Land institution of China:overall framework,structural evolution,and regulation intensity

China's land institution can be defined broadly or narrowly. By examining the broad definition of the land institution, we found that there were prerequisite, complementary, and substitutional relationships among the various systems. These relationships were verified through discussion of the structural evolution of each system. Based on these relationships, three methods for quantification were used to measure the regulation intensity and intra-provincial differences in each system among 31 provinces, municipalities, and autonomous regions in China in 2014. The statistics analysis shows that provinces used to pursue outstanding performances in land institution but few provinces could outperform the other provinces in all types of systems. The statistics results also indicate that the provinces which executed land institution earlier often hold significant advantages in institutional innovations but it is still not clear whether they can maintain the advantages. This study recommends that the Chinese government should improve the overall framework of regional land institution based on land systems' relationships and evolutionary patterns. Furthermore, the government should optimize the spatial distribution of regional land institution based on the intra-provincial differences in land-regulation intensity.

Low-cost portable dielectric spectrometer based on mini-vector network analyzer and open-ended coaxial probe technology

As a simple,fast,and non-destructive measuring technology,dielectric spectroscopy is usually used to analyze the dielectric properties of agricultural products and food,and then to predict the main components of materials.However,the large and expensive vector network analyzers(VNA)with expensive analysis software applied in measuring dielectric properties make research limited to the laboratory.To acquire dielectric spectra in situ,a model for solving relative complex permittivity was derived,and its performance was validated.Then,a low-cost portable dielectric spectrometer with a mini VNA,a Raspberry Pi,and a coaxial probe as core parts was developed over the frequency range of 100-3000 MHz.The stability and accuracy of the developed spectrometer were tested using milk and juice.The results indicated that the relative errors of the model were within±5%for dielectric constant(ε′)and loss factor(ε″).The coefficients of variation of measuredε′andε″by the developed spectrometer at 100-3000 MHz were less than 1%and 2%,respectively.Compared with the dielectric properties obtained by using a commercial dielectric measurement system,the relative errors of measuredε′andε″were within±3.4%and±6.0%,respectively.This study makes fast,non-destructive,and on-site food quality detection using dielectric spectra possible.

肝纤维化治疗:从传统方法到纳米材料递送系统

Liver diseases seriously affect human health.Metabolic dysfunction-associated steatohepatitis(MASH)is a highly prevalent chronic liver disease that has a global prevalence of 32.4%,but this is increasing at an alarming rate[1].Cirrhosis is the 11th most common cause of death worldwide,and there was a 47%increase in mortality between 2010 and 2021[2].

Design and test of the bilateral throwing soil-covering device for straw mulching machine in orchards

Aiming to lack the function of soil covering in the developed orchard straw mulching machine(OSM),a kind of bilateral counter-throwing soil-covering device was developed to eliminate the orchard fire risk caused by the straw layer.The soil-covering device was suspended at the rear of the OSM.Its core component was a pair of throwing wheels installed on both sides of a frame.Hydraulic motors drove the throwing wheels to take soil on-site and cover the straw layer.The adjustment range of the space between the throwing wheels on both sides was 1.4-2.1 m.Based on the analysis of soil-covering quantity,soil-covering width,thickness uniformity of soil layer,and power consumption,the key parameters such as the radius,the number of the vane,and the minimum rotation speed of the throwing wheels were determined.It was proved that the thickness uniformity of the soil layer by bilateral counter-throwing was better than by unilateral,and bottom throwing was better than top throwing.The blade of the soil cutter consisted of a straight blade and a curved blade,and the sliding-cutting angle was 14°-40°.The field test results showed the soil-covering device had good performance with a width of 1.4-2.2 m,a thickness of the soil-covering layer(TSL)of 23.2-40.7 mm,a standard deviation(SD)of 1.4-2.9 mm,width uniformity of 100%,and leakage rate of zero.The established model,between the thickness of soil-covering layer and trenching depth,throwing angle,and rotation speed of the throwing wheels,has a determination coefficient of 0.9757 and can be used to guide the operating parameters.The soil cutter reduced the power consumption and impact load of the throwing wheels by 64.77%and 60.88%,respectively.This work provides a type of new equipment for the mechanization technology of straw mulching in arid and semi-arid orchards.

Effect of inferior vena cava respiratory variability-guided fluid therapy after laparoscopic hepatectomy:a randomized controlled clinical trial

Background:After major liver resection,the volume status of patients is still undetermined.However,few concerns have been raised about postoperative fluid management.We aimed to compare gut function recovery and short-term prognosis of the patients after laparoscopic liver resection(LLR)with or without inferior vena cava(IVC)respiratory variability-directed fluid therapy in the anesthesia intensive care unit(AICU).Methods:This randomized controlled clinical trial enrolled 70 patients undergoing LLR.The IVC respiratory variability was used to optimize fluid management of the intervention group in AICU,while the standard practice of fluid management was used for the control group.The primary outcome was the time to flatus after surgery.The secondary outcomes included other indicators of gut function recovery after surgery,postoperative length of hospital stay(LOS),liver and kidney function,the severity of oxidative stress,and the incidence of severe complications associated with hepatectomy.Results:Compared with patients receiving standard fluid management,patients in the intervention group had a shorter time to anal exhaust after surgery(1.5±0.6 days vs.2.0±0.8 days)and lower C-reactive protein activity(21.4[95%confidence interval(CI):11.9-36.7]mg/L vs.44.8[95%CI:26.9-63.1]mg/L)24 h after surgery.There were no significant differences in the time to defecation,serum concentrations of D-lactic acid,malondialdehyde,renal function,and frequency of severe postoperative complications as well as the LOS between the groups.Conclusion:Postoperative IVC respiratory variability-directed fluid therapy in AICU was facilitated in bowel movement but elicited a negligible beneficial effect on the short-term prognosis of patients undergoing LLR.Trial Registration:ChiCTR-INR-17013093.

A rapid method of identifying mastitis degrees of bovines based on dielectric spectra of raw milk

Bovine mastitis is the most complex and costly disease in the dairy industry worldwide.Somatic cell count(ScC)is accepted as an international standard for diagnosing mastitis in cows,but most instruments used to detect scC are expensive,or the detection speed is very low.To develop a rapid method for identifying mastitis degree,the dielectric spectra of 301 raw milk samples at three mastitis grades,i.e.,negative,weakly positive,and positive grades based on ScC,were obtained in the frequency range of 20-450o MHz using coaxial probe technology.Variable im-portance in the projection method was used to select characteristic variables,and principal component analysis(PCA)and partial least squares(PLS)were used to reduce data dimension.Linear discriminant analysis,support vector classification(SvC),and feed-forward neural network models were established to predict the mastitis degrees of cows based on 22 principal components and 24 latent variables obtained by PCA and PLS,respectively.The results showed that the SvC model with PCA had the best classification performance with an accuracy rate of 95.8%for the prediction set.The research indicates that dielectric spectroscopy technology has great potential in developing a rapid detector to diagnose mastitisincowsinsituoronline.

Structural,spectroscopic,and dielectric characterizations of Mn-doped 0.67BiFeO_(3)-0.33BaTiO_(3)multiferroic ceramics

0.67BiFeO_(3)-0.33BaTiO_(3)multiferroic ceramics doped with x mol%MnO_(2)(x=2-10)were synthesized by solid-state reaction.The formation of a perovskite phase with rhombohedral symmetry was confirmed by X-ray diffraction(XRD).The average grain sizes were reduced from 0.80mm to 0.50mm as increasing the Mn-doped levels.Single crystalline nature of the grains was revealed by high-resolution transmission electron microscopy(HRTEM)images and electron diffraction patterns.Polar nano-sized ferroelectric domains with an average size of 9 nm randomly distributed in the ceramic samples were revealed by TEM images.Ferroelectric domain lamellae(71°ferroelectric domains)with an average width of 5 nm were also observed.Vibrational modes were examined by Raman spectra,where only four Raman peaks at 272 cm^(-1)(E-4 mode),496 cm^(-1)(A_(1)-4 mode),639 cm^(-1),and 1338 cm^(-1)were observed.The blue shifts in the E-4 and A_(1)-4 Raman mode frequencies were interpreted by a spring oscillator model.The dieletric constants of the present ceramics as a function of the Mn-doped levels exhibited a V-typed curve.They were in the range of 350-700 measured at 10^(3)Hz,and the corresponding dielectric losses were in range of 0.43-0.96,approaching to 0.09 at 10^(6)Hz.

Recent progress in molten salt synthesis of low-dimensional perovskite oxide nanostructures, structural characterization,properties, and functional applications: A review

Molten salt synthesis （MSS） method has advantages of the simplicity in the process equipment, versatile and large-scale synthesis, and friendly environment, which provides an excellent approach to synthesize high pure oxide powders with controllable compositions and morphologies. Among these oxides, perovskite oxides with a composition of ABO3 exhibit a broad spectrum of physical properties and functions （e.g. ferroelectric, piezoelectric, magnetic, photovoltaic and photocatalytic properties）. The downscaling of the spatial geometry of perovskite oxides into nanometers result in novel properties that are different from the bulk and film counterparts. Recent interest in nanoscience and nanotechnology has led to great efforts focusing on the synthesis of low-dimensional perovskite oxide nanostructures （PONs） to better understand their novel physical properties at nanoscale. Therefore, the low-dimensional PONs such as perovskite nanoparticles, nanowires, nanorods, nanotubes, nanofibers, nanobelts, and two dimensional oxide nanostructures, play an important role in developing the next generation of oxide electronics. In the past few years, much effort has been made on the synthesis of PONs by MSS method and their structural characterizations. The functional applications of PONs are also explored in the fields of storage memory, energy harvesting, and solar energy conversion. This review summarizes the recent progress in the synthesis of low-dimensional PONs by MSS method and its modified ways. Their structural char- acterization and physical properties are also scrutinized. The potential applications of low-dimensional PONs in different fields such as data memory and storage, energy harvesting, solar energy conversion, are highlighted. Perspectives concerning the future research trends and challenges of low-dimensional PONs are also outlined. ~ 2017 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science ＆ Technology.

Extracting the time delay signature of coupled optical chaotic systems by mutual statistical analysis

The time delay （TD） signature is a critical parameter in optical chaos-based applications. The feasi- bility of extracting the TD has been a crucial issue that significantly influences the performance of these applica- tions. In this paper, statistical analyses have been conducted to extract the TD signatures from different types of coupled optical chaos systems. More specifically, a mutually coupled semiconductor laser chaotic system, an intensity-coupled electro-optic chaotic system, and a phase-coupled electro-optic chaotic system are studied in detail. These systems are proposed to resist the attack strategies against the TD signature. They are proved to be effective under statistical analyzes, such as the self- correlation fimction （SF） and mutual information （MI）. However, only a single output has been considered for the attack process in the existing research. We demonstrated that the TD signature can still be extracted by analyzing the mutual statistical relationship between the different output signals which are generated simultaneously by the coupled system. Furthermore, we find that the extraction strategy is effective for a wide parameter range in these schemes.

SIZE EFFECTS IN PEROVSKITE FERROELECTRIC NANOSTRUCTURES:CURRENT PROGRESS AND FUTURE PERSPECTIVES

Perovskite ferroelectric nanostructures offer a wide range of functional properties(e.g.,dielectric switchability,piezoelectricity,pyroelectricity,high permittivities and strong electro-optic effects),which have received much attention in theelds of microelectronic devices miniaturization over the last few years.Pronounced size effects of the functional properties have been demonstrated in the perovskite ferroelectric nanostructures.Besides its intrinsic scientic value,fundamental understanding of the size effects in perovskite ferroelectric nanostructures has become critical item for developing a new generation of revolutionary nanodevices.In this article,a comprehensive review of the state-of-the-art research progress on the size effects in perovskite ferroelectric nanostructures which have been achieved from both experiment and theory is provided.It begins with a historical perspective of the size effects in perovskite ferroelectrics,and then highlight the recent progress on the theoretical studies of the size effects in perovskite ferroelectric nanostructures which have been achieved by using different numerical approaches(e.g.,phenomenological approaches,rst-principle computations and the Ising model in a transverseeld).The current progress of the experimental testing of the size effects in perovskite ferroelectric nanostructures(e.g.,nanoparticles,nanowires,nanotubes and nanolms)is summarized.Finally,the perspectives toward the future challenges of the size effects in perovskite ferroelectric nanostructures is reviewed.