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The aim of this study was to evaluate the effects of dietary supplementation of bamboo leaf extract (BLE) on the growth performance, antioxidant traits, immune function, and lipid metabolism of weaning piglets. After weaning at 21 days, two hundred and forty healthy piglets (Large White × Landrance) were randomly assigned to 4 treatments with 6 pens and 10 piglets per pen. The control group (Ctr) received a maize-soyabean based diet, and the test groups received the control diet plus 0.5%, 1%, or 2% (w/w) BLE, respectively. The experiment was carried out for 5 weeks. At the end of it, average daily feed intake in the 1% BLE group was decreased (p < 0.05). Plasma concentrations of malondialdehyde were decreased with supplementation of 1% and 2% BLE. Immunoglobulin G concentrations and lysozyme activity in plasma were significantly increased in piglets supplemented with BLE. Diets with 1% and 2% BLE increased (p < 0.05) plasma concentrations of low density lipoprotein-cholesterol and reduced (P < 0.01) high density lipoprotein-cholesterol levels. Higher triglyceride concentrations were observed in the 0.5% (P < 0.01) and 2% (p < 0.05) BLE groups. In conclusion, these novel findings demonstrate that supplementation of BLE to the diet improved the antioxidant activity, immune function, and lipid metabolism of weaning piglets.
Through the combination subject of scientific research, the design method of the winch driven by contactless magnetic coupling is researched for the core purpose of the turning shaft sealing in a deepwater environment. This method has six design phases, including domestic and foreign information query and retrieval, graphic analyses of relevant structures, innovative design of 2D assembly sketches, a theoretical computation of structure parameters, the 3D modeling and motion simulation and engineering drawing. This method is of generality, which can provide examples for the postgraduate students and engineering personnel in self-renovation design of scientific research
Cabin placement layout is an important part of ship cabin layout design. A good cabin placement layout can improve the efficiency of the ship’s cabin arrangement. However, optimisation of the layout of cabin placement is not widely studied and more often relies on the experience of the staff. Thus, a novel methodology combining systematic layout planning and a genetic algorithm to optimise the cabin placement is presented in this paper. First key elements are converted by a systematic planning method that is often applied in factory layout, and a preliminary cabin placement layout model is established according to these key elements. Then the circulation strength and adjacency strength are taken as sub-objectives to establish a mathematical model, and an improved genetic algorithm is used to optimise the model. The result of the optimisation is compared with the initial schemes to verify the validity of the algorithm. Finally, the human factors are introduced according to the actual situation. The AHP method is used to select the layout scheme of the cabin that is most likely to be applied in the actual cabin layout
When an offshore oil field completed and put into production, new subsea pipelines and the new cable need to be established. Cable protection pipe clamp is used to fix cable protection pipe on the jacket. In order to avoid the problem of traditional steel structure clamp splice, counterpoint, fastening difficulty when installed cable protection pipe under water, reduce the risk and workload of under water, This paper develop a new type of portable connecting riser clamp –“backpack clamp” which solve the riser cable protection pipe difficult underwater installation problem. The main structure of backpack clamp used three valves type structure. The load characteristic of a clamping device was determined by the Morison equation which was a classical theory. Clamp device underwater mechanics analysis model was established. The minimum tension pre-tightening force was determined. The results show that the strength of the base meets the requirements after strength analysis with finite element analysis method, stability and strength experiments, which means the clamp based on resin matrix composite is feasible
With the rapid development of the marine economy and continuous improvement of the industry, the scale of the offshore engineering is increasing. This raises interest in studying, theoretically and experimentally, gripping and bearing mechanisms for large-scale holding and lifting tools used in foundation pile installations. In this paper, the embedded gripping mechanism is studied based on the theory of elastic-plastic mechanics. The embedded and bearing performance of the tooth is simulated and the influence factors are studied. In addition, the device used in the simplified embedded experiment on the tooth of the embedded block is designed. The relationship between embedded depth, load, and tooth profile angle is identified and validated. Meanwhile, the embedded performance of linear and ring type teeth is compared experimentally in order to select the suitable type of tooth for various situations. This comparison makes the basis for designing an upending gripper for the marine pile foundation, which can realize the operation of holding the pile to prevent its falling
Ethylene response factor (ERF) is an important component in ethylene or pathogen-induced defensive response of plants. However, physiological effects of ERF on plants have not been fully elucidated. We previously identified an ERF gene, OsERF1, in rice. It up-regulated ethylene-responsive genes expression and influenced growth and development of the transgenic Arabidopsis. Here, we report that similar to other seedlings with constitutive ethylene response, OsERF1 seedlings were suppressed in their root growth. Interestingly, the suppressed root growth was restorable by light irradiation. Detailed analysis showed that OsERF1 inhibited cell elongation without influencing cell number in hypocotyls and leaves of the transgenic Arabidopsis. In addition, homozygous OsERF1 was fatal and heterozygous OsERF1 was harmful in Arabidopsis. These findings expand our understanding of ERF.
The reliability and safety of offshore platform are an important research aspect in marine engineering. The jacket platform is mainly used for oil development and submarine drilling, and the long-term work in the marine environment will be subjected to different loads, which will lead to the damage of the structure part of the offshore platform. It affects the structural strength of the platform. For the repair of jacket damage, grouted reinforcement technology is adopted, which has the advantages of simple underwater installation and low cost. The reinforcement technology of the grout hoop has been applied to the engineering projects abroad, but the stress and serialization design of the hoop in the marine environment need further study. This paper will combine the ocean current and wave force to carry out the research of underwater work and prevent loosening, and put forward the parametric design method for the specific size of the hoop. Two types of experimental models are designed: short bolt form clamp and long bolt form clamp. The mechanical experiment of the long bolt clamp is carried out, and the relationship between the slipping force and the bolt preload is analyzed, so as to verify the theoretical analysis
Sewage sludge was cross-linked with epichlorohydrin to increase its mechanical strength and applicability as an absorbent material. We investigated the effect of the conditions of the cross-linking reaction on the mechanical strength and Cu (II) adsorption capacity of epichlorohydrin cross-linking sewage sludge (ECS). Experimental results showed that cross-linking can raise signifi cantly the mechanical strength of sewage sludge. To improve the adsorption capacity of ECS, carboxymethyl cross-linked sewage sludge (CCS) with maximal adsorption capacity (65mg/g) for Cu (II) was synthesized from ECS by using chloroacetic acid as the etherifi cation agent. The experimental results showed that the adsorption properties of CCS for Cu (II) could best be described by the pseudo-second order model and Langmuir model, and the adsorption mechanism was ion exchange. Our data suggest that CCS is a promising absorbent for removal of heavy metals from wastewater.
Macaroblattula ellipsoides gen. et sp. nov., Elisama cuboides sp. nov. and E. extenuata (Ren, 1995) of the dominant cockroach family Blattulidae are described from the Late Jurassic/Early Cretaceous Yixian Formation of western Liaoning in China. Forewing venation of E. extenuata reveals low variation (CV for total number of veins = 6.22), which indicates active flight of this advanced taxon. Presence of Macaroblattula gen. nov. suggests a generic variation and high adaptability of the family. Taxonomic composition supports the transitional Late Jurassic/Early Cretaceous age of the Yixian Formation and dominance of the family Blattulidae within assemblage indicates their significance in food chain.
Background: Kidney has long been thought to be a body’s largest organ of elimination for maintaining acid-base balance. In recent years, the research on kidneys has mainly focused on the structural characteristics of the kidney of single age group animals. In this paper we used histological and immunohistochemical methods to observe and compare the structure characteristics of yak kidney and the expression of epidermal growth factor receptor (EGFR), bone morphogenetic protein-2 (BMP-2) and p53 in the kidney of yaks of three different age groups. The aim of the study was to investigate histological characteristics of age-related changes in the kidney of yak and expression and localisation of kidney-related factors. Materials and methods: Fifteen healthy male and female yaks from highland plateaus (three groups: newborn, adult and old yaks, n = 5 per group). Histological methods were used to compare the relevant characteristics of the kidney of yaks. The immunohistochemistry method was used to observe the expression and localisation of EGFR, BMP-2, and p53 of the kidney of different ages, and the optical density value was measured and analysed by using image analysis software. Results: This is an overall observation of the kidney tissue section, which includes the surface of the renal capsule and the internal parenchyma. In the renal parenchyma, there are renal corpuscles, renal tubules. The internal substance included cortex and medulla, which were bounded by the arched artery. In the cortex, there were renal corpuscles, convoluted part of renal tubules (proximal convoluted tubule and distal convoluted tubule) and collecting tubules. The medulla included straight parts of renal tubules (proximal straight tubule and distal straight tubule), thin segments and collecting tubules. It was observed that the organisational structure of the kidney of yaks did not change with age, but the degree of development of the internal structure (glomeruli, renal tubules and collecting tubules) of the kidney changed with age. Immunohistochemical results demonstrated that EGFR and BMP-2-positive reaction in the newborn group was mainly distributed in the proximal tubule epithelial cells, and widely distributed in the adult and old groups. However, the p53-positive reaction was widely distributed in the newborn, adult and old groups. Conclusions: The results revealed that the kidney structure tended to be completed with age, and the function of the kidney gradually improved. EGFR and BMP-2 had the effect of promoting kidney development. However, p53 had been widely distributed in the newborn kidney of the yaks. It is suggested that p53 had been involved in cell migration and metabolic differentiation and self-renewal in the new stage. (Folia Morphol 2019; 78, 1: 114–123)
The adsorption behavior and the adsorption mechanism of the persistent organic pollutant DDT existing extensively in soils around the world are the key to solve the DDT-contaminated soils. Hence, in this paper, selective extraction and batch experimental method were used to examine the adsorption of DDT on farmland soils H and S in Northeast China. Simultaneously, the parameters indicating soil properties and composition such as soil particle, organic matter, and minerals, ect. were analyzed. Results show that the shape and the best fitted model of adsorption isotherm of DDT in both soils were L-type and Freundlich model, respectively. Smaller soil particle had greater adsorption capacity to DDT. The effects of organic matter and minerals on the adsorption of DDT were related to the composition and the origin of organic matter and minerals. Both SiO2 and illite-montmorillorite mixed-layer could hardly adsorb DDT, and the iron oxides could adsorb DDT, while the function of manganese oxides was inhibitory of DDT adsorption. Organic matter had greater adsorption capacity to DDT than iron oxides. The adsorption capacity of the plant residues is the greatest, followed by the aromatic substances from the plant and the products from microbial degradation.
This research aimed to determine whether low moisture content storage improves the longevity and storability of Zygophyllum xanthoxylon (Bge.) Maxim seeds. The seeds of Z. xanthoxylon were dried from 11.43 to 4.81%, 3.81 and 2.41% moisture content in a desiccating container with silica gel. After storage for 24 months their level of vigor was measured. After the ageing process, some physiology indices, including the relative electrical conductivity, SOD, PER, CAT, volatile aldehydes and malondialdehyde were tested. The results indicated that SOD, PER and CAT activities of the low moisture content seeds were higher than the control seeds while volatile aldehydes and malondialdehyde were lower than the control group. The electrical conductivity showed that there was obvious statistical difference between low moisture content seeds with the control group. All the results showed that low moisture content storage is beneficial for maintaining the vigor of Z. xanthoxylon seeds. Thus Z. xanthoxylon seeds can be stored with low moisture content at ambient temperature condition for a long time.
The concentrations of catalpol in the culture solutions, roots, stems and leaves of Rehmannia glutinosa Libosch. were determined by HPLC. The biological activity of catalpol was detected with Arabidopsis thaliana L. seedlings. The results showed that all R. glutinosa Libosch. vegetative organs contained catalpol. Catalpol was also found in culture solutions in which the R. glutinosa Libosch. seedlings were grown. Catalpol inhibited seed germination and root growth in A. thaliana L., respectively, at concentration 80 and 20 µmol/dm³. These results suggest that R. glutinosa Libosch. may produce catalpol and secrete it into the culture solutions. Catalpol acts as an antimicrobial and allelopathic agent; the secretion of catalpol into the R. glutinosa Libosch. rhizosphere may provide a competitive advantage for root establishment through local suppression of soil microorganisms and inhibition of the growth of competing plant species. However, autotoxicity of catalpol in R. glutinosa Libosch. may occur, which may be relevant to the obstacle in its continuous cropping.
Crosstalk in wiring harness has been studied extensively for its importance in the naval ships electromagnetic compatibility field. An effective and high-efficiency method is proposed in this paper for analyzing Statistical Characteristics of crosstalk in wiring harness with random variation of position based on Polynomial Chaos Expansion (PCE). A typical 14-cable wiring harness was simulated as the object of research. Distance among interfering cable, affected cable and GND is synthesized and analyzed in both frequency domain and time domain. The model of naval ships wiring harness distribution parameter was established by utilizing Legendre orthogonal polynomials as basis functions along with prediction model of statistical characters. Detailed mean value, mean square error, probability density function and reasonable varying range of crosstalk in naval ships wiring harness are described in both time domain and frequency domain. Numerical experiment proves that the method proposed in this paper, not only has good consistency with the MC method can be applied in the naval ships EMC research field to provide theoretical support for guaranteeing safety, but also has better time-efficiency than the MC method. Therefore, the Polynomial Chaos Expansion method
The application of nitrogen fertilizers can improve the soil environment and influence the nutrition and quality of plants; there are also significant impacts of soil types on soil microbial communities. Research on the coupling effects between the rates of nitrogen fertilizer and the soil types on soil microbial metabolic activities under field conditions are currently lacking. In this study, we investigated the effect of five different N fertilization rates on three types of soils (meadow black, alluvial, and sandy soil) that were over 8-year-long planted maize. Illumina Miseq sequencing methods were used to characterize the soil microbial communities. Real-time PCR were adopted to calculate the relative abundance of N, C, and P-cycling functional microbial. Results indicated that different N rates can significantly change soil available nutrients and effectively reduce soil pH. The structure of the soil bacterial communities and diversity did not change after the fertilization of N during the study period. However, it can be found that soil types can substantially influence the structure of bacterial communities in soil, meanwhile, there was a significant correlation between pH and the composition of bacterial communities. Although the composition of the soil microbial community did not influence the fertilization rate of N, they can be indirectly affected by pH. There was significant difference (P<0.05) in the relative abundances of the nutrient cycling functional genes of the rhizosphere soil under different nitrogen levels, with nitrogen application and soil type the main influencing factors. The results showed that the excessive application of N fertilizer did not increase the yields of maize, thus it is important to investigate the reasonable fertilization rates of N fertilizer to protect the ecological balance of crop soils.
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