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Compared with the conventional magnetic means (such as ferromagnetic contacts), controlling a spin current by electrical methods could largely reduce the energy consumption and dimensions of nano-devices, which has become a focus of research in spintronics. Inspired by recent progress in the synthesis of an iron-based metal-organic nanostructure, we investigate the spin-dependent electronic transport of the molecule of Fe3-terpyridine-phenyl-phenyl-terpyridine-Fe3 (Fe3-TPPT-Fe3) through first-principles calculations, and propose a three-terminal device without ferromagnetics. By applying a gate voltage, not only the spin polarization can be switched between 100% and -100% to achieve a dual-spin filter, but also its fine regulation can be realized, where the transmission with any ratio of spin-up to spin-down electron numbers is achievable. Analysis shows that the particular transmission spectra are the key mechanism, where two peaks reside discretely on both sides of the Fermi level with opposite spins. Such a feature is found to be robust to the number of Fe atoms and TPPT chain length, suggesting that it is an intrinsic feature of such systems and very conducive to practical applications. The electrical control (such as an electric field) of spin polarization is realized at the single-molecule level, showing great application potential.

In order to explore the temporal and spatial distribution characteristics of atmospheric aerosol optical depth (AOD) in the urban agglomeration on the northern slope of the Tianshan Mountains, the temporal and spatial distribution characteristics and trends of changes in the AOD in the study area from 2000 to 2019 were analyzed by MODIS aerosol products(MCD19-A2). For 2016-2019, when the AOD was relatively stable, the parameters such as the AOD and Ångström wavelength index (

The key to understanding the transport and deposition process of salt dust to Ebinur Lake involves the quantitative evaluation of the aerosol concentration and characteristics in Jinghe County. Based on the data of the CE-318 sun photometer station in Jinghe County during 2019, the characteristics of the aerosol optical depth (AOD) and Angström exponent (

Inspired by the recent experimental progress on the synthesization of a new type of molecule, a polyyne wire doped with the organometallic Ru ( dppe ) 2 fragment, which exhibits superior electronic properties to similar organic molecules reported before, we studied the electronic transport of it contacted with Au electrodes through first-principles calculations. Multiple striking negative differential resistance (NDR) behavior is observed, where the current could decrease to nearly zero. Moreover, such a phenomenon is found to be robust to the conformational change of the molecule, indicating it is the intrinsic feature of it. Further analysis shows that it is the suppression of the transmission peaks at the border of the bias window that results in the NDR. And, the suppression is resulted from the decay of the local density of states in the two-probe system, especially in the central axis of the molecule, where the states are found to originate from the p orbital of C atoms and the d orbital of Ru atoms. The multiple striking NDR behavior is achieved at the single-molecule level under low bias, showing great application potentials. These findings may throw light on the development of molecular devices.

Inspired by recent progress of experimental fabrication of partial structure of the helical graphenes, we construct helical graphene nanoribbons and study the electronic structure and transport properties of them, through first-principles calculations. It is found that a metal-semiconductor transition occurs when the pitch of the configuration changes, and the whole transition process can be divided into three regimes, i.e., metallic, fast changing bandgap, and slowly changing bandgap ones. Further analysis shows that, interlayer transmission, interlayer interaction (bilayer graphenelike state) and intralayer interaction are the mechanisms behind, respectively. Moreover, such a transition and corresponding mechanisms show good robustness to the size of the helical graphene nanoribbons, suggesting great application potential. As the systems are pure-carbon and graphene-based ones, as well as an adjustable and reversible bandgap, such configurations might be quite useful in future nanodevices.

Six palladium(II) complexes, [Pd(bipy)(Bzphe-N,O)] (I-a), [Pd(bipy)(p-Mbzphe-N,O)]·2H2O (I-b), [Pd(bipy)(p-Nbzphe-N,O)]·2H2O (I-c), [Pd(phen)(Bmined by X-ray diffraction. The cytotoxicity test indicates that the complexes exert cytotoxic effects against KB, BGC-823, Bel-7402, and HL-60, but none of them shows higher cytotoxicity than cisplatin. The structure-activity relationship suggests that bomined by X-ray diffraction. The cytotoxicity test indicates that the complexes exert cytotoxic effects against KB, BGC-823, Bel-7402, and HL-60, but none of them shows higher cytotoxicity than cisplatin. The structure-activity relationship suggests that both N-containing ligands and N-carbonyl reagent have important effect on cytotoxicity, however, the IC50 values do not show definite correlation with their variation.

In 1960s, Rosenberg discovered the anticancer activity of cisplatin, and heralded a new era of anticancer drug research based on metallopharmaceuticals. During the past 40 years, carboplatin, nedaplatin, oxaliplatin, eptaplatin, lobaplatin and dicycloplatin have been successfully developed. Although some results were achieved for platinum anticancer drugs, some problems often limited their clinical use by severe toxic side-effects, as well as the intrinsic and acquired resistance possessed by various cancers. In order to solve these problems, new metal-based anticancer drugs were started to found. Based on the similarity of structural and chemical properties between platinum(Ⅱ) and palladium(Ⅱ) complexes, palladium(Ⅱ) complexes as the potential antitumor drug have become an attractive field. This review summarized the current development of palladium(Ⅱ) complexes as potential antitumor agents, and the structure-activity relationship were studied, which will be valuable for guiding the synthesis of new type palladium(Ⅱ) anticancer drugs.

In this paper, a new method that is based on the transmission contribution degree is proposed, which can effictively imprve on-line verification of relay protection setting.Actually, all protection devices of a line are treated as a whole in this method. Furthermore, the network maximum flow and complex network theory are both applied in this method, which is on the view of the structural point of the grid. The importance index of protection device in a line is determined by the transmission contribution degree. As a result, on-line verification of relay protection setting is according to the descending order of the indexes. IEEE 39-bus system is used to simulate, on the whole, the simulation and analysis of the calculation results to verify the reasonableness and correctness of the method.

This paper focused on the uniaxial ultimate-bearing-capacity of large size concrete filled steel tubular (CFST) columns. Two aspects were investigated experimentally. To verify the feasibility of similarity principles for large size components, a series of uniaxial compressive experiments were conducted using different scaled specimens, the prototype of which is a CFST arch rib in an authentic arch bridge. Meanwhile, two specimens with same scale were tested axially and eccentrically to investigate the difference of bearing capacity resulted from the pierced-column. The experimental results show that the size effect on the bearing capacity of the rib is so insignificant that the scaled specimen can be used to obtain the maximum capacity of the full-scale component. The inserted steel tubes in the middle of the column cause the reduction of its capacity and the reduction factor from axial loading is bigger than that from bias load. Moreover, the eccentricity reduces the effect of piercing on the capacity of CFST column.

Based on the nonlinear dynamic time history analysis, a multi-span RC highway bridge with high damping rubber bearings was studied, to investigate the damping ratio and seismic performance of the bridge and high damping rubber bearings compared with the rubber bearings. Results show that the application of high damping rubber bearings can reduce the seismic response of substructures of the bridge under longitudinal and transversal seismic excitations to some extent. But what is more important is that high damping rubber bearings wont suffer shear and displacement failure which may happen on rubber bearings. As a result, the pounding response and residual displacement can be dispelled.

It is necessary to study the dynamics and load-bearing characteristics of ropes in order to guarantee the stability and reliability of hoisting equipments. Based on ADAMS, a parametric coupling model of rope winded along cylindrical helix is built by force field. An optimized simulation method, cooperating fixed joints with angle sensors under the control of script, is recommended. Studying on the construction system of deep vertical shaft wall, the bucket is placed at static equilibrium position by preload defined in force field and dynamics behaviors of the center of mass in bucket are researched. The results indicate that the displacement curve is successive and complete, thus it confirms that the driving method is reasonable and feasible. This method could not only guarantee the accuracy and stability but also increase simulation efficiency, providing a new simulation approach for one kind of flexible body such as ropes and cables.

This paper lists the problems during the stability analysis of long span CFST arch bridge and the corresponding modeling method. Based on the construction control of an orthotropic long span CFST arch bridge, a FEM model had been established to analysis the stability of its rib during the concrete pumping. The conclusion shows significant importance to the bridge’s construction process.

The full length cDNA sequence of CBF3 (CRT/DRE-binding factor) was cloned from Vitis amurensis by reverse transcription polymerase chain reaction (RT-PCR) using the primers designed based on CBF genes available in GenBank. Sequence analysis showed that the gene had 854 bp long and its coding sequence contained 720 bp, encoding a protein with 239 amino acids and an AP2 structural domain. The molecular mass of CBF3 was predicted to be 25.9 kDa and its theoretical isoelectric point was 7.02 and aliphatic index was 59.29. The average hydropathicity of the protein was -0.551. The tertiary structures of CBF3 were also analyzed. The prokaryotic expression vector pGEX-4T-CBF3 containing CBF3 gene was constructed and CBF3 fusion protein (52 kDa) was produced in Escherichia coli after induction with 1 mmol L^(-1) IPTG. Further studies are needed to evaluate its potential application for improving plant resistance to cold and other stress condition such as drought and salinity.

The Jinshui River, a tributary of the Hanjiang River, is an important region of water conservation for the Middle Route of South to North Water Transfer Project. However, water quality has been deteriorated in recent years, in particular nitrogen increasing pollution. In this study, the wet deposition of atmospheric nitrogen in the Jinshui watershed was investigated between Feb. 2012-Feb. 2013, and the corresponding contribution to the river N loading was calculated using N retention model. The results indicated that the volume-weighted concentration of dissolved total nitrogen (DTN) was 0.24-2.89 mg x L(-1), consisting of ammonium (NH(4+)-N) (42.8%), nitrate (NO3- N) (13.3%) and dissolved organic nitrogen (DON) (43.9%), which decreased with rainfall volume as a result of dilution. The wet deposition of atmospheric N was mainly from anthropogenic pollution and the flux was between 4.97-7.00 kg x (hm2 x a)(-1), dominated by seasonal rainfall, of which about 81% occurred in spring and summer and the flux in a decreasing order of upstream, downstream, and middlestream. The wet deposition contributed approximately 34,000-46,000 kg N to the river, accounting for only 5.05%-6.78% of the contribution by fertilizers, which was too small to be the main source of the river N loading.

In this paper, the principles and a new method to design a virtual frequency characteristic test instrument (VFCTI) system based on the "Virtual Instrument" theory are introduced. This VFCTI has distinct merits such as low cost, high accuracy, stable performance and small size. Then, circuit diagrams, the components we chose and photos of the whole system are offered to achieve main functions in hardware design. Design ideas and program flow are also given in software design. Meanwhile, it describes the primary functions and test analysis process of the panel, designed by CVI. Finally, it is proved to be an effective method to test frequency characteristic rapidly by testing some actual circuits, which will have bright applications in future.

In this paper, a high performance sampling phase-locked dielectric resonator oscillator is designed and realized. The experimental result shows that it can achieve 9.35 dBm output power at 11.5 GHz, low phase noise of -111.36 dBc/Hz at 10 kHz offset carrier, -112.18 dBc/Hz at 100 kHz offset carrier and -140 dBc/Hz at 1 MHz offset carrier, and a spurs level better than -80 dBc. Such oscillator has advantages of high performance, small dimension and high efficiency in frequency multiplication.