Feasibility of using T-shaped feedback in teraohmmeters

The paper investigates the feasibility of using T-shaped feedback in teraohmmeters. Theoretical and experimental dependences of the output voltage of the T-shaped feedback converter on the measured resistance and circuit parameters are obtained. The use of T-shaped feedback is found to decrease the reference resistance rating from 10 GOhm to 100 Ohm that indicates 100-fold reduction (with an error of less than 1%)

Planting stock cultivation in combined schools of forest nurseries

Various methods of initiation and cultivation agrotechnology of the planting stock were studied in the combined schools and combined school-sowing departments of forest nurseries. Differences in biometric indices of saplings and seedlings of different wood species aspects were detected. The comparative analysis of the planting stock growth indices was carried out at cultivation in an open ground and in school-sowing department of forest nursery

Agricultural technology of growing deciduous seedlings for reforestation purposes

A large variety of soil conditions in the forest fundof the Republic of Belarus requires reforestation by various tree species, of which a significant roleis played by deciduous species. Growing seedlings of deciduous species requires strict observance of all agricultural activities (preparation of soil, eradication of weeds, pests control, crown care, application of mineral and organic fertilizers, etc.). The paper dwells upon the study of technology and the growth of deciduous seedlings grown in close-planting forest nurseries of forest enterprises of the Republic of Belarus

Peculiarities of agricultural engineering cultivation of european white birch seedlings in forest nurseries

Data of researches on application of various agricultural practices are resulted at cultivation seedlings of birch. Optimum terms of sowing seeds which allow to raise the yield of a standard planting material and its biometrics are established. Various variants of seeds closing are described, allowing to enrich quality of a planting material of a birch. Optimum doses of the basic fertilizers and additional fertilizing at cultivation of birch seedlings and also technology of its cultivation in the closed ground are resulted

Modern technologies of norway spruce seedlings growing in nurseries

Researches on various ways of making and technology of cultivation of saplings of a Picea Abies at the compacted schools are conducted. Dependence of application of different practies on individual qualities of saplings, such as the mass of root system, a ratio of above-ground and root parts, diameter of a root neck and height is established. The best term of a making of the compacted school is the late summer during the maximum growth of roots – from August 1 to September 5. Planting at a later date amounts to their winter storage

Influence of seeding rates seeds at exit standard seedlings pine in indoor growing

Investigations to determine the output of standard pine seedlings at different seeding rate of pine seeds in the greenhouse conditions. For the cultivation of seedlings it was used as a substrate of peat bogs transition milling work piece with a dose of application of mineral fertilizers, N70P150K 90. Pine seeds were sown in Egedal a scatter planter beds with a width of one meter seeding rates of 6.8; 11.0; 14.0 g/m 2. To estimate the output of seedlings that meet regulatory requirements, use trial-analysis based on a normal distribution. With the increase of pine seed sowing rate was observed decrease in the yield percent of standard seedlings and increase custom. It is not noted a significant change in percent yield seedlings height of 7 cm. With seeding rate is 6.8 g/m 2 output of standard seedlings was 94.5%, while and 14.0 g/m 2 – 88.4%. Significant changes were observed in the output of larger seedlings 12 cm. When seeding rate of 6.8 g/m 2 yield was 57.9%, with 11.0 g/m 2 – 46.0%, and at 14.0 g/m 2 – 27.2%. Therefore, the indoor planting pine material should be grown in a medium-density plantings with a seeding rate of 11–12 g per 1 m 2, which will be combined with economical consumption of seeds with an optimal output of standard planting material

The content of nutrients and the acidity of the substrate for growing containerized seedlings of pine and spruce

The results of studies of the content of mobile forms of phosphorus and potassium, ammonia nitro-gen, mobile iron compounds and the sum of exchangeable bases of calcium and magnesium in the sub-strate at the beginning and end of the growing season when seedlings of Scots pine and Norway spruce in containers. The content of nutrients in the substr ate to the end of the growing season has decreased significantly. The number of mobile forms of phosphorus has decreased in 2.3 times, potassium 2 times, ammonia nitrogen up to 19 times exchangeable bases of calcium and magnesium in 1.5 times. This is due to the consumption of the seedlings of nutrients, as well as their leaching from the substrate during irrigation. Therefore, to maintain the necessary balance of nutrients in the substrate during the vegetation period it is necessary to observe a scien tific system of fertilization.The acidity of the sub-strate also decreased from 5.2 to 6.3 pH. Water for irrigation has the acidity close to neutral (pH = 7.1). To maintain the optimum acidity of the substrate, the pH of irrigation water should be in the range of not higher than 5.5 to 6.0. Therefore, when using irrigation water with neutral acidity is necessary to carry out activities according to its acidification

Density of States and Conductivity of Granular Metal or Array of Quantum Dots

The conductivity of a granular metal or an array of quantum dots usually has the temperature dependence associated with variable range hopping within the soft Coulomb gap of density of states. This is difficult to explain because neutral dots have a hard charging gap at the Fermi level. We show that uncontrolled or intentional doping of the insulator around dots by donors leads to random charging of dots and finite bare density of states at the Fermi level. Then Coulomb interactions between electrons of distant dots results in the a soft Coulomb gap. We show that in a sparse array of dots the bare density of states oscillates as a function of concentration of donors and causes periodic changes in the temperature dependence of conductivity. In a dense array of dots the bare density of states is totally smeared if there are several donors per dot in the insulator.Comment: 13 pages, 15 figures. Some misprints are fixed. Some figures are dropped. Some small changes are given to improve the organizatio

Accelerated synthesis of Sn-BEA in fluoride media:effect of H₂O content in the gel

Sn-BEA synthesis in concentrated gels results in 2.5–4 fold reduction of crystallization time and formation of smaller zeolite crystals.</p