Analysis of Growth Laws of Leaves of Flue-cured Tobacco in Various Periods

The growth laws of leaves of flue-cured tobacco in different positions in various periods were summarized. The results showed that the growth speed of new leaves of flue-cured tobacco increased constantly until their growth was the fastest, and then it reduced irreversibly. The length and width of leaves in each position increased fastest when they grew depending on photosynthates instead of or- ganic compounds from functional leaves. Therefore, it is concluded that the increases of leaf length, width and area, and dry matter, and the peak of photosynthetic rate appear successively during the process of leaves of flue-cured tobacco, and the leaf area correction coefficient of leaves of flue-cured tobacco is related to the shape of leaves, which are affected by leaf position and the variety of flue-cured tobacco. The study can provide scientific reference for further research on the growth laws of leaves of flue-cured tobacco.

Study on the Growth Law of 23-year-old Castanopsis fissa Plantation

This paper studies the growth law of 23-year-old Castanopsis fissa planta- tion in Haiming forest farm （Pingguo County, Baise City, Guangxi Province） with the method of stem analysis. The results show that the average DBH, tree height and volume of the 23-year-old C. fissa plantation are 19.4 cm, 20.4 m and 0.326 1 m3 respectively. The fast growing periods of DBH, tree height and volume are the 2^nd- 8^th, 6^th-11^th, 6^th-23^nd year. Annual increment curve and average increment curve of volume haven＇t intersected in the 23 years, which means the 23-year-old C. fissais plantation has not reached the quantitative mature age. The growth equations of DBH, tree height and volume are D=1.713 3T-0.050 6T2＋0.000 7T2-1.942 2, H= 1.925 7T-0.039 8T2-2.489 0, V=-0.010 4T-0.002 4T2-4.084 8e^-0.005 T2＋0.012 7. Ac- cording to the volume regression equation of Castanopsis fissa, it will reach quanti- tative maturity in the 24~ year.

The Quantitative Law of Network Information Growth

Based on the assumptions of ＂information transfer＂ and ＂information creation＂, this paper educes the multiplied growth mechanism of network information： that the gross quantity of network information （Im） is about n times as much as the quantity of real network information （Ir）. According to this theoretical model, we give a uniform explanation to all kinds of information growth models in existence, and put forward some proposals, such as ＂forbidding information transfer＂ and ＂building up the central information base＂, to control the repeated information flooding on the network and facilitate the full use of network information.

Study on Growth and Decline Law of Contagious Pleuro-pneumonia in Piglets

In order to establish the immune procedure for Actinobacillus pleuropneumonia and to determine the date for the first immunization on piglets, the growth and decline law of A. pleuropneumonia material antibodies in the piglets borne by cows inoculated with A. pleuropneumonia vaccines （type I, II, and VII） before delivery was detected. The results showed that type I, II, and VII maternal antibodies in piglets decreased gradually with the age growing overall, and was at the critical protection value at the ages of 42-50 days （type I） and 28 days （type VII）, lower than the quantification rate; and the antibodies all turned to be negative until the ages of 70 days （type I）, 60 days （type VII） and 35 days （type II）. The first immunization should be carried out at the age of 42-50 days using type I A. pleuropneumonia vaccine, and at the age of 28 days using type VII A. pleuropneumonia vaccine. However, type II A. pleuropneumonia maternal antibody had lower level and positive rate and could not well protect piglets, so the various A. pleuropneumonia vaccines differed in the date for the first immunization. In order to achieve a better immunization effect, A. pleuropneumonia vaccines with different valences should be further researched and developed.

From Sequential to Parallel Growth of Cities： Theory and Evidence from Canada

This paper examines city growth patterns and the corresponding city size distribution evolution over long periods of time using a simple New Economic Geography(NEG) model and urban population data from Canada. The main findings are twofold. First, there is a transition from sequential to parallel growth of cities over long periods of time: city growth shows a sequential mode in the stage of rapid urbanization, i.e., the cities with the best development conditions will take the lead in growth, after which the cities with higher ranks will become the fastest-growing cities; in the late stage of urbanization, city growth converges according to Gibrat′s law, and exhibits a parallel growth pattern. Second, city size distribution is found to have persistent structural characteristics: the city system is self-organized into multiple discrete size groups; city growth shows club convergence characteristics, and the cities with similar development conditions eventually converge to a similar size. The results will not only enhance our understanding of urbanization process, but will also provide a timely and clear policy reference for promoting the healthy urbanization of developing countries.

STRONG LAW OF LARGE NUMBERS AND GROWTH RATE FOR NOD SEQUENCES

In the paper,we get the precise results of Hájek-Rényi type inequalities for the partial sums of negatively orthant dependent sequences,which improve the results of Theorem 3.1and Corollary 3.2 in Kim(2006)and the strong law of large numbers and strong growth rate for negatively orthant dependent sequences.

Development of Karst Formation in Area 4 of Tahe Oilfield

The main oil-bearing formation of Area 4 of Tahe oilfield is in Yingshan Group of Ordovician consisted of thick pure limestone. The types of the pore space contain the pore, fissure, cave as well as fracture formed by solution collapse. The primary porosity and tectonic fracture are of poor growth. Therefore, the formation growth is mainly controlled by hydraulic units of the palaeo-karst. There are three palaeo-hydraulic zones: vadose zone (including infiltration sub-zone and percolation sub-zone), phreatic zone and tranquil zone. They are identified by retrieving the palaeo-geographical karst environment. The pore space of the infiltration zone is mainly solution fissures, small solution cavities and solution pores. The growth and lateral connection of the formation are favorable. The reservoir/formation ratio is 0. 54. The pore space of the phreatic zone developed large size cavities and fractures related to cave collapse. The height of the cavity can reach 71m. The fractures by collapse have a influencing range of more than 100m, and its reservoir/formation ratio is 0. 51. But the lateral connection is unfavorable. The percolation subzone and the tranquil zone are of relatively poor growth with the reservoir/ formation ratio less than 0. 3.

Containment effort reduction and regrowth patterns of the Covid-19 spreading

In all countries the political decisions aim to achieve an almost stable configuration with a small number of new infected individuals per day due to Covid-19.When such a condition is reached,the containment effort is usually reduced in favor of a gradual reopening of the social life and of the various economical sectors.However,in this new phase,the infection spread restarts and,moreover,possible mutations of the virus give rise to a large specific growth rate of the infected people.Therefore,a quantitative analysis of the regrowth pattern is very useful.We discuss a macroscopic approach which,on the basis of the collected data in the first lockdown,after few days from the beginning of the new phase,outlines different scenarios of the Covid-19 diffusion for longer time.The purpose of this paper is a demonstration-of-concept:one takes simple growth models,considers the available data and shows how the future trend of the spread can be obtained.The method applies a time dependent carrying capacity,analogously to many macroscopic growth laws in biology,economics and population dynamics.The illustrative cases of France,Italy and United Kingdom are analyzed.

Balanced biosynthesis and trigger threshold resulting in a double adder mechanism of cell size control

How cells accomplish cell size homeostasis is a fascinating topic, and several cell size regulation mechanisms were proposed: timer, sizer, and adder. Recently the adder model has received a great deal of attention. Adder property was also found in the DNA replication cycle. This paper aims to explain the adder phenomenon both in the division-centric picture and replication-centric picture at the molecular level. We established a self-replication model, and the system reached a steady state quickly based on evolution rules. We collected tens of thousands of cells in the same trajectory and calculated the Pearson correlation coefficient between biological variables to decide which regulatory mechanism was adopted by cells. Our simulation results confirmed the double-adder mechanism. Chromosome replication initiation and cell division control are independent and regulated by respective proteins.Cell size homeostasis originates from division control and has nothing to do with replication initiation control. At a slow growth rate, the deviation from adder toward sizer comes from a significant division protein degradation rate when division protein is auto-inhibited. Our results indicated the two necessary conditions in the double-adder mechanism: one is balanced biosynthesis, and the other is that there is a protein trigger threshold to inspire DNA replication initiation and cell division. Our results give insight to the regulatory mechanism of cell size and instructive to synthetic biology.

Hybrid Cellular Automaton-Parabolic Thick Needle model for equiaxed dendritic solidification

A hybrid Cellular Automaton(CA)-Parabolic Thick Needle(PTN)model is developed for the simulation of an equiaxed dendritic grain.It is implemented by solving conservation equations with the Finite Element(FE)method at two scales.At the scale of the microstructure,dendritic branches are approximated by a network of PTN.The solute field is computed in the liquid using a FE mesh with minimum size smaller than the diffusion length ahead of the dendrite tips,giving access to a detailed description of each dendrite tip growth velocity as well as solutal interactions between branches.At the simulation domain scale,volume averaged heat and solute transfers are solved on a coarser FE mesh.The average volumetric fraction of phases is deduced from a field giving the fraction of dendritic microstructure together with a microsegregation model.Because the PTN themselves grow on CA cells,the dendrite tip growth velocity is transferred to the vertices of the polygon associated to the CA growth shape.Similarly,the field giving the fraction of dendritic microstructure is deduced from the fraction of CA cells part of the mushy zone,which include cells containing PTN network.Advantages of the new multiple scale CAPTN model include solutal interaction between dendrite branches together with long range transfer of heat and solute mass,together with the role of latent heat release on equiaxed solidification.