[en] The Grain for Green Project is one of the important projects implemented by the Chinese government to control soil erosion on the Loess Plateau, and its successful implementation has brought remarkable ecological benefits to relevant regions in China. The land use change is the most intuitive representation. Meanwhile, the soil erosion and soil nutrient distribution has also been influenced to produce significant changes. In this research, the characteristics of soil erosion and nutrient loss characteristics of soils from different land utilization types including apple, shrub, forest, grass and gully land, and their relationship were quantitative evaluated with 137Cs tracer technique in a typical watershed, which is located in Yan'an city of northern Shaanxi province in China. Results showed that soil erosion was observed in the all-land use types but shrub land, however, the degree of soil erosion was slight (the maximum value of soil erosion rate for 151.27 t/km²•a). The soil erosion of forest was significant differences with apple, shrub and gully but not with grassland. As will as there were significant differences in among shrub, apple orchard and gully. The soil nutrient loss, soil nutrient status and soil erosion degree showed a very similar pattern of spatial variation, with the difference that the correlation coefficients were different. In addition, there was highly significantly positive correlation between three indicators. However, Soil total nitrogen, total phosphorus, organic matter, N/P and C/P significantly affected the total nitrogen loss, total phosphorus loss and organic matter loss, but C/N ratio and nutrient loss were not significant. Soil nutrient loss in small watershed was more closely related to the soil carbon and nitrogen and soil erosion. The basic contents of different nutrients affected their nutrients loss laws, by and large, soil erosion affected soil nutrient loss and results in differences in nutrient distribution in the small watershed.

[en] Thin films of erbium doped Pb(Zr_0.35Ti_0.65)O₃ (PEZT35) and Pb(Zr_0.52Ti_0.48)O₃ (PEZT 52) as well as their multilayer heterostructures PEZT35/PEZT52 were processed on platinized Silicon substrates via solution deposition. The results of microstructure, ferroelectric, dielectric and pyroelectric properties are reported. It is shown that heterostructures can be successfully used to tune the dielectric and pyroelectric properties. The figure of merit for pyroelectric applications calculated for all films are found to be substantially lower than that of modified PZT ceramics because of the higher dielectric constants and loss tangents obtained. The voltage and current responses of the detector elements measured using a modulated laser source and a lock-in amplifier show better results for PEZT35 at low frequencies. A pyrovoltage output amplitude of up to 1 mV could be obtained on unpoled specimens, using platinum top electrodes

[en] Spinless fermions on a lattice with nearest-neighbor repulsion serve as a toy-version Hubbard model and have a symmetry-broken even/odd superlattice at half filling. At infinite repulsion, doped holes form charged stripes that are antiphase walls (as noted by Mila [Phys. Rev. B 49, 14047 (1994)]). Exact-diagonalization data for systems up to 36 sites around 1/4 filling, and also for one or two holes added to a stripe of length up to 12, indicate stability of the stripe-array state against phase separation. In the boson version of the model, the same behavior can be stabilized by addition of a term with four creation/annihilation operators

[en] Both laser shadowgraphy and holographic interferometry are used to investigate the evaporative convection in binary drops. The former is a very simple optical procedure which is used for qualitative investigating of morphology of the evaporative convection in binary drops and the latter is a specially technique to record accurate the profile changes of evaporating binary drops. The two methods are only non-intrusive means of visualizing the inside flow in binary drops on a flat plate and calculating accurately their profile change and evaporation rate, respectively. Many interesting new phenomena in the evaporation processes of the binary drops were revealed by these two method

[en] In autumn 2010, the phytoplankton samples were collected in Zhalong Wetland. A total of 347 species belonging to 78 genera,6 phyla were identified, Chlorophyta and Bacillariophyta were dominated phytoplankton communities, including 143 species of Chlorophyta, 116 species of Bacillariophyta, 45 species of Cyanophyta, 39 species of Euglenophyta, 3 species of Pyrrophyta, 1 species of Chrysophyta. In the core area 66 genera, 222 species were identified, in the buffer area 63 genera, 210 species were identified, in the experiment area 63 genera, 167 species were identified. The dominant species in Zhalong Wetland included Cyclotella meneghiniana, Chlorella vulgaris, Trachelomonas volvocina, Nitzschia sp.. The average phytoplankton density was 12.13*10/sup 6/ in Zhalong Wetland, the phytoplankton density of Bacillariophyta was highest (32.82*10/sup 6/ ind L/sup -1/), and then Chlorophyta (23.73*10/sup 6/ ind L/sup -1/) and Cyanophyta (11.43*106 ind L-1), respectively. The results of cluster analysis showed that phytoplankton community structure could be divided into three types, and within-group similarities of phytoplankton community structure was not high, but inter-group non-similarity was high. Based on the species composition, phytoplankton density, phytoplankton pollution indicator, it suggested that Zhalong Wetland was mesotrophic state. (author)

[en] Air plasma spraying technology was used to prepare ZrB₂–NiCr coatings for the surface protection of gears and improving their service time. The morphology of the coating was investigated by means of scanning electron microscope. The generation of new phases and decomposition of old phases in the powders and coatings were explained by Gibbs free energy calculations. The hardness and wear resistance of the coatings were measured using a Vickers microhardness tester and a ball-on-disk tribometer, respectively. The results showed that ZrB₂–NiCr composite coatings present typical thermal spraying morphologies, and mainly contain ZrB₂, Ni₄B₃ and Ni phases. In addition, the coating with an added 20 wt%ZrB₂ demonstrated the lowest wear loss and highest hardness (812 HV), which was about five times that of the substrate. The wear process generated some plate-like debris for the 20ZrB₂–NiCr composite coating, which suggested the occurrence of adhesive and oxidative wear, while the other coatings also showed signs of adhesive and fatigue wear on observation of the worn surfaces. (paper)

[en] The Jinci spring is a famous karst spring in north China and the leakage of the Fenhe river has a significant effect on the recharge of the Jinci Spring. However, the mechanism and process of the river leakage into shallow karst aquifer is very complicated due to lack of long-term monitoring for river water and subsurface water, and quantitative characterization of the leakage recharge process. In 2018, 11 river sections along the Fenhe river have been monitored so as to calculate the amount of river leakage during different river section, in which the influx of the branch stream was considered. Combined with long-term annual data of two hydrological stations along the Fenhe river from 1987 to 2017 a new regression equation of the river discharge and the leakage coefficient was established to calculate the annual average leakage into shallow karst aquifer along the Fenhe river. It was concluded that, the annual average seepage quantity of Fenhe reservoir-Zhaishang section was 0.866m3/s and the annual average seepage quantity of Zhaishang-Saoshi section was 0.574m3/s. Moreover, we carried out the hydrological dynamics monitoring daily on the rainfall rate, river discharge, groundwater lever of the Quaternary aquifer and shallow karst aquifer from the Luojiaqu to the Longweitou area. In considering of local geological structure and hydrogeological conditions, a three-dimensional heterogeneous karst groundwater model was established to simulates the nonlinear leakage process. The results showed that, the average leakage of Luojiaqu-Suoyu section is 0.95m3/s in 2018. In addition, the biggest loss of the Fenhe river water was at Cema-Longweitou section, so it was inferred that there might exist large faults or broad karst fissures below the river bed in this section. Therefore, if the water supplement project is constructed in the strongly leakage section, it would have a great help to the recovery of the Jinci Spring.

[en] The authors discuss an optical method, based on holographic and shearing interferometry, was developed to record the profile changes of liquid droplet evaporating on a flat plate. Interfacial flow phenomena can be studied interferometrically in real time. Detailed profiles of evaporating droplets were calculated according to the time variant interference fringe patterns. Evaporation processes of analytically pure liquids and two-component liquids were tested and experimental results are shown in sequential photos

[en] Thin films of erbium doped lead zirconate titanate (PZT) of different thickness were deposited by sol-gel technique on Pt/TiO₂/SiO₂/Si substrates. Capacitance-voltage measurements show that the dielectric constant continuously increases with the thickness. This is interpreted in terms of effects due to a low permittivity interfacial layer in series with the ferroelectric bulk. The linear fit of the reciprocal of capacitance vs. thickness leads to a true dielectric constant of the ferroelectric of 774 and interfacial capacitance of 14.6 nF. The leakage current properties also depend on thickness and temperature. The calculated interfacial potential barrier height amounts to 0.81 and 0.74 eV, respectively for erbium doped and pure PZT thin films

No abstract available