赴日黑工的灰色人生

被遣返人员多对海外打工抱有梦想，只等赚足了钱再回来。只有被遣送回来后，才觉得悔不当初。

Study on Artificial Propagation Techniques for Glyptosternum maculatum in Tibet

This study aimed to explore artificial propagation techniques for Glyptosternum maculatum that is endemic in the Yarlung Zangbo River. Total 86 female fish in weight of 0.065-0.250 kg were selected, and the average weight of every 15 fish was 0.30 kg. Oxytocic drugs were injected into the base of pectoral fins of the female fish. The results showed that the total amount of female fish with artificial insemination was 59. The gloss weight of the fertilized eggs was 897.5 g with total amount of 57 440, thus the average fecundity was 1 194 eggs/fish. The fecundity showed a positive correlation with body weight （P〈0.01）. The average induction ratio and fertilization rate were 69% and 73.5%, respectively. The optimum water temperature for hatching of the fertilized eggs was 13-14 ℃ with dissolved oxygen of 6.0- 7.2 mg/L. The accumulated temperature for embryonic development of G. maculatum ranged from 2 592 to 2 916℃·h. This set of completely artificial propagation techniques has a very important significance for the artificial breeding of G. maculatum.

Development of Artificial Diet for Erigonidium graminicolum(sundevall)

[Objective] This study was to find out the artificial diet formula for Erigoni- dium graminicolum （Sundevall） to realize its indoor artificial breeding. [Method] Using orthogonal decomposition method, the diet most suitable for the normal and quick growth of Erigonidium graminicolum （sundevall）, was developed by adding different species and different proportions of fresh insects to the artificial diet based on the formula of total nutrient solution proposed by Zhao Jing-zhao. [Result] The most suit- able formula for the development and growth of Erigonidium graminicolum （Sundevall） is 10 ml of egg white, 2 g of honey, 2 g of sucrose, 10 ml of water, 5 g of Ci- cadella viridis, moderate amount of cornmeal, compound vitamin B1 and vitamin C1. [Conclusion] The development of new type artificial diet can provide timely and nec- essary material premise for its large-scale indoor propagation.

Activities of Urease and Phosphatase in Integrated Vertical Flow Constructed Wetland and Purification Effect of Black and Malodorous River

[Objective]The activities of urease and phosphatase in integrated vertical flow constructed wetland and purification effect of black and malodorous river were studied.[Method]Honeycomb stone and soft filler were used as matrix,the biological grid integrated vertical flow constructed wetland system was built to strengthen treatment for black and malodorous river,and the activities of urease and phosphatase of two fillers in different functional areas of constructed wetland were tested to study the film formation property of two fillers in different functional areas.[Result]Both urease and phosphatase activities on biofilm of soft filler were significantly higher than on biofilm of honeycomb stone filler;indicating that choosing soft filler was more advantageous to the growth of biofilm;and urease activity had significant correlation with total nitrogen removal rate,while phosphatase activity had no significant correlation with total phosphorus removal rate.[Conclusion]This study provided evidences for utilizing the activities of urease and phosphatase to evaluate the purification effect of black and malodorous river and choose appropriate filler.

Study on the Degradation Trend of Ryegrass-White Clover Artificial Grassland

[Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass （Lolium perenne） - white clover （ Trifolium repens） artificial grassland in Maiping Township, Guizhou Province as the research object, the grassland vegetation of 40 quadrate from different areas （area around the sheep shed, hilltop, hillside, flatland at the foot of the hill） were analyzed by comparing the dominance and richness index. [ Result] Degradation of different degrees appeared in various areas of this artificial grassland. To be specific, the degradation of grassland around the sheep shed was not serious for less consumption by the sheep; however, the areas on the hilltop and hillside degenerated to the grassland types of dallis grass （ Paspalum dilatatum Poir. ） -Indian lovegrass （ Eragrostis pilosa） and dallis grass - cogongrass [ Imperata cylindrica （ Linn. ） Beauv. ], respectively, and the area at the foot of the hill degenerated to the grassland type dominated by garland chrysanthetnum （ Chrysanthemum coronarium L. ） and knotgrass （ Paspalum distichum L. ）. [ Conclusion ] This study provided a basis for grassland improvement as well as the efficient and sustainable utilization of grazing-type artificial grassland in South China.

Optimization of Conditions for the Extraction of Melanin from Walnut Husk

[Objective] This study was conducted optimize the conditions for the ex- traction of melanin from walnut husk. [Method] Melanin was isolated from walnut husk through alkali extraction and acid precipitation, and the factors that may influ- ence the extraction efficiency： temperature, duration, NaOH concentration and solid- liquid ratio were set at different levels. [Result] The optimal conditions for the ex- traction of melanin from walhut husk were temperature of 80 ℃, extraction duration of 120 min, NaOH concentration of 70 mol/L, and solid-liquid ratio of 1：20. [Conclu- sion] The optimal conditions for the extraction of melanin from walnut husk deter- mined in the present study will provide references for the development and utiliza- tion of natural melanin.

Preparation and application of active gangue＇s carbon black

After three-stage pulverization, dry-distillated activation and coupling agent surface modification, the kaolinite-typed gangue of Sichuan Hongni Coal Mine（SHCM） can be manufactured into activated gangue＇s carbon black. Its surface area is 〉25 m^2/g, and possesses carbon black＇s carbon framework and structure. It can be used as strengthening agent of high polymer material such as rubber.

The Natural Forest Protection Program in China： A Contingent Valuation Study in Heilongjiang Province

In 1998, the Chinese Government implemented the NFPP （Natural Forest Protection Program）, which included logging restrictions, protected areas, replanting, and a range of other policies aimed at safeguarding the state of the country＇s forests and reducing the risk of erosion and flooding. A second phase of this program is currently being discussed. In this paper, contingent valuation is used to estimate the WTP （willingness to pay） for maintaining the program among the inhabitants in Heilongjiang Province in northern China. The results show that, even with fairly conservative assumptions, the aggregated WTP for maintaining the program for another five years is some 3.24 billion yuan per year. This can be compared with the current cost of the Program in the province, which is some 1.57 billion yuan per year.

Interrelation between Seasonal Grazing Behavior of Guizhou Black Goat and Grassland Productivity

In order to discover the relationship of the Guizhou black goat seasona grazing behavior traits and grassland productivity, the varieties of grazing behavior of Guizhou black goat and its relationship with the grassland productivity under different grazing intensity in all seasons on Guizhou karst artificial grassland were studied. Obvious differences for goat grazing behavior were found under differen grazing intensity in either the same season or different seasons. The grazing behav ior in the same season showed that it could significantly reduce the mouth eating grass within 5 minutes, each step number, feeding speed, each food intake, daily feed intake（P0.05） under high grazing intensity. In different seasons, it could in crease the feeding time within 5 min, marching step, standing time and intake（P0.05） in the spring; while in the summer, it could improve intake mouth number each mouth eating grass number and feeding rate（P0.05）. It had no obvious dif ference in ruminant behavior parameters in the same season under different grazing intensity, but in different seasons, it can obviously increase ruminant within 5 minutes, number of ruminant feed group（P0.05） in the spring, and it can obviously in crease the time and number of each food group chew（P0.05） in the summer. The correlation analysis of main goat grazing behavior parameter showed that it had good correlation among other parameters except within 5 min walk time, each feed intake and daily feed intake（P0.05）.The relationship between goat grazing behavio parameters and grassland productivity showed that, the foraging time and standing time within 5 min were lower in the medium level of grassland productivity, while number of food intake, every step to eat grass and daily feed intake were higher with increasing grassland productivity, goats feeding speed was reduced, but each intake was increased.

Pectinase Production by Aspergillus Niger P-6021 on Citrus Changshan-huyou Peel in Slurry-state Fermentation

The peel of Citrus changshan-huyou, coupled with wheat bran, could be utilized by Aspergillus niger P-6021 in slurry-state fermentation to produce pectinase with suitable enzyme composition for application in apple juice processing. The production of pectinase is improved by additional nitrogen source substances and mineral supplements. The ratio of carbon source substances to nitrogen source substances in the medium also has significant effect on the pectinase production by A. niger P-6021 in slurry-state fermentation. In the optimized medium composition, the maximal enzyme activity could reach 42 U.L^- 1 （polymethylgalacturonase）, 6.7 U.L^- 1 （polymethygalacturatesterase）, and 4.3 U.L^-1 （polymethylgalacturonate lyase）, respectively, after 3 days at 180 r.min^- 1 and 30℃. The crude pectinase shows significant effect to improve the yield and clarification of apple juice. Keywords Aspergillus niger, slurry-state fermentation, pectinase, Citrus changshan-huyou, apple juice

Genome editing in Drosophila melanogaster： from basic genome engineering to the multipurpose CRISPR-Cas9 system

Nowadays, genome editing tools are indispensable for studying gene function in order to increase our knowledge of biochemical processes and disease mechanisms. The extensive availability of mutagenesis and transgenesis tools make Drosophila melanogaster an excellent model organism for geneticists. Early mutagenesis tools relied on chemical or physical methods,ethyl methane sulfonate(EMS) and X-rays respectively, to randomly alter DNA at a nucleotide or chromosomal level. Since the discovery of transposable elements and the availability of the complete fly genome, specific genome editing tools, such as P-elements, zinc-finger nucleases(ZFNs) and transcription activator-like effector nucleases(TALENs), have undergone rapid development. Currently, one of the leading and most effective contemporary tools is the CRISPR-cas9 system made popular because of its low cost, effectiveness, specificity and simplicity of use. This review briefly addresses the most commonly used mutagenesis and transgenesis tools in Drosophila, followed by an in-depth review of the multipurpose CRISPR-Cas9 system and its current applications.