Research on the Prediction of Load Regulation Capacity for Supercritical Thermal Power Unit

Both the modeling and the load regulation capacity prediction of a supercritical power plant are investigated in this paper. Firstly, an indirect identification method based on subspace identification method is proposed. The obtained identification model is verified by the actual operation data and the dynamic characteristics of the system are well reproduced. Secondly, the model is used to predict the load regulation capacity of thermal power unit. The power, main steam pressure, main steam temperature and other parameters are simulated respectively when the unit load is going up and down. Under the actual constraints, the load regulation capacity of thermal power unit can be predicted quickly.

Pulse-Width Pulse-Frequency Based Optimal Controller Design for Kinetic Kill Vehicle Attitude Tracking Control

The attitude control problem of the kinetic kill vehicle is studied in this work. A new mathematical model of the kinetic kill vehicle is proposed, the linear quadratic regulator technique is used to design the optimal attitude controller, and the pulse-width pulse-frequency modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the reaction thrusters. The methods to select the appropriate parameters of pulse-width pulse-frequency are presented in detail. Numerical simulations show that the performance of the LQR/PWPF approach can achieve good control performance such as pseudo-linear operation, high accuracy, and fast enough tracking speed.

Glycerol monolaurate improves intestinal morphology and antioxidant status by suppressing inflammatory responses and nuclear factor kappa-B signaling in lipopolysaccharide-exposed chicken embryos

Medium-chain fatty acids and their derivatives are natural ingredients that support immunological functions in animals.The effects of glycerol monolaurate(GML)on intestinal innate immunity and associated molecular mechanisms were investigated using a chicken embryo model.Sixty-four Arbor Acres broiler embryos were randomly allocated into four groups.On embryonic day 17.5,the broiler embryos were administered with 9 mg of GML,which was followed by a 12-h incubation period and a12-h challenge with 32μg of lipopolysaccharide(LPS).On embryonic day 18.5,the jejunum and ileum were harvested.Results indicated that GML reversed the LPS-induced decline in villus height and upregulated the expression of mucin 2(P<0.05).GML decreased LPS-induced malondialdehyde production and boosted antioxidant enzyme activity(P<0.05).GML alleviated LPS-stimulated intestinal secretion of interleukin(IL)-1β,IL-6,and tumor necrosis factor-a(TNF-a)(P<0.05).GML also normalized LPS-induced changes in the gene expression of Toll-like receptor 4,nuclear factor kappa-B p65(NF-κB p65),cyclooxygenase-2,NOD-like receptor protein 3,IL-18,zonula occludens 1,and occludin(P<0.05).GML enhanced as well the expression of AMP-activated protein kinase a1 and claudin 1(P<0.05).In conclusion,GML improved intestinal morphology and antioxidant status by alleviating inflammatory responses and modulating NF-κB signaling in LPS-challenged broiler embryos.

Energy saving and environment-friendly element-transfer reactions with industrial application potential

Herein we wish to propose the concept of"element-transfer reaction",which may afford the access to elemental compounds by transferring certain elements from easily available resources efficiently,concisely and precisely.A good element-transfer reaction with industrial application potential shall not generate waste and is performed under energy-saving and environment-friendly conditions.During the past decade,we have developed a series of methods for the synthesis of fluorine-and seleniumcontaining compounds via the fluorine-and selenium-transfer reactions,while the redox reactions we re considered to be the oxygen-and hydrogen-transfer reactions as well and were also widely studied by our group for producing the high-value-added fine chemicals.Some of these technologies have been successfully industrialized.This review summarizes our staged research results on fluorine-,oxygen-,hydrogen-and selenium-transfer reactions and makes a prospect on the developing trend in the field.

Evasion guidance algorithms for air-breathing hypersonic vehicles in three-player pursuit-evasion games

In practical combat scenario,the cooperative intercept strategies are often carefully designed,and it is challenging for the hypersonic vehicles to achieve successful evasion.Based on the analysis,it can be found that if several Successive Pursuers come from the Same Direction(SPSD)and flight with a proper spacing,the evasion difficulty may increase greatly.To address this problem,we focus on the evasion guidance strategy design for the Air-breathing Hypersonic Vehicles(AHVs)under the SPSD combat scenario.In order to avoid the induced influence on the scramjet,altitude and speed of the vehicle,the lateral maneuver and evasion are employed.To guarantee the remnant maneuver ability,the concept of specified miss distance is introduced and utilized to generate the guidance command for the AHV.In the framework of constrained optimal control,the analytical expression of the evasion command is derived,and the constraints of the overload can be ensured to be never violated.In fact,by analyzing the spacing of the pursers,it can be classified whether the cooperative pursuit is formed.For the coordination-unformed multiple pursers,the evasion can be achieved lightly by the proposed strategy.If the coordination is formed,the proposed method will generate a large reverse direction maneuver,and the successful evasion can be maintained as a result.The performance of the proposed algorithms is tested in numerical simulations.

Underestimation of phosphorus fraction change in the supernatant after phosphorus adsorption onto iron oxides and iron oxide–natural organic matter complexes

The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this study.With an initial P concentration of 20 mg/L（I =0.01 mol/L and pH = 7）,it was shown that the colloid（1 kDa-0.45 μm） component of P accounted for 10.6%,11.6%,6.5%,and 4.0%of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite（FH）,goethite（GE）,ferrihydrite-humic acid complex（FH-HA）,goethite-humic acid complex（GE-HA）,respectively.The 〈1 kDa component of P was still the predominant fraction in the supernatant,and underestimated colloidal P accounted for 2.2%,55.1%,45.5%,and 38.7%of P adsorption onto the solid surface of FH,FH-HA,GE and GE-HA,respectively.Thus,the colloid P could not be neglected.Notably,it could be interpreted that Fe3＋ hydrolysis from the adsorbents followed by the formation of colloidal hydrous ferric oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant.And colloidal adsorbent particles co-existing in the supernatant were another important reason for it.Additionally,dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant.Ultimately,we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P,even when considering other contaminants such as organic pollutants,heavy metal ions,and arsenate at the sediment/soil-water interface in the real environment.

Chloro-free synthesis of LiPF_(6)using the fluorine-oxygen exchange technique

A hydrogen fluoride-free and chloro-free method for synthesizing LiPF_(6) was developed.Employing CaF_(2) as the direct fluorinating reagent instead of hydrogen fluoride made it much safer and more environmentfriendly than conventional methods and reduced the metal residues in product owing to the relatively low-acid reaction conditions less corrosive to equipments.The use of P_(2)O_(5) as phosphorus source instead of traditionally employed PCl_(5) significantly reduced the chloro residue in product.Ca(H_(2)PO_(4))_(2),the only by-product of the process,could be easily converted into Ca_(3)(PO_(4))_(2),a best-selling chemical.The above advantages not only reduce the production costs by ca.20%,but also significantly improve the product purity.The fluorine-oxygen exchange reaction is a completely new technique for LiPF_(6) production and may bring about technological revolution in the related industry.

Efficient and accurate online estimation algorithm for zero-effort-miss and time-to-go based on data driven method

This paper introduces a novel and efficient algorithm for online estimation of zero-effortmiss and time-to-go based on data driven method.Only missile-target separations are utilized to construct the estimation models,and a practical Fisher fusion algorithm is derived to acquire the estimates with high accuracy and computational efficiency.Further,the two parameters can be online estimated at a particular time.Meanwhile,the kinematics equations of the missile-target engagement are independent,and assumptions of the missile guidance system dynamics and behaviors of the missile and target are completely out of consideration.Moreover,the effectiveness and applicability are explicitly verified through various simulation scenarios.

Petri nets semantics ofπ-calculus

As π-calculus based on the interleaving semantics cannot depict the true concurrency and has few supporting tools,it is translated into Petri nets.π-calculus is divided into basic elements,sequence,concurrency,choice and recursive modules.These modules are translated into Petri nets to construct a complicated system.Petri nets semantics for π-calculus visualize system structure as well as system behaviors.The structural analysis techniques allow direct qualitative analysis of the system properties on the structure of the nets.Finally,Petri nets semantics for π-calculus are illustrated by applying them to mobile telephone systems.