还原温度对Pd-CeO2/Al2O3催化剂加氢脱硫性能的影响

采用浸渍法制备CeO2改性的Pd/Al2O3加氢脱硫催化剂,考察了还原温度和还原-氧化预处理对Pd/Al2O3和Pd-CeO2/Al2O3催化剂加氢脱硫性能的影响.结果表明,Pd/Al2O3的活性受还原温度的影响很小.Pd-CeO2/Al2O3还原温度的升高使CeO2发生迁移,导致催化剂表面Pd原子数减少,同时削弱了Pd-Ce界面效应,从而使催化剂的活性降低.还原-氧化预处理使Pd-CeO2/Al2O3的活性有较大提高,预处理能促使Pd的再分散,增加了对H2的吸附活化能力,在Pd-Ce的界面效应共同作用下使催化剂拥有较高的活性.     

全Pd三效催化剂研究涂层材料的研究

制备了作为Pd三效催化剂涂层材料组成的活性Al2O3/金属氧化物添加剂试样,用BET法、XRD法及H2－TPR法对这些涂层原材料体系进行表征。结果表明：金属氧化物添加剂提高了活性Al2O3的热稳定性;添加ZrO2改善了CeO2的热稳定性;与含Ca的试样不同,含La试样没有贮氧能力。用含有Al2O3-CeO2/ZrO2和Al2O3-La2O3/BaO的涂层材料制备的Pd催化剂有好的CO,HC和NOx同时净化的三效性能和低的起燃活性。加入0．003％（V／V）SO2降低了催化剂活性,含La2O3/BaO涂层材料的Pd催化剂上NOx反应易被SO2中毒。     

Al_2O_3负载Pd-Cu催化剂催化1,2-二氯乙烷加氢脱氯性能

采用共浸渍法制备了一系列Al2O3负载金属Pd、Cu催化剂.通过元素分析（ICP）、氮气吸脱附（BET）、X射线粉末衍射（XRD）、透射电镜（TEM）等技术对催化剂进行了表征,并以1,2-二氯乙烷气相加氢脱氯为探针反应,考察了Pd-Cu/Al2O3催化剂的钯铜比、反应温度、反应时间等因素对催化活性以及反应产物乙烯选择性的影响.结果发现,提高Cu负载量可在催化剂中形成Pd-Cu合金,并促进催化剂对乙烯的选择性.此外,当温度为250℃,Pd、Cu负载量分别为0.78%和1.9%时的Pd-Cu/Al2O3催化剂对1,2-二氯乙烷的催化加氢脱氯效果最佳,最终产物乙烯的选择性可达到80%以上.     

Pt/SiO_2-Al_2O_3抗硫型柴油车尾气净化氧化催化剂的制备及性能

使用浸渍法制备了一系列SiO2含量不同的改性Al2O3材料,并以此为载体制得一系列Pt/SiO_2-Al_2O_3柴油车尾气净化氧化催化剂(DOC).N2吸附-脱附实验和扫描电子显微镜(SEM)检测证实,SiO_2以多孔形式均匀覆盖在Al2O3表面,没有明显影响Al2O3的织构性质.运用热重法对各催化剂的抗硫性进行了表征,结果证实,SiO_2的引入有效提高了Pt/Al_2O_3催化剂的抗硫性;经硫累积实验后,所制备的Pt/SiO_2-Al_2O_3系列催化剂硫酸盐累积量均小于1.0 wt.%,而Pt/Al_2O_3的硫酸盐累积量约为3.94 wt.%.催化剂活性检测结果表明,适量SiO_2的引入不会影响Pt/Al_2O_3催化剂的活性;当SiO_2引入量为18 wt.%时,Pt/SiO_2(18%)-Al_2O_3催化剂不仅抗硫性能优异而且具有更好的耐久性,模拟柴油车使用160000 km后,其催化活性未明显降低.因此,本研究认为SiO_2在Pt/Al_2O_3DOC催化体系中,可以起着抑制硫中毒及提高耐久性的作用.     

应用电感耦合等离子体质谱(ICP-MS )的八级杆碰撞/反应池(ORS)技术测定地质样品中的铂、铭、钯

建立了电感耦合等离子体质谱(ICP-MS)的八级杆碰撞/反应池(ORS)技术测定地质样品中Pt,Pd,Rh的方法.结果显示,王水溶样、微波消解,可以有效地提高Pt、Pd、Rh的溶出率.ORS技术的使用,有效地消除了多原子离子对待测元素的干扰,特别是对Pd的干扰,使Pt、Pd、Rh的测定结果准确.Pt,Pd、Rh的检出限分别为0.47ng·g-1,0.44ng·g-1,0.065n·g-1,精密度为1.11%-2.57%.此方法为复杂基体样品中贵金属元素的快速、准确分析提供了一种新的途径.     

催化臭氧氧化降解罗丹明B的初步研究

研究了过渡金属硝酸盐及Al2O3为载体担载催化剂在罗丹明B臭氧氧化过程中的催化作用,考察了温度、pH值以及催化剂浓度等因素对反应的影响.结果表明,过渡金属离子可显著地提高罗丹明B的脱色速率,而担载型过渡金属氧化物催化剂活性较低.较低的pH值和反应温度有利于罗丹明B的催化臭氧化.罗丹明B溶液经过催化臭氧氧化后COD去除率可提高24%.     

液相催化加氢法去除Cr（Ⅵ）

采用浸渍法合成出Pd/Al2O3催化剂,通过ICP、XRD、TEM和Zeta电位等表征手段对催化剂的组成和形貌进行了表征.在液相催化加氢还原Cr（Ⅵ）的反应中,分别研究了催化剂加入量、Cr（Ⅵ）初始浓度、pH值、Pd负载量等因素的影响.结果表明,该催化剂表面酸性影响催化还原效果,此反应属于吸附抑制型.     

有序介孔 Pd(Ⅱ)有机金属催化剂的制备及其在水介质Barbier反应中的应用

采用正硅酸乙酯(TEOS)和有机金属Pd(Ⅱ)硅烷在表面活性剂作用下共聚,合成出有序介孔有机金属Pd(Ⅱ)催化剂,通过FTIR、NMR、XRD、TEM、N2吸附脱附等方法对催化剂进行了表征;在水介质Barbier反应中,该催化剂与均相催化剂的催化活性相当,且能够重复使用,有望在绿色化工中推广应用.     

非均相Fenton催化剂深度处理维生素C废水的试验

为了探究非均相Fenton催化剂对实际废水的处理效果,以维生素C二级生化出水为研究对象,分别考察了针铁矿、磁铁矿和硫铁矿烧渣等含铁矿物质以及部分金属或金属氧化物的吸附性能和非均相Fenton技术的催化氧化性能.选取硫铁矿烧渣作为负载催化剂,融合CuO、Al2O3、TiO2、NiO、Cr2O3、Ag2O,利用高温微孔技术制备非均相Fenton催化剂,当H2O2、FeSO4投加量分别为6.87、4.29 mmol·L-1时,COD去除率能稳定达到70%左右.     

LaCu_xZn_(1-x)Al_(11)O_(19-δ)六铝酸盐催化剂分解N_2O的催化性能

采用共沉淀法制备Cu和Zn取代的六铝酸盐(LaCuxZn1-xAl11O19-δ,0.2,0.4,O.5,0.6,0.8,1)催化剂,考察了催化剂对N2O的分解活性.结果表明,在1200℃焙烧4 h可以形成完整的六铝酸盐晶型,Cu和zn能够取代Al3+很好地促进六铝酸盐晶体结构的形成;LaCuxZn1-xAl11O19-δ催化剂对N2O分解有很好的催化活性,其中LaCu0.8Zn0 2Al11O19-δ活性最好.在LaCuxZn1-xAl11O19-δ六铝酸盐中,Cu为N2O催化分解的主要活性元素,Zn有助于提高催化剂的稳定性,但Zn在催化剂中的作用很小.     

Rapid,recurring, structured survey versus bioblitz for generating biodiversity data and analysis with a multispecies abundance model

A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.     

Compliance with and ecosystem function of biodiversity offsets in North American and European freshwaters

Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.     

Representation of the world's biophysical conditions by the global protected area network

Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.     

Quantitative composition of the defensive secretion ofBledius species (Coleoptera: Staphylinidae: Oxytelinae) is adapted to naturally occurring predators

Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.     

A palaeo-hydrogeological model for arsenic contamination in southern and south-east Asia

An argument is presented in which areas of natural arsenic contamination of modern groundwaters throughout Asia have a common origin. Arsenic originally accumulated in oceanic ferro-manganoan sediments of the eastern Palaeo-Tethys. This was further concentrated through oceanic crustal extinction in what later became the south-east Chinese accreted mineralised terrain. Proto-Himalayan uplift of this area created the palaeo-drainage systems of the Ganges – Brahmaputra, Irrawaddy, Mekong, and Red Rivers, with consequent headwater erosion of arsenic-rich sediments. Their downstream deposition as immature and easily redistributed Neogene sandstones, silts, and iron-rich clays has created secondary and tertiary reservoirs of adsorbed and authigenic arsenic, from which the current arsenic-rich groundwaters have evolved. Considering river basins within the above palaeo-hydrogeological framework provides a basis for assessing the risk of arsenic in groundwater basins of south and south-eastern Asia.     

Democracy versus development: New urban debates

The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.     

Cost‐effective conservation of an endangered frog under uncertainty

How should managers choose among conservation options when resources are scarce and there is uncertainty regarding the effectiveness of actions? Well‐developed tools exist for prioritizing areas for one‐time and binary actions (e.g., protect vs. not protect), but methods for prioritizing incremental or ongoing actions (such as habitat creation and maintenance) remain uncommon. We devised an approach that combines metapopulation viability and cost‐effectiveness analyses to select among alternative conservation actions while accounting for uncertainty. In our study, cost‐effectiveness is the ratio between the benefit of an action and its economic cost, where benefit is the change in metapopulation viability. We applied the approach to the case of the endangered growling grass frog (Litoria raniformis), which is threatened by urban development. We extended a Bayesian model to predict metapopulation viability under 9 urbanization and management scenarios and incorporated the full probability distribution of possible outcomes for each scenario into the cost‐effectiveness analysis. This allowed us to discern between cost‐effective alternatives that were robust to uncertainty and those with a relatively high risk of failure. We found a relatively high risk of extinction following urbanization if the only action was reservation of core habitat; habitat creation actions performed better than enhancement actions; and cost‐effectiveness ranking changed depending on the consideration of uncertainty. Our results suggest that creation and maintenance of wetlands dedicated to L. raniformis is the only cost‐effective action likely to result in a sufficiently low risk of extinction. To our knowledge we are the first study to use Bayesian metapopulation viability analysis to explicitly incorporate parametric and demographic uncertainty into a cost‐effective evaluation of conservation actions. The approach offers guidance to decision makers aiming to achieve cost‐effective conservation under uncertainty.     

A framework to measure the wildness of managed large vertebrate populations

As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.     

Sexual Predators,Energy Development,and Conservation in Greater Yellowstone

Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.     

Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus,a bruchid beetle pest of kidney beans

Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.