Pioneering rural technology in India     

Holden C 《Science (New York, N.Y.)》1980,207(4427):159

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High energy physics     

Quigg C 《Science (New York, N.Y.)》1980,208(4447):1025-1026

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Northern peoples     

Utermohle CJ 《Science (New York, N.Y.)》1980,209(4456):585-586

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Documents of technology     

Condit CW 《Science (New York, N.Y.)》1980,210(4465):56-57

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Origin and mechanism of large-scale climatic oscillations     

Sergin VY 《Science (New York, N.Y.)》1980,209(4464):1477-1482

Numerical experiments with a simplified thermodynamic model of the glacier-ocean-atmosphere global system have been performed. Characteristic regimes of the system are auto-oscillations with periods varying between 20,000 and 80,000 years. The longer climatic waves are generated by the influence of variations of the earth's orbital parameters. Computed changes of glacial area, temperature, sea level, and other climate characteristics have values within expected ranges. The transition from a relatively warm epoch (when continental ice sheets are absent) to conditions characteristic of the Pleistocene is modeled. The calculated curves show how weak temperature fluctuations have been followed by large-scale oscillations.  相似文献   

Cogeneration of electric energy and nitric oxide     

Vayenas CG  Farr RD 《Science (New York, N.Y.)》1980,208(4444):593-594

A solid electrolyte fuel cell operating on ammonia fuel has been constructed and tested. The yield of nitric oxide can exceed 60 percent with simultaneous electric energy production. Two dimensionless numbers have been identified which govern the product selectivity and power output of this fuel cell. The cell appears to be a promising candidate for nitric acid and electric energy cogeneration.  相似文献   

Innovation: Japan races ahead as u.s. Falters     

Holden C 《Science (New York, N.Y.)》1980,210(4471):751-754

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Evaluation of rabbit excreta as an ingredient in broiler diets     

H. O. Elemele  D. R. Rao  C. B. Chawan 《British poultry science》1980,21(5):345-349

1. Dry rabbit excreta were found to contain 188.1 g crude protein, 6.6 g non‐protein nitrogen, 0.3 g ammonia, 89.8 g moisture, 8.0 g ether extractives, 135.2 g crude fibre, 266.9 g ash and 19.18 MJ gross energy/kg. Methionine and lysine contents were 3.95 and 4.29 g/100 g protein, respectively.

2. In one experiment, 0, 50, 100 or 200 g rabbit excreta/kg were substituted for maize in a broiler diet. Chickens receiving the diet containing 200 g rabbit excreta/kg gained significantly less weight to 8 weeks of age than those receiving other diets.

3. In a second experiment, 0, 100, 150 or 200 g rabbit excreta/kg were substituted primarily for maize in a broiler diet to provide equal energy and protein contents. Weight gains to 8 weeks of birds receiving these diets did not differ significantly. The uncorrected metabolisable energy content of the excreta was 9.15 MJ/kg.

4. There were no gross pathological changes in the birds fed on the experimental diets.  相似文献   

Factors affecting the hatchability of eggs from broiler breeders     

Susan Kirk  G. C. Emmans  R. McDonald  D. Arnot 《British poultry science》1980,21(1):37-53

1. Four experiments were carried out on eggs from broiler breeding flocks between 26 and 60 weeks of age. The effects of storage and incubation conditions on hatchability were tested.

2. Collecting eggs hourly rather than five hours after lay slightly reduced hatchability (P<0.10). Pre‐storage fumigation of almost un‐contaminated eggs had no effect on hatchability even after storage for 8 d. Storing eggs in unsealed polythene bags did not affect hatchability of eggs stored for 5 or 8 d.

3. Eggs stored for 2 d hatched better when held at 18 °C than at 15 °C (P<0.05). Eggs stored for 8 d at 15 °C hatched better than eggs stored for 8 d at 18 °C (P< 0.01). Best hatchability was in eggs stored in unsealed polythene bags at a room temperature of 15 °C. When older eggs were allowed 30 to 40 min more in the setter for each day of storage, the decline in hatchability was 0.5 to 0.6 percentage units per day in storage as compared with a decline of 1.2 percentage units per day when eggs of different storage times, up to 8 d, were set simultaneously.

4. Those eggs which showed a weight loss during incubation of near average for their relative humidity (RH) treatment tended to hatch better than others except under conditions of very low RH (0.36), when best hatchability was associated with lower than average weight loss.

5. In eggs from a young flock (28 to 44 weeks of age) hatchability of fertile eggs was depressed by 1 percentage unit with an increase in RH of 0.17, and by 1 percentage unit with each decrease of 0.06 in RH from a control RH of 0.53. In eggs from the same flock between 48 and 60 weeks of age hatchability was depressed by 1 percentage unit with each 0.037 increase in RH from 0.44 to 0.70.

6. Eggs from a young flock (34–49 weeks) hatched significantly better when maintained at 0.82 rather than at 0.66 (P<0.05) or 0.95 (P<0.10) RH during the hatching period from 19 to 21 d of incubation. Eggs from an older flock (51–61 weeks) hatched better at 0.82 and at 0.‐92 than at 0.72 RH during the same period, but the differences were not significant.  相似文献   

Detection of antibody against transmissible gastroenteritis virus of pigs by indirect immunoperoxidase antibody test     

Y Kodama  M Ogata  Y Shimizu 《American journal of veterinary research》1980,41(1):133-135

Immunoperoxidase intibody (IPA) test was developed for detecting antibody against transmissible gastroenteritis (TGE) virus of pigs. The IPA antibody titers in sera collected in the field from 82 pigs were approximately seven times higher than those obtained in a serum-neutralization test. The correlation between the TGE antibody concentrations in the IPA and serum neutralization tests was positive (r = +0.74). The IPA tests appears to have the potential for routine laboratory use for serologic diagnosis of TGE.  相似文献