天然有机物的相对分子质量分布及亲疏水性对微滤膜组合工艺中膜污染的影响

研究采用混凝沉淀+粉末活性炭吸附+高锰酸钾+浸没式微滤膜的组合工艺对太湖水进行中试试验,通过高效凝胶色谱(HPSEC-UV-TOC)和三维荧光(3DEEM)的测定方法,着重考察有机物的相对分子质量(Mr)分布和亲疏水性对膜不可逆污染的影响.凝胶色谱分析表明:预处理可几乎完全去除大分子有机物(Mr>10×103),但仅能去除部分的中等分子(10×103>Mr>1×103)和小分子(Mr<1×103)有机物.研究发现化学清洗水中的有机物相对分子质量多为中等分子和小分子,说明导致膜不可逆污染的主要是中等分子和小分子有机物.此外,洗膜水中强疏和中性亲水组分含量远高于弱疏和极性亲水,说明强疏和中性亲水组分是不可逆污染的主要物质.三维荧光分析表明,芳香族蛋白质和溶解性微生物产物是造成膜不可逆污染的主要污染物.     

亚硝酸钠对人肝癌SMMC-7721细胞侵袭能力的影响

为了研究亚硝酸钠对人肝癌SMMC-7721细胞侵袭能力的影响,用0.25 mmol.L-1 亚硝酸钠孵育细胞48 h,然后收集细胞培养液上清.用人工基底膜包被的Transwell小室记录细胞侵袭能力,考马斯亮蓝及α-微管蛋白免疫荧光染色观察细胞骨架,western blot检测细胞基质金属蛋白酶（MMPs）表达.结果显示,用亚硝酸钠孵育SMMC-7721细胞48 h,穿膜细胞为211.5±17.6个,较对照组176.3±15.5个具有显著性差异（P﹤0.05）;用亚硝酸钠孵育48h细胞培养液上清加无血清培养液组细胞穿膜数为165.12±7.90个,较无血清培养液阴性对照组30.32±11个明显增多（P﹤0.05）;细胞培养液上清加含10%牛血清白蛋白（FBS）组细胞穿膜数为186.73±9.41个,较单纯含10%FBS阳性对照组细胞穿膜数170.54±9.6个也增多（P﹤0.05）. 0.25 mmol.L-1 亚硝酸钠处理细胞48 h,细胞骨架微丝聚合呈应力纤维,沿细胞纵轴延伸,使细胞胞体伸长,微管蛋白聚合;MMP-2 和MMP-9蛋白表达增加.上述结果说明,亚硝酸钠通过诱导细胞骨架重排,促进人肝癌SMMC-7721细胞侵袭能力.     

Precision of the radiochemical OH measurement method

Twenty-eight radiochemical ¹⁴C tracer measurement of tropospheric hydroxyl radical (OH) concentrations were obtained at a rural site near Washington State University, Pullman, WA (117°W, 47°N). Diurnal OH concentration variations were observed for the five days between 9 August and 14 August 1990. These data made it possible to estimate the midday precision and detection limit of the radiochemical OH measurement method. Experiments performed at a peak O₃ photolysis rate J (O(¹D)) of (3.0±0.2) × 10⁻⁵ s⁻¹ yielded a mean midday OH concentration of (5.6±0.1 (1σ)) × 10⁶ cm⁻³. Other data put an upper bound of 16% on fluctuations of instrument sensitivity. Low-light or nighttime background OH concentrations were less than (2.6±2) × 10⁵ cm⁻³. A lower detection limit of 10⁵ cm⁻³ was obtained when extra care was taken with the low-level ¹⁴C counting procedure.     

Analysis of temperature effects on seasonal and interannual variation in CH4 emission from rice-planted pots

Rice (Oryza sativa L.) paddies are one of the major sources of atmospheric methane (CH₄), a greenhouse gas. To elucidate the quantitative relationship between CH₄ emission from rice paddies and temperature, 6 years data of CH₄ emission from pot experiments were analyzed in terms of the sum of effective temperature (∑(T−15); T is the daily mean air temperature (°C)). The base temperature of 15 °C was adopted as the 0 °C physiological temperature for methanogens. Significant positive correlations between total CH₄ emission throughout the rice growth period and ∑(T−15) were observed for pots with rice straw (RS) application at a rate of 6 g kg⁻¹ soil, which corresponds to 6 t ha⁻¹ (r=0.830⁷¹), and those without RS application (r=0.818⁷¹). It was confirmed that temperature is a major factor affecting the interannual variation in CH₄ emission. For the 1993 and 1995 data sets that include seven and four levels of RS application, the relationship between seasonal CH₄ emission and RS application rate could be expressed using linear functions (r=0.988⁷¹, 0.996⁷¹), the slopes of which were similar to each other. Based on these findings, we confirmed that the dependence of seasonal CH₄ emission on both temperature and RS application rate can be described by a single linear equation.     

Polynuclear aromatic hydrocarbon degradation by heterogeneous reactions with N2O5 on atmospheric particles

The degradation of particulate polynuclear aromatic hydrocarbons (PAH) on atmospheric soot particles in the presence of gas phase dinitrogen pentoxide (N₂O₅) was explored. Dilute diesel and wood soot particles containing PAH were reacted with∼10ppm of N₂O₅ in a 200 ℓ continuous stirred tank reactor (CSTR). To provide a stable source of particles for reaction in the CSTR, diesel or wood soot particles were injected at night into a 25 m³ Teflon outdoor chamber. The large chamber served as a reservoir for the feed aerosol, and the aerosol could then be introduced at a constant flow rate into the CSTR. PAH-N₂O₅ heterogeneous rate constants for wood soot at 15°C ranged from2 × 10⁻¹⁸to5 × 10⁻¹⁸ cm³ molecules⁻¹ s⁻¹. For diesel soot the rate constants at 16°C were higher and ranged from5 × 10⁻¹⁸to30 × 10⁻¹⁸ cm³ molecules⁻¹ s⁻¹. Comparisons with other studies suggest that sunlight is the most important factor which influences PAH decay. This is followed by ozone, NO₂, N₂O₅ and nitric acid. The rate constants of nitro-PAH formation from a parent PAH and N₂O₅ were of the order of1 × 10⁻¹⁹−1 × 10⁻¹⁸ molecules⁻¹s⁻¹. The uncertainty associated with all of these rate constants is± a factor of 3. Given, however, the small magnitude of the rate constants and the low levels of N₂O₅ present in the atmosphere, we concluded that PAH heterogeneous reactions with gas phase N₂O₅ degrade particle-bound PAH or to form nitro-PAH from PAH arenot very important. (Direct application of the specific rate constants derived in this study to ambient atmospheres should not be undertaken unless the ambient particle size distributions and chemical composition of the particles are similar to the ones reported in this study.)     

Was wissen wir über Neutronensterne?

There are 10^9±0.5 neutron stars in the Galaxy. They are born in supernova explosions. Isolated neutron stars are observed as (radio-)pulsars, in some cases also as γ-ray pulsars and as IR-, optical and X-ray pulsars. Binary neutron stars, when accreting mass from their companion, become flickering, periodic and/or bursting X-ray sources, and probably also γ-ray bursters. They may all derive from binary star systems. The masses of population-I-neutron stars are compatible with (1.4 ±0.2)M _⊙; their surface magnetic fields fall almost exclusively within 10^12.2 and 10^13.2 Gauss (at birth). The radii of population-II-neutron stars are (10 _-3 ⁺⁶ )km. Even in exotic sources like SS 433 and Cyg X-1, the compact core may well be a neutron star.     

Efficacy of Cinnamaldehyde Against Enteric Viruses and Its Activity After Incorporation Into Biodegradable Multilayer Systems of Interest in Food Packaging

Cinnamaldehyde (CNMA), an organic compound that gives cinnamon its flavor and odor, was investigated for its virucidal activity on norovirus surrogates, murine norovirus (MNV) and feline calicivirus (FCV), and hepatitis A virus (HAV). Initially, different concentrations of CNMA (0.1, 0.5 and 1 %) were individually mixed with each virus at titers of ca. 6–7 log₁₀ TCID₅₀/ml and incubated 2 h at 4 and 37 °C. CNMA was effective in reducing the titers of norovirus surrogates in a dose-dependent manner after 2 h at 37 °C, while HAV titers were reduced by 1 log₁₀ after treatment with 1 % of CNMA. When incubation time was extended, HAV titers were reduced by 3.4 and 2.7 log₁₀ after overnight incubation at 37 °C with 1 and 0.5 % of CNMA, respectively. Moreover, this paper analyzed, for the first time, the antiviral activity of adding an active electrospun interlayer based on zein and CNMA to a polyhydroxybutyrate packaging material (PHB) in a multilayer form. Biodegradable multilayer systems prepared with 2.60 mg/cm² (~9.7 %) of CNMA completely inactivated FCV according to ISO 22196:2011, while MNV titers were reduced by 2.75 log₁₀. When the developed multilayer films were evaluated after one month of preparation or at 25 °C, the antiviral activity was reduced as compared to freshly prepared multilayer films evaluated at 37 °C. The results show the excellent potential of this system for food contact applications as well as for active packaging technologies in order to maintain or extend food quality and safety.     

Preparation of MnO2 decorated Co3Fe1Ox powder/monolithic catalyst with improved catalytic activity for toluene oxidation

In this paper, KMnO₄ was used to pre-treat Co₃Fe-layered double hydroxides (LDH) precursor to prepare MnO₂ decorated Co₃Fe₁O_x catalyst. The toluene oxidation performance of the catalyst was investigated systematically. The optimized 0.1MnCF-LDO catalyst exhibited the best catalytic performance, and the temperatures of 50% and 90% toluene conversion (T₅₀ and T₉₀) were 218 and 243°C, respectively. The apparent activation energy (E_a) was 31.6 kJ/mol. The characterization results showed that the pre-redox reaction by KMnO₄ could increase the specific surface area, Co³⁺ species amount and oxygen defect concentration of the catalyst, which are the main reason of the improved toluene catalytic activity. Besides, this method was also applied to enhance toluene oxidation of iron mesh based monolithic catalyst. The 0.1MnCF-LDO/Iron mesh (IM) catalyst showed a 90% toluene conversion at around 316°C which was much lower than that of without MnO₂ addition (359°C). In addition, the water resistant of all the catalysts was studied as well, all the samples showed relatively good water resistance. The toluene conversion still remained to be over >80% even in the presence of 10 vol.% water vapor.     

Assessing the net atmospheric impacts of wood production and utilization

The main objective of the study was to calculate net atmospheric impacts for wood production and utilization in Finnish boreal forest conditions. Net atmospheric impacts were calculated by comparing net CO₂ exchanges of the wood production and utilization to the reference management regime. Net CO₂ exchanges were simulated with a life cycle assessment (LCA) tool for a Scots pine (Pinus sylvestris L.) stand (MT, Myrtillys-type) in central Finland (Joensuu region, 62°39 N, 29°37 E) over two consecutive rotation periods (100?+?100 years/200 years). Net atmospheric impacts were calculated both for sawn timber and pulpwood, and expressed in kgCO₂m^?3. According to the results, the production of pulp and sawn timber produced emissions of 0.20 and 0.59 kgCO₂m^?3 over the 200-year period, respectively, when the unmanagement regime was used as the reference management regime. When 50 % of the processing waste of timber was accounted as an instant emission to the atmosphere, the atmospheric impact increased to 0.55 kgCO₂m^?3 in pulpwood and to 1.27 kgCO₂m^?3 in sawn timber over the 200 year period. When turnover rates of sawn timber in the technosystem were decreased by 30 % and the share of energy use was decreased to 30 %, the atmospheric impact decreased by 17 % and 4 % for pulpwood and sawn timber, respectively, compared to the default wood degradation and energy use of 50 %. The utilized LCA approach provided an effective tool for approaching net atmospheric impacts originating from the ecosystem carbon (C) flows and variable wood utilization. Taking the ecosystem production and utilization of wood (i.e. degradation of technosystem C stock) into account, in terms of net CO₂ exchange, the mitigation possibilities of wood compared to other products can be accounted for more precisely in the future and C sequestration credited more specifically for a certain wood product.     

Torpor at high ambient temperature in a neotropical didelphid,the grey short-tailed opossum (Monodelphis domestica)

The grey short-tailed opossum, Monodelphis domestica, has been an established research animal for more than five decades, but relatively, little is known about its thermophysiology. Here we studied core body temperature (T _b) and metabolic rate (MR) of female adult M. domestica housed in the laboratory at an ambient temperature (T _a) of 26 °C. In expanding previous reports, the average recorded core T _b of M. domestica was 34.3 °C. The T _b of an individual M. domestica can drop below 30 °C (minimal T _b: 28.6 °C) accompanied by a reduction in MR of up to 52 % even while having ad libitum access to food. These findings demonstrate for the first time the presence of spontaneous torpor in M. domestica. Metabolic suppression at relatively high T _a and T _b furthermore broadens our perspective on the use of torpor as a metabolic strategy not just restricted to cold climates.     

Synergistic effects of Cu species and acidity of Cu-ZSM-5 on catalytic performance for selective catalytic oxidation of n-butylamine

In this work, a series of Cu-ZSM-5 catalysts with different SiO₂/Al₂O₃ ratios (25, 50, 100 and 200) were synthesized and investigated in n-butylamine catalytic degradation. The n-butylamine can be completely catalytic degradation at 350°C over all Cu-ZSM-5 catalysts. Moreover, Cu-ZSM-5 (25) exhibited the highest selectivity to N₂, exceeding 90% at 350°C. These samples were investigated in detail by several characterizations to illuminate the dependence of the catalytic performance on redox properties, Cu species, and acidity. The characterization results proved that the redox properties and chemisorption oxygen primarily affect n-butylamine conversion. N₂ selectivity was impacted by the Brønsted acidity and the isolated Cu²⁺ species. Meanwhile, the surface acid sites over Cu-ZSM-5 catalysts could influence the formation of Cu species. Furthermore, in situ diffuse reflectance infrared Fourier transform spectra was adopted to explore the reaction mechanism. The Cu-ZSM-5 catalysts are the most prospective catalysts for nitrogen-containing volatile organic compounds removal, and the results in this study could provide new insights into catalysts design for VOC catalytic oxidation.     

Semivolatile organic compounds in the ambient air of Denver,Colorado

A filter-polyurethane foam plug high volume air sampler was used to collect the particle (P) and vapor (V) phases of four classes of semivolatile organic compounds (SOC) in Denver, CO: n-alkanes. polychlorinated biphenyls (PCB), polycyclic aromatic hydrocarbons (PAH), and organochlorine pesticides. The carbon preference index (CPI) of n-alkanes in the V or P phases alone was skewed by temperature-dependent V/P partitioning; a combined gaseous + particulate CPI was preferred. The CPI suggested that the alkanes in Denver air were predominently petrogenic. Total PCB were calculated as the sum of individual congeners and also as Aroclor equivalents, with good agreement between the two methods. Apparent V/P distributions of these compound classes were expressed as A(TSP)/F, were A and F are the adsorbent- and filter-retained SOC concentrations (ng m⁻³) and TSP is the total suspended particle concentration (μg m⁻³). Values of A(TSP)/F were related to the average sampling temperature (T, K) through: log [A(TSP)/F] = m/T + b. Fitted log A(TSP)/F at 5°C correlated well with p_L⁰ at 5°C, the SOC liquid vapor pressure. No differences were observed in partitioning behavior among the four SOC types.     

The role of copper and oxalate in the redox cycling of iron in atmospheric waters

During daytime, the redox cycling of dissolved iron compounds in atmospheric waters, and the related in-cloud transformations of photooxidants, are affected by reactions of Fe and Cu with hydroperoxy (HO₂) and superoxide (O₂⁻) radicals and the photoreduction of Fe(III)-oxalato complexes. We have investigated several of the important chemical reactions in this redox cycle, through laboratory simulation of the system, using γ-radiation to produce HO₂/O₂⁻. At concentrations comparable to those measured in atmospheric waters, the redox cycling of Fe was dramatically affected by the presence of oxalate and trace concentrations of Cu. At concentrations more than a hundred times lower than Fe, Cu consumed most of the HO₂/O₂⁻, and cycled between the Cu(II) and Cu(I) forms. Cu⁺ reacted with FeOH²⁺ to produce Fe(II) and Cu(II), with a second order rate constant of approximately 3 × 10⁷ M⁻¹s⁻¹. The presence of oxalate resulted in the formation of Fe(III)-oxalato complexes that were essentially unreactive with HO₂/O₂⁻. Only at high oxalate concentrations was the Fe(II)C₂O₄ complex also formed, and it reacted relatively rapidly with hydrogen peroxide (k = (3.1 ± 0.6) × 10⁴ M⁻¹s⁻¹). Simulations incorporating measurements for other redox mechanisms, including oxidation by ozone, indicate that, during daytime, Fe should be found mostly in the ferrous oxidation state, and that reactions of FeOH²⁺ with Cu(I) and HO₂/O₂⁻, and to a lesser degree, the photolysis of Fe(III)-oxalato complexes, are important mechanisms of Fe reduction in atmospheric waters. The catalytic effect of Cu(II)/Cu(I) and Fe(III)/Fe(II) should also significantly increase the sink function of the atmospheric liquid phase for HO₂ present in a cloud. A simple kinetic model for the reactions of Fe, Cu and HO₂/O₂⁻, accurately predicted the changes in Fe oxidation states that occurred when authentic fogwater samples were exposed to HO₂/O₂⁻.     

Growth,morphology and yield of wheat,barley and oats grown at elevated atmospheric CO2 concentration in a cool,maritime climate

The effects of elevated CO₂ concentration on the growth, yield and quality of spring wheat (Triticum aestivum L., cv. ‘Sport’), barley (Hordeum vulgare, cv. ‘Thule’) and oats (Avena sativa, cv. ‘Kapp’) were studied. The study was performed from 20 April to 24 August in ten field chamber units each of 9 m² in a cool (12.6°C) maritime climate under long days (14.6–18.1 h), on the southwest coast of Norway (59°N, 6°E). The total biomass increased at high CO₂ concentration, by 11% and 20% in wheat and barley, respectively. The proportion of small grains increased by 6% in wheat and 26% in barley, but the total grain yield was not affected. The weight of chaff increased by 9% and 19% in wheat and barley, respectively. Plant height was significantly reduced during the growing season at elevated CO₂, by 8–19% in barley and by 9–25% in oats until 6 July when no significant difference in height was found. After 6 July, barley plants at elevated CO₂ were significantly taller than at ambient CO₂ concentration and oats were not affected. Elongation in wheat was not affected by CO₂ concentration at any time in the growing season. No difference in developmental rate could be detected between plants at normal and elevated CO₂ concentrations. The protein content of the grain decreased by 8% in barley, but was not significantly affected in the other species.     

In-cloud scavenging and deposition of sulfates and nitrates: Case studies and parameterization

Scavenging of sulfates and nitrates—two most common ions leading the cloudwater acidity—was investigated during field studies atop a site in Mt. Mitchell (35°44′05″N, 82°17′15″W) State Park where the highest peak (2038 m MSL) of the eastern U.S. is located. Experiments were conducted during the growing seasons (15 May–30 September) of 1986 and 1987 using an instrumented meteorological tower (16.5 m tall) and a passive cloudwater collector. A cloud episode that occurred on 12 October 1987, was also comprehensively investigated. Clouds were frequently observed in which the Fraser fir and red spruce stands stayed immersed 28% and 41% of the time during the 1986 and 1987 seasons, respectively. Rate of cloudwater deposition on the forest canopy was determined using an inferential cloud deposition model. It was found by analysing nine short duration (lasting 8 h or less) and 16 long duration cloud events that the ionic concentration (SO₄²⁻ and NO₃⁻) is inversely proportional to the rate (I_c) of cloudwater deposition (in mm h⁻¹) and can be expressed by the following relationship: [SO₄²⁻] = aI_c^−b or [NO₃⁻] = aI_c^−b. Theoretical arguments leading to these relationships are presented. The b values for predicting NO₃²⁻ concentration are found in the range of 0.14–1.24 (mean = 0.48) for short duration and 0.062–0.63 (mean = 0.27) for long duration cloud events, respectively. The corresponding b values for predicting NO₃⁻ concentrations are 0.19–1.16 (mean = 0.49) and 0.072–0.59 (mean = 0.27), respectively. When the b parameter was between 0.2 and 0.6, the correlation coefficients between measured and predicted ionic concentrations were found to exceed 0.7. The parameter a is shown to represent the maximum ionic flux for a given cloud event. The ratio of the a parameter for SO₄²⁻ to NO₃⁻ varied between 1.75 and 6.95, indicating that the SO₄²⁻ contributes to the total ionic concentration substantially more than the NO₃⁻ leading to the conclusion that the cloudwater acidity is primarily due to the presence of sulfuric acid which has been demonstrated to cause foliar injury and growth retardation in red spruce trees. The above parameterization is similar to the one that is frequently used to relate ionic concentration in precipitation to the rainfall rate. In order to understand physico-chemical processes leading to the proposed parameterization schemes, meteorological and chemical variables are comprehensively analysed for one short duration and two long duration cloud events. The concentrations of principal ions (SO₄²⁻, NO₃⁻, H⁺ and NH₄⁺) during the short duration cloud events were found to be much higher than those during the long duration ones, especially at colder temperatures. Such short cloud events have a potential of causing foliar narcosis in red spruce stands because of unusually acidic cloudwater to which these stands stay exposed intermittently during each growing season.     

Investigation of the common intermediates over Fe-ZSM-5 in NH3-SCR reaction at low temperature by in situ DRIFTS

The surface species formed in the reaction of NO and NO₂ with pre-adsorbed NH₃ over a Fe-ZSM-5 catalyst (1.27 wt.% Fe, SiO₂/Al₂O₃ = 25) at low temperature (140°C) were studied by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Through using a background spectrum of NH₃-saturated Fe-ZSM-5, we clearly observed the formation of common intermediates resulting from the reaction of NO₂ or NO + O₂ with pre-adsorbed NH₃. This presents strong evidence that the oxidation of NO to form surface nitrates and nitrites is the key step for standard SCR at low temperature. In addition, the results suggest that in the SCR reaction at low temperature, the NH₄⁺ ions absorbed on Brønsted acid sites are less active than NH₃ adsorbed on Lewis acid sites related to Fe species.     

Hot bats: extreme thermal tolerance in a desert heat wave

Climate change is predicted to increase temperature extremes and thus thermal stress on organisms. Animals living in hot deserts are already exposed to high ambient temperatures (T _a) making them especially vulnerable to further warming. However, little is known about the effect of extreme heat events on small desert mammals, especially tree-roosting microbats that are not strongly protected from environmental temperature fluctuations. During a heat wave with record T _as at Sturt National Park, we quantified the thermal physiology and behaviour of a single free-ranging little broad-nosed (Scotorepens greyii, henceforth Scotorepens) and two inland freetail bats (Mormopterus species 3, henceforth Mormopterus) using temperature telemetry over 3 days. On 11 and 13 January, maximum T _a was ～45.0 °C, and all monitored bats were thermoconforming. On 12 January 2013, when T _a exceeded 48.0 °C, Scotorepens abandoned its poorly insulated roost during the daytime, whereas both Mormopterus remained in their better insulated roosts and were mostly thermoconforming. Maximum skin temperatures (T _skin) ranged from 44.0 to 44.3 °C in Scotorepens and from 40.0 to 45.8 °C in Mormopterus, and these are the highest T _skin values reported for any free-ranging bat. Our study provides the first evidence of extensive heat tolerance in free-ranging desert microbats. It shows that these bats can tolerate the most extreme T _skin range known for mammals (3.3 to 45.8 °C) and delay regulation of T _skin by thermoconforming over a wide temperature range and thus decrease the risks of dehydration and consequently death.     

N-doped CoAl oxides from hydrotalcites with enhanced oxygen vacancies for excellent low-temperature propane oxidation

A series of nitrogen-doped CoAlO (N-CoAlO) were constructed by a hydrothermal route combined with a controllable NH₃ treatment strategy. The effects of NH₃ treatment on the physico-chemical properties and oxidation activities of N-CoAlO catalysts were investigated. In comparison to CoAlO, a smallest content decrease in surface Co³⁺ (serving as active sites) while a largest increased amount of surface Co²⁺ (contributing to oxygen species) are obtained over N-CoAlO/4h among the N-CoAlO catalysts. Meanwhile, a maximum N doping is found over N-CoAlO/4h. As a result, N-CoAlO/4h (under NH₃ treatment at 400°C for 4 hr) with rich oxygen vacancies shows optimal catalytic activity, with a T₉₀ (the temperature required to reach a 90% conversion of propane) at 266°C. The more oxygen vacancies are caused by the co-operative effects of N doping and suitable reduction of Co³⁺ for N-CoAlO/4h, leading to an enhanced oxygen mobility, which in turn promotes C₃H₈ total oxidation activity dominated by Langmuir-Hinshelwood mechanism. Moreover, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) analysis shows that N doping facilities the decomposition of intermediate species (propylene and formate) into CO₂ over the catalyst surface of N-CoAlO/4h more easily. Our reported design in this work will provide a promising way to develop abundant oxygen vacancies of Co-based catalysts derived from hydrotalcites by a simple NH₃ treatment.     

Mediterranean shrublands carbon sequestration: environmental and economic benefits

To date, only a few attempts have been done to estimate the contribution of Mediterranean ecosystems to the global carbon cycle. Within this context, shrub species, composition and structure of the Mediterranean shrublands developing along the Latium coast (Italy) were analyzed in order to evaluate their contribution to carbon (C) sequestration, also taking into consideration the economic benefits at a national level. The considered shrublands had a shrub density of 1,200?±?500 shrubs ha^?1. Shrubs were classified into small (S), medium (M) and large (L), according to their volume (V) and leaf area index (LAI). The total yearly carbon dioxide (CO₂) sequestration per species (SC_y) was calculated multiplying the total photosynthetic leaf surface area (spt) of each species by the mean yearly photosynthetic rate and the total yearly photosynthetic activity time (in hours). Q. ilex and A. unedo had the highest SC_y (46.2?±?15.8 kg CO₂ year^?1, mean value), followed by P. latifolia (17.5?±?6.2 kg CO₂ year^?1), E. arborea, E. multiflora, C. incanus, P. lentiscus, R. officinalis, and S. aspera (6.8?±?4.2 kg CO₂ year^?1, mean value). The total yearly CO₂ sequestration per shrub (SC_shy) was 149?±?5 kg CO₂ year^?1 in L, decreasing 30 % in M and 80 % in S shrubs. Taking into account the frequency of S, M and L and their SC_shy, the total CO₂ sequestration of the Mediterranean maquis was quantified in 80 Mg CO₂ ha^?1?year^?1, corresponding to 22 Mg C ha^?1?year^?1. From a monetary viewpoint, this quantity could be valued to more than 500 US$ ha^?1?year^?1. Extending this benefit to the Mediterranean shrublands throughout the whole country, we obtained a nationwide estimated annual benefit in the order of $500 million.     

城市生活垃圾滚筒筛分选特性研究

滚筒筛筛分是生活垃圾分选中常用的工艺,国内目前有关滚筒筛分选生活垃圾的研究尚不多见.因此,本实验通过自行设计的一台处理能力为150kg.h-1的滚筒筛,采用实际生活垃圾进行分选实验,确定最佳运行参数范围.结果表明,当滚筒筛孔径为120mm时,在V实测/V极限（V实测为滚筒转动时实时测定转速,V极限为物料与滚筒一起转动时...