The smallest administrative unit of the sixth national census-township (town) is selected as the basic unit, the population spatial distribution characteristics at the township (town) level in karst mountainous areas of northwest Guangxi are analyzed by using Lorenz curve and spatial correlation analysis method, and the influence intensity of natural factors on regional population spatial distribution is detected by using geographic detector method. The results show that: 1. the spatial distribution of population at the township (town) level has the characteristics of imbalance, showing generally significant positive correlation and certain aggregation; 2. There are significant differences in the impact of the spatial distribution of various natural factors on the population distribution. For the towns without karst distribution in the northwest and central south of the study area, the population density increases with the increase of factors conducive to human residence, but the average population density is only 79 people/km². In the towns with karst distribution in the East and south, the spatial distribution of population density and natural factors is not a simple increase or decrease relationship, but fluctuates with the change of karst distribution area. 3. The factor detection results of the geographic detector show that the altitude has the greatest impact on the spatial distribution of population. The interactive detection results show that the impact intensity of any two natural factors after superposition and interaction presents nonlinear enhancement and two factor enhancement. It can be seen that the karst mountain area in northwest Guangxi is similar to other areas. Altitude is one of the main factors affecting the spatial distribution of population, but the river network density and unique geological landform of karst mountain area have a strong catalytic effect on the spatial distribution of population. The superposition and interaction with other factors can further strengthen the impact on population distribution.

In November 2018, the sample plot survey method was used to analyze the population characteristics of Lithocarpus polystachyus in the natural secondary forest with different disturbance intensity in Jianning, Fujian Province, and compile its population static life table. The results showed that the number of individuals in the population was small, but it was clustered. With the increase of interference intensity, the first and second age seedlings and young trees decreased. The population types affected by human disturbance are all lacking level V trees, and the population type belongs to primary population (N₁); The undisturbed population lacks level I and II seedlings and young trees, but there are level V trees, and the population type belongs to medium decline population (S₂). In general, all populations of L. polystachyus are unstable and belong to the transitional type. In the static life table, the mortality of level I and II seedlings and young trees is high, the survival rate has a small peak in level III and IV, and then the survival rate decreases rapidly, and the average life expectation of level II is the highest. It shows that artificial conservation measures and appropriate space re-lease are needed to maintain the stability of the population.

We analyzed the relationship between nutrient (N and K) parceling and population density on the severity of onion downy mildew under no-tillage fertigation cultivation in the conditions of Alto Vale do Itajaí (Barzil). For this purpose, field trials were conducted in the years 2017, 2018 and 2019, in Ituporanga (Barzil). The treatments corresponded to four population densities (300, 400, 500 and 600 mil plants ha^-1) subjected to applications of nitrogen (150 kg N ha^-1) and potassium (127.5 kg K₂O ha^-1) distributed throughout the vegetative cycle of the crop via fertigation on a weekly, biweekly and monthly basis, based on the absorption curve of these nutrients for the cultivar Empasc 352-Bola Precoce. In fertigated no-tillage systems, nutrient (N and K) tranches do not influence the severity of downy mildew. The severity of downy mildew increases linearly with increasing population density, especially from 500 mil plants per ha^-1.

I summarize the current regulatory decisions aimed at combating the debt load of the population in Russia. Further, I show that the level of delinquency of the population on loans is growing despite the regulatory measures taken. In my opinion, the basis of regulatory policy should move from de facto pushing personal bankruptcies to preventing them. I put forward a hypothesis and statistically prove the expediency of quantitative restrictions on one borrower. It is necessary to introduce reports to the credit bureaus of some types of overdue debts, which are not actually reported now. It is also necessary to change the order of debt repayment established by law, allowing the principal and current interest to be paid first, which will prevent the expansion of the debt.

Entering the era of knowledge economy, various academic researches are blossoming under the social environment of double creation, but looking at the disputes of intellectual property cases in recent years, most of them happen in the college students group, the reasons for this phenomenon can be summarized as the blurring of the intellectual property education program, the system is too traditional and conservative, and the teaching concept is thin and so on. In view of this phenomenon, the author proposes to cultivate the intellectual property education of university students in the mode of "three constructions", so as to stimulate the vigor of social innovation and provide theoretical support for the scientific and technological research of university students.