广东省西江流域水力资源及其开发

根据水利部下发的《关于开展全国农村水力资源调查评价工作的通知》要求,对广东省水力资源进行了全面普查,该文只论述西江流域片水力资源及其开发情况。对西江流域河流水力资源量进行了估算,并提出了相应的河流梯级开发方案,指出水力资源开发存在的主要问题和水力资源开发前景。

The Use of Hydrogen as a Fuel for Inland Waterway Units

Escalating apprehension about the harmful effects of widespread use of conventional fossil fuels in the marine field and in internal combustion engines in general, has led to a vast amount of efforts and the directing of large capital investment towards research and development of sustainable alternative energy sources. One of the most promising and abundant of these sources is hydrogen. Firstly, the use of current fossil fuels is. discussed focusing on the emissions and economic sides to emphasize the need for a new, cleaner and renewable fuel with particular reference to hydrogen as a suitable possible alternative. Hydrogen properties, production and storage methods are then reviewed along with its suitability from the economical point of view. Finally, a cost analysis for the use of hydrogen in internal combustion engines is carried out to illustrate the benefits of its use as a replacement for diesel. The outcome of this cost analysis shows that 98% of the capital expenditure is consumed by the equipment, and 68.3% of the total cost of the equipment is spent on the solar photovoltaic cells. The hydrogen plant is classified as a large investment project because of its high initial cost which is about 1 billion US$; but this is justified because hydrogen is produced in a totally green way. When hydrogen is used as a fuel, no harmful emissions are obtained.

The development and optimization of ELISA for the determination of tetrodotoxin

Objective： To optimize the ELISA for the determination of tetrodotoxin. Methods： A competitive enzyme-linked immunosorbent assay （ELISA） was used. In the ELISA, 100 μl antigen （1. 0 μg/ml） was coated on the microtiter plate for 60 min at 37 C or over night at 4 C. The plate was then washed 3 times with PBS-T for 3-5 s each time. The optimal incubation time for monoclonal antibody （mAb）, goat anti-mice IgG peroxidase conjugate and OPD were 30 min, 20 min and 10 min at 37 C, re- spectively. Results.. The detection limit is 0. 05 ng in each well. The curve was linear for TTX doses be- tween 5-5 000 ng/ml （0. 25-250 ng for every assay）. The linear regress equation was Y = 0. 30 88X-0.17 41 （R=0.99 01）. The average callback for TTX of muscles and gonads were 99.74% and 100.30%, respectively. The sensitivity of optimization ELISA was 5 times than traditional method and the time of 1.8 h were saved. Conclusion： The optimized ELISA is an ideal method for the determination of tetrodotoxin.

Recovery of gonadal development in tiger puffer Takifugu rubripes after exposure to 17β-estradiol during early life stages

The aim of the present study was to investigate the long-term effects of 17l）-estradiol （E2） exposure on gonadal development in the tiger puffer （Taktfugu rubripes）, which has a genetic sex determination system of male homogametic XY-XX. Tiger puffer larvae were exposed to 1, 10 and 100 μg/L E2 from 15 to 100 days post-hatch （dph） and then maintained in clean seawater until 400 dph. Changes in sex ratio, gonadal structure and gonadosomatic index （GSI） were monitored at 100, 160, 270 and 400 dph. Sex-associated single nucleotide polymorphism （SNP） markers were used to analyze the genetic sex of samples, except those at 100 dph. Exposure had a positive effect on the conversion of genetically male gonads into phenotypically female gonads at 100 dph. However, gonads from 60% of genetic XY males in the 1-μg/L E2 group and 100% in the 10-μg/L E2 group developed intersexual gonads at 160 dph; gonads of all genetic XY males in the two treatment groups reverted to testis by 270 dph. While 38%, 57% and 44% of gonads of XY fish in the 100-gg/L E2 group reverted to intersexual gonads at 160, 270 and 400 dph, respectively, none reverted to testis after E2 treatment. In addition, E2 exposure inhibited gonadal growth of both genetic sexes, as indicated by the clear dose-dependent decrease in GSI at 270 and 400 dph. The results showed that exposure to E2 during the early life stages of tiger puffer disrupted gonadal development, but that fish recovered after migration to clean seawater. The study suggests the potential use of tiger puffer as a valuable indicator species to evaluate the effects of environmental estrogens on marine fish, thereby protecting valuable fishery resources.

Analyses of local ingredients and dishes on menus of the Budapest-Middle-Danube touristic region

The background of the study is based on previous studies dealing with the areas of Transdanubia of Hungary. Those works have proved the hypothesis of author that local ingredients and dishes represent minimum role on menus. The question is how similar or different the choice of menus of Budapest-Middle-Danube compared with the previously examined areas of Hungary. There can be another question about the usage of local ingredients available near to the catering units. This piece of work has studied 79 menus of Budapest-Middle-Danube, Hungary. The material was collected from different types of restaurants, small restaurants （vendeglo in Hungarian） and roadside restaurants （csarda in Hungarian）. The method of the work was on the one hand, data collecting, and on the other hand, examination of the differences between the catering units in details： the number of dishes, the right order of dishes, the appearance of local ingredients and dishes, the consideration of seasonality, the usage of different cooking methods and group of dishes. The study reflects the main problems of countryside restaurants in Hungary. Only minimum number of dishes could be connected to local dishes out of more than thousands. All in all, dishes are not as precise and perfect as the ＂old ones＂, so that is why it is important for every expert keep the traditions alive in daily routines and strategic mean too.

Design and evaluation of control systems for a real canal

The distant downstream proportional integral(PI) feedback control was applied to the W-M lateral canal of the Maricopa Stanfield Irrigation and Drainage District located in central Arizona,U.S.A.Proper configuration of those controls for the ca-nal can be challenging.Towards this end,an integrated approach to the design of an automatic control system for the canal was proposed.This approach presented herein is not only a systematical review of previous work,but also represents a further ad-vance of the previous simulation study by Tsinghua University(Shang et al,2011) on relating the canal control algorithm to local PI controls for the real canal.To evaluate the control system potential,performance of the control algorithm that was ob-tained through implanting predicative module into linear quadratic regulator(LQR) was analyzed with singular value bode.Additional "manufactured" tests were conducted to compare with the control system that is currently in use.The results indi-cated that the developed control system rather than the system in current use had considerable potential to closely match dis-charge at the downstream check structures with those ordered by water users while maintaining the water level throughout the length of the canal.