Voronoi cell finite element method for heat conduction analysis of composite materials.

In this paper, Voronoi cell finite element method (VCFEM) based on assumed flux hybrid formulation has been presented for heat conduction problem of particle reinforced composites material. The heat fluxes satisfying a priori internal thermal balance are directly approximated independently in the matrix and the inclusion respectively. The temperatures on element boundary and matrix-inclusion interface are interpolated by nodal temperature. The thermal balance on the interelement boundary and matrix-inclusion interface is relaxed and introduced into the functional by taking the temperature as Lagrange multiplier. In this way, a functional containing two variables of heat flux and temperature is proposed. Full field heat flux and effective thermal conductivity are obtained. Feasibility and effectiveness of the proposed approach are verified through several numerical examples.

First description of the male of Oecobiusprzewalskyi Hu & Li, 1987 (Araneae, Oecobiidae) from Shigatse City, Tibet, China.

Background: With 90 described species, the genus Oecobius Lucas, 1846 is the largest genus of the family Oecobiidae Blackwall, 1862, five of which are known from China. Since Oceobiusprzewalskyi was described by Hu & Li in 1987, no males of this species have ever been reported. New information: The male of Oceobiusprzewalskyi is described for the first time, based on the specimens collected in Tibet Autonomous Region. Morphological description and illustrations are given.

Characterization and Origin Analysis of Heavy Oil in the Western Sag of the Liaohe Basin.

This article systematically examines the physical characteristics, group composition characteristics, and geochemical characteristics of heavy oil in the Western Sag of the Liaohe Basin. The examination is based on the separation and quantitative analysis of crude oil and rock samples, as well as the analysis of test results from gas chromatography with saturated hydrocarbons and aromatic hydrocarbons. It also analyzes the generation mechanism and main controlling factors of heavy oil. The results show that heavy oil has low wax content (1.8-9.2%), a low freezing point (-19-38 °C), low sulfur content (0.28-0.5%), high colloid and asphaltene content, high density (0.926-1.008 g/cm3), and high viscosity (328-231910 mPa·s). The physical properties of the heavy oil in the same formation decrease from the depression's edge toward its center and within the same area, and the physical properties in different formations also have an inverse relationship with burial depth. Biodegradation is the main reason for the formation of heavy oil. Based on the biodegradation degree, there are four types of heavy oil: undegraded, weakly degraded, moderately degraded, and severely degraded. The main controlling factors of biodegradation are temperature and the water environment. This study provides a method for studying the genetic mechanism of heavy oil, an approach for discovering similar genetic oil and gas, and a basis for the transformation of heavy oil field development.

Research on the Formation Mechanism of Health Insurance Fraud in China: From the Perspective of the Tripartite Evolutionary Game.

The problem of fraud in China's health insurance has existed for a long time and is becoming more serious, which needs to be solved urgently. This article constructs a tripartite evolutionary game model to study the formation mechanism of the Health Insurance fraud, game participants including medical administrative organization (MAO, a government department responsible for health insurance supervision), medical institutions (MI, such as hospitals), and insured individuals (II, who participating in medical and healthcare insurance). By analyzing the equilibrium of the tripartite evolutionary game, this paper makes an in-depth study on the formation and resolution of health insurance fraud. The results show that: (1) How to prevent the fraud behavior of the medical institutions is the difficulty and core of the problem. It is necessary to achieve effective supervision of the MAO, improve the internal management of the MI and give play to the supervisory role of the II. (2) The regulatory behavior of the MAO needs to focus on protecting the interests of the II, not only to encourage them to actively play the role of supervision and reporting but also to prevent their collusion with MI. (3) On the one hand, the MAO needs to strengthen supervision and increase the punishment for fraud. On the other hand, they also need to take incentive measures to guide all subjects to form a sound internal management mechanism.

Highly sensitive multi-stage terahertz parametric upconversion detection based on a KTiOPO4 crystal.

In this Letter, we demonstrate a highly sensitive multi-stage terahertz (THz) wave parametric upconversion detector based on a KTiOPO4 (KTP) crystal pumped by a 1064-nm pulsed-laser (10 ns, 10 Hz). The THz wave was upconverted to near-infrared light in a trapezoidal KTP crystal based on stimulated polariton scattering. The upconversion signal was amplified in two KTP crystals based on non-collinear and collinear phase matching, respectively, to improve detection sensitivity. A rapid-response detection in the THz frequency ranges of 4.26-4.50 THz and 4.80-4.92 THz was achieved. Moreover, a dual-color THz wave generated from THz parametric oscillator using KTP crystal was detected simultaneously based on dual-wavelength upconversion. The minimum detectable energy of 2.35 fJ was realized with a dynamic range of 84 dB at 4.85 THz, which gives a noise equivalent power (NEP) of the order of 21.3 pW/Hz1/2. By changing the phase-matching angle or the wavelength of the pump laser, it is suggested that the detection of the THz frequency band of interest in a wide range from approximately 1 to 14 THz is possible.

[Effects of increasing field temperature on photosynthetic characteristics of summer maize].

A field experiment was conducted to study the effects of increasing field temperature on the grain yield and photosynthetic characteristics of summer maize cultivars ND108 and YD13. The results showed that under increasing field temperature in the period from male tetrad to maturing stage, the grain yield of ND108 and YD13 decreased by 46.6% and 45.1%, leaf area index (LAI) decreased by 15.4% and 11.5%, and net photosynthetic rate of ear leaf decreased by 22.85% and 18.14%, respectively, compared with the control. The contents of leaf chlorophyll a and b, especially that of chlorophyll a, decreased obviously, and the activities of ribulose-1,5-bisphosphate carboxylase (PEPCase) and phosphoenolpyrovate carboxylase (RuBPCase) in the leaves of the two cultivars decreased by 51.1% and 32.4%, and 29.5% and 7.7%, respectively.

[Effects of high field temperature on summer maize grain yield and quality].

A field study with two summer maize cultivars ND108 and YD13 showed that increased field temperature (3 degrees C) at the stage from male tetrad to maturity had significant effects on their grain yield and quality. The grain yield of ND108 and YD13 decreased by 46.6% and 45.1%, grain crude protein content increased by 11.6% and 2.02%, ether extract content decreased by 38.9% and 9.6%, starch (mainly amylopection) content decreased by 7.0% and 8.4%, and lysine content decreased by 58.9% and 51.2%, respectively.

[Effects of shading on the growth, development and grain yield of summer maize].

Under field condition, this paper studied the effects of shading on the growth, development, and grain yield of summer maize varieties ND108 and YD13. The results showed that shading decreased maize yield significantly, and the effect was differed with different shading period and intensity. With a shading intensity of 50% and 90%, the grain yield of ND108 and YD13 was decreased by 67.5% and 79.4%, and 82.9% and 86.7% when shading at flowering-maturing stage, and by 34.1% and 55.3%, and 47.2%, 65.7% when shading at joining-flowering stage, respectively. Shading at seedling-joining stage had a relatively smaller effect, with the grain yield decreased by 16.9% and 24.5%, and 18.9% and 24.3%, respectively. Shading had a larger effect on YD13 than on ND108, and the effect of shading period was larger than that of shading intensity. Under shading, the growth and development of maize was retarded, and the effect was increased with increasing shading intensity. Shading at joining-flowering stage affected spike differentiation significantly, reflecting in the marked decrease of the numbers of silks and tassels, and the effect was also larger on YD13 than on ND108. The leaf and plant growth was restrained significantly when shading at seedling stage and at flowering-maturing stage.

[Individual grain yield potential and nitrogen utilization efficiency of Zea mays cultivars widely planted in North China].

With field experiment and under low-density condition, this paper studied the individual grain yield (GY) and nitrogen utilization efficiency (NUE) of fifty Zea mays cultivars widely planted in North China since 1990s. Exploring analyses and normality tests showed that the 1000-kernal weight (KW), above-ground biomass per plant (AB), grain harvest index (HI(G)), NUE, and nitrogen harvest index (HI(N)) were all conformed to normal distribution, with N (265.1, 44.50(2)), N (322.3, 36.91(2)), N (515.8, 64.73(2)), N (0.514, 0.06(2)), N (43.0, 5.37(2)), and N (0.643, 0.06(2)), respectively. The GY ranged from 198.35 to 345.22 g.plant(-1), KW from 241.50 to 391.82 g.1000 kernal(-1), AB from 402.34 to 712.84 g.plant(-1), HI(G) from 0.39 to 0.63, NUE from 31.18 to 57.35 g grain.g N(-1), and HI(N) from 0.47 to 0.74. Correlation analyses indicated that GY positively and significantly correlated with NUE (partial correlation coefficient was 0.471, P = 0.001), while KW negatively and significantly correlated with NUE (Pearson correlation coefficient was -0.427, P = 0.002). Through hierarchical cluster analyses for GY and NUE, the test Zea mays varieties could be sorted into 3 types, i.e., high-GY with high-NEU, low-GY with low-NEU, and mediate type. Currently, only 24 percent of Zea mays cultivars in North China were of high-GY with high-NEU type, and thus, its breeding should be strengthened in the future.

[Effect of sulfate supply level on characteristics of N and S metabolism and on root vigor of corn].

The effects of different sulfate supply level on N and S metabolism and on root vigor of corn were quantitatively studied with Hoagland solution under greenhouse conditions. The results showed that in S-deficient solution, root vigor and leaf nitrate reductase (NR) activity significantly rdduced, top root ratio (T/R) increased, and S and N accumulation in tops and roots decreased. The partition of S decreased in roots and incompletely expanded leaves, but increased in senescent leaves and sheaths-stems; while the partition of N increased in roots, but decreased in incompletely and fully expanded leaves. The content of protein, protein N, protein S, and sulfate S significantly reduced, percentage of non-protein N increased, inorganic S/total S ratio decreased, and total N/total S ratio increased. The protein N/protein S ratio in tops had no observable changes, but increased significantly in roots, showing that root was a sensitive organ to S-deficiency. There was a close relationship between protein content and NR activity in S-deficiency. Deficient or excessive S supply limited N and S metabolism of corn plant. N/S or inorganic S/total S ratio in roots was a sensitive index to indicate the deficiency of S supply, which was 10.7 or 0.302 under normal condition, respectively.