Improved POLSAR Image Classification by the Use of Multi-Feature Combination

Polarimetric SAR (POLSAR) provides a rich set of information about objects on land surfaces. However, not all information works on land surface classification. This study proposes a new, integrated algorithm for optimal urban classification using POLSAR data. Both polarimetric decomposition and time-frequency (TF) decomposition were used to mine the hidden information of objects in POLSAR data, which was then applied in the C5.0 decision tree algorithm for optimal feature selection and classification. Using a NASA/JPL AIRSAR POLSAR scene as an example, the overall accuracy and kappa coefficient of the proposed method reached 91.17% and 0.90 in the L-band, much higher than those achieved by the commonly applied Wishart supervised classification that were 45.65% and 0.41. Meantime, the overall accuracy of the proposed method performed well in both C- and P-bands. Polarimetric decomposition and TF decomposition all proved useful in the process. TF information played a great role in delineation between urban/built-up areas and vegetation. Three polarimetric features (entropy, Shannon entropy, T11 Coherency Matrix element) and one TF feature (HH intensity of coherence) were found most helpful in urban areas classification. This study indicates that the integrated use of polarimetric decomposition and TF decomposition of POLSAR data may provide improved feature extraction in heterogeneous urban areas

Quantum criticality in interacting bosonic Kitaev-Hubbard models

Motivated by recent work on the non-Hermitian skin effect in the bosonic Kitaev-Majorana model, we study the quantum criticality of interacting bosonic Kitaev-Hubbard models on a chain and a two-leg ladder. In the hard-core limit, we show exactly that the non-Hermitian skin effect disappears via a transformation from hard-core bosonic models to spin-1/2 models. We also show that hard-core bosons can engineer the Kitaev interaction, the Dzyaloshinskii-Moriya interaction and the compass interaction in the presence of the complex hopping and pairing terms. Importantly, quantum criticalities of the chain with a three-body constraint and unconstrained soft-core bosons are investigated by the density matrix renormalization group method. This work reveals the effect of many-body interactions on the non-Hermitian skin effect and highlights the power of bosons with pairing terms as a probe for the engineering of interesting models and quantum phase transitions.Comment: 9 pages, 6 figure

Farmer differentiation and cultivated use system resilience from a perceptive behavioral perspective: influencing mechanisms and governance strategies

IntroductionThe adaptive management strategy of the cultivated land use system is crucial for achieving sustainable development, particularly when viewed from the perspective of perceptual behavior. This study integrated farmers’ behavior, perceptions, and willingness into the resilience evaluation index system of the cultivated land use system.MethodsBy resilience calculation method of cultivated land use system and linear regression method, it also explored the effect of farmer differentiation on the resilience of cultivated land use systems under the influence of socioeconomic systems, thereby providing a scientific reference for the adaptive management of cultivated land use systems.ResultsThe key findings are as follows: First, in general, the production resilience of the peasant household cultivated land use system was low, with significant resilience differentiation of resource elements and stratification of ecological and scale structures. However, the total resilience remained relatively stable. Second, farmers’ cultivated land use systems exhibit uneven resilience, with a lack of production and ecological protection, indicating low efficiency and weak functioning of the cultivated land use system. Third, farmers’ differentiation into non-agricultural employment is high, with low dependence on land. The resilience of the cultivated land use system varies significantly among different types of farmers, with imbalance and production deficiency being the main types of resilience in the farmland use system. Fourth, the economic differentiation of farmers and the differentiation of cultivated land use negatively affected the resilience of the cultivated land use system; the more pronounced the differentiation, the lower the resilience.DiscussionBased on these findings, the primary management strategies to enhance the resilience and adaptability of the cultivated land use system include improving the production resilience of the system, increasing the enthusiasm of different types of farmers to invest in the resource elements of the cultivated land use system, promoting the transformation of ecological protection consciousness and behavior among various types of farmers, and improving the willingness for cultivated land transfer

Lifshitz Scaling Effects on Holographic Superconductors

Via numerical and analytical methods, the effects of the Lifshitz dynamical exponent $z$ on holographic superconductors are studied in some detail, including $s$ wave and $p$ wave models. Working in the probe limit, we find that the behaviors of holographic models indeed depend on concrete value of $z$. We obtain the condensation and conductivity in both Lifshitz black hole and soliton backgrounds with general $z$. For both $s$ wave and $p$ wave models in the black hole backgrounds, as $z$ increases, the phase transition becomes more difficult and the growth of conductivity is suppressed. For the Lifshitz soliton backgrounds, when $z$ increases ($z=1,~2,~3$), the critical chemical potential decreases in the $s$ wave cases but increases in the $p$ wave cases. For $p$ wave models in both Lifshitz black hole and soliton backgrounds, the anisotropy between the AC conductivity in different spatial directions is suppressed when $z$ increases. The analytical results uphold the numerical results.Comment: Typos corrected; Footnote added; References added; To be published in Nuclear Physics

Structure and tanning properties of dialdehyde carboxymethyl cellulose: Effect of degree of substitution

Content: Developing novel tanning agents from renewable biomass is regarded as an effective strategy for sustainable leather industry. In this study, a series of dialdehyde carboxymethyl cellulose (DCMC) were prepared by periodate oxidation of carboxymethyl cellulose (CMC) with varying degrees of substitution (DS: 0.7, 0.9 and 1.2). The structural properties of DCMC were characterized. Size Exclusive Chromatography measurements showed that CMC underwent severe degradation during periodate oxidation, resulting in the decline of weight-average molecular weight from 250,000 g/mol to around 13,000 g/mol. FT-IR analysis illustrated that aldehyde group was successfully introduced into DCMC. The aldehyde group content of DCMC decreased from 8.38 mmol/g to 2.95 mmol/g as the DS rose from 0.7 to 1.2. Interestingly, formaldehyde was found to be produced in DCMC, and its content was 159.4, 151.7 and 38.4 mg/L, respectively when the DS of CMC was 0.7, 0.9 and 1.2, respectively. Further analysis by HPLC found that fructose was formed during oxidative degradation, and was subsequently oxidized to generate formaldehyde. This was in accordance with the fact that higher DS resulted in lower formaldehyde content in DCMC. The whole reaction mechanism is still under investigation at the moment. Tanning trials showed that the shrinkage temperature and thickening rate of DCMC tanned leather decreased as the DS increased. This should be due to the difference in aldehyde content of DCMC. Leather tanned by DCMC-0.7 (DS of CMC was 0.7) had the highest shrinkage temperature of 81°C and thickening rate of 76%. It was noteworthy that the formaldehyde content in DCMC tanned leather was only 0.11-0.40 mg/kg even though DCMC contained a small amount of formaldehyde. In general, we hope the work on dialdehyde tanning agent derived from CMC could provide some essential data for the development of sustainable tanning material and process. Take-Away: 1. Higher degree of substitution (DS) of CMC resulted in lower aldehyde group content of DCMC. 2. The formaldehyde content of DCMC was negatively correlated with DS. 3. The tanning performance of DCMC with lower DS was better

Lifshitz effects on holographic pp-wave superfluid

In the probe limit, we numerically build a holographic $p$-wave superfluid model in the four-dimensional Lifshitz black hole coupled to a Maxwell-complex vector field. We observe the rich phase structure and find that the Lifshitz dynamical exponent $z$ contributes evidently to the effective mass of the matter field and dimension of the gravitational background. Concretely, we obtain the Cave of Winds appeared only in the five-dimensional anti-de Sitter~(AdS) spacetime, and the increasing $z$ hinders not only the condensate but also the appearance of the first-order phase transition. Furthermore, our results agree with the Ginzburg-Landau results near the critical temperature. In addition, the previous AdS superfluid model is generalized to the Lifshitz spacetime.Comment: 14 pages,5 figures, and 1 table, accepted by Phys. Lett.

The study on permeability ratio curve of polymer/SAA binary system and two-phase of viscous crude

According to the different proportion of making up solution of the binary combination system which use of hydrophobic associating polymer and Sulfonate Gemini Surfactant, determinating of its viscosity and interfacial tension before injection. Simulation of the bohai suizhong 36-1 oilfield actual situation, the constant speed nonsteady state method is used for the determination of permeability ratio curve of water drive and binary combination drive, and the experimental data were processed by J.B.N. Method. Analysis of the pros and cons of existing several kinds of the viscosity processing methods for non-Newtonian fluid flow in the core, put forward a new method of viscosity processing, and compared the binary combination drive relative permeability curve which use of the different viscosity processing method. Laboratory findings show that the binary multisystem flooding in oil relative permeability is higher than water flooding, the water relative permeability is lower than water flooding, SOR is lower than water drive; Mass fraction of surfactant and polymer concentration of the binary multisystem have influence on the permeability ratio curve modality

Biodegradation of Ammonia in Biofiltration Systems: Changes of Metabolic Products and Microbial Communities

In the first stage, the feasibility of using the waste materials from coal power plants (i.e., coal slag) and landscapes (i.e., wood chip and compost) as packing media in various biofiltration systems for ammonia (NH3) removal was investigated. In the second stage, the optimized biotrickling system packed with coal slag was employed to investigate the effects of inlet concentration on NH3 treatment performance. A complete NH3 removal was achieved at concentrations of up to 250 ppm at an empty bed retention time of as low as 8 s, which is shorter than most previously reported biofiltration systems. Results of metabolic product analysis indicated that half of introduced NH3 was oxidized to nitrate and the rest was converted to ammonium ion at low loadings, while nitrite and ammonium ions predominate at high loadings. A bacterial community shift was observed with regard to the loading rates and pH conditions. In addition, there were no common operating problems, such as clogging and compaction, in the operation for more than 1 year