the cell corners (abs280 nm 0.80) and compound middle lamellae (abs280 nm 0.48), while secondary wall showed lower lignin absorbance values (abs280 nm0.29 - 0.35). The deposition of phenolic extractives in ray parenchyma and epithelial cells of resin canals were emphasized by a significantly higher UV-absorbance (abs280 nm 0.68 to 0.78) when compared to the cell wall associated lignin. The content of acetone-soluble extractives of spruce clones varied between 1.1% - 1.8%. The x-value (natural durability) for all spruce clones after exposure to C. puteana and P. placentawas >0.90 (durability class 5, not durable). Most of clones after degradation by G. trabeum had x-value > 0.90 with exception of clones B15 and V9 that showed x-value ≤ 0.90 (durability class 4, slightly durable). Natural durability of spruce clones did not correlate with stem diameter, density, content of lignin and extractives.

Effects of forest management on biomass stocks in Romanian beech forests

Background: Forest management aims at obtaining a sustainable production of wood to be harvested to generate products or energy. However, the quantitative influence of forest management and of removals by harvest on biomass stocks has rarely been analysed on a large scale based on measurements. Two hypotheses prevail: management induces a reduction of wood stocks due to cuttings, versus no impact because of increased growth of the remaining trees. Using data collected for 2840 permanent plots across Romania from the National Forest Inventory representing^2.5 Mha, we have tested to what extent different management types and treatments can influence the biomass stock and productivity of beech forests, and attempt to quantify these effects both on the short and long terms. Three main types of beech forest management are implemented in Romania with specific objectives: intensive wood production in production forests, protection of ecosystem services (e.g. watersheds, avalanche protection) in protection forests, and protection of the forest and its biodiversity in protected forests. Production forests encompass two treatments differing according to the stand regeneration method: the age class rotation management and the group shelterwood management. Results: We show that forest management had little influence on the biomass stocks at a given stand age. The highest stocks at stand age 100 were observed in production forests (the most intensively managed forests). Consequences of early cuttings were very short-termed because the increase in tree growth rapidly compensated for tree cuttings. The cumulated biomass of production forests exceeded that of protected and protection forests. Regarding the treatment, the group shelterwood forests had a markedly higher production over a full rotation period. The total amount of deadwood was primarily driven by the amount of standing deadwood, and no management effect was detected. Conclusions: Given the relatively low-intensity management in Romania, forest management had no negative impact on wood stocks in beech forests biomass stocks at large scale. Stand productivity was very similar among management types or treatments. However cumulated biomass in production forests was higher than in protection or protected forests, and differed markedly according to treatments with a higher cumulated biomass in shelterwood forests.

Determination of riding comfort on cycleways using a smartphone application

Well maintained cycleways will encourage more people to cycle,as the condition of cycleways is important for the safety,accessibility and riding comfort of cyclists.Despite that,only a few models used to describe the quality of service for cyclists take the surface condition into account.Objective measuring methods are needed to enable reliable and effective assessment of surface conditions,and measurable performance criteria related to the needs of cyclists should be developed.The purpose of this study has been to test the reliability and validity of using accelerometers in smartphones to assess the riding comfort on cycleways.A smartphone application converting three-dimensional accelerometer measurements into a single indicator for cycleways has been used to assess road surfaces in two field studies,in Sweden and Norway,respectively.Both studies assessed test sections of varying quality.To relate the measurements to subjective riding comfort assessments by cyclists,recruited cyclists collected quantitative data using the app,whilst also rating their perceived riding comfort by completing a survey.Measurements were also related to standard road surface condition indicators,generated from a road surface tester equipped with 19 laser sensors:international roughness index(IRI),mega-and macrotexture.The results show that it is possible to describe the unevenness of a cycleway using the technology present in smartphones.A software application can be used to collect and analyse data from the acceleration sensors in the phone,which can then be used to describe the riding comfort of cyclists.It is mainly the unevenness in the 50-1000 mm sizerange that create the greatest discomfort for cyclists,and intermittent vibrations are perceived as more uncomfortable than more evenly distributed vibrations.Therefore,IRI is not a relevant measurement for describing the riding comfort of cyclists.

路表纹理包络轮廓计算及其对抗滑性能的影响

为了分析轮胎与路表的接触特性及其对路面抗滑性能的影响,采用路面纹理测量车(road surface tester)获取路表纹理二维轮廓离散数据,运用印痕法模型,利用MATLAB软件计算路表纹理包络轮廓,进一步计算了包络轮廓对应的平均断面深度(mean profile depth,MPD)、宏观纹理表面构造水平指数LMa(macro texture indices calculated with texture level)、粗大纹理表面构造水平指数LMe(mega texture indices calculated with texture level)等纹理指标,并与初始轮廓纹理指标进行对比;最后计算包络轮廓、初始轮廓纹理参数MPD、LMa与路面摩擦因数(longitudinal frictional coefficient,LFC)的相关性系数,分析了路表纹理包络轮廓对路面抗滑性能的影响。研究结果表明:包络轮廓纹理参数与初始轮廓纹理参数相关性良好(判定系数R2>0.85);包络轮廓MPD值较初始轮廓MPD值有明显下降,且初始轮廓MPD值越大,包络轮廓MPD值下降幅度也越大;包络轮廓表面构造水平指数较初始轮廓表面构造水平指数下降,LMa的下降幅度比LMe的下降幅度高10%左右;印痕法参数S取值对包络轮廓纹理参数有较大影响,S值越小,其对应的包络轮廓纹理参数值较初始轮廓纹理参数值下降的幅度越大;此外,包络轮廓纹理参数与摩擦因数的判定系数较初始轮廓纹理参数与摩擦因数的判定系数有较大提升,其中MPD与摩擦因数的判定系数提高了约35%,LMa与摩擦因数的判定系数提高了约23%;印痕法参数S值越小,包络纹理参数与摩擦因数的判定系数越高。该结果可为研究胎-路接触特性对路用性能的影响提供参考。

Effective and Sustainable Flood and Landslide Risk Reduction Measures:An Investigation of Two Assessment Frameworks

Natural events such as floods and landslides can have severe consequences.The risks are expected to increase,both as a consequence of climate change and due to increased vulnerabilities,especially in urban areas.Although preventive measures are often cost-effective,some measures are beneficial to certain values,while some may have negative impacts on other values.The aim of the study presented here was to investigate two frameworks used for assessing the effectiveness and sustainability of physical and nonphysical flood and landslide risk reduction measures.The study is based on literature,available information from authorities and municipalities,expert knowledge and experience,and stakeholder views and values.The results indicate that the risks for suboptimization or maladaptation are reduced if many aspects are included and a broad spectrum of stakeholders are involved.The sustamability assessment tools applied here can contribute to a more transparent and sustainable risk management process by assessing strategies and interventions with respect to both short- and long-term perspectives,including local impacts and wider environmental impacts caused by climate change,for example.The tools can also cover social and economic aspects.The assessment tools provide checklists that can support decision processes,thus allowing for more transparent decisions.

Influence of morphology on high-temperature rheological properties of bitumen modified with styrene-butadiene-styrene(SBS)copolymer

Different microstructures of the same polymer-modified bitumen(PMB)were obtained by subjecting the bitumen modified with styrene-butadiene-styrene(SBS)copolymer to isothermal annealing at various temperatures.The effects of the morphology on the rheological properties of SBS-modified bitumen were investigated within the hightemperature range.The PMB microstructures were quantitatively evaluated using image analysis.A dynamic shear rheometer was used to measure the rheological parameters of the PMB samples and perform the multiple stress creep and recovery(MSCR)test.A quantitative basis could be established on which to discuss the relationship between the PMB morphology and rheology.The image analysis indicated that conditioning by isothermal annealing evidently led to a difference in the microstructure of the samples.Variation of the thermal history is demonstrated to be a practical way to vary the morphology of the PMB with the same raw materials and formulation.Compared with the two-phase morphology,the single-phase microstructure tended to have a narrower linear viscoelastic(LVE)region of the PMB.Within the LVE region,especially at low frequencies,the homogenous PMB can store more energy when experiencing loadings and is more elastic.Outside the LVE region,based on the MSCR test results,the homogenous morphology could assist in reaching a higher percentage of strain recovery after the creep period.