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Copper is widely used in the power industry due to its good electrical conductivity. However, owing to its low hardness and resistance to abrasion, copper is prone to damage when working under harsh environmental conditions. In order to protect the power equipment and improve the surface strength of the material, this study explores the feasibility of using laser cladding technology to prepare a protective layer on the copper substrate. The phase, microstructure and element distribution of the cladding layer were analyzed, and the changes in the microhardness of the cross-section were measured. The wear resistance of the two cladding layers was tested and compared with the wear resistance of pure copper. The experimental results show that the cladding layer has uniform structure distribution, fine grains, and no element segregation; the hardness of the cladding layer is greatly increased, and the average hardness of the CuCr20 cladding layer is 155.8 HV, which can reach 2.2 times that of the substrate. The average hardness of the CuCr40 cladding layer is 254.4HV, which can reach 3.6 times that of the matrix. The wear resistance of the CuCr40 cladding layer is higher than that of the CuCr20 cladding layer, which can reach three times that of pure copper. Experiments have proved that the protective effect can be achieved by preparing a laser cladding layer on the surface of pure copper.

In this paper, we studied the positive integer solutions of a typical Diophantine equation starting from two basic equations including a Diophantine equation and a Pell equation, and we will prove all the positive integer solutions of the typical Diophantine equation.

In this paper, we studied the integer solutions of the typical Diophantine equations with some important theories in quadratic fields and the fundamental theorem of arithmetic in the ring of quadratic algebraic integers. We proved all the integer solutions of the Diophantine equation Χ2 − 21 = 4y5.

By observing that the infinite triangle obtained from some generalized harmonic numbers follows a Riordan array, we using connections between the Stirling numbers of both kinds and other inverse generalized harmonic numbers. we proved some combinatorial sums and inverse generalized harmonic number identities.

High speed encoder is the key element of high speed analog-to-digital converter (ADC). Therefor the type of encoder, the type of code, bubble error suppression and bit synchronization must be taken into careful consideration especially for folding and interpolating ADC. To reduce the bubble error which may resulted from the circuit niose, comparator metastability and other interference, the output of quantizer is first encoded with gray code and then converted to binary code. This high speed encoder is verified in the whole time-interleaved ADC with 0.18 Bi-CMOS technology, the whole ADC can achieve a SNR of 45 dB at the sampling rate of 5GHz and input frequency of 495MHz, meanwhile a bit error rate (BER) of less than 10-16 is ensured by this design.

A structure of ADCs which combines fold-interpolation and pipeline is introduced, as well as corresponding digital calibration method. The simulation shows that the performances of the ADC after calibration are improved a lot. The SFDR achieves 62dB at a sampling rate of 800MHz, when the input analog signal is at 397MHz.

Recently, many mobile user authentication schemes with user anonymity for wireless communications have been proposed. In 2012, Li and Lee proposed a novel user authentication and privacy preserving scheme with smart cards for wireless communications. In 2013, Jeon et al. proposed an improved user authentication scheme, and claimed their scheme achieves user anonymity and more efficient. On the basis of their work, we put forward a new user authentication scheme using elliptic curve cryptography with user anonymity for wireless communications. The security and performance analysis show that the new scheme is more secure and efficient for wireless communications.

Magnetic molecularly imprinted polymers (MMIPs) based on poly [2,2’-(p-oxidiphenylene)-5,5’-bibenzimidazole] (OPBI) composites were synthesized for the selective adsorption and detection of nonylphenol (NP) from water samples. During polymerization, Fe3O4@C was used as supporter and magnetic substance and OPBI not only was used as crosslinking agent but also functional monomer. Morphology of Fe3O4@C and MMIPs were investigated by scanning electron microscopy (SEM). The kinetics of adsorption followed the pseudo-first-order model. Selectivity of MMIPs was further demonstrated through HPLC analysis of the water samples, in which bisphenol A (BPA), phenol, 4-nitrophenol (4-NP) and tetrabromobisphenol (TBBPA) were dissolved respectively. The result showed that MMIPs had more effectively recognition capability of NP than other contrasts.

Magnetic chitosan microspheres were prepared with reversed-phase suspension methodology using glutaraldehyde as cross-linking reagent for sorption of PFOS. In this study, the SEM image of MCTS showed that it had well-shaped spherical form with smooth surface, and its mean particle size was 4.2 μm from the particle size analyzer. Additionally, the sorption kinetics followed the mechanism of the pseudo-second-order equation, and the magnetic chitosan microspheres had a high sorption amount of 865.95 mg g-1 for PFOS due to the electrostatic interaction.

In view of the solar array of the solar wing UAV, this paper presents a method of using Bird model and HDKR model to calculate the solution of sun light intensity, and thus the power can be calculated. According to the engineering requirements, it is convenient to calculate the results using DO model in fluent software. Both methods are relatively easy to calculate the surface of the solar array power generation. Finally, this paper makes a detailed analysis on the UAV solar array power characteristics. The flight latitude, season, heading angle and pitch angle of the solar powered UAV have an influence on the power generation characteristics and rules. The results show that the power of the solar power generation quantity, is not only related with the attributes of the battery itself, but also greatly influenced by the weather, season, the UAV flight attitude as well as the latitude and longitude.

Password authentication scheme using smart cards is an important part of securely accessing the server program. In 2012, Chen et al. proposed a robust smart-card-based remote user password authentication scheme. Recently, Li et al. discovered the scheme of Chen et al. cannot really ensure forward secrecy, and it cannot achieve the goal of efficiency for wrong password login. Then, they proposed an enhanced remote user password authentication scheme based on smart cards. In this paper, we propose a novel authentication scheme by using elliptic curve cryptography. The new scheme can achieve both the user anonymity and the goal of efficiency of incorrect password detection, and can also establish a session key for the subsequent secure communication. Moreover, we show by a detailed analysis that it requires lower computation cost while improving the security of the scheme.

The transmission between title bar information of engineering drawing and PDM is a key factor to realize design of engineering drawing based on PDM platform. This paper primarily adopts Object ARX to conduct secondary development of AutoCAD so that the title bar and related information of engineering drawing in the PDM system can be transmitted between AutoCAD and PDM. KeyWords:PDM; Title Bar Information; BOM; Information Transmission

The inspection of sheet strips post high-speed punching mainly relies on the manual off-line inspection with basic inspection equipment or CCD equipment. Such inspections cannot reflect the real-time conformity of strip machining, and in severe cases, lead to rejects in batches, causing a tremendous waste in production. Now that the application of charge-coupled device (CCD) technology in product inspection is relatively mature, it would be a very good thought to adopt the CCD technology to realize real-time online inspection of conformity of the high-speed punched strips. KeyWords: CCD technology; strip; online automatic inspection; progressive die

Based on the nanoporous network structure features of silica aerogel, the gas-solid coupled heat transfer model of silica aerogel is analyzed, and the calculation formulas of the gas-solid coupled, the gas thermal conductivity and the heat radiation within the aerogel are derived. The thermal conductivity of pure silica aerogel is calculated according to the derived heat transfer model and is also experimentally measured. Moreover, measurements on the thermal conductivities of silica aerogel composites with different densities at ambient conditions are performed. And finally, a novel design of silica aerogel based integrated structure and thermal insulation used for withstanding the harsh thermal environment on the Martin surface is presented.

In this paper, we analyze and point out several weaknesses in the dynamic ID-based remote user authentication schemes using smart card for multi-server environments, and present the countermeasures to enhance the security of the schemes. Taking Li et al.'s scheme for instance, we demonstrate that their scheme does not provide forward secrecy and key privacy for the session keys, and cannot resist offline password guessing attack. Furthermore, the reasons of these security weaknesses are analyzed through extending the attacks to its predecessors. Finally, the improved ideas of local verification and authenticated Diffie-Hellman key agreement are presented to overcome the weaknesses mentioned above.

Failure mode mitigation process is vague, unfocused, and its effects on RMS index are not clear for complex product development. Firstly, a complete failure mode mitigation closure process and an approach of failure mode mitigation basing on logic decision were proposed. Secondly, the effect models of failure mode mitigation on RMS index were established, and the decision model of the failure mode mitigation order through the rough set theory was put forward. Finally, an example of the fuel system is given to validate the approach and models. The paper proved that the relationship between the achievement process of RMS index.

As the poor development of domestic semiconductor industry in China, the manufacturing of electronic equipments highly depends on the import of electronic components, especially monolithic integrated chips. Unfortunately, numerous counterfeit parts have been found in the supply chain because of the embargo, obsolete and other complicated reasons. Once these counterfeit electronic components were used, they can have devastating effects on the security and reliability of the electronic equipments. This paper analyses the reason of the emergence, source and types of counterfeit electronic components, and expound the method of identification and avoiding use of those counterfeit parts in the process of electronic equipments manufacturing, which is based on destructive physical analysis of electronic components and the database of basic characteristics information of imported electronic components.

A method to evaluate surface defects, size of metal plate was put forward base on infrared thermography and time sequence images features. Put 45# steel plate as the object, firstly, time-sequence images in cooling process was got based on infrared thermography technology; Secondly, according to the change features of gray value in normal area and defect area of time sequence images, an identification was made to tell in which image the different factors exists. Finally, combined statistical differences between normal and defect area with image processing techniques to achieve the defect area evaluation. On the basis of laboratory studies, trials of 45# steel sheet were carried out in laboratory and the expected goals were reached. Proposed method enables the average relative errors for each evaluated defect area are less than 7 percent. which can provide a useful reference for the evaluation of defect area of infrared nondestructive testing field.

Molecular imprinting has been considered as one of the most useful techniques for the preparation of specific receptors. In this study, a novel molecularly imprinted material (MIP) has been developed by combining PFOS as the template with soluble polybenzimidazole which wrapped over the surface of ferroferric oxide as the carrier. Kinetics experimental showed MIP had a sorption amount of 117.6mg/g for PFOS, high than 74.6mg/g of the none-imprinted polymer adsorbents（NIP）. Additionally, in the competitive environment with other pollutants, the sorption amount of PFOS for MIP is greater than NIP, due to the electrostatic interaction in recognizing the target compound.

The framework and functions of Soft Science Laboratory about provincial electric power company operation monitoring and decision-making simulation are introduced. Based on the theory of recognizing-analysis-tracing-handling, a network topology which reflects the operation status on enterprise business flow and performance flow is put forward. Through monitoring the key indicators on the network topology, abnormal changes are detected. Combined with analyzing external policies, the Soft Science Laboratory makes a prediction and a timely warning. And it assists the leadership of the company to make corresponding decisions in order to improve the company's lean operation level.

this paper first determines the deformation modes of punching small-hole punches by analyzing the forms of the stress applied to die working parts. It analyzes the disadvantages of existing methods for preventing the buckling problem in punching small holes such as protective jackets and proposes a method for preventing the buckling of punches by reducing the punching force so as to make it possible to punch smaller holes.

Based an identity-based signature scheme, we givea certificateless signature scheme. And then we propose a certificateless blind signature (CLBS) scheme in this paper. This schemeis more efficient than those of previous schemes by pre-computing the pairing e (P, P)=g. Based on CL-PKC, it eliminates theusing of certificates in the signature scheme with respect to thetraditional public key cryptography (PKC) and solves key escrowproblems in ID-based signature schemes. Meanwhile it retains themerits of BS schemes. The proposed CLBS scheme is existentialunforgeable in the random oracle model under the intractabilityof the q-Strong Diffie-Hellman problem.

Recently, the telecare medical information system, which enables various healthcare delivery services, has been paid more and more attention in countries with aging populations. Using the telecare medical information system, it is possible to bring the advantages of telemedical directly into the patients home. At the same time, it faces some common security threats, thus, only authorized users should be granted the access to this system for the privacy concern. There are many authentication schemes studying protection of user medical information. Unfortunately, these schemes are still vulnerable to some common cyber attacks or has inefficient computational and communication cost. To remedy the weaknesses of these schemes, we propose an enhanced scheme based on elliptic curve cryptography to ensure necessary security and reduce computation load in this paper. By security analysis, we also demonstrate that our scheme is secure and efficient. Therefore, our scheme is suitable for telecare medical information system.

In this paper, we present an 8-bit 5 Gsample/s time-interleaved analog-to-digital converter (TI ADC). A 4-phase low jitter clock is designed to control four 1.25 Gsample/s sub-ADCs which is implemented using folding and interpolating architecture. Digital calibration is used to adjust the offset error and gain error of sub-ADCs. Meanwhile, serial peripheral interface (SPI) is adopted to adjust mismatch of gain and sample time between sub-ADCs. The whole TI ADC is designed using a 0.18m SiGe BiCMOS process. The whole ADC has a SNR of about 45 dB at the input frequency of 495 MHZ and an equivalent ENOB of 7.2 bits.

A high speed open-loop track/hold circuit in 0.18um CMOS process is presented. Open-loop and differential architecture are adopted to obtain high bandwidth and high speed;time-interleaved structure is used to reach a high sampling rate;source negative feedback and offset compensation are used to improve the linearity of the circuit.Simulation results show that with 396.875MHz input, 1.6GSPS sampling rate, driving the pre-amplifier of ADC, the thack/hold circuits SFDR(spurious-free dynamic range) is 75.8dB,satisfying the demand of 12 bits ADC.The circuit features high sampling rate,wide bandwidth,high SFDR and universal.

MIL-101, a metal-organic framework material, was synthesized by the high-temperature hydrothermal method. Triethylenetetramine (TETA) modification enabled the effective grafting of an amino group onto the surface of the materials and their pore structure. The crystal structure, micromorphology, specific surface area, and pore structure of the samples before and after modification were analyzed with an X-ray diffractometer, scanning electron microscope, specific surface and aperture tester, and infrared spectrometer. The carbon dioxide adsorption properties of the samples were determined by a thermal analyzer before and after TETA modification. Results show that moderate amino modification can effectively improve the microporous structure of MIL-101 and its carbon dioxide adsorption properties. After modification, the capacity of MIL-101 to adsorb carbon dioxide decreased only by 0.61 wt%, and a high adsorption capacity of 9.45 wt% was maintained after six cycles of adsorption testing at room temperature and ambient pressure.

In 2011, Lee et al. analyzed the security weaknesses of Hsiang et al.s scheme and proposed a security dynamic ID-based multi-server remote user authentication scheme. They claimed that their protocol is secure and efficient. However, we observe that Lee et al.'s scheme is still vulnerable to stolen smart card attack, malicious server attack. To remedy these security weaknesses, we propose an improved dynamic ID-based remote user authentication scheme for multi-server environment. Besides, security analysis and performance analysis show that compared with other remote user authentication schemes, the proposed scheme is more secure and possesses lower computation cost. As a result, the proposed scheme seems to be more practical for users with portable mobile devices in multi-server environment.

Certificateless short signature schemes can not only have the advantage of certificateless signature, but also provide a short signature size in communication. However, all existing certificateless short signature schemes only proven secure against a normal adversary which can only obtain the valid signature for the original public key rather than a super adversary which can obtain the valid signature for the replaced public key. Recently, Fan et al. proposed a certificateless short signature scheme which is very efficient, but we found it is still cannot against super adversary. In this paper, we first analysis their scheme, and then present an improved scheme which can against super adversaries. Furthermore, our scheme can provide both the strongest security level and the shortest signature size compared the existed provably secure certificateless short signature scheme.

Recently, several protocols came into being successively to meet the requirement of efficient operations in low-power roaming environment with the fast advance of communication technologies. Unfortunately, these protocols are not a suitable candidate for special requirements in automobile roaming system such as low consumption, high performance and convenience since these protocols pay more attention to a common network environment. In this paper, we address the problem of mutual authentication and key agreement with user anonymity for an automobile roaming system. More specifically, we propose the protocol employs elliptic curve cryptography system to enhance operational efficiency and take into account common attacks and give corresponding resist measures to ensure security. The analysis shows our scheme is user friendly and secure.

Hybrid active power filter has been used widely in the engineering application. It often be in idle and low power working state. The grid inverter can't keep in real-time rated output conditions, the output capacity of it got wasted. A kind of new-type HAPF device of microgrid was put forward. This device can realize grid-connected power generation of distributed generation and do not affect the original improve power quality function of HAPF. An improved id-iq composite instructions current detection and synthesis method was used, the simulation results were given in the end.

In order to design a moving target fast tracking system with respect to a real-time and stable tracking process, especially when the shape of moving target or its environment condition changes, a new algorithm named SURF-KMs is proposed. SURF-KMs combines the advantages of SURF algorithm with a cluster analysis of K-means method. First, feature points are collected and then they generate the matching template vectors based on the SURF algorithm. Second, the feature points and the center of the target are estimated by using the K-means method to determine the target's cluster scope and update the tracking window. Finally, a self-adapting updating strategy for matching template is also proposed in order to track moving target automatically. Experimental results indicate that SURF-KMs is mostly able to achieve a stable tracking while with the monitored target rotating, scale changing, and also the environment illumination glittering. Moreover, it can satisfy the system requirements of tracking stability, higher precision and anti-jamming. (2013) Trans Tech Publications, Switzerland.

We use S-Parameter Methodto extract device parameter of InAlN/GaN HEMT in this paper. We find thatparasitic capacitance and parasitic inductance can be extracted in traditionaltest structure method, but do nothing about parasitic resistor. Cold parameter methodcan extract parasitic resistor efficiently, but there is greater error inparasitic capacitance and parasitic inductance extraction. We propose a methodwhich combines test structure method and cold parameter method to extract parasitic parameteraccurately. We can acquire intrinsic parameters through getting rid ofparasitism parameters, and can fitting test outcome satisfactorily. It canreflect accurately the physical characteristics of GaN HEMT devices, and givesfeedback and guidance to device technology at the same time.

The simulator provides a virtual emulational condition. It can test the functions of infrared missile by simulating the movement of the target and the interferes. A target simulator with multiple interferences is provided in this paper. The blackbody is used as radiating source. The simulator’s construction, principle and the realization of motion track are mentioned. It has been proved that the simulator can meet the demands of development of missile. And the simulator is universal because the interference source has three bands.

It is regarded that the magmatic activity is over in Upper Hercynides and become stable platform in Mesozoic era in the Shanshan county, Xinjiang province, China. According to the regional geology investigation , rhyolitic porphyry and porphyry granite are broken out. Based on the analysis of rock petrology features, petrochemistry, geochemistry, the latest researches of formation and isotope dating results, it is believed that intrusion is formed in cretaceous period and is the result of Yanshan movement.

The tribological characteristics of nickel-aluminium bronze CuAl10Ni5Fe4 against 30CrMnSiA steel after the prior corrosion treatment was studied at the M2000A model wear tester. The wear rate of corroded specimen was less than that of uncorroded specimen at the early stage of prior corrosion treatment, while the wear resistances deteriorated and the average friction coefficient slightly declined with the extension of prior corrosion period. The tests of CuAl10Ni5Fe4 sliding bearing at PLS-100 swing tribometer were used to validate the results. The wear resistances of CuAl10Ni5Fe4 sliding bearing increased slightly after a short period of prior corrosion, and the average friction coefficient decreased slightly after a long term of prior corrosion. A suitable period of prior corrosion treatment can enhance the wear resistance performance of CuAl10Ni5Fe4 bearing. The tribological characteristics of CuAl10Ni5Fe4 sliding bearing tested by PLS-100 rack swing tribometer are consistent with the conclusions of the tests at M2000A model wear tester.

The Qinghai-Tibet Railway(QTR) is the highest and longest plateau railway in permafrost region in the world. The Qinghai-Tibet Railway in permafrost area locates in the hinterland of Qinghai-Tibet Plateau, which belongs to a low latitude, high altitude permafrost area. In this area, that the poor thermal stability, high ice content, and many other complex factors seriously impacts survey and design of The Qinghai-Tibet Railway. Permafrost is a special soil, it has many features different from the ordinary soil. And permafrost thawing layer has seasonal freezing-thawing process every year, along with a few of adverse geological phenomenon, which results in a series of engineering problems. This paper introduces the basic characteristics of permafrost along Qinghai-Tibet Railway, expounds the permafrost hazards of railway engineering, such as frost heaving, freeze thawing, frost boiling of roadbed, thaw collapse and mud flow, bridge foundation frost heaving and thaw settlement, deformation and cracking, culvert foundation freeze-thaw deformation, tunnel lining frost heaving and so on. Briefly analyzes the influence mechanism of permafrost to railway engineering. And then, proposes a temporary prescript for the railway engineering in different type of permafrost area. It is that each engineering in different area has to adopt different design concept and different prevention measures. At last, proposes the prevention measures and suggestions for the railway engineering in the permafrost region, such as reasonable control of embankment height, rubble air-cooled embankment, crushed stone slope protection with thermal insulation subgrade, heat pipe subgrade, ventilating pipe subgrade and so on.

A new technique for reducing the offset of latch-type sense amplifier has been proposed and effect of enable signal voltage upon latch-type sense amplifier offset in SRAM has been investigated in this paper. Circuit simulation results on both StrongARM and Double-tail topologies show that the standard deviation of offset can be reduced by 31.23% (StrongARM SA) and 25.2% (Double-tail SA) , respectively, when the voltage of enable signal reaches 0.6V in TSMC 65nm CMOS technology. For a column of bit-cell (1024 bit-cell), the total speed is improved by 14.98% (StrongARAM SA) and 22.26% (Double-tail SA) at the optimal operation point separately, and the total energy dissipation is reduced by 30.45% and 29.47% with this scheme.

Groundwater management is base on an sufficient dynamic monitoring network of groundwater depth and quality. Whil the monitoring network in Ordos Bain is insufficient due to the network is not been finished yet. Thus, in this paper, the dynamic type mapping method of groundwater based on GIS developing is used to optimize the distribution of dynamic monitoring positions. The purpose of the optimization is to observe reginal dynamics of groundwater with less monitoring wells. The reginal groundwater depth has a impact of hydroecology. Thus the optimization also consider the distribution of vegetations which are closely related with groundwater. The optimization shows that at least 28 new monitoring wells are needed depend on the existing groundwater monitoring network. The monitoring positions of 28 new wells are also estimated by the method.

In this study, Regenerated chrome tanning agent is prepared from chrome sludge by hydrogen peroxide oxidation. The regenerated chrome tanning agent was characterized by IR which reveals that organic acid and protein polypeptide combined with chrome have been mostly removed. A small part of organic acid and protein polypeptide, not oxidized, increases the masking effect of the product. The application results show that the shrinkage temperature (Ts) of wet blue leather can reach 100°C and the leather has good feeling of handle and fullness which shows it has same properties with commercial chrome tanning agent.

The tribological behaviour of precipitation-hardening stainless steel 0Cr17Ni4Cu4Nb against 30CrMnSiA steel under sliding condition was tested using the M2000A model wear tester. The surface roughness, hardness and load under the dry or grease lubricated conditions were studied. It indicated that the volume wear, mass wear, wear rate and friction coefficient were all large, and the main wear mechanism was the adhesive wear under the dry friction. The grease lubrication can effectively reduce the volume wear and friction coefficient, and enhance the wear resistance properties of 0Cr17Ni4Cu4Nb. The tribological properties were the best when the surface roughness was 0.8μm under the grease lubricated friction. Meanwhile the volume wear was also small when its hardness was low. The hardness was higher and the friction coefficient was more stable after the heat treatment on 0Cr17Ni4Cu4Nb. The volume wear and friction coefficient were both increased with the increasing of the loads under the grease lubricated friction.

RF-MEMS resonator can meet the development of communication and attract great attention now. Applied to electric system, mechanical resonator caused some difficulties to the circuit design， the electric parameters should be extracted. Through mechanical-electrical analogy the electronic parameter is extracted and the electrical equivalent circuit established. ANSYS is used to simulate the vibration of the disk. Using the electronic parameters, an oscillator is designed and simulated.

Mixed-ligand Pt(II) complexes containing pyrazine (C4N2H4, pz) and dibenzyl sulfoxide [C6H5CH2)2SO, DBzSO] ligands have been studied using density functional theory (DFT) methods with a particular emphasis on the theoretical1H-NMR spectra of the methylene protons. The DFT optimization calculations on Pt(DBzSO)Cl2(pz) and {Pt(DBzSO)Cl2}2(pz) predicted the structure parameters, vibrational frequency and1H-NMR spectra. Different structures of DBzSO will affect the bond lengths and angles in the complexes, except for the pz ligands. The [shift(Pt(II)complex)-shift(sulfoxide)] values of trans-Pt(DBzSO)(pz)Cl2were smaller than those for cis-Pt(DBzSO)(pz)Cl2and the calculation results appear to be reasonable. The1H-NMR spectra of the methylene protons of cis- and trans-{Pt(DBzSO)Cl2}2(pz) indicate that these two structures have high symmetry.

Dibenzyl sulfoxide [C6H5CH2)2SO, DBzSO] has been studied using density functional theory (DFT) methods with a particular emphasis on the theoretical 1H-NMR spectra of the methylene protons. The 1H-NMR chemical shifts of the methylene protons of DBzSO can be divided into two main types. Four possible structures of DBzSO were considered and the total energies were calculated for both a vacuum and in CDCl3 solvent. The change of length of S-O and S-C bonds in solvent was more obvious than that of the C(CH2)-C(C6H5) bonds; The S-O bond was longer and S-C bond was shorter in CDCl3. The essence effect of solvent on the properties of dibenzyl sulfoxide should come from the change of the geometrical structure. The change of shift Δx, [shift (solvent) - shift (vacuum)] showed that the effect of solvent on methylene protons of dibenzyl sulfoxide was apparent. Except of the other H of the rings, the two ortho H which were near S-O bond appeared more sensitivity on the solvent. The optimized structures in CDCl3 were in good agreement with the experimental data. The NMR peaks of methylene protons should be split more apparently in actual circumstance and the complex split of CH2 1HNMR peaks should be explained in some degree.

The crystal structure models of three kinds of different Al(OH)3 crystals, which are gibbsite, bayerite and nordstradite, are built respectively according to the corresponding experimental crystal lattice. Geometry optimizations are implemented by CASTEP program module using general gradient approximation (GGA) and local density approximation (LDA) methods respectively based on density functional theory (DFT). Total energy, electronic structure, atomic and bond populations are also calculated. The calculation results of total energy indicate that gibbsite is steadier than the other two from the point of view of energy, and the effect of basis set of GGA-PW91 is highest. At the same time, energy bond structure and density of states calculated at GGA-PW91 and LDA-CA-PZ levels show that the different of energy gap ΔE (ELUMO-EHOMO) at the first group of BZ is not obvious, and that the highest value of ΔE of gibbsite is more lower than the other two Al(OH)3 crystals. It may be likely to say that gibbsite may be more active than the other two crystals. According to the analysis of populations, it can be found that bond populations value of H-O and Al-O bonds of gibbsite is smallest in three different Al(OH)3 crystals, it is to say that the combination force of H-O and Al-O bonds of gibbsite is smallest and gibbsite may be more easier to be calcined theoretically.

The thermodynamics properties of synthesize reactions of Ph3SnR (R= N (C4H4), N(C8H6), C6H5) and CpM(CO)2CY(M=Cr, Mn; Y=S, Se), the total energy and Mulliken atomic charges of the compound products M(CO)2CY-Ph3XR(M=Cr, Mn; X=Sn, Ge; Y=S, Se; R= N(C4H4), N(C8H6), C6H5) with different substitute positions on the benzene ring were investigated using DFT method. The calculation results of total energy showed that the ligand was determinant of the favourable substituted position and the central metal of two different type ligands CpCr(CO)2CY(Y=S, Se) and CpMn(CO)2 CY(Y=S, Se) was the key factor; whether the reactants Ph3SnR( R= N(C4H4), N(C8H6)) and Ph3SnR( R= C6H5) had the pyrrole or not had effect on the character of substituted position. The Mulliken atomic charges of central metal Sn and Ge showed that the atom charge value of Sn and Ge of M(CO)2CY-Ph4X was smaller than M(CO)2CY-Ph3XN (C4H4) and M(CO)2CY-Ph3XN(C8H6) (M=Cr, Mn; X=Sn, Ge; Y=S, Se) correspondingly; electron-donating trend of Ph3GeR group was stronger than that of Ph3SnR group; the pyrrole group had some conjugation effects which made the electronic distribute more even. The calculation results of thermodynamics properties of the synthesize reactions of Ph3SnR(R=N(C4H4), N(C8H6), C6H5) and CpCr(CO)CS showed that the reaction possibility was small at the general condition; ligand CpMn(CO)2CY(Y=S, Se) was more favorable to the reaction than CpCr(CO)2CY(Y=S, Se); different substituted positions would have effect on the reaction possibility apparently. Decreasing temperature would be favorable to the possibility of the reactions, but increasing temperature might be favourable to the rate of reactions.

Mutations of K-ras gene have been proven to play important roles in human tumor progression. Point mutations of K-ras gene located in codons 61 are gene hot spot mutation regions in patients with gastric cancer. A simple and effective capillary electrophoresis (CE) method for point mutation detection in codon 61 of K-ras gene was established. The polymerase chain reaction (PCR) fragments included codon 61 of K-ras gene were analyzed by single-strand conformation polymorphism (SSCP)-CE method. The CE analysis was performed by using a 1×Tris–borate–EDTA (TBE) buffer containing 3.0% (w/v) poly (ethylene oxide) (PEO) (MW 300 000) under reverse polarity with 15 oC and voltage of 15 kV. Forty-two gastric cancer patients were analyzed using this developed method. K-ras gene mutation was found in 17 cases (40.5 %) and the results showed that K-ras gene mutation in gastric cancer tissue is a usual event, and the SSCP-CE was feasible for mutation detection of K-ras gene in populations. Detection of gene mutation of gastric cancer tissue by PCR - SSCP has a certain value to diagnosis of gastric cancer and to prevent gastric cancer associated with clinical and pathological features, living habits of different patients by detection mutation of K-ras gene codon 61.

Stable leather superfine powder suspension was got by superfine powder of leather solid wastes, maleic anhydride(MAH) and acrylic acid(AA). The best MAH、AA modifying conditions with grafting ratio as index were discussed by orthogonal test according L9(34) factor levels, and the results show that modified productsⅠis got by the total amount of MAH account for 50% of the amount weight of leather superfine powder at 80°C for 3 hours in the solution of N,N-dimethyl formamide (DMF). The MAH modified products was filtered and washed with water to reserve, and then was further modified by AA and MA being designed orthogonal test according L9(34)factor levels for optimum conditions with grafting ratio as index. The best modification conditions were as follows: ammonium persulfate(APS) as the initiator, the mass of initiator accounted for 2% of total weight of monomers , the volume ratio of AA and MA was 5, and the reaction temperature was 90 °C for 3 hours in 12% aqueous solution. The monomer grafting percentage of the products was 37.8%. The product was characterized by infrared spectroscopy (IR) and Size analyzer.

The tribological behaviour of beryllium copper alloy QBe2 against 30CrMnSiA steel under sliding condition were tested at the M2000A model wear tester. It studied the hardness, surface roughness, load and prior corrosion of QBe2 specimens under the dry or grease lubricated conditions. The volume wear and friction coefficient were relatively better when the hardness of QBe2 was lager under the grease lubricated sliding friction. The volume wear was the smallest when surface roughness was 0.8μm, and its tribological properties were the best under the grease lubricated sliding friction. Meanwhile the values of wear loss, wear rate and average friction coefficient under the grease lubricated friction were one level smaller than that under the dry friction. The volume wear and friction coefficient decreased with the loads declined under the grease lubrication condition. Prior corrosion process made the lubricant effect worse, which obviously reduced the wear-resisting property of QBe2 and enlarged its wear rate and friction coefficient.

The advantages and disadvantages of the current constant-flow control method for the constant-flow pump (CFP) are analyzed. By using the experimental data and the BP neural network (BPNN), the model between outlet pressure and flow loss coefficient established. In order to realize constant-flow control for the CFP, a feed-forward controller based on the model is set up finally. Experiments show that this controller can improve the flow control accuracy for the CFP greatly.