[Effects of crude oil pollution on soil moisture infiltration with loessial soil and aeolian sandy soil]. / åŽŸæ²¹æ±¡æŸ“å¯¹é»„ç»µåœŸå’Œé£Žæ²™åœŸæ°´åˆ†å ¥æ¸—çš„å½±å“.

Crude oil may block soil pores, affect soil water repellency, and change soil water movement. In this study, soil column simulation was used to study the effects of different crude oil pollution levels (0, 0.5%, 1%, 2%, 4%) on the water infiltration processes in loessial soil and aeolian sandy soil. The results showed that soil wetting front speed and infiltration rate of those two soils decreased with increasing crude oil content. The time needed for wetting front reaching the bottom of the soil column was the longest under 4% crude oil polluted soil, which was 4 times and 48 times longer than that of no crude oil polluted soil for loessial soil and aeolian sandy soil, respectively. The cumulative infiltration of loessial soil decreased with increasing crude oil content, while it increased to the max and then decreased as the crude oil content increased in aeolian sandy soil. The cumulative infiltration curves of aeolian sandy soil with high crude oil contents (2% and 4%) presented "up-tail" phenomenon. Kostiakov infiltration model and Philip infiltration model could better fit the infiltration process than Green-Ampt model for loessial soil with different crude oil content. However, the two models could only well fit the infiltration process for aeolian sandy soil with low crude oil content (0, 0.5%, 1%). Crude oil pollution could significantly affect soil water infiltration process, especiall in aeolian sandy soil.

[Spatial Patterns of Nitrogen and Phosphorus in Soil and Their Influencing Factors in a Typical Agro-pastoral Ecotone].

Soil nitrogen and phosphorus influence physical, chemical, and biological processes in soil, therefore, clarifying their contents and spatial patterns is of great significance for soil resource management and utilization. The spatial patterns of soil total nitrogen (TN) and phosphorus (TP) and the influencing factors in Jungar Banner were studied using classical statistical and geostatistical methods. The results showed that soil TN and TP contents decreased with soil depth, and the weighted mean values of TN and TP were 0.29 g·kg-1 and 0.26 g·kg-1, respectively. The nugget effect values of soil TN and TP were concentrated in the ranges 0.15-0.43 and 0.34-0.53, respectively, indicating that soil TN (except in the 0-10 cm and 80-100 cm zones) and TP were moderately spatially dependent, dominated by structural and random factors. The spatial distributions of soil nutrients were related to soil layers and elements, even in same layer, while the distributions of TN and TP were not consistent. Soil total nitrogen was mainly affected by soil organic carbon, while TP was mainly affected by latitude, altitude, vegetation, and soil texture.

Revegetation pattern affecting accumulation of organic carbon and total nitrogen in reclaimed mine soils.

Selecting optimal revegetation patterns, i.e., patterns that are more effective for soil organic carbon (SOC) and total nitrogen (TN) accumulation, is particularly important for mine land reclamation. However, there have been few evaluations of the effects of different revegetation patterns on the SOC and TN in reclaimed mine soils on the Loess Plateau, China. In this study, the SOC and TN stocks were investigated at reclaimed mine sites (RMSs), including artificially revegetated sites (ARSs) (arbors (Ar), bushes (Bu), arbor-bush mixtures (AB), and grasslands (Gr)) and a natural recovery site (NRS), as well as at undisturbed native sites (UNSs). Overall, the SOC and TN stocks in the RMSs were lower than those in the UNSs over 10-13 years after reclamation. The SOC stocks in the RMSs and UNSs only differed in the top 0-20 cm of the soil (p < 0.05). Except for those in Ar, the SOC and TN stocks in the ARSs were significantly larger than those in the NRS (p < 0.05). Compared with those in the NRS, the total SOC stocks in the 100 cm soil interval increased by 51.4%, 59.9%, and 109.9% for Bu, AB, and Gr, respectively, and the TN stocks increased by 33.1%, 35.1%, and 57.9%. The SOC stocks in the 0-100 cm soil interval decreased in the order of Gr (3.78 kg m-2) > AB (2.88 kg m-2) ≥ Bu (2.72 kg m-2), and the TN stocks exhibited a similar trend. These results suggest that grasslands were more favorable than woodlands for SOC and TN accumulation in this arid area. Thus, in terms of the accumulation of SOC and TN, grassland planting is recommended as a revegetation pattern for areas with reclaimed mine soils.

[Characteristics and Mechanism of Copper Adsorption from Aqueous Solutions on Biochar Produced from Sawdust and Apple Branch].

In order to utilize the waste biomass resources efficiently, two raw materials of sawdust and apple branch were selected to produce biochars at 450℃ by oxygen-limited pyrolysis, and the adsorptions of Cu2+ in aqueous solutions were evaluated. The effects of initial Cu2+ concentration and contact time in batch sorption experiments were investigated by the four kinds of isothermal adsorption models (Langmuir, Freundlich, Temkim, D-R model) and the four kinds of adsorption kinetics models (Pseudo first-order, Pseudo second-order, Elovich model, Intraparticle diffusion model). The influencing factors of adsorption characteristics about sawdust biochar (JB) and apple branch biochar (PB) were discussed by characterizing their elemental composition, functional groups, surface area, surface morphology and scanning electron microscope. The results showed that:1The adsorption equilibrium of PB and JB was reached in three hours and six hours, respectively, and the maximum adsorption capacity of PB and JB reached 15.85 mg·g-1 and 17.44 mg·g-1, respectively. Compared with other studies, these biochars showed higher Cu2+ adsorption performance. 2The adsorption kinetics was best fitted by the pseudo-second order model, while the isothermal adsorption was best described by Langmuir isotherms. This indicated that the beneficial adsorption process via monolayer was affected by intraparticle diffusion, surface adsorption and liquid film diffusion. 3The adsorption mechanism for Cu2+ is a complex interaction of physical and chemical factors. Electrostatic interaction of physical adsorption is mainly adsorption mechanism, Chemical adsorption mechanism includes generally ligand exchange (phenolic hydroxyl)/ion exchange (H+) and cationic-π. It was demonstrated that JB and PB could be considered as promising materials to immobilize heavy metals in contaminated water or soil.

[Effect of Biochar on Soil Greenhouse Gas Emissions in Semi-arid Region].

This study aimed to investigate the effects of biochar addition on the emission of greenhouse gases from farmland soil in semi-arid region. Through an in-situ experiments, the influence of sawdust biochar(J) and locust tree skin biochar (H) at three doses (1%, 3%, and 5% of quality percentage) on C2, CH4 and N2O emissions were studied within the six months in the south of Ningxiaprovince. The results indicated that soil CO2 emission flux was slightly increased with the addition doses for both biochars, and the averaged CO2 emission flux for sawdust and locust tree skin biochar was enhanced by 1. 89% and 3. 34% compared to the control, but the difference between treatments was not statistically significant. The soil CH4 emission was decreased with the increasing of biochar doses, by 1. 17%, 2. 55%, 4. 32% for J1, J3, J5 and 2. 35%, 5. 83%, 7. 32% for H1, H3, H5, respectively. However, the difference was statistically significant only for J5, H3 and H5 treatments (P <0. 05). Across addition doses, there was no apparent effect on soil N2O emission. Our study indicated that the biochar has no significant influence on soil CO2 and N2O emissions within six months in semi-arid region and can significantly influence soil CH4 emissions (P < 0. 05). As for biochar type, the locust tree skin biochar is significantly better than the sawdust biochar in terms of restraining CH4 emission(P = 0. 048).

Fasciculols H and I, two lanostane derivatives from Chinese mushroom Naematoloma fasciculare.

Two new highly oxygenated fasciculol-type lanostane derivatives, fasciculols H and I (1 and 2, resp.), together with five known compounds, 3-7, were isolated from the fruiting bodies of the Chinese toxic mushroom Naematoloma fasciculare. Their structures were elucidated on the basis of spectroscopic analyses including 2D-NMR (HMBC, HSQC, NOESY, (1)H,(1)H-COSY). Compounds 5-7 were identified for the first time in this mushroom. Compounds 1, 3, 4, and 5 were evaluated for inhibitory activity against human glioma cell line U87 and nuclear factor-κB.

[Effects of loess soil stabilization on Lolium perenne L. growth and root activity].

Taking the loess soils with bulk density 1.2 g cm(-3), 1.3 g cm(-3), and 1.4 g cm(-3) from Ansai, Shaanxi Province as test objects, a pot experiment was conducted to study the effects of different amendment amount of soil stabilizer (EN-1 stabilizer) on the growth and root activity of ryegrass (Lolium perenne L.). Within the range of the bulk densities, the leaf chlorophyll content, root activity, root/shoot ratio, root biomass, and plant biomass of L. perenne all decreased with increasing soil bulk density, and were higher under the amendment of EN-1 stabilizer, as compared with the control. With increasing amendment amount of EN-1 stabilizer, the leaf chlorophyll content, root activity, root/shoot ratio, root biomass, and plant biomass had a trend of increased first and decreased then. Soil bulk density and stabilizer amendment amount had significant interactive effect on the root biomass and plant biomass. Overall, the values of the test indices were the highest under 1.3 g cm(-3) soil bulk density and 0.15% EN-1 stabilizer amendment amount.

Antifungal activity of alkaloids from the seeds of Chimonanthus praecox.

Two alkaloids, D-calycanthine (1) and L-folicanthine (2), were isolated from the active MeOH extract of the seeds of Chimonanthus praecox LINK. The structures of the two compounds were established by (1)H- and (13)C-NMR, and MS (FAB, ESI) analyses. In the in vitro tests, compounds 1 and 2 showed significant inhibitory activities against five plant pathogenic fungi Exserohilum turcicum, Bipolaris maydis, Alternaria solani, Sclerotinia sderotiorum, and Fusarium oxysportium, among which B. maydis was found to be the most susceptible to 1 with an EC(50) value of 29.3 microg/ml, followed by S. sderotiorum to 2 with an EC(50) value of 61.2 microg/ml. To our knowledge, this is the first report of isolation and LC/MS/MS identification as well as of antifungal properties of these alkaloids from the seeds of this plant.

[Profile variability of soil properties in check dam on the Loess Plateau and its functions].

To understand the profile variability of soil properties of check dam and its possibility of engineering control over non-point source pollution, we used classical statistics to characterize the profile change of soil properties of a 5.20 m depth soil profile in the typical check dam on the Loess Plateau. The roles of check dam as organic carbon storage and available nutrients storage were discussed. The results showed that: 1) The bulk density and sand content of dam-head were lower than dam-tail, while, soil water content, silt, loam, organic carbon, available P, NO3(-) -N and NH4+ -N were higher than dam-tail. The bulk density for both dam-head and dam-tail showed weak variability while other properties showed moderate variability. All variables followed a normal distribution except sand in dam-head and soil moisture in dam-tail. 2) The change pattern of soil moisture on the soil profile for both dam-head and dam-tail was saw-tooth type. The change trends of soil organic carbon, available P and NH4+ -N were comparable to that of soil moisture. 3) The correlations among soil water content, organic carbon, bulk density, silt, loam, sand, available P, NO3(-) -N and NH4+ -N were significant (p < 0.05) except the relationship between bulk density and NO3(-) -N, NH4+ -N and relationship between available P and NH4+ -N in dam-tail. The positive or negative correlation of soil properties both in dam-head and dam-tail were coincident. 4) The check dam can be an important carbon storage on the Loess Plateau, and the organic carbon storage in dam-head was higher than dam-tail. The storage of organic carbon in 400-520 cm depth was the biggest for dam-head, in 0-100 cm depths for dam-tail. 5) The check dam is an enrichment sink of available nutrients. The storage of available P, NO3(-) -N and NH4+ -N in dam-head were higher than dam-tail, and the range of storage was: NH4+ -N > available P > NO3(-) -N. The coefficient of enrichment for NH4+ -N and NO3(-) -N were 1.132 and 1.956, respectively. 6) As the sink of soil nutrients, check dam has an important theoretical value for region carbon balance, ecological environment reconstruction and the effective control over non-point source pollution.

[Development process of crust in black soil of Northeast China].

In a simulated rainfall experiment, the microstructure, bulk density, and shear strength of black soil were determined to study the development process of crust during rainfall, and the effects of the crust on soil infiltration. The results showed that with the process of rainfall, surface soil layer became compact, soil shear strength and bulk density increased, and infiltration decreased. In a period of 120 minutes rainfall, a stable crust layer in 3-4 mm thickness formed, whose bulk density increased by 14.13% and porosity decreased by 6.45%. The removal of raindrop beat weakened the development of crust, with soil porosity decreased by 3.27%, bulk density increased by 7.11%, and accumulated infiltration increased by 41.1%. The black soil in Northeast China had a stable soil structure, and raindrop beat was the dominant factor resulting in the development of crust. During the process of rainfall, no obvious eluviation was observed.

[Spatial variability and the relationships of soil mineral N and topographic factors in a small watershed].

Objective of this study was to understand the spatial pattern of soil properties and topographic factors and their relationships in a small watershed. We used classical statistical coupling with geo-statistical theory to characterize and compare the spatial variability of soil mineral N and topographic factors in the wind-water erosion crisscross region on the Loess Plateau. The results show that: 1) The nitrate's variable extent is strong while other properties are moderate variability, and the impacts of soil types, land uses on variable extent are significant. 2) All properties have different spatial dependence extent in the study area. Ammonium and elevation are strong spatial dependence while nitrate, slope gradient and slope aspect are moderate spatial dependence. 3) The analysis results of fractal dimension and spatial heterogeneity proportion are coherent, and the decreased sequence is: nitrate (1.9826) > slope aspect (1.9767) > slope angle (1.9420) > ammonium (1.8791) > elevation (1.7461). 4) In 0 degrees C/90 degrees C, 45 degrees C/135 degrees C aspects, nitrate is isotropy while elevation is anisotropy, and others are weak anisotropy. 5) Ammonium and elevation have strong spatial autocorrelation while nitrate has not. There exist extremely notable positive correlations between nitrate and ammonium, slope gradient and aspect, and the negative correlations between ammonium, slope aspect and elevation, which indicate that the distribution of ammonium and slope gradient have elevation gradients.