With the improvement of people's living standards, water heaters almost into the various households. In the energy-saving emission reduction has become the trend of the times today, saving energy and reducing carbon emissions is the most fashionable way of life. Air source heat pump water heaters are increasingly being used in people's lives. It is well known that it has many advantages, safety, energy saving, comfort, environmental protection, but there are some factors that affect its development and promotion. This paper mainly discusses the development history of air source heat pump technology at home and abroad, working principle, working flow, turbo technology at present stage, efficient heat exchange, and the research status of air source heat pump technology, such as new type refrigerant and dual frequency compression frequency conversion, then it discusses the application of air source heat pump technology, has the advantage, and finally discusses its application and the existence of two major problems and suggestions for improvement.
Dushan county, Guizhou province, is located in the southernmost tip of Guizhou province. It belongs to the temperate climate of the subtropical region and is one of the centers of the karst east Asia area. The total area of the county is 242220 hectares, of which 169142 hectares are rocky desertifi cation or endangered desertification state. At present, the problem of rocky desertification has seriously affected the ecological environment of the county, which is one of the important factors that restrict the local social living standard and economic development. Therefore, it is of great significance to promote the social and economic development of the county by investigating and analyzing the spatial differentiation rules, present situation and harm of rocky desertification in Dushan county.
The effects of Zn2+ stress on seed germination, seedling growth and chlorophyll content were studied in order to better understand the effect of heavy metal Zn on the growth and development of green plants. The concentration gradient of Zn2+ was 20, 50,100,150,200,300,500,700mg / L, and deionized water was used as control. The results showed that under the Zn2+ stress condition, the germination index of the rhubarb seeds increased with the increase of Zn2+ concentration. Germination potential, germination rate and germination index were the highest when Zn2+concentration was 100mg / L, the conductivity was the lowest at zinc concentration of 100mg / L, the root length, stem length and chlorophyll content of Zn2+ gradually reduced. The results showed that the amount of Zn2+ could promote seed germination, but the root length, bud length and chlorophyll content of seedlings could be affected by different degrees. The zinc fertilizer should be used in the production.
In this paper, the pollination and biology of apricot in Hongfeng and New Century were studied. The results are as follows: (1) The est pollination with the red variety is early, new century's best pollinating varieties is camel yellow. (2) The flowering period of different cultivars was different, and the flowering period of Hongfeng and other varieties was 3 - 7 days later than that of Baxing water apricot and other varieties, which provided germplasm for further breeding of late flowering varieties. (3) Hongfeng, the new century and other varieties of self-flowering rate of 0 - 3.61% range, is self-incompatible varieties. (4) The pollen germination rate of different cultivars was higher than 50%, which indicated that the pollen was mature and the fertility was strong, and the reason of low percentage of self-pollination was pollen abortion, the main reason was self and so on.
Ebola virus is a potent infectious disease virus that can cause Ebola haemorrhagic fever caused by human and primate. It has high mortality and easy infectivity to form a great obstacle to the steady development of human society. The profound understanding of the virus is particularly important harm. In this paper, a number of mathematical models are established to solve this problem. The software is used to analyze and predict the propagation of Ebola virus. The residual analysis is used to test the model. Finally, the effects of various control measures on controlling the epidemic are analyzed. In order to solve the problem, we will establish the infectious disease model to dynamically describe the spread of the virus in the 'virtual orangutan population'. Considering that the latent population is analyzed in this question, we will improve the model. Join the latent group (), and the migrants are divided into self-healing () and the dead (), to establish a suitable solution to this problem model. According to the relevant data given in the title, differential equations were established. For the second question, this question involves the one-way transmission of the virus across the species, so we can improve the model, on the basis of human contact with orangutans infected groups, the establishment of a one-way model to solve this problem. On the basis of the problem one, the differential equation is established, the model is predicted and tested. In the case of question 3, the number of human susceptible groups is much higher than that of the orangutan infection group by comparing the relevant data with the increase of the cure rate to 80% after the intervention of the outside experts. Therefore, the original data of human populations from experts can be ignored. Since then the virus spreads within a single species, the differential equation can be established according to the model in question 1 and the data values in the virtual human population are predicted. For question 4, the effect of the measures such as the strict enforcement of the various epidemic control measures and the improvement of the drug effect on the control of the epidemic are analyzed by comparing the above-mentioned models with the control measures.
Taxus cuspidata Sieb. ET. Zucc. is a taxus of Taxaceae, a rare third-order relict species distributed in northeastern China, and a wild endangered plant species protected by national level I. Taxol (paclitaxel, trade name taxol) and cephalomannine (cephalomannine) are all diterpenoids contained in the genus Taxus, with broad-spectrum anti-tumor activity and unique anti-cancer mechanism. In this study, the distribution of paclitaxel and cephalomannine in the leaves of Taxus cuspidata in different parts and different growth stages was discussed. The results showed that the content of two substances in the leaves of the majority of the crowns was lower than that of the biennial and tertiary there were no significant differences in the contents of two substances in the two-year and three-year-old
foliage. There was no significant difference in the contents of the two layers in the three levels of the noodles, and
the content of the male was slightly higher than that of the dark. The content of paclitaxel in the leaves of natural
northeast yew was the highest at dormancy period, and the content of flowering and fruit was not much different. The
content of Cephalotaxin was the highest in dormancy period, and that of cephalosporin the content of paclitaxel and
cephalomannine in each plant were significantly different. There was significant difference between the two plants.
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