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In order to meet the unmanned needs of thin coal seam fully mechanized mining faces and address the issue of requiring dedicated personnel to monitor the cables of existing coal mining machines, an automatic cable dragging system for coal mining machines has been designed, The system has a rated power of 15 kW, a maximum length of 400m for the working face, and is suitable for a maximum speed of 30 m/min, This article focuses on the overall design, parameter design, and adaptation design of the automatic cable dragging system for coal mining machines, It elaborates in detail on four key technologies: the design of the cable chain transmission system based on dynamic simulation analysis, the track floating alignment technology suitable for complex working faces, the self adaptive control technology based on speed and torque, and the fast cable disassembly and assembly technology. The system design, mechanical structure, control strategy, fault protection, and other difficulties have been solved, It solves the problems of system design, mechanical structure, control strategy, and fault protection, and achieves that the cable clamp is always in a slightly tensioned state, Engineering application was carried out in the 14301 working face of Zhangjiamao Coal Mine, achieving adaptive and normalized operation of the entire working face, with a follow-up rate of 94.7%, The system has a reasonable structure, high reliability, convenient disassembly and maintenance, and can be retrofitted on existing working faces, It has strong scalability and promotes the progress of unmanned mining technology in thin coal seams.

In 2021, the price of most of the domestic coal skyrocketed, affecting the stable supply of electric power supply in some regions, while the price of Xinjiang Zhundong coal remains stable at a low level. Thus, the study of safe and stable large-scale combustion of Zhundong coal in boilers is more and more important for the energy supplyHowever, fouling and slagging often occur on the heating surfaces of the boiler due to the characteristics of Zhundong coal and the high temperature of the flue gas. The effects of the operating parameters, including the primary air velocity, operating oxygen content, air staging and coal fineness on the combustion temperature and NOx emission were investigated on a four-corner tangentially fired boiler of 660 MW capacity, which burned 95% Zhundong coal to get the relevant control criterion. Based on the research, the improvement of control function for contamination of heating surfaces was implemented under steady and dynamic working conditions. Finally, the influence of the improvement on the contamination of the heating surfaces was proved by the method of the contamination monitoring of heated surfaces. The results show that, at 660 MW load condition, the operating oxygen content had the most obvious influence on the flue gas temperature at the outlet of the furnace. The flue gas temperature decreased 99 °C when it increased from 2.0% to 3.5%. The reduction of the operating oxygen content and the local mean stoichiometric ratio of the main combustion zone could lead to a significant reduction of NOx emission and the change of the coal fineness had no obvious effect on NOx emission. After the improved control function was implemented, the rate of flue gas temperature decreased from 6.18 to 4.26 °C min−1 during the load increase process, the maximum temperature decreased from 1104 to 1023 °C under 660 MW. The heat absorption ratio of the platen superheater, low-temperature superheater and low-temperature reheater increased by 0.6%, 1.6% and 0.9%, respectively, indicating that the fouling and slagging was significantly reduced. At 330 MW load condition, increasing the coal fineness R90 to around 4.9% of the uppermost mill could effectively reduce the flue gas temperature near the bottom of the high-temperature reheater, reduce the deposition of combustible matter and fly ash, and inhibit the formation of fouling and slagging.

Aiming at the problem of autonomous obstacle avoidance of fixed-wing UAVs in a complex, dense and multi-obstacle environment, a path planning algorithm for fixed-wing UAVs based on a safe flight corridor is proposed. The difficulty of avoiding dense obstacles lies in the choice of obstacle circumvention and traversal: although circumvention is safer, the flight cost is greater; although the traversal cost is lower, the safety threat is higher. How to quickly solve the optimal path is the core issue. This paper firstly defines a safe flight corridor innovatively based on the maneuvering characteristics of fixed-wing UAVs and the Dubins curves. By comprehensively considering UAV flight safety and flight costs, an obstacle threat evaluation function is constructed. Secondly, in view of the computational complexity caused by the dense obstacles, an obstacle clustering algorithm based on obstacle density is proposed, and the nonlinear evaluation function in a high dynamic environment is quickly approximated by Monte Carlo sampling method. Finally, simulations verify the effectiveness of the proposed algorithm in solving dense obstacle avoidance for fixed-wing UAVs.

In the process of fault diagnosis for the core components of the integrated modular avionics power conversion module, selecting appropriate features can effectively improve the efficiency and classification accuracy of the model, and greatly reduce the computational complexity of the learning algorithm. This paper first designs a typical Sepic structure DC-DC converter model to simulate the typical fault types of the DC-DC converter; secondly, the corresponding original data is obtained through simulation; after data preprocessing, feature extraction and using multiple feature selection fusion algorithm, BP neural network method is used finally for fault diagnosis analysis of DC-DC converter. The simulation verifies the effectiveness of the above method.

A novel curing agent produced by our independent research and development is used to solidify the municipal sludge taken from Tianjin. GCTS true triaxial apparatus is used to conduct unconsolidated and undrained tests on the sludge solidified soil under different drying-wetting cycles. The stress-strain characteristics and strength index variation of the sludge solidified soil under drying-wetting cycles are investigated. The test results indicate that the stress-strain curve of the sludge solidified soil is approximately linear in the initial stage, and the failure stress increases with the increasing medium principal stress ratio b under the same conditions. At the same value of b, the failure stress decreases with the increasing number of drying-wetting cycles. After 1, 3, 5, 7 and 10 cycles, the failure stress values of the sludge solidified soil under different confining pressures all show the downward tendency. When the cycles are over 5 times, the reduction in the failure stress tends to be flat. When the value of b is small and the number of cycles is less than 3, strain softening occurs in the stress-strain curve, which appears as hardening with the increase of the confining pressure and the value of b. The values of c and φ of the sludge solidified soil show a decreasing trend with the increasing number of drying-wetting cycles, and finally tend to be stable. On this basis, the variation of values of c and φ under different principal stress ratios are analyzed, and the relationships between the values of c and φ and the number of drying-wetting cycles and the principal stress ratio are established respectively. Moreover, the prediction formula for the initial elastic modulus Ei and the asymptotic value of deviator stress (σ1−σ3)ulti which considers the influence of different confining pressures and the principal stress ratio is constructed.

BackgroundWith the development of accelerator technology, the accelerator-based Boron Neutron Capture Therapy (BNCT) has attracted more and more attention, and metallic 9Be is one of the most suitable materials for neutron-producing targets.PurposeThe study aims to investigate the possibility of obtaining BNCT neutron sources based on proton cyclotron with energy of 14 MeV and current intensity of 80 μA.MethodsGeant4 was used to simulate the neutron beam properties of Be target bombarded by 14 MeV proton beams and to optimize the target thickness. In addition, spherical natural uranium was considered as a neutron multiplier, the neutron beams generated by the combination of different materials and thicknesses of Beam Shaping Assembly (BSA) were investigated by simulation.ResultsThe optimized irradiated field at beam outlet of proton cyclotron can reach 95.6% of epithermal neutrons, and 6.26×107 n·cm-2·s-1 of the epithermal flux rate.ConclusionsThis design solution can be initially used for the technical verification of BNCT neutron source experimental terminal.

Characteristics of wireless communication environment and multi-antenna radiation in coal mine tunnel were analyzed. An adaptive multi-antenna technology was proposed on basis of tunnel waveguide theory and adaptive array antenna technology. Basic composition and principle of the adaptive multi-antenna in coal mine tunnel were introduced. Meanwhile, key technologies needed to be further studied were discussed. The adaptive multi-antenna in coal mine tunnel can selectively control number, type and intensity of guided wave modes according to channel characteristics, so as to improve underground status of wireless communication coverage from the source and performance of coal mine wireless communication system.

Based on half-mode substrate-integrated cavity antenna, a mine-used wearable folded half-mode substrate-integrated cavity antenna was designed considering requirements for underground wearable antenna. Width of antenna is reduced by use of folded geometry, and planar antenna is realized with horizontal feeding probe structure. The simulation results show that the antenna resonates at 5 GHz, -10 dB bandwidth is 254 MHz, the maximum gain is 5.4 dBi, radiation efficiency is 70%, and the antenna has radiation direction with wide beamwidth and low back radiation. Besides, -10 dB bandwidth of the antenna can be increased with thicker upper substrate.

Based on half-mode substrate-integrated cavity antenna, a mine-used frequency-switchable half-mode substrate-integrated cavity antenna was designed considering requirements for underground wireless communication and personnel real-time monitoring. Effect on resonance frequency by adding shorting pin in different positions inside cavity was analyzed. Based on the analysis, capacity of frequency-switching in band of 2.45-3.07 GHz was realized by installing removable screw through several pre-designed holes on the antenna. A prototype of the proposed antenna was fabricated with conductive fabric, conductive threads and leather substrate. The design of the proposed antenna was finally validated by agreement between the simulation and test results.

In view of complex electromagnetic wave propagation environment and outstanding multipath effects in coal mine, major anti-multipath methods of mine wireless communication were analyzed. According to the characteristics of cooperative communication technology, cooperative communication was proposed to apply to mine WMN communication system, and mine C-WMN communication system architecture was given. On the basis of geometry characteristics of several typical environments in mine, the corresponding modes of cooperative relay of C-WMN were analyzed.

A two-arms planar spiral antenna was designed for long-narrow confined space like tunnels. The antenna is composed of two symmetrical arms which are structured by four equiangular helix lines. Compared with traditional omni-directional antenna, the antenna has greater potential for reducing reflection loss of radio waves by tunnel walls. Because of circular polarization characteristics, the antenna has potential for weakening influence of multi-path effect, and bidirectional radiation characteristic can make the antenna to improve radiation efficiency. The simulation results show that when the antenna with five cores works at 2.4 GHz, half power beam width in 3 dB is more than 60 degree and gain is more than 4 dB while the antenna with ten cores is 120 degree and 6 dB seperately.

For difficulty of monitoring of energy consumption of crane by use of wired transmission, a hardware and software design scheme of Sink node of perception system of energy consumption for mine crane based on wireless sensor network were proposed. The node uses wireless radio frequency chip CC2530 to realize acquisition and wireless transmission of working parameters of the crane, uses Ethernet controller ENC28J60 to convert received sample data into Ethernet data packet, then uploads it to background monitoring center. Transplantation of uIP protocol stack in CC2530 chip and compiling of performance functions of the Sink node were described in details based on analysis of data communication flow and features of the uIP protocol stack. The test result verifies that the design scheme can realize transmission of TCP data packet accurately and meet requirement of data transmission of the perception system of energy consumption for mine crane.

In view of problems of low intelligentization and high energy consumption of existing mine lighting system, a design scheme of mine intelligent lighting system based on Internet of Things for perception mine was proposed, system architecture was given, and node of wireless sensing subnet and implementation process of system control were introduced. The system can distinguish the target and set up lighting state independently according to the moving target location and tag number, so as to achieve energy saving effect. At the same time, the state information of all nodes in the network was uploaded to the ground monitoring center, so as to easy to control and maintain. When people is in distress, the system also can be used as emergency indicator system, and has function of avoiding risk.

In view of problem that EPA network only supports real-time data transmission inside segments but not across segments, a real-time adaptive scheduling algorithm for across segments delay in EPA was proposed. Transmission process of across segments in EPA was analyzed, data transmission delay modeling of across segments in EPA was given, and real-time data transmission of across segments was realized through change of filtering rule of across segments transmission message in EPA and transformation of statement message of aperiodic data.

For common non-destructive measurement methods of anchor stock have problem that vibration wave ca't couple well with the anchor stock, the paper proposed a new non-destructive measurement method of anchor stock legth based on electricity standing wave. The method is based on equivalent principle between transmission line and antenna, and uses standing wave theory of transmission line to measure length of metal anchor stock, that is, scan input signal frequency, when the first minimum voltage of the anchor stock appears, the corresponding signal wavelength is 4 times of anchor stock length, and the anchor stock length can be calculated. The measured result shows that the method has convenient coupling and good measurement result.

The paper analyzed three storage algorithms of chain storage algorithm, hash table storage algorithm and hash binary tree storage algorithm which are applicable to the card reader of personnel positioning system in term of search time and storage capacity. It gave usage efficiency and application condition of the three kinds of storage algorithms respectively. The test results showed that the search time of the chain storage algorithm grows in linear, the hash table storage algorithm is significantly better than the chain storage algorithm; if the tested data is increased, advantage of the hash table storage algorithm will be more apparent. When the data is bigger, the hash search binary tree storage algorithm is superior than the hash table storage algorithm, and when number reaches 8 000 people above required by standard of industry, choosing the hash search binary tree storage algorithm is more reasonable.

Based on the multimode theory and ray theory of electromagnetic wave propagation in coal mine tunnels, the paper established a wireless channel model of wireless signal in mine tunnels, deduced formula of coherence bandwidth of wireless channel considered to important parameters influenced by the coherence bandwidth, such as propagation distance, tunnel section size, carrier frequency, antenna polarization, antenna location, medium electrical parameters. It simulated influence of the above parameters on the coherence bandwidth in a rectangular tunnel with width 4 m, height 3 m, and obtained theoretical results that the coherence bandwidth of the mine channel is proportional to the frequency, inverse proportional to propagation distance, the tunnel section size and the relative medium electrical parameters, to change position of antenna in the rectangular section tunnel is less influenced on coherence bandwidth.

In view of problem that it need make protocol conversion for adaptation between IEEE802.15.4 and IPv6 when interconnecting mine WSN with 6LoWPAN technology and Internet, the paper proposed a design scheme of IPv4/IPv6 adaptation layer. The scheme uses design idea of division and integration: firstly making design for IPv4 adaptation layer and IPv6 adaptation layer separately, then integrating IPv4 adaptation layer and IPv6 adaptation layer through analyzing the two designs to make IPv4 adaptation layer and IPv6 adaptation layer become optional IPv4/IPv6 adaptation layer. The paper also introduced application implementation of the scheme in gateway of mine personnel location system. The next research emphasis is to find corresponding hardware to support the scheme applied in practice.

A 3D three-phase segmentally variable density perforation optimization model for horizontal wells is built by coupling reservoir fluid filtration, near wellbore inflow and wellbore conduit flow based on reservoir numerical simulation. The effects of 8 factors (filtration difference between heel/toe and middle intervals, imperforated interval, permeability heterogeneity, oil layer thickness heterogeneity, porosity heterogeneity, wellbore pressure drawdown, maximum perforation density, and perforation optimization principles) on perforation density and inflow profile, and that of fluid viscosity, casing diameter and pipe wall coarseness on well bore pressure drawdown, are analyzed for segmentally variable density perforation of horizontal wells. Results show that filtration difference between heel/toe and middle intervals, imperforated interval, permeability heterogeneity and oil layer thickness heterogeneity have significant effects on segmentally variable density perforation. In particular, different perforation density optimizations may occur when filtration difference between heel/toe and middle interval is not considered; imperforated interval may affect inflow profile; well bore pressure drawdown can be ruled out for segmentally variable density perforation of most horizontal wells onshore in China. The contrast between predicted and actual production of Well AT9-7H in the Tahe Oilfield indicates that the model is highly accurate. Key words: horizontal well, segmentally variable density perforation, reservoir numerical simulation, imperforated interval, inflow profile, heterogeneity

The paper indicated that sensor mine Internet of things is extension and extended application based on integrated automation of coal mine, it is different from integrated automation system in a great degree; it is also different from application of surface Internet of things due to the characteristics of coal mine application. The paper introduced characteristics of sensor mine Internet of things which mainly show in several aspects of integrated application of multiple systems, opening of sensor layer and application platform and being suitable for constructing logic subsystems. It analyzed key technologies of sensor layer, network layer and application layer and common technology with cross-layer, and gave openness requirements and standard construction of sensor mine Internet of things. The paper has certain reference value for better understanding construction of sensor mine Internet of things.

The paper discussed relationship of sensor mine and digital mine and integrated automation of mine, and pointed out that the concept of sensor mine is sublimation of concepts of both digital mine and integrated automation of mine. It also gave sensor mine model based on three-layer digital mine model. It presented explicitly that the core problem of sensor mine is three kinds of sensing, which is to sense disaster omen to realize early warning, to sense environment to realize active safety guarantee, and to sense health status of mine equipments to realize foreknowledge maintain. The key of construction of sensor mine system is building of sensor layer network and the goal is to decrease disasters and ensure safety.

The paper introduced development, basic concept, hierarchy structure, standards and typical application about Internet of things and indicated main problems existing in application of Internet of thing. Meanwhile, it proposed that the application model of surface Internet of things could not be copied in construction of Internet of thing of sensor mine, so as to avoid problems of new information island and subsystem island. The content of the paper is for understanding series papers of Internet of Things and Sensor Mine which will be contiuously published in journal Industry and Mine Automation.

For difficulty of monitoring status of energy consumption of crane by use of wired transmission technology, a design scheme of monitoring node of energy consumption based on wireless sensor networks was proposed. The node uses CC2430 chip based on ZigBee technology as master chip, and achieves real-time acquisition and wireless transmission of energy consumption data of crane, which has advantages of low power consumption, low cost, strong anti-interference ability and adaptive capacity.

The paper deduced formula of electromagnetic wave attenuation caused by wall roughness under combined effects of multi wave mode according to transmission theory of multi wave mode, and simulated and analyzed effect of wall roughness on attenuation characteristics of electromagnetic wave by multi mode model. Matlab simulation results show that influence of wall roughness on attenuation characteristic increases with frequency. Due to combined effects of waveguide and wall roughness, there is a frequency range with low attenuation of 0.4-2 GHz in wave propagation in coal mine tunnels.

The paper pointed out that M2M platform of Internet of things of sensor mine should provide open interfaces for services of application layer and suit to requirements of perfecting 'six systems' for safe act of rescue, leaders going into mine and disaster monitoring of coal mine. It gave four-layer structure of Internet of things of coal enterprise, pointed out that construction of Internet of things of sensor mine is a key of construction of Internet of things of whole coal enterprise and main functions of the other layers should be safety and resource management of coal mine, and analyzed application modes of Internet of things of coal enterprise of mining group, province and the state. At last, it proposed problems which need paying attention to in construction of Internet of things of sensor mine.

The wood was used as raw material to obtain the wood skeleton by matrix-removal. And the high-strength wood-based composite hydrogels with PVA/PAM double network structure were constructed by in-situ polymerization. The change rules of macro/micro functional morphological characteristics, mechanical properties, optical properties and chemical composition of the wood-based composite hydrogels were systematically investigated by adjusting the mass ratio of PVA and PAM in the hydrogel system. The results show that introducing a small amount of PVA into the PAM/wood skeleton composite hydrogels and constructing a double network structure can effectively enhanced the mechanical properties of the wood-based composite hydrogels. As a result, the wood-based composite hydrogels show tensile properties with a maximum tensile strength and fracture elongation of 16.47 MPa and 11.61%. Furthermore, the wood-based composite hydrogel is used as a flexible substrate with a conductivity of 1.8 S/m to assemble and build sensor components. The results indicate that the flexible sensor exhibits stable and repeatable relative current signal changes under a variety of deformations.

A KCN-KE model combining K-means color network and Kansei Engineering was constructed to solve the problem of poor coupling between color gene and user's perceptual demand in the study of Miao embroidery clothing color in Southeast Guizhou. Firstly, the original image set was selected and grouped by Delphi method. Then, the K-means clustering algorithm was used to extract color and calculate the correlation between color weights, so as to construct the color network model of Miao embroidery clothing in Southeast Guizhou. On this basis, the color perceptual image survey samples of Miao embroidery clothing in Southeast Guizhou were constructed, and the perceptual image vocabulary was used to investigate the perceptual image. By mapping RGB color space to HSL color space, the coding of color elements was clarified, and the simultaneous equation between perceptual image vocabulary and color elements of Miao embroidery clothing in Southeast Guizhou was established by using multiple linear regression analysis to construct the KCN-KE model. The effectiveness of the KCN-KE model was verified by case design. The results show that the recognition accuracy of perceptual words is above 94%, and the average recognition rate is 95.78%. The KCN-KE model can provide a theoretical reference for the quantitative analysis of Miao embroidery clothing color in Southeast Guizhou. [ABSTRACT FROM AUTHOR]

In the large-scale satellite constellation technology, the establishment of satellite internal network is the top priority. As the network capacity of the constellation continues to expand and the number of satellite nodes continues to increase, the previous multiple access technology can no longer meet the network capacity requirements of large-scale constellations. In order to meet the requirements of massive connections of satellite nodes in large-scale constellation for new networking communication methods, this paper establishes a sparse spread spectrum inter-satellite communication system with sparse code multiple access (SCMA) as the core. At the same time, the channel characteristics of large-scale constellation are analyzed and the corresponding inter satellite channel model is established in MATLAB. Based on this channel model, the performance of the system is simulated. The simulation results show that under the same signal energy to noise ratio, the sparse spread spectrum inter-satellite communication system established in this paper has better BER characteristics compared with orthogonal frequency division multiple access (OFDMA) and code division multiple access (CDMA). In addition, the threshold signal energy to noise ratio of the system is more than 2 dB better than that of CDMA technology, and the utilization rate of time-frequency resources is 50% higher than that of OFDMA technology.

Using the modified Grübler-Kutzbach's formula of mechanism mobility, the calculation of the mobility of combined mechanism may produce wrong results. In order to correctly calculate the mobility of combined mechanism, and to consider that the calculation method of the mobility of combined mechanism is convenient for engineers for study and application, according to the modified Grübler-Kutzbach's formula of the mechanism mobility, the calculation formula of mobility of combined mechanism is deduced. The general calculation formula of mobility of mechanism is obtained. The attentions of calculating mobility of combined mechanism are proposed. The method of dividing the combined mechanism into basic mechanisms is given. Numerical examples are given. The modified Grübler-Kutzbach's formula of mechanism mobility can only be used to calculate mobility of a basic mechanism, and to calculate mobility of combined mechanism in that each basic mechanism has the same common constraint. The mobility of general combined mechanism should be calculated by the calculation formula of mobility of combined mechanism. The mobility of combined mechanism is equal to the sum of the mobility of each basic mechanism.

Objective To isolate a strain of lysing carbapenem-resistant Klebsiella pneumoniae phage, and explore its biological characteristics and whole genome information. Methods The phage was isolated and purified from waste water of the General Hospital of Western Theater Command Hospital by the double-layer agar plate method. The morphology of phage was observed by transmission electron microscopy, and its biological properties and in vitro antibacterial activity were determined. Whole-genome sequencing was used to analyze its structural characteristics, and a phylogenetic evolutionary tree and the comparative genomic analysis was conducted to analyze the evolutionary relationships of phage. Results A virulent phage was isolated and named vB_KpnP1, which formed a 2~3 mm transparent circular spot surrounded by a distinct halo; Electron microscopy showed that the head size of the phage was about 68.2 nm×64.3 nm, and the tail length was about 11 nm; The head of the phage was a regular icosahedron with a non-contractile short tail, which was thus identified as a member of the Autographiviridae family and the Caudovirales order; the optimal multiplicity of infection was 0.0 001, the incubation period was 10 min, the lysis period was 30 min, and the amount of lysis was 26 PFU/cell; The adsorption rate was about 80% in 10 min. The phage was insensitive to chloroform and was stable at temperatures of 10~50 ℃ and pH values of 4~12; The lysis rate of carbapenem-resistant Klebsiella pneumoniae was 54.55% (12/22), and the host spectrum was wide; In vitro antibacterial test showed that it could inhibit the growth of host bacteria. Phage vB_KpnP1 was double-stranded DNA (dsDNA) with a 40 352 bp of full genome length, and 53.09% of GC content. It contained 50 CDS. Conclusion A virulent Klebsiella pneumoniae phage, vB_KpnP1, with the potential to treat carbapenem-resistant Klebsiella pneumoniae infections, is successfully isolated.

In this paper, a flame/spark detection device for wood dust based on atomic emission spectrometry to improve the reliability of detection with the emission spectrum of potassium was designed. Based on the theory that the internal elements of dust could be excited by heat, the detection device was built by using high-precision spectral elements, high-speed A/D conversion and ARM, and the real-time spectral characteristics were obtained through the network port. The results showed that the spectral method had significant characteristics which can obtain the obvious potassium spectrum, so that could be used as the detection basis of the detection device. The device had the advantages of low cost, high precision, and small volume, which could be widely used in enterprises. In this paper, the design idea of dust spark detection device was enriched. The device can quickly and accurately obtain the real-time dust spectrum state, which can provide technical support for preventing dust explosion accidents. [ABSTRACT FROM AUTHOR]

In the calculation of mobility of the mechanism using the modified Grübler-Kutzbach's formula of mechanism mobility, the common constraint of the mechanism has to be solved. In order to obtain the common constraint of the mechanism with a simpler method and on the basis of defining the common constraint of the mechanism, the coordinate direction of the mechanism without common constraint is obtained according to the mobility of kinematic pair and the constraint direction of the kinematic pair whose absolute motion is not zero, and then the common constraint of the mechanism is determined in other coordinate direction. The total number of coordinate directions with and without the common constraint of the mechanism is 6. The common constraint of the mechanism is equal to the number of coordinate directions with common constraint. This method does not need the screw theory to solve the common constraints of the mechanism, which is convenient for engineering and technical personnel to solve the common constraints of the mechanism. It is also convenient for the modified Grübler-Kutzbach's formula of the mechanism mobility to be popularized and applied in engineering and technical personnel.

The top deadly cancer sites in terms of global deaths are lung， stomach， liver， breast and colon cancers. In recent years， more and more studies have shown that cancer-related inflammation plays a crucial role in the development and prognosis of the cancer， such as neutrophil-lymphocyte ratio， monocyte-lymphocyte ratio and platelet-lymphocyte ratio. In 2014， the systemic immune inflammatory index （SII） was first defined. SII combined with peripheral platelets， lymphocytes and neutrophils serves as a comprehensive prognostic parameter， which reflects the balance of immune status and host inflammation more comprehensively than a single inflammatory index. Furthermore， it shows obvious advantages in predicting cancer prognosis. In this article， the application of SII in the prognosis of five common solid cancers was reviewed， aiming to provide the basis for clinical evaluation of cancer prognosis.

Objective To observe the effect of dopamine pretreatment of the root canal on improving the bonding performance of AH-plus sealer. Methods A total of 32 freshly isolated permanent teeth with a single canal were collected, with no caries, no fracture of roots, and a root canal curvature0.05). Root canals treated with 2 mg/mL dopamine had the highest bonding strength in all groups (P

The MYB type transcription factors are involved in plant development and response to abiotic stress. GmMYB52 was significantly up-regulated after salt treatment. In order to gain more information about GmMYB52, GmMYB52 of Williams 82 was cloned by RT-PCR. Bioinformatic analysis showed the CDS of GmMYB52 was 1083 bp, encoding 360 amino acid residues. A MYB domain was found in the region of 110 to 160 amino acid residues from N-terminal. Blast results showed that GmMYB52 are highly homologous to GmMYB62, AtMYBSt1 from Arabidopsis, MtMYB52 from Medicago sativa, OsMYBS3 from Oryza sativa, and CcMYB-like protein J from Cajanus cajan. Quantitative PCR (qPCR) results indicated that the transcription level of GmMYB52 was upregulated under ABA and low temperature stresses, under salt, drought and cold stresses, show a bimodal pattern. GmMYB52 was nearly expressed in all detected tissues, except in pods at maturing stage, and its expression level was relatively higher at seedling or flowering stages than those at maturing stage. The transcription level of GmMYB52 was high in stem, leaf, and flower, during seedling and blooming stages, and low in root and pods during maturity stage. Subcellular localization results showed that GmMYB52 was located in the nucleus which is in agreement with the localization characteristics of typical transcription factors. Yeast hybrid assay indicated that GmMYB52 had transcriptional activation functions and could bind to several MYB cis-acting element motifs. In conclusion GmMYB52 is a typical 1R-MYB transcription factor, and able to bind MYB cis-acting element motifs. We speculate GmMYB52 is involved in response to the abiotic stress and ABA signal transduction pathway. [ABSTRACT FROM AUTHOR]

The fungal- or bacterial-origin vector elements are commonly used in transgenic crops, which raise great concerns about the safety of GM foods. In the study, we isolated the pea (Pisum sativum) terminator, rbc-T, and constructed a transformation vector by replacing the Agrobacterium terminator nos-T with rbc-T. The minimum transformation fragment consisting of Ubiquitin promoter, GUS reporter gene and terminator rbc-T was transformed into common wheat by particle bombardment method. Meanwhile a minimum transformation fragment with the Agrobacterium terminator nos-T was used as the control. The T2 transgenic lines were regenerated after PCR validation of the transformation. In the transgenic lines carrying both kinds of terminators, GUS gene expression was detected by GUS histochemical staining and enzyme activity analysis, indicating that the pea terminator rbc-T is applicable as an alternative of the Agrobacterium terminator nos-T in transgenic wheat research. [ABSTRACT FROM AUTHOR]

Biotic stresses, like plant diseases and insect pests, and abiotic stresses, such as drought and salt, heavily threaten plant growth and influence crop yield and quality. Osmotic stress resulting from water deficiency in the soil is one of major hurdles. Nuclear Factor Y (NF-Y) is a heterotrimeric protein, consisting of NF-YA, NF-YB, and NF-YC in plant. NF-Y plays significant roles in the pathway responding to osmotic stresses in plants. We acquired a gene GmNF-YCa, a member of regulatory subunit NF-YC family in soybean (Glycine max L.), by screening a soybean cDNA library using yeast two-hybrid system. The full sequence of GmNF-YCa is 864 bp, encoding 287 amino acids and having a NF-YC motif, belonging to NF-YC subfamily. GmNF-YCa is a hydrophilic protein with a molecular weight of 31.6 kD and isoelectric point of 5.07, and containing a transmembrane domain and no any signal peptides. Sequence analysis showed that NF-YC subfamily was highly conserved among various species. Promoters of GmNF-YCa contained various abiotic stresses and light responsive elements, such as ARE, Box 4, GATA-motif, Box I, ACE, ABRE, and CAT-Box. According to tissue-specific analysis, GmNF-YCa had the highest expression level in germination stage. Quantitative real-time PCR suggested that GmNF-YCa was induced by sucrose stress and mannitol treatment. GmNF-YCa was transformated to Arabidopsis successfully by Agrobacterium-mediated method and the overexpressed Arabidopsis was prepared for the function characterization analysis. Overexpression of GmNF-YCa could improve tolerance of transgenic Arabidopsis to osmotic stress in the germination stage, and enhance root development with more lateral roots in sucrose and mannitol treatments. [ABSTRACT FROM AUTHOR]

Based on the data collected from three oceanographic surveys in the east area of north (30.68°—30.83° N,121.67°—121.87° E), the east area of south (29.95°—30.24° N,121.60°—121.85° E), and the west area of north (30.58°—30.77° N,121.31°—121.56° E) Hangzhou Bay during the autumn of 2009, 2011 and 2012, we analyzed the species composition, ecological groups and the similarity of zooplankton community, as well as influencing factors. The results indicated that a total of 14 species belonging to 6 groups were identified in the west area of north Hangzhou Bay. Tortanus vermiculus was the predominant species. The zooplankton assembles were mainly influenced by the runoff strength of the Qiantang River. The zooplankton fauna was mainly composed of the subtropical estuarine brackish-water species, accounting for 79.8% in the total abundance. A total of 19 species belonging to 6 groups were identified in the east area of north Hangzhou Bay. The composition of zooplankton community was mainly influenced by the Changjiang diluted water and offshore water of the East China Sea. It was mainly composed of warm-temperature and subtropical nearshore low-salinity species, accounting for 43.5% and 31.1% in the total abundance, respectively. In the east area of south Hangzhou Bay, a total of 25 species belonging to 7 groups were identified. The composition of zooplankton community was mainly influenced by the offshore water of the East China Sea. The dominate eco-group types were subtropical nearshore low-salinity and subtropical nearshore species, accounting for 72.3% and 18.3% in the total abundance, respectively. And the ecological groups of species with the highest abundance was Labidocera sinilobata, accounting for 65.3% in the total abundance. By hierarchical cluster analysis and non-metric multidimensional scaling (NMDS) method, it was found that the zooplankton communities in the three parts of Hangzhou Bay were significantly different, which were closely associated with the impacts of different water masses from these parts. [ABSTRACT FROM AUTHOR]

In order to solve the problem of redundant time slot allocation for single node sectors, too large overhead and excessively long time spent for beamforming training under mobile scenarios in existing directional MAC protocols, this paper proposes high slot utilization rate and fast directional MAC protocol(HUFD-MAC) for Terahertz wireless personal area networks. The HUFD-MAC protocol uses redundant single node sectors to transmit downlink data and reduces the number of transmitted beam training frames based on time information. This effectively improves the utilization of time slots, reduces network overhead, and decreases the time required for beamforming. The simulation results show that compared with the IEEE 802.15.3c and ACAP-MAC protocols, the network overhead of HUFD-MAC is reduced by about 3.23%, and the MAC layer throughput is increased by about 8.50%.

The existing opportunistic network routing algorithms based on bargaining game has excessive control overhead caused by the excessive interaction process of nodes, the additional overhead caused by requesting for useless messages，the additional cost and the delay caused by the low probability of the transaction between the two parties. Besides, when the number of remaining messages in the SV list drops to 1，this condition will result in overhead as well. In response to the above problems, this paper proposes an efficient opportunity network routing algorithm——EORB. The algorithm reduces redundant overhead by adopting adaptive streamlined packet digest，adaptively merging SVDP messages and purchase messages, and comprehensively considering the game strategy of buyers′ and sellers′ benefits. It accelerates the message forwarding rate and improves the arrival rate of messages. The simulation results show that the algorithm effectively improves the rate of message delivery,reduces system overhead and reduces average end-to-end delay of messages.

Asymmetrical dicationic ionic liquid 1-(1-pyridinium-1-yl) pentane-(1-methylpiperidinium) bi [bis (trifluoromethanesulfonyl) imide] ([PyC5Pi] [NTf2]2) was prepared through molecular design theory, and its structure was characterized with IR and H NMR. The thermal stability, thermal decomposition kinetic parameters and thermal decomposition mechanism model function of the ionic liquid were studied by using non-isothermal thermogravimetric analysis method, equal-transition ratio method and multivariate non-linear-regression method. The results showed that the thermal stability of the[PyC5Pi] [NTf2]2 was better. According to equal-transition ratio method, the average activation energy and average pre-exponential factor of[PyC5Pi] [NTf2]2 were 160. 10 kj/mol and 9. 17 respectively. Multivariate non-linear-regression method indicated that the ionic liquid was re-tier autocatalytic reaction (CnB), n = 1. 592 6, Kcat = 5. 602 7, corresponding to the thermal decomposition mechanism model function f(α) = (1-α)1.592 6 (1 + 5. 602 7α), E = 169.71 kJ ⋅ mol-1, lg A = 9. 59, respectively. The results were consistent with that of equal-transition ratio method. [ABSTRACT FROM AUTHOR]

Based on data from bottom trawl surveys during spring and summer of 2010, the species composition and community structure of fish community in Lüsi fishing ground were investigated and compared with those at different latitudes. A total of 21 were identified in spring and 28 identified in summer. In spring, it was mainly composed of warm-temperate fish (9 species), accounting for 45. 2% and 72. 9% in the individual density and biomass density, respectively. Warm-temperate species Larimichthys polyactis, Cynoglossus joyneri and Cynoglossus semilaevis were dominant in spring. In summer, warm water species appeared in large numbers by 21, accounting for 75. 2% and 71. 7% in the individual density and biomass density, respectively. Collichthys lucidus and Coilia mystus were the predominant species in summer. One way-ANOVA indicated that the temperature and salinity between spring and summer in Lüsi fishing ground were significantly different, which resulted in the succession of fish community, i. e. the gradual decrease of the warm-temperate, neritic and nearshore species and the concomitant gradual increase of warm-water and estuarine species. [ABSTRACT FROM AUTHOR]