In order to explore the effect of cadmium stress on root vigor and accumulation of five kinds of conventional metal elements in Salix variegata, a hydroponic experiment with different cadmium treatments were conducted. The cadmium treatments included 0 mg·L-1 (CK), 2 mg·L-1 (T1), 10 mg·L-1 (T2), 20 mg·L-1 (T3) and 50 mg·L-1 (T4). The root vigor and distribution of cadmium and five kinds of conventional metal elements (including Ca, Mg, Mn, Zn and Fe) in S. variegata were tested. The results showed that: 1) The root vigor of S. variegata decreased with increasing cadmium stress gradually. Compared to control, the root vigor decreased significantly in treatments with the cadmium concentration reaching and exceeding 10 mg·L-1. 2) With increasing the cadmium concentration, the abilities of S. variegata to absorb and accumulate Fe in leaves were inhibited significantly; the abilities to absorb and accumulate Mg, Mn and Fe in phloem were inhi-bited significantly; the abilities to absorb and accumulate Ca, Mg, Mn, Zn and Fe in xylem had no significant differences; and the abilities to absorb and accumulate Ca, Mg, Mn, Zn and Fe in root were inhibited significantly. It could be concluded that cadmium had antagonistic effect on the accumulation of the other metal elements, especially Zn in plant root. 3) With increasing concentrations of cadmium, the translocation factors of Ca, Mg, Mn and Zn increased significantly when compared to control, while there was no significant influence on Fe. 4) Under cadmium stress, there was a significantly negative correlation between the accumulations of cadmium and Ca in S. variegate root, and a very significantly negative correlation between the accumulations of cadmium and the other four kinds of conventional metal elements, indicating that the change of conventional metal elements in S. variegate root could be one of the indices of the degree of cadmium stress.以秋华柳为试验材料,采用水培试验方式,设置CK(0 mg·L-1 Cd2+)、T1(2 mg·L-1 Cd2+)、T2(10 mg·L-1Cd2+)、T3(20 mg·L-1Cd2+)、T4(50 mg·L-1Cd2+)5种镉处理浓度,通过对秋华柳根系活力,叶、韧皮部、木质部和根部的镉含量,以及Ca、Mg、Mn、Zn、Fe 5种常规金属元素含量的测定,研究了不同浓度镉胁迫下秋华柳根系活力及Ca、Mg、Mn、Zn、Fe 等金属元素含量的变化.结果表明:1)秋华柳根系活力随着镉处理浓度的增加而逐渐下降,当镉浓度≥10 mg·L-1时,根系活力与对照相比显著下降.2)随着镉处理浓度的增加,秋华柳叶中Fe的积累受到显著抑制;韧皮部Mg、Mn、Fe的积累受到显著抑制;木质部Ca、Mg、Mn、Zn、Fe 等5种常规金属元素的积累无显著性差异;根部5种常规金属元素的吸收和积累受到显著抑制,表现出镉对其他金属元素积累的拮抗作用.其中,50 mg·L-1的镉胁迫下,根部Zn的积累量降幅最大,受Cd的抑制最明显.3)各处理组Fe的转移系数与对照相比均无显著性差异;Ca、Mg、Mn、Zn的转移系数均高于对照,且在一定的镉处理水平上差异显著.4)镉胁迫下,秋华柳根部镉的积累量与Ca的积累量呈显著负相关,与其他4种常规金属元素的积累量呈极显著负相关,说明根部常规金属元素的变化可作为秋华柳受镉毒害程度的指示之一.
Vitrified microsphere insulation mortar is a new type building insulation mortar which developed in recent years, with having the advantages of well workability, high intensity and fire prevention. But because the vitrified microsphere we use of which much exists on the defects of high dry density and bad insulation effect, it analyzed deeply kinds of factors which influence on the physical and mechanical properties of vitrified microsphere insulation mortar, making use of orthogonal experiment to optimize the composition materials of insulation mortar. The orthogonal test results show that the most influential raw materials factors to mortar insulation properties and 28d compressive strength followed by aggregate, polypropylene fiber, fly ash and latex powder.
Wild boars (Sus scrofa) are hosts of several viruses that result in highly destructive diseases. Identifying and cataloging viruses carried by wild boars is a logical approach to evaluate the range of potential viruses and help with the conservation of both wild boars and cultivated pigs, as well as human beings, considering the possibility of zoonotic virus transmission from pigs to humans. In this study, eight lung tissue samples and 11 mixtures of anal and pharyngeal swabs were collected from 11 healthy wild boar individuals. Viral metagenomic analyses were conducted to detect virus diversity in wild boars. 1,199 contigs from a total of 184,434 de novo assembled contigs were determined as viral sequences, of which 71 contigs had a high level of sequence similarity to known RNA viruses. The dominant viruses were Sakobuvirus A and Posavirus 1, both of which belong to the Picornavirales family. A draft genome of Sakobuvirus A, covering 80.6% of the genome of the feline Sakobuvirus A strain, as well as a whole genome sequence of a Posavirus 1 strain with a length of 9,226 bp were obtained. Although there is little information on the etiology and pathogenesis of these two Picornavirales strains, their detection will enrich the information in the Picornavirales database and further expedite Picornavirales research on genetic diversity, epidemiology, and evolution.
In order to study the deformation mechanism of the weak layer in diabase dikes under long-term loading at a hydropower dam foundation, in situ plate loading tests were performed. A damage creep model which improved the five-parameter generalized Kelvin model was established to describe the creep behavior of the weak layer. In this model, the deterioration effect of the rock parameters is considered and the creep parameters of the rock deteriorate gradually. This model is applied in a slope design for a dam foundation at a hydropower station. Long-term stability of the slope after excavation is evaluated. It shows that when damage creep is considered, the displacement is larger compared with the case of ignoring damage creep. The study shows that the deterioration effect of the rock parameters is of full importance for the project design and construction safety.
Since ancient times, Fujian folk beliefs are particularly developed, the temple, hundreds of gods, frequent religious activities, many believers constitute the basic content of Fujian folk beliefs.Since the reform and opening up, due to the special historical conditions of Fujian and Taiwan, Southeast Asia, the close relationship between overseas Chinese, as well as the implementation of religious freedom policy, etc., Fujian folk beliefs have been faster recovery and development, causing great interest at home and abroad scholars.As an important part of Fujian and Taiwan regional culture, the formation of far-reaching traditional forces, Fujian and Taiwan society can't be underestimated the impact.Although the folk beliefs of Fujian and Taiwan have distinct regional characteristics, it is rooted in the fertile soil of the profound Chinese culture, which is derived from the long five thousand years of Chinese civilization.Fujian and Taiwan folk beliefs play an important role in the development of cross-strait relations and promote the improvement of political and economic exchanges between the two sides of the Taiwan Strait.
The greater short-nosed fruit bat (Cynopterus sphinx) is a social species, widely distributed in southern Asia. We used microsatellite and mfDNA markers to assess whether this fruit bat has a sex biased dispersal pattern. We also assessed signatures of sex-biased migration using microsatellite data. No significant heterozygosity deficiency (FIS), lower assignment value (mAIc) and variance of assignment (vAIc) were found between females and males, which does not support the hypothesis that dispersal in C. sphinx is sex biased. When microsatellite genotype frequency and mfDNA haplotype distribution patterns were subjected to the AMOVA, we found that genetic partitioning was higher at mfDNA (ΦST) than autosomal markers (FST) in both sexes. There is a higher value for males than females in both the mtDNA and microsatellite data, and both adult males and females also exhibited more variation within than among populations, but without significant results. Our results indicated that C. sphinx displayed various sexual population structures and there is no sex-biased dispersal, which is in accordance with concomitant ecological studies.
Durability design of the concrete structure directly concerns structural durability, the current system of the structural durability design has not formed, merely limited to theoretical analysis condition of the environmental zoning, material preparation and structure life. This article has carried on the durability design factor analysis ,including the environment function, the durable condition monitoring design, the life design, the state control, the material design, repairable design and the mechanical design, based on this the establishment durability design method system is proposed, and the research method of establishing this system is discussed.
Harmonic minimization in PWM inverters is a complex optimization problem which involves non-linear transcendental equations having multiple local minima. In this paper, a solution to the harmonic minimization problem using the particle swarm optimization (PSO) has been proposed to solve the SHE problem. It overcomes the complicated computations associated with conventional iterative techniques. As an example, in this paper a bipolar PWM inverter with seven switching angles per quarter cycle with varying modulation index is considered, and the optimum switching angles are calculated offline to eliminate the 5th,7th, 11th,13th,17th and 19th harmonics. The simulated results are also validated by experiment.
The development of micro-nanomanufacturing technology leads to higher requirement for measurement technology, which gives birth to the ultra-precision measurement technology. As a kind of low coherence interferometry technology, spectral interferometry has been proposed. In this paper, the theory and system of white light spectral interferometry were described in detail, and the measurement principle of micro-structure was analyzed. The spectral interference signal was recorded and the phase information was retrieved from it by using five-step phase shifting algorithm, which includes the phase change on reflection from the stucture. So the optical path difference (OPD) can be obtained, which represents the height information. Three methods including slope method, single wavelength method and least square method were discussed based on the theory deduction and the experimental analysis. A step height standard was measured and the results show that this method has a good accuracy.
According to the requirement of aircraft fuel quality property calculation, this paper studied pretreatment methods for tank CATIA model. Firstly, extract outside surfaces of wing skins, start and end wing ribs, front and back spars and then joint them to create a complete closed surface by additional repairing surfaces gap. Secondly, inside the closed surface, bool operation is utlized to remove actual bodies of fuel tank structures and internal accessories from the model of fuel tank. Direct accurate calculation of fuel quality property in CATIA environment is then achieved. Finally,simulation is carried out with an real aircraft fuel tank, comparison between simulation results and test data shows that relative error of pretreated fuel tank volume model is less than 1%, which satisfies engineering requirements.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)