tailieunhanh - Báo cáo lâm nghiệp: "Ecological light measurement in forests using the light degradation effect in hydrogenated amorphous silicon(a-Si:H)"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế, đề tài: "Ecological light measurement in forests using the light degradation effect in hydrogenated amorphous silicon(a-Si:H). | Ann Sci For 1997 54 539-552 Elsevier Inra 539 Original article Ecological light measurement in forests using the light degradation effect in hydrogenated amorphous silicon a-Si H c Ammer1 G Krotz2 1 Lehrstuhl fur Waldbau und Forsteinrichtung der Ludwig-Maximilians-Universitat Munchen Hohenbachernstr. 22 85354 Freising 2 Daimler Benz AG Postfach 800465 81663 Miinchen Germany Received 29 August 1996 accepted 17 February 1997 Summary A method is presented for ecological light measurements in forests based on the principle that light produces electrically active defects within the mobility gap in semiconductors from hydrogenated amorphous silicon a-Si H causing measurable changes in the photoconductivity of the semiconductor. A comparison with measurements of the relative illuminance in mixed montane forests led to reasonable results. Suitability for field experiments drawbacks and possible improvements of this low-cost integrating measurement method which requires no external energy source are discussed at length. radiation mixed forests I amorphous silicon Resume Mesure de la lumière en forets au moyen de la degradation par la lumière du sili-cium amorphe hydrogéné a-Si H . Une methode est presentee pour la mesure de la lumière en forcts basée sur utilisation de semiconducteurs à base de silicium amorphe hydrogéné a-Si H . Une com-paraison avec la mesure de réclairement relatif dans des forets mélangées de montagne conduit à des résultats raisonnables. Les defauts et les ameliorations possibles de cette méthode peu coũteuse pour des mesures intégrées ne nécessitant pas de source extérieure d energie sont discutés en detail par les auteurs. lumière forets mélangées silicium amorphe Correspondence and reprints Tel 49 2161 714686 fax 49 2161 714646 540 c Ammer G Krotz INTRODUCTION Countless field tests have shown that under natural conditions the crucial factor in plant growth ie the factor determining photosynthesis capacity in particular in conjunction with sufficient