市场化、南北差距及其根源——基于作物性质的政治经济学考察

中国经济发展的区域差异及其根源,一直备受学界关注。其中,市场化发育的区域差异是解释经济发展差距的重要线索。然而,市场发育区域差异的生成根源却未能得到恰当的处理与阐释。文章试图从作物性质的政治经济学维度,构建“政府管制-作物性质-逃避策略”的逻辑框架,探讨区域经济发展差距背后市场发育的决定机理。文章认为,如果将市场化进程视为政府管制放松的过程,那么管制放松就可以区分为主动管制放松与被动管制放松。由可实施逃避策略所决定的被动管制放松及其所触发的市场化进程往往具有不可逆性。由此,逃避策略选择的区域差异性,将导致区域市场化发育程度的不同进而带来经济增长的差异。基于全国1997-2016年面板数据的实证分析表明:由“无政府主义”的作物种植所表达的管制逃避策略,能够显著促进市场化的发育程度;作物种植差异及其所蕴含的种植文化特性,共同决定了南北市场化差异;源于2013年全面开展的农地确权,进一步强化“南强北弱”的管制逃避,导致南北经济差异不断扩大。本研究有助于为中国区域经济增长差异提供新的洞见,从而为缓解不平衡不充分发展问题并推进中国区域经济的协调发展提供政策依据。

玉米连作障碍对土壤理化性质及作物生长的影响

为了探讨玉米连作障碍对土壤理化性质及作物生长的影响,本文采用了文献综述和实验数据分析相结合的方法。研究发现,玉米连作障碍导致土壤酸碱度失衡、土壤有机质含量下降及养分元素分布不均,这些因素共同影响了土壤的理化性质。同时,连作障碍对玉米的生长周期、株高、叶面积等生长指标产生了负面影响,最终导致作物产量和品质下降。此外,连作障碍还显著降低了玉米对环境逆境的抵御能力。这些结果表明,玉米连作障碍对土壤和作物的负面影响是显著的,在玉米生产中需要采取有效的土壤管理和作物生产策略,以减轻连作障碍带来的不利影响,推动农业实现可持续发展。

Acetylation of Chinese bamboo flour and thermoplasticity

Chinese bamboo flour was chemically modified by acetylation with acetic anhydride by using trichloroacetic acid as an activation agent and the optimized condition for acetylation of bamboo flour was determined as the trichloroacetic acid amount 6.0 g per 1.5-g bamboo flour, ultrasosonication duration 40 min and the reaction time 1 h at 65℃. The composition, microstructure and thermal behavior of acetylated bamboo flour were preliminarily characterized by FT-IR, DSC and SEM etc. The acetylated bamboo flour can be molded into sheets at 130℃ and 10 MPa, indicating the modified bamboo flour possesses thermalplastic performance.

Preparation, characterization, and catalytic performance of high efficient CeO_2-MnO_x-Al_2O_3 catalysts for NO elimination

A series of CeO2‐MnOx‐Al2O3 mixed oxide catalysts （Ce：Mn：Al mole ratio=6：4：x, x=0.25, 0.5, 1, 2） were prepared by a simple one‐step inverse co‐precipitation method to investigate the influence of the incorporation of Al3＋ into CeO2‐MnOx mixed oxides. CeO2‐MnOx, CeO2‐Al2O3, and MnOx‐Al2O3 mixed oxides, and CeO2 were prepared by the same method for comparison. The samples were characterized by XRD, Raman, N2 physisorption, H2‐TPR, XPS, and in situ DRIFTS. The catalytic re‐duction of NO by CO was chosen as a model reaction to evaluate the catalytic performance. The incorporation of a small amount of Al3＋into CeO2‐MnOx mixed oxides resulted in a decrease of crys‐tallite size, with the increase of the BET specific surface area and pore volume, as well as the in‐crease of Ce3＋and Mn4＋. The former benefits good contact between catalyst and reactants, and the latter promotes the adsorption of CO and the desorption, conversion and dissociation of adsorbed NO. All these enhanced the catalytic performance for the NO＋CO model reaction. A reaction mecha‐nism was proposed to explain the excellent catalytic performance of CeO2‐MnOx‐Al2O3 catalysts for NO reduction by CO.

ON THE DIFFERENCES OF THE NATURES OF AUPOINTS AND CHINESE HERBAL MEDICINES

The acupoints and Chinese herbal medicines are quite different in their natures. In the present paper, the authors expound the differences of the natures between the acupoints and Chinese herbal medicines from a） substance carriers, b） the underlying mechanism in actions, and c） individual characteristics, etc..

Bioactive compounds of sea cucumbers and their therapeutic effects

Abstract Sea cucumbers belong to the Class Holothuroidea of marine invertebrates. They are commercially valuable and prized as a food and folk medicine in Asia. Nutritionally, sea cucumbers have an impressive profile of valuable nutrients such as vitamins, minerals and amino acids. A number of unique biological and pharmacological activities/properties, including anticancer, anticoagulant/antithrombotic, antimicrobial, antioxidant, antihyperlipidemic, antihyperglycemic, anti-inflammatory, antihypertension and radioprotective, have been ascribed to various compounds isolated from sea cucumbers. The therapeutic properties and medicinal benefits of sea cucumbers can be linked to the presence of a wide array ofbioactives, especially triterpene glycosides, acid mucopolysaccharide, sphingoid bases, glycolipids, fucosylated chondroitin sulfate, polysaccharides, phospholipids, cerebrosides, phosphatidylcholines, and other extracts and hydrolysates. This review highlights the valuable bioactive components as well as the multiple therapeutic properties of sea cucumbers with a view to exploring their potential uses as functional foods and a natural source of new multifunctional drugs.

Effect of Organic Manure and Chemical Amendments on Soil Properties and Crop Yield on a Salt Affected Entisol

A field experiment was conducted for two consecutive years in a farmer's field at Haji Mora Village, Dera Ismail Khan (D.I. Khan) in the Northwest Frontier Province (NWPP) of Pakistan to compare various management practices, such as the effect of various organic manures and gypsum in a rice-wheat cropping system on a saline-sodic Entisol (Zindani soil series). The treatments consisted of 1) a control (rice-wheat), 2) gypsum, 3) farmyard manure (FYM), 4) berseem (Trifolium alexzndrinum L.) as green manure (GM), and 5) dhancha (Sesbania sp.) as GM. All treatments increased yields of both rice and wheat significantly (P < 0.01) over the control, with the green manure treatments proving more economical than the others; while they decreased pH, electrical conductivity (EC), and sodium adsorption ratio (SAR) of the soil. Saturation percentage and available water of the soil were raised for all treatments due to an increase in organic matter content of the soil.

Effect of Tillage and Planting Methods on the Soil Properties, Grain Drill Performance, and Wheat Yield

The effect of conservation tillage methods and seeding machines on the soil physical properties, performance of grain drill, wheat yield, and wheat yield components was evaluated. The research was conducted in a split block experimental design with twelve treatments and four replications, and a local wheat variety （Shiraz） was planted in this study. Main plots were tillage methods including： （1） primary tillage using moldboard plow without moldboard; （2） primary tillage with disk harrow; and （3） primary tillage with chisel plow. Subplots were grain drill types including： （1） planting with Taka grain drill without furrower; （2） planting with Taka grain drill having furrower; （3） planting with Hamadan Machine Barzegar grain drill having furrower and runner opener; 4） planting with grain drill having ripple opener. Parameters including mean weight diameter of clods （MWD）, soil bulk density, uniformity of seed planting depth, seed distribution uniformity, seed emergence, crop yield, and crop yield components were measured. SAS software was used to analyze the collected data and the method of benefit to cost ratio was used to compare the treatments from the economic point of view. Results indicated that tillage method had no significant effect （P = 0.05） on the measured parameters. Plant per unit area, seed emergence, uniformity of seed planting depth, and MWD were significantly affected by the grain drill type （P 〈 0.05） while, the type of grain drill had no significant effect on the rest of measured parameters. Taka grain drill without furrower had the highest uniformity of planting depth and proper soil MWD, and grain drill with ripple opener had the highest seed emergence and plant per unit area. Interaction between tillage methods and grain drill types affected the soil MWD, seed emergence, and crop yield （P 〈 0.05） in such a way that the combination of primary tillage with disk harrow and planting with grain drill having ripple opener provided the highest crop yield.

Social-Aware Cooperation Among Mobile Terminals for Wireless Downlink Transmission

This paper investigates the social-aware cooperation(SAC) among mobile terminals(MTs), motivated by the fact that modern smart devices have much improved context awareness. Aware of the social ties, the cooperative network contains two layers of property: social and physical. In order to observe how the social awareness benefit the cooperation performance, we first formulate the social ties between MTs into parameters that can describe the cooperative behaviors by taking the mobility feature into account, defined as the conviction-approval-suspicion(CAS) model. Limited by the processing capability, partner selection is of great practical significance. To this end, the social-aware partner selection strategy is analyzed, and a significant superiority is observed compared to social-unaware selection. By analyzing the cooperative throughput, an explicit relationship between the degrees-of-freedom gain and the social-physical property is finally derived. Simulation results validate the theoretical analysis.

Study on Water-Soluble Organic Reducing Substances: II. Organic Reducing Substances Produced from Anaerobic Decomposition of Milk Vetch (Astragalus sinicus L.)

The characteristics of electric charge and molecular weight distribution,oxidation-reduction regimes,e.g.Eh and amounts of organic reducing substances produced by milk vetch during anaerobic decomposition process,were studied by using electrochemical methods.Interaction between soils and organic reducing substances was also observed.The results indicate that the organic reducing substances were mainly the organic compounds with negative and amphoteric charges,which were distributed in two groups at anodic peak potentials of 0.25 and 0.69 volt in differential pulse voltammograms,respectively.Their apparent molecular weights are all less than 700 daltons,in which those active in oxidation-reducion reaction were distributed in the fraction with apparent molecular weight less than 200 daltons.The organic reduction substances can be oxidized by manganese oxides in their interaction with soils.

Comparative studies on the biochemical characteristics of natural actomyosin isolated from PSE and normal pork

Biochemical changes of natural actomyosin from fresh pale, soft, exudative (PSE) and normal pork were studied,and the effects of different storage temperatures and different incubation temperature and times on sample superprecipitation,total sulfhydryl (-SH) content, and ATP (adenosine triphosphate) sensitivity were investigated. The results demonstrated that ATPase activity and thermal stability of PSE actomyosin were lower than those of normal pork; and that PSE actomyosin had higher -SH content than that of normal pork at all incubation temperatures and times tested.

Interspecific competition and allelopathic interaction between Karenia mikimotoi and Dunaliella salina in laboratory culture

Algal allelopathy is a manifold ecological/physiological phenomenon that is focused on chemical interactions and autotoxicity. We investigated the allelopathic interactions between Karenia mikimotoi and Dunaliella salina in laboratory cultures based on different temperature （15℃, 20℃, and 25℃） and lighting （40,80, and 160 umol/（m2·s）） conditions. The growth of D. salina in bi-algae culture （1：1 size/density） was significantly restrained. The results of cell-free filtrate culture indicate that direct cell-to- cell contact was not necessary in interspecific competition. Further experimental results demonstrated that allelochemicals released from K. miMmotoi were markedly influenced by both temperature （P=0.013） and irradiance （P=0.003）, resulting in different growth characteristics olD. salina in filtrate mediums. Compared with the plateau period, K. mikimotoi exudates in the exponential phase had a stronger short-term inhibition effect on D. salina in normal conditions. A clear concentration-dependent relationship was observed in the effect of allelochemicals released from K. mikimotoi with low-promoting and high-repressing effects on D. Salina in a short time-scale. In addition, allelopathic substances remain stable and effective under high temperature and pressure stress. Many flocculent sediments adhering with D. salina cells were observed in all filtrate mediums, while the quantity and color depended on the original culture conditions.

STUDY ON THE PHYSICAL CHEMICALPROPERTIES OF FFA-1 ION EXCHANGE FIBER

The physical and chemical properties of FFA-1 ion exchange fiber have beencharacterized with IR spectrum. thermal analysis and SEM means. The PH titrationcurve, swelling rate, mechanical properties, resistance drop of filter layer as well asthe dynamic adsorption for SO2 was determined These experiments provided theessential parameters for the practical application of FFA-1 material in adsorption oftoxic gases.

A New Energy Concept

According to the uncertainties in the results and the wide diversity of how to approach the subject, a new concept for energy is proposed： Energy is an exchange between two different concentrations, the concentration of time in space outside what we call matter and the concentrated phase of time in matter space which is the matter itself. The concept of motion for energy is replaced by time-space interactions with time taken as solid matter. Motion enhances the exchange between the mass and its surrounding time in space, annihilation and creation are special forms of this exchange. During the motion of a mass, it increases as a result of this dissolution. Time concentration in Fock space is responsible for the collision phenomena in physics. In this paper, a new mathematical operator （the equal operator） is introduced.

Evaluation of Some Physical Properties of Cucumber （Cucumis sativus L.）

Cucumber is one of the important vegetables in many countries. Information about physical properties of cucumber is necessary for designing, grading, sorting and processing operations. In this study, some physical properties such as diameter, length, height, and weight of three varieties of cucumber （Green Gold, Dharwad, and Super Dominus） were measured. The results revealed that there was no significant difference （P〈0.01） in the density values of the studied varieties, but regarding other physical properties there were a significant difference （P〈0.01） among them. The average density for Green Gold, Dharwad and Super Dominus were 0.98, 0.95 and 0.94 g/cm^3, respectively. Green Gold cucumber had the highest diameter, volume, weight, flesh diameter, geometric mean diameter and sphericity. Dharwad and Super Dominus varieties with 15.49 cm length and 4.61 length to diameter ratio had the highest length and length to diameter ratio, respectively. Smallest skin thickness （1.48 cm） was for Super Dominus. Surface area of Green Gold, Dharwad and Super Dominus were 192.29, 192.4 and 131.2 cm^2. As well as there was a high and positive correlation between weight and volume in the studied varieties. There was a non-significant and low correlation （0.56） between diameter and length in Super Dominus. There was also a high and positive correlation between diameter and geometric mean diameter in all the varieties.

Influence of Ozone Injection on Corrosion Behavior of Steel in Water Ballast Tank

Ozone is the principal active substances and usually employed in ballast water management systems. In the present study, the corrosion protective effect of ozone was conducted by immersion test and electrochemical techniques. It was found that corrosion protective effect was revealed in the range of 2.0 to 2.7 ppm of ozone concentration in seawater. The ratio of the rust area of specimen became 20% in that concentration region. The rusted area is strongly influenced by the ozone concentration and the flow rate determined by FEM （finite element method）. Ozone has a good influence for ballast tanks, i.e., ozone can delay the rust of ballast tanks, provided that the suitable concentration of ozone is selected. In this case, ozone may stop the corrosion at the defects, if a part of the paint in ballast tank is peeled off. However, ozone may also promote the corrosion of steel when the ozone concentration is very high, e.g., 10 ppm. Attention should be paid to the ozone concentration, if we use ozone as an active substance for ballast water management systems.

Influence of Intermolecular Hydrogen Bonding to Spin Crossover Property of Iron （111） Complexes with a N3O2 Pentadentate Ligand and a Monodentate Ligand

Three iron （III） complexes with the formula of [Feat（X）L2]BPh4 were studied, in which a pentadentate Schiff-base ligand （H2L2 = bis （3-methoxysalicylideneiminopropyl） methylamine） and a counter anion BPh4 were fixed, and three monodentate ligands, 3-Mepy （3-methylpyridine）, 4-NH2py （4-aminopyridine）, and 2-Meim （2-methylimidazole） were used as the axial ligand X. The temperature dependence of magnetic susceptibility measurements demonstrated that [Fem（3-Mepy）L2]BPh4 showed a gradual spin equilibrium between HS （high-spin） （S = 5/2） and LS （low-spin） （S = 1/2） states, [Fem（4-NH2py）L2]BPh4 showed a steep SCO （spin crossover） and [FeIH（2-Melm）L2]BPh4 was in the HS state even at 100 K. The single crystal X-ray analyses demonstrated that [FelH（4-NH2py）L2]BPh4 has an one-dimensional chain structure constructed by intermolecular hydrogen bonding between 4-amino group of 4-NH2py and methoxy oxygen of adjacent molecular-cation. The crystal structure of [FenI（3-Mepy）L2]BPh4 has no such intermolecular interaction and its SCO site behaves independently, and the crystal structure of [FeIII（2-Meim）L2]BPh4 has a NH...n interaction between imidazole group of 2-Meim of cation and a phenyl group of anion BPh4. The result demonstrates that the intermolecular hydrogen bonding affects SCO profile significantly.

Interaction between Cross-Linked Polyacrylamide and Water and Solute Flow in a Sand and Loam

Superabsorbents such as cross-linked PAM （polyacrylamides） are frequently used to increase water availability to plants. Commercial PAM providers suggest that besides its increasing water availability, PAMs also increase nutrient availability to plants. To test this premise, four application rates （0.0 g·kg^-1, 0.33 g·kg^-1, 1.66 g·kg^-1, 3.33 g·kg^-1 and 6.66 g·kg^-1） ofa PAM were mixed with sandy and loamy soils to evaluate its effect on nutrient leaching and retention in these soils. Miscible displacements of chloride were conducted on columns of PAM-soil mixtures and results were evaluated by an equilibrium CDE （convection dispersion equation） model. Increasing the PAM rates up to 1.66 g·kg^-1 resulted in increased early appearance and dispersive transport of chloride in sand. In addition, increasing the PAM rates gradually caused increased tailing of the breakthrough curves of chloride in both soils. These suggested that PAM increased preferential transport of chloride while it increased retention of chloride in soils. Effect of PAM on preferential transport and retardation of CI was greater in sand than loam.

Tillage and Poultry Manure Effects on Soil Physical Properties, Nutrient Status, Growth, Dry Matter and Grain Yield of Sorghum

The effects of different tillage systems and poultry manure on soil physical properties, performance and nutrients in sorghum were studied for three years at Owo, southwest Nigeria. There was factorial combinations of herbicide-based zero tillage （ZT）, manual clearing （MC）, disc ploughing （P）, ploughing plus harrowing （P＋H） and ploughing plus double harrowing （P＋2H）, and two rates of poultry manure at 0 and 7.5 Mg ha^-1. Herbicide-based zero tillage and manual clearing reduced soil temperature and conserved more water than mechanized tillage techniques. Poultry manure reduced soil bulk density and temperature and increased soil water and porosity. There was a percentage decrease of leaf N, P, K, Ca and Mg concentrations, plant height, leaf area, stem girth, root dry weight, dry matter and grain yield in ascending order for herbicide-based zero tillage, manual clearing, ploughing, ploughing plus harrowing and ploughing plus double harrowing while percentage increases were recorded in a descending order for all the various combinations of tillage with poultry manure in that order. Poultry manure in combination with tillage increased dry matter and grain yield by 33.1 and 39.5%, respectively in comparison with tillage only. The manure-zero tillage methods increased dry matter and grain yield by 8% and 15%, respectively when compared with manure-mechanized tillage methods. Zero tillage or manual clearing in combination with 7.5 Mg ha^-1 poultry manure was most suitable for sorghum cultivation.

XU Xiaohui,CHEN Hui'e and WANG Gangcheng College of Construction Engineering,Jilin University,Changchun 130026,China

On the basis of geological investigating work and experimental studies on slide zone soil of one landslide in Tibet,the authors analyzed granulometric composition,clay mineral composition and physical and mechanical properties for the soil in the slide zone.The soil samples are gravel containing fine particle.Particles larger than 2 mm occupy the main proportion with the content 51.5%--68.5%.The relative content of clay minerals is low.The clay minerals are illite smectite mixed layer and kaolinite,and their relative contents are 6%--13% and 4%-11%,respectively.The main mineral ingredient is quartz and the relative content is over 30%.Therefore,the soil’s hydrophily is poor.The cohesion and internal friction angle are high,causing preferable physical-mechanical features of slide zone soil.On the basis of the obtained data,the landslide stability is evaluated by means of limit equilibrium method.The safety factors are 3.191 and 1.92 respectively under both natural and normal water level conditions.The study results show that the landslide is stable.It can provide the appropriate basis and reference for landslide stability evaluation and landslide control in Tibet.