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Saline-alkali soil reclamation and utilization in china:progress and prospects

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Frontiers of Agricultural science and Engineering 2024年第2期11卷 216-228页

作者： guangzhou WANG Gang NI Gu FENG Haley MBURRILL Jianfang LI Junling ZHANG Fusuo ZHANG State Key Laboratory of Nutrient Use and Management(SKLNUM) College of Resources and Environmental SciencesNational Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China The institute of Ecology and Evolution University of OregonEugeneOR97403USA

Soil salinity is a global threat to the productivity of arable land. With the impact of population growth and development of social economy in china, the area of arable land has been shrinking in recent decades and is approaching a critical threshold of 120 Mha, the minimum area for maintaining the national food security. Saline-alkaline land, as important backup reserve, has been receiving increased attention as an opportunity to expand land resources. This review first summarizes the general principles and technologies of saline soil reclamation to support plant growth, including leaching salts or blocking the rise of salts, and soil fertility enhancement to improve the buffering *** the progress in this area in china is described including the customization of technologies and practices used in different saline-alkali regions. Following the soil management strategies, the concept of selecting crops for saline soil is proposed. This encompasses halophyte planting, salt-tolerant crop breeding and the application of saline-adapted functional microorganisms to improve the adaptation of crops. Finally, the current problems and challenges are evaluate, and future research directions and prospects proposed for managing this major soil constraint.

关键词： Food security land reserve reclamation saline-alkali soil utilization

A REAL-TIME MATHEMATICAL MODEL FOR TWO DIMENSIONAL TIDAL FLOW AND WATER QUALITY

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Journal of Hydrodynamics 1991年第3期3卷 35-40页

作者： Zeng Fan-tang Xu Zhen-cheng Chen Xian-cheng, south china institute for {3. sciences, NEPA, Yuancun, guangzhou 510655, P.R.china south china Inst for environmental Sciences Guargzhou China

A real-time mathematical model for two dimensional tidal flow and water quality is presented in this paper. The control-volume-based-finite-difference method and the 'power interpolation distribution' advocated by Patankar [4] have been employed, and new boundary condition for tidal flow is recommended. The model is un- conditionally stable and convergent, and able to deal with irregular estuarine topography and movable boundary problems. Practical application of the model is illustrated by an example for the Swatou Bay. A fair agreement be- tween the values measured and computed demonstrates the validity of the model developed.

关键词： A REAL-TIME MATHEMATICAL MODEL FOR TWO DIMENSIONAL TIDAL FLOW AND WATER QUALITY

Design of environmental decision support system and its application to water quality management

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Journal of Geographical sciences 2001年第2期11卷 170-178页

作者： ZENG Fan-tang, DU Ling, LIN Kui, SHEN Qian (south china institute of {3. sciences, sepa, guangzhou 510655, china) south china institute of {3. sciences SEPA

EDSS is a comprehensive software system for water quality management in tidal river networks in general and for the Pearl River Delta in particular. Its purpose is to provide a practical tool that could assist government agencies in decision making for the efficient management of water resources in terms of both quantity and quality. By combining the capabilities of geographical information system (GIS), database management system (DBMS), model base management system (MBMS) and expert system, the aim is to improve the quality of decision making in what is becoming an increasingly complex area. This paper first outlines the basic concepts and philosophy adopted in developing EDSS, the system architecture, design features, implementation techniques and facilities provided. Thereafter, the core part of the system—the hydrodynamic and water quality models are described briefly. The final contribution in this paper describes the application of EDSS to the Pearl River Delta, which has the most complicated tidal river network patterns as well as the fastest economic development in the world. Examples are given of the real-world problems that can be addressed using the system, including cross-boundary water pollution analysis, regional drinking water take-up site selection, screening of important polluters, environmental impact assessment, and water quality zoning and planning. It is illustrated that EDSS can provide efficient and scientific analytical tools for planning and decision-making purposes in the information era.

关键词： EDSS GIS DBMS water quality zoning the Pearl River Delta

Impacts of Typhoons Tianying and Dawei on seagrass distribution in Xincun Bay,Hainan Province,china

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Acta Oceanologica Sinica 2011年第1期30卷 32-39页

作者： YANG Dingtian HUANG Daojian CAS key Laboratory of Tropical Marine environmental Dynamics South China Sea Instituteof Oceanology Chinese Academy of Sciences Guangzhou 510301 China south china institute of {3. sciences Ministry of Environmental Protection of thePeople＇s Republic of China Guangzhou 510655 China

More than 50% of the typhoons landing in china have landed on the southeast coast, where they have caused great pressure on the coastal environment. Seagrass, one of the most important con- stituents of coastal ecosystems, is also greatly affected by typhoons. In order to clarify how seagrass distribution variation is affected by typhoons in coastal areas in southeast china, data of Typhoons Dawei and Tianying （category 4 and category 2 respectively, which just ran through the southern part of Hainan province） have been studied. In situ observation and satellite remote sensing data （CBERS-china Brazil Earth Resources Satellite） in 2004 and 2006 were used to retrieve seagrass distribution in Xincun Bay, Hainan province. In situ observations showed that leaf length, stem biomass and above ground biomass on average showed evidence of reduction after Typhoons Tiany- ing and Dawei. However, seagrass density showed no evidence of reduction after typhoon Tianying and Dawei passed by and increased rapidly in January 2006. From results of satellite remote sensing data, seagrass distribution can be detected with high accuracy, and the area of seagrass distribution on the south coast of Xincun Bay in 2006 after the typhoon passed by was smaller than that in 2004 in region A and B. However, in region C, area of seagrass coverage under 20% increased. These results demonstrated that typhoons Tianying and Dawei damaged seagrass bed and helped seagrass to get rid of aged and dead leaves, and this correspondingly facilitated seagrass growth.

关键词： seagrass Typhoon Tianying and Dawei Xincun Bay

SYNTHESIS AND OPTICAL PROPERTIES OF A NOVEL ORGANIC/INORGANIC HYBRID NONLINEAR OPTICAL POLYMER VIA SOL-GEL PROCESS

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Chinese Journal of Polymer science 2001年第4期19卷 421-427页

作者： Hong-xia Xi Zhong Li Zhao-xi Liang The institute of Chemical Engineering south china University {3. 510640 china The institute of Polymer science, Zhongshan University {3. 510275, china 华南理工大学广东广州中山大学广东广州

A new organic/inorganic hybrid nonlinear optical (NLO) material was developed by the sol-gel process of an alkoxysilane dye with tetraethoxysilane. A NLO moiety based on 4-nitro-4 ' -hydroxy azobenzene was covalently bonded to the triethoxysilane derivative, i.e, gamma -isocyanatopropyl triethoxysilane. The preparation process and properties of the sol-gel derived NLO polymer were studied and characterized by SEM, FTIR,H-1-NMR, UV-Vis, DSC and second harmonic generation (SHG) measurement. The results indicated that the chemical bonding of the chromophores to the inorganic SiO2 networks induces low dipole alignment relaxation and preferable orientational stability. The SHG measurements also showed that the bonded polymer film containing 75 wt% of the akoxysilane dye has a high electro-optic coefficient (r(3.)) of 7.1 pm/V at 1.1 mum wavelength, and exhibit good SHG stability, the r(3.) values can maintain about 92.7% of its initial value at room temperature for 90 days, and can maintain about 59.3. at 100 degreesC for 3.0 min.

关键词： sol-gel process nonlinear optical material alkoxysilane dye dipole alignment relaxation chromophore

Raman Spectroscopic Analysis of the Effect of Ultraviolet Irradiation on Calf Thymus DNA

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Acta Biochimica et Biophysica Sinica 2005年第1期37卷 39-46页

作者： Yu-Long TANG Zhou-Yi GUO~* institute of Laser and Life science.south{3. Normal University,guangzhou 51063.,china institute of Laser and Life science South China Normal UniversityGuangzhou 510631 China

Raman spectroscopy was used for the first time to detect the effect of independent UVA(ultraviolet-A:3.0-400 nm)and UVB(ultraviolet-B:280-3.0 nm)irradiation on the calf thymus DNA inaqueous *** both UVA and UVB irradiation for 1 h or 3.h,the damage to the conformation of DNAwas rnoderate,but the reduction of the B-form DNA component was *** UVA and UVB causedsignificant damage to the deoxyribose moiety and bases,among which the pyrimidine base pairs were moreseriously *** appeared to be preferential damaging sites on DNA molecules caused by UVA andUVB irradiation,UVA irradiation caused more damage to the deoxyribose than UVB irradiation,while UVBirradiation caused more significant damage to the pyrimidine moiety than UVA *** UVB irradia-tion for 3.h,unstacking of the AT base pairs and the cytosine ring took place,severe damage to the thyminemoiety occurred,and some base pairs were ***,with either UVA or UVB irradiation for 3.h,the photoreactivation of DNA *** damage to the DNA caused by UVB was immediate,while thedamage caused by UVA was proportional to the irradiation *** experimental results partly indicatethe formation of some cyclobutane pyrimidine dimers and(6-4)pbotoproducts.

关键词： Raman spectroscopy deoxyribonucleic acid(DNA) ultraviolet irradiation(UV) base pair

RAZUMIKHIN-TYPE THEOREMS FOR ASYMPTOTIC STABILITY OF IMPULSIVE STOCHASTIC FUNCTIONAL DIFFERENTIAL SYSTEMS

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Journal of Systems science and Systems Engineering 2010年第1期19卷 72-84页

作者： Pei CHENG~1 Feiqi DENG~2 Xisheng DAI~3.Systems Engineering institute,south china University of Technology,{3. 510640,china Systems Engineering institute South China University of Technology Guangzhou China

In this paper, we investigate the pth moment uniformly asymptotic stability of impulsive stochastic ftmctional differential systems by extending some Razumikhin-type theorems. Based on the Lyapunov functions and Razumikhin techniques, some criteria are established and their applications to impulsive stochastic delay systems are proposed. An illustrative example shows the effectiveness of our results.

关键词： Stochastic functional differential systems Impulse Razumiltial theorems Asymptotic stability

The　photon　theory　hypothesis　about　photon　tunneling　microscope＇s　subwavelength　resolution

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光电子·激光 1996年第4期7卷 236-239+259页

作者： Yanbin Zhu Junfu Ma(Laser Li fe science institute, south{3. Normal University, guangzhou 51063.,P.R.china) 华南师范大学激光生命科学所广东广州

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关键词： tunneling hypothesis microscope about resolution subwavelength theory The photon

Characteristics of high-sulfate wastewater treatment by two-phase anaerobic digestion process with Jet-loop anaerobic fluidized bed

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Journal of environmental sciences 2007年第3期19卷 264-270页

作者： WEI Chao-hai, WANG Wen-xiang, DENG Zhi-yi, WU Chao-fei School of environmental science and Engineering, south{3. University of Technology, guangzhou 510640,{3.. School of environmental science and Engineering South China University of Technology Guangzhou 510640 China

A new anaerobic reactor, Jet-loop anaerobic fluidized bed （JLAFB）, was designed for treating high-sulfate wastewater. The treatment characteristics, including the effect of influent COD/SO42 ratio and alkalinity and sulfide inhibition in reactors, were discussed for a JLAFB and a general anaerobic fiuidized bed （AFB） reactor used as sulfate-reducing phase and methane-producing phase, respectively, in two-phase anaerobic digestion process. The formation of granules in the two reactors was also examined. The results indicated that COD and sulfate removal had different demand of influent COD/SO4^2- ratios. When total COD removal was up to 85%, the ratio was only required up to 1.2, whereas, total sulfate removal up to 95% required it exceeding 3.0. The alkalinity in the two reactors increased linearly with the growth of influent alkalinity. Moreover, the change of influent alkalinity had no significant effect on pH and volatile fatty acids （VFA） in the two reactors. Influent alkalinity kept at 400-500 mg/L could meet the requirement of the treating process. The JLAFB reactor had great advantage in avoiding sulfide and free-H2S accumulation and toxicity inhibition on microorganisms. When sulfate loading rate was up to 8. 1 kg/（m^3.d）, the sulfide and free-H2S concentrations in JLAFB reactor were 58.6 and 49.7 mg/L, respectively. Furthermore, the granules, with offwhite color, ellipse shape and diameters of 1.0-3.0 mm, could be developed in JLAFB reactor. In granules, different groups of bacteria were distributed in different layers, and some inorganic metal compounds such as Fe, Ca, Mg etc. were found.

关键词： Jet-loop anaerobic fluidized bed reactor sulfate wastewater two-phase anaerobic digestion process granule sludge