摘要：Plants growing in nutrient-rich environment are predicted to be less defended than conspecifics under nutrient ***,less is known about the effects of nutrient levels on tolerance and induced resistance,and whether the effects differ between native and introduced populations of invasive *** performed a greenhouse experiment with introduced(the USA)and native(Argentina)genotypes of Alternanthera philoxeroides in order to study the effects of soil nitrogen levels on plant growth,constitutive and herbivore(Agasicles hygrophila)-induced chemical defense,and herbivory *** measured total biomass,elongation rate(as proxy of growth rate),carbon and nitrogen,and the concentration of triterpenoid saponins(defensive chemicals)in leaves and *** resistance(+33%higher leaf triterpenoid saponins in control treatment at low nitrogen level)and tolerance[less decreased total biomass after herbivory treatment(−24%and−15%for high and low nitrogen levels)]were favored at lower nitrogen level,while induced resistance was favored at higher nitrogen level(+24%increased leaf triterpenoid saponins after herbivory treatment at high nitrogen level).Constitutive resistance and tolerance exhibited trade-offs with growth rate,while induced resistance positively correlated with growth ***,the introduced genotypes had−6%lower content of leaf carbon in the presence of herbivores than the native genotypes at low nitrogen level,but such difference was absent at high nitrogen *** results indicate that soil nitrogen levels influence the preference of different defensive strategies of plant,and interweave with herbivory to determine the performance of introduced genotypes.

摘要：根据博德特氏菌(Bordetellasp.)的16S rRNA基因序列,设计荧光原位杂交(FISH)检测博德特氏菌的寡核苷酸探针FW_iso_62和FW_iso_761,在20%～60%甲酰胺均有很强的荧光信号。采用探针FW_iso_62及其竞争探针,结合Nycodenz和DAPI技术,建立定量检测土壤中博德特氏菌的DAPI-FISH方法。该方法可排除土壤颗粒的自动荧光对细菌信号的掩盖,保证图片中有大量微生物供统计分析,还能有效保存微生物的原位信息。应用该方法分析土壤中1,2,4-三氯苯降解菌-博德特氏菌,结果未受氯苯污染的农田土壤中没有检测到博德特氏菌,而氯苯污染土壤中检测到大量的博德特氏菌,每克土壤含3.78×106个。将该污染土壤中分离的博德特氏降解菌及其降解菌群接种至农田土壤中,降解菌的数量均随培养而增加,一个月后分别占DAPI计数的1.7%和3.8%。本研究设计的探针可有效用于复杂环境样品中博德特氏菌的定性与定量检测。

摘要：Aims Intensive land management practices can compromise soil biodiversity,thus jeopardizing long-term soil *** mycorrhizal fungi(AMF)play a pivotal role in promoting soil productivity through obligate symbiotic associations with ***,it is not clear how properties of plant communities,especially species richness and composition influence the viability of AMF populations in *** Here we test whether monocultures of eight plant species from different plant functional groups,or a diverse mixture of plant species,maintain more viable AMF *** address this question,we extracted AMF spores from 12-year old plant monocultures and mixtures and paired single AMF spores with single plants in a factorial design crossing AMF spore origin with plant species *** Findings AMF spores from diverse plant mixtures were more successful at colonizing multiple plant species and plant individuals than AMF spores from plant ***,we found evidence that AMF spores originating from diverse mixtures more strongly increased biomass than AMF from monocultures in the legume Trifolium repens *** viability and ability to interact with many plant species were greater when AMF spores originated from 12-year old mixtures than *** results show for the first time that diverse plant communities can sustain AMF viability in soils and demonstrate the potential of diverse plant communities to maintain viable AMF propagules that are a key component to soil health and productivity.

摘要：设计廉价和高效的双功能催化剂应用于CO_(2)还原和O_(2)还原反应(CO_(2)RR和ORR)是实现碳中和的理想选择.因此,本文研制出铌原子分散固定在氮掺杂有序介孔碳(Nb-N-C)上的双功能CO_(2)RR和ORR催化剂用于锌-空气电池(ZAB)自驱动CO_(2)RR.得益于高铌原子利用率和有序介孔结构,Nb-N-C催化剂展现出高达90%的CO法拉第效率,ORR的半波电位活性为0.84 V,ZAB的峰值功率活性为115.6 mW cm-2.此外,采用两个串联的ZABs单元作为自供能CO_(2)RR系统的电源,能够连续将C O_(2)转化为C O.该自供能系统前10小时的C O平均产率为3.75μmol h-1mg-1cat.理论计算表明,铌原子分散固定在氮掺杂的碳上形成Nb–N配位键,从而有效地降低CO_(2)RR的决速中间体*COOH和ORR的决速中间体*O的生成能垒.

摘要：Hydrogel-Ⅰ was fabricated via sodium alginate in situ-embedding with MAL powders and then applied to decontaminating Pb(Ⅱ) from water. Conditions for preparing Hydrogel-Ⅰ and the adsorption of Pb(Ⅱ) over Hydrogel-I were optimized through response surface methodology coupled with central composite design. XPS revealed that the groups of —OH, —COO—, —NH, —NHand —CSS— carried by Hydrogel-Ⅰ were responsible for the uptake of Pb(Ⅱ). Ions exchange, surface complexation, electrostatic attraction and pore-filling effect contributed to the adsorption process. Adsorption performances of Pb(Ⅱ) by Hydrogel-Ⅰ and MAL powders were compared. Although they exhibited similar adsorption rate and maximum adsorption capacity(qm), the reusing ability of Hydrogel-Ⅰ was better and it was easier to be separated from aqueous solution after treatment. Even compared with organic hydrogel materials,Hydrogel-Ⅰ presented relatively quick adsorption speed and high adsorption capacity. It can be concluded that Hydrogel-Ⅰ could be an alternative scavenger for the treatment of Pb(Ⅱ) from aqueous solution.

摘要：This paper demonstrates a Geographic Information Systems （GIS） procedure of classifying and mapping forest management category in Baihe Forestry Burea, Jilin Province, China. Within the study area, Baihe Forestry Bureau land was classified into a two-hierarchy system. The top-level class included the non-forest and forest. Over 96% of land area is forest in the study area, which was further divided into key ecological service forest （KES）, general ecological service forest （GES）, and commodity forest （COM）. COM covered 45.0% of the total land area and was the major forest management type in Baihe Forest Bureau. KES and GES accounted for 21.2% and 29.9% of the total land area, respectively. The forest management zones designed with GIS in this study were then compared with the forest management zones established using the hand draw by the local agency. There were obvious differences between the two products. It suggested that the differences had some to do with the data sources, basic unit and mapping procedures. It also suggested that the GIS method was a useful tool in integrating forest inventory data and other data for classifying and mapping forest zones to meet the needs of the classified forest management system.

摘要：Due to their unique surface chemistry,highly adjustable metal components,hydrophilicity,and high carrier concentrations,MXenes are applied in a variety of *** to other two-dimensional(2D)materials,building heterostructures with additional materials to form a 3D porous architecture for MXenes can significantly enhance their functionality and ***,the open structures and well-defined pathways of these 3D structured MXenes can improve ionic and electronic transport,thereby promoting their applications in electrochemical energy storage,sensing,catalysis,and *** this review,the recent efforts made on preparing 3D porous MXenes with heterostructures,focusing on MXenes/C,MXenes/inorganics,and MXenes/polymers were *** discussion covers aspects ranging from the design to synthesis of 3D porous MXenes,and their applications in photocatalysis,environmental monitoring and electrochemical energy *** review is concluded by presenting the prospects and insights on exploring the relationships between the porosity formation mechanisms,properties and applications of the 3D porous MXenes *** review can provide meaningful guidance for the design,fabrication and application of 3D porous MXenes in high-performance materials and devices.

摘要：In order to understand the effects of thinning on microsite conditions and natural regeneration in the larch plantation, thinning experiment was conducted in a 40-year-old Larix olgensis plantation in Qingyuan County in eastern Liaoning Province, China in 2003-2004 Five thinning treatments （0%, 10.2%, 19.8%, 29.7% and 40.3% thinned） were designed on the same site. After thinning, canopy openness and the microsite conditions such as photosynthetic photon flux density （PPFD）, soil moisture content, and soil temperature were measured in one growing season. Meanwhile, the investigation of natural regeneration was conducted at the end of the growing season. The results showed that the canopy openness increased with the increase of thinning intensities. PPFD and soil temperature and soil moisture content in different soil layers were positively relative with canopy openness after thinning. The richness of regenerating tree species did not significantly increase （p=0.30） after one growing season since thinning, but the regeneration density and frequency of tree species increased significantly （p〈0.05）. In addition, the number of regenerating tree species increased, and the increment was correlated with the characteristics of iudividual tree species. The increasing percentage of regenerating seedlings of the shade-intolerant tree species was more than that of shade-tolerant tree species. Among the investigated regeneration species, the biggest response of seedling emergency to the canopy openness was Phellodendron amurense. This paper confirmed the following conclusions： after thinning, the variety of regenerating tree species was correlative with the characteristics of regenerating tree species, and the distribution of unthinned trees and the site conditions in the investigated larch plantation were the additional factors influencing, the regeneration.