In order to fair and optimize rational cubic B-spline curves used frequently in engineering, and to improve design system function, some formulae on the degree and the knot vector, of the product of three B-spline functions, are presented; then Marsden’s identity is generalized, and by using discrete B-spline theory, the product of three B-spline functions is converted into a linear combination of B-splines. Consequently, a monotone curvature variation (MCV) discriminant for uniform planar rational cubic B-spline curves can be converted into a higher degree B-spline function. Applying the property of positive unit resolution of B-spline, an MCV sufficient condition for the curve segments is obtained. Theoretical reasoning and instance operation showed that the result is simple and applicable in curve design, especially in curve fair processing.

This paper presents a novel approach to consider optimal multi-degree reduction of Bézier curve with G¹-continuity. By minimizing the distances between corresponding control points of the two curves through degree raising, optimal approximation is achieved. In contrast to traditional methods, which typically consider the components of the curve separately, we use geometric information on the curve to generate the degree reduction. So positions and tangents are preserved at the two endpoints. For satisfying the solvability condition, we propose another improved algorithm based on regularization terms. Finally, numerical examples demonstrate the effectiveness of our algorithms.

This paper presents the matrix representation for the hyperbolic polynomial B-spline basis and the algebraic hyperbolic Bézier basis in a recursive way, which are both generated over the space Ω_n=span{sinht, cosht, tⁿ⁻³, …, t, 1} in which n is an arbitrary integer larger than or equal to 3. The conversion matrix from the hyperbolic polynomial B-spline basis of arbitrary order to the algebraic hyperbolic Bézier basis of the same order is also given by a recursive approach. As examples, the specific expressions of the matrix representation for the hyperbolic polynomial B-spline basis of order 4 and the algebraic hyperbolic Bézier basis of order 4 are given, and we also construct the conversion matrix between the two bases of order 4 by the method proposed in the paper. The results in this paper are useful for the evaluation and conversion of the curves and surfaces constructed by the two bases.

The algorithm for the approximate solution of a geodesic connecting two given points on a simple surface is discussed in this paper. It arises from practical demands of the filament winding technique. Geodesic is the shortest path connecting two given points on a surface and it can also be regarded as the extremal curve of the arc length functional. The nonlinear equation system of the geodesic on some discrete points by means of the direct variation method is explored. By employing Newton’s iterative method, this nonlinear system is transformed into a linear one. And the approximate solution to the geodesic is obtained by solving the resultant linear system. This paper also proves that the iteration is convergent under certain circumstance. Moreover, the result is illustrated with three examples and an appropriate comparison between the analytical solution and the approximate solution to the geodesic is described on the cone surface.

In this work we present a probabilistic learning approach to model video news story for retrospective event detection (RED). In this approach, both content and time information on a news video is utilized to transcribe the news story into terms, which are divided into classes by their semantics. Then a probabilistic model, composed of sub-models corresponding to the semantic classes respectively, is proposed. The model’s parameters are estimated by EM algorithm. Experiments showed that the proposed approach has better detection resolution.

In this paper we give a short survey on a problem on extremal quasiconformal extensions. It had been a conjecture for a long time that the dilatations K₀(h) and K₁(h) are equal before Anderson and Hinkkanen disproved this by constructing concrete examples of a family of affine mappings of some parallelograms. The problem also engendered many interesting results. At the end of the current paper, we discuss relationships among K₀(h), H(h) and K₁(h) as a concluding remark.

Reliability is a very important target of linear induction motors. In this paper, the reliability model of the motor is established, the reliability indexes are defined, the faults’ modes are analyzed and classified according to their effect and damage, the sequential sampling plan is discussed and its acceptable fault rate (ACFR) and refusable fault rate (REFR) are presented, and then, the detailed reliability compliance field test method is introduced with one case. With the method, engineers can verify the reliability of linear induction motors expediently.

The repairable system with preventive maintenance is one of the typical systems with wide useful applications in engineering. If the system can be made as good as new by preventive maintenance, both the life stochastic variable of different periods and fault correction time stochastic variable form monotonous stochastic process. Based on the above assumption and the available results, in this paper we discuss the maintenance and replacement policy of the repairable system with preventive maintenance. The intervals of preventive maintenance, T, and the times of system failure, N, are introduced and the vector Markov process method is used. The formulation of steady state average profit rate can be deduced to solve the optimization problem of the maintenance and replacement policy.

A new approach is proposed in this paper for the problem of the target motion analysis (TMA) with signal propagation time delay. This problem is an unobservable tracking problem in which the acoustic signal transmits with time delay. We present an intelligent range parameterized unscented Kalman filter (IRPUKF) algorithm to estimate the state of the nonlinear unobservable tracking system and propose a recursive model parameter online adjustment method to deal with the time delay in signal propagation. In a simulation of tracking target using a maneuvering acoustic sensor with signal time delay case study, the effectiveness and efficiency of the proposed algorithm is testified to perform better, compared with the range parameterized extended Kalman filter (RPEKF) algorithm.

Aiming at value reduction, a sort of RSVR algorithm was presented based on support in association rules via Apriori algorithm. A more effective reduction table can be obtained by deleting those rules with less support according to least support— minsup. The reduction feasibility of this algorithm was achieved by reducing the given decision table. Testing by UCI machine learning database and comparing this algorithm with least value reduction algorithm indicate the validity of RSVR algorithm.

A passive control strategy with nonlinear observer is proposed, which can be used to control a class of chaotic dynamical systems to stabilize at different equilibrium points. If the nonlinear function of chaotic system satisfies Lipschitz condition, the nonlinear observer can observe the state variables of the chaotic systems. An important property of passive system is studied to control chaotic systems, that is passive system can be asymptotically stabilized by state feedback controller whose state variables are presented by nonlinear observer. Simulation results indicated that the proposed chaos control method is very effective in a class of chaotic systems.

In this work, synchronization of chaotic Colpitts circuits, using adaptive controllers to combat circuit parameter mismatches and channel distortions, is studied by numerical simulations. Synchronization errors caused by different main circuit components are compared, and compensation for time-constant and time-varying circuit parameter mismatches is demonstrated. Different kinds of channel distortions, including time-constant and time-varying channel attenuation, Additive White Gaussian Noise (AWGN) are all investigated by numerical simulations and discussed. Simulation results indicated that the synchronization performance of chaotic Colpitts circuits can be greatly improved by applying adaptive controllers when parameter mismatches and channel attenuation are considered as time-constant or time-varying, but have no obvious enhancements regarding the effect on AWGN channel.

The problems of determining the global asymptotic stability and global exponential stability for a class of norm-bounded nonlinear neutral differential systems with constant or time-varying delays are investigated in this work. Lyapunov method was used to derive some useful criteria of the systems’ global asymptotic stability and global exponential stability. The stability conditions are formulated as linear matrix inequalities (LMIs) which can be easily solved by various convex optimization algorithms. Moreover, for the exponentially stable system, the exponential convergence rates of the system’s states can be estimated by some parameters of the LMIs. Numerical examples are given to illustrate the application of the proposed method.

Some high-speed protocols such as HSTCP have been proposed to improve the ability of bandwidth utilization in high-speed networks. However, the increased scalability of high-speed TCP leads to many dropped packets in a single loss event in drop tail environment. In addition, there exists burstiness on short time scales that may cause lots of packets loss. In this paper, we analyze the problem of packet loss, and then propose ACWAP (Adaptive Congestion Window Adjustment plus Pacing) algorithm to reduce the loss rate of high-speed TCP. Along with pacing algorithm for avoiding burstiness on short time scales, ACWAP uses delay information to estimate the network state and adaptively changes the increase parameter to 1 before congestion to reduce the number of dropped packets. Many simulation results show our proposed algorithm can reduce the number of dropped packets in a single loss event, alleviate synchronized loss phenomena and improve the RTT unfairness while keeping the advantages of high-speed TCP.

This work investigates the effects of exhaust gas recirculation (EGR) and operation parameters including engine speed, equivalence ratio, coolant-out temperature, and intake charge temperature on the basic characteristics of a single-cylinder homogeneous charge compression ignition (HCCI) engine powered with reformulated iso-octane fuels. The running range of iso-octane HCCI engine can be expanded to lower temperature and more load by adding di-tertiary butyl peroxide (DTBP) in the fuel. The combustion timing advances with the increase of DTBP concentrations, coolant temperature and equivalence ratio. The effects of EGR on the combustion and emissions are remarkable when the EGR rate is higher than 25%, and the combustion phase is sharply postponed and the UHC and CO emissions deteriorate. The intake charge temperature has a moderate effect on combustion and emissions when it is lower than 35 °C; but the combustion timing advances, the combustion duration shortens, and sometimes it leads to knock combustion when the intake charge temperature increases to above 35 °C.

Gaseous pressure-volume-temperature (PVT) properties were measured at temperatures from 371.21 to 413.29 K and corresponding pressures from 1.2445 to 4.9718 MPa. An isochoric cell apparatus was used in the present measurements with uncertainties estimated to be ±1.5 kPa for pressure and ±6 mK for temperature. Comparison of the measured PVT data with the reported virial-type equation of state showed satisfactory agreement within ±0.28% in pressure and within ±0.33% in density. The purity of the HFC-161 sample used in this work was 99.74 mass %.

A Galerkin method was used to investigate steady, fully developed flow of Oldroyd-B fluids through curved pipes of circle cross-section. By using Galerkin method, large values of curvature ratio, Reynolds number and Weissenberg number can be discussed. The powers of the series of the Galerkin method in the present work are chosen carefully. Both effects of Reynolds number and Weissenberg number on axial velocity and stream function are discussed even for large values of the two non-dimensional parameters. It was discovered that the combined effect of large Reynolds number and Weissenberg number decreases the outward shifts of maximum axial velocity and maximum stream function. Axial normal stress of creeping flow is also studied here. The large Weissenberg number makes the stress concentration occur on the inner bend of the pipe.

The passive electromagnetic damper has the same configuration as that of the electromagnetic bearing, but no sensors and no closed loop control are needed. Its robustness and no-contact structure are its great advantages. When the rotor vibrates, the electromagnetic field intensity in the air gap is altered, then fluctuating currents in the damper coils and eddy currents inside the surface layer of rotor are created. Damping force is caused by the fluctuating currents, while retardation torque is generated by eddy currents. The characteristics of a damper may be improved by adding an additional electrical circuit. Numerical studies showed that damping coefficient increases with increasing static current, but decreases with increasing frequency. And the damping coefficient of the improved damper at higher frequency is more evident than that of the original damper. Experimental results showed that the resonant vibration around the first critical speed was obviously suppressed by both types of passive electromagnetic damper.

Of several formulas for calculating bursting pressure of mild steel vessel, the Faupel formula is the most famous one. In fact, Faupel formula is conservative in calculating mild steel pressure. Based on hundreds of bursting experiments on mild steel pressure vessels such as Q235(Gr.D), 20R(1020) and, after statistically analyzing data on bursting pressure, it was found that the Faupel formula had some errors in calculation. The authors derived a more approximate modified formula from the data, which proved more general after examining the data on other mild steel pressure vessels with different diameters and shell thickness.

Fault diagnosis is an important method of improving the safety and reliability of air conditioning systems. When the fan in fan-coil unit is shut down, there are temperature variations in the conditioned space. The heat exchanger efficiency is lower and the temperature in the room will change while the heat load of the room is stable. In this study, fault data are obtained in an experimental test rig. Thermal parameters as suction pressure and room temperature are selected and measured to establish a characteristic description to represent states of system malfunction. A new approach to fault diagnosis is presented by using real data from the test rig. Using the artificial neural network (ANN) in self-learning and pattern recognition modes, the fault is diagnosed with the perceptron (one type of ANN model) suitable for pattern classification problems. The perceptron network is shown to distinguish types of system faults correctly, and to be an artificial neural network architecture especially well suited for fault diagnosis.

In order to reconstruct typical off-road terrain surface for vehicle performance virtual test, a terrain generation method with controllable roughness was proposed based on fractal dimension. Transverse profile sampling and unevenness characteristics of typical off-road terrain were discussed according to the choices of appropriate wavelength and sampling interval. Since the off-road terrain in virtual environment is self-similar, the method of calculating the discrete fractal Gauss noise and its auto-correlation function were analyzed. The terrain surface fractal dimension was estimated by determining the Hurst coefficient. As typical off-road terrain is rugged terrain, the method of reconstructing it using fractal modelling is presented. The steps include calculating statistical variations in the absolute value of the difference in elevation between two points, plotting the points in log-log space, identifying linear segments and estimating fractal dimension from the linear segments slope. The constructed surface includes information on potholes, bumps, trend and unevenness of terrain, and can be used as the excitation of vehicle performance virtual test.

Experimental and theoretical research showed that in predicting concrete’s elastic modulus, it should be modelled as a three-phase composite material at a mesoscopic level, consisting of aggregates, interfacial transition zone (ITZ) and cement paste, and that the proportions, mechanical properties and interaction of the three phase constituents should all be considered in the prediction. The present paper attempts to develop a numerical method that can predict the elastic modulus of three-phase concrete made with two different aggregates. In this method, the mesostructure of concrete is simulated and the lattice type model is modified to take into account the mechanical properties of the cement paste, ITZ, and fine and coarse aggregates of concrete. The finite element method is then employed for analyzing the stress and strain in concrete and therefore for determining its elastic modulus. Finally, the developed numerical method is verified by comparison with the experimental results obtained from the research literature. The paper concludes that the numerical method can predict with reasonable accuracy the elastic modulus of concrete made with two different aggregates.

A condition assessment model for cable-stayed bridge was proposed, and a cable tension, elevation and frequency condition assessment model was then applied. With the optimized cable tensions as criterion, upper and lower bounds were then introduced. With the elevation of bridge completion as benchmark, and with the allowable vertical displacement of control points to interpolate to generate the upper and lower bounds of elevation, algorithm of condition assessment was programmed. Using moderate index model to interpolate linearly, and with the application of variable weight synthesizing principle (VWSP) and correlation of slope coefficient, according to a set of inspection and monitoring data, performance condition of cable tension, elevation and frequency were calculated. Results showed that with the decrease of balanced coefficient α, the assessment result is a process of degradation. The more divergent the variable weight is, the more severe is the degradation of the bridge component, and the larger is the curvature of curve α-V. Eventually, the model predicted that, for those bridge components whose grade of single survey point is exactly the same, the curvature of curve α-V is constant zero, i.e. there is no correlation between the assessment result and the balanced coefficient α. Numerical simulation showed that it agrees quite well with the expectation.

A time-domain solution of layered ground vibration due to moving load has been developed based on the thin layer method. Fourier-Laplace transforms are applied to derive the transformed domain solution that satisfies the boundary conditions of horizontal infinities. The eigen-decomposition approach is used with respect to the Laplace parameter, and the final ground response solution is constructed with the mode superposition method. The reliability and computation accuracy of the solution are proved by comparison with a closed-form solution. A single soil stratum on rigid bedrock is used to reveal the vibration features induced by a rectangular load moving at speeds below or above ground Rayleigh wave velocity.

We report here the first zircon SHRIMP U-Pb chronological result yielding age of (619±7) Ma (11 spots) for the Dufek granite, the largest one of the Early Paleozoic granitoids in the Sør Rondane Mountains, East Antarctica. The analyzed zircon crystals are euhedral, have zonal patterns and Th/U ratios of 0.22~1.04, indicating magmatic genesis. The single zircon crystal has the ²⁰⁶Pb/²³⁸U age of 664 Ma to 600 Ma with the analyzed spots being from the core parts and mantle-rim part of the zircon grains. The result of 619 Ma analysis shows beyond doubt that the Dufek granite formed during 620 Ma is much older by at least 70 Ma than that of the previously widely believed (500~550 Ma) obtained by Rb-Sr, Sm-Nd and K-Ar isotopic analyses of the Sør Rondane Mountains Pan-African granitoids. Previous chemical characteristics and isotopic data supported that the Dufek granite has chemical affinity with A-type granites under within-plate setting. The U-Pb age of 620 Ma for magmatic zircons in the Dufek granite therefore may represent the age of earlier melt crystallization that occurred at the Late Neo-Proterozoic during the extensional tectonic setting during/after Gondwanaland formation.

This paper reports ⁴⁰Ar-³⁹Ar ages of northwestern China’s Tarim Basin Permian basalts. ⁴⁰Ar-³⁹Ar age dating for basaltic samples from the Yingan section, Keping area and Damusi section of the southwestern part of Tarim Basin yields plateau ages of (281.8±4.2) Ma and a weighted mean value of (290.1±3.5) Ma respectively. This study combined with previous data indicates that the basaltic rocks from the studied area formed during 282~290 Ma. ⁴⁰Ar-³⁹Ar age dating from the basalts addresses a tectonothermal event in the Tarim Basin that occurred during the Early Permian of 278~290 Ma.

The quantum chemical method was employed to study the anionic polymerization mechanism of propylene oxide. All the structures are optimized completely at the HF/6-31G+(d) level. The calculated results showed that the ring-opening reaction between the anionic nucleophiles and propylene oxide is feasible, and that the products are mainly secondary alcohols. The anionic ring-opening polymerization of propylene oxide proceeds by nucleophilic attack of the secondary alcohol propagating anion on monomer. The calculated results satisfactorily agree with the experimental facts.

The effect of N,N,N′,N′-tetraalkyl terephthalamide (TATA) on the crystallization of polypropylene (PP) was studied by means of differential scanning calorimetry, wide angle X-ray diffraction and polarized optical microscopy. It was found that the addition of TATA effectively induced the formation of β-crystalline form of PP. With the increase of TATA content both the total crystallinity degree (x) and crystallinity degree for β-crystalline form (x_β) of PP increased significantly, while the crystallinity degree for α-crystalline form (x_α) decreased. Polarized optical micrographs indicated that the addition of TATA led to a substantial decrease in the size of spherulites of PP and the boundaries of spherulites were hardly distinguished. TATA could significantly improve the impact strength, flexural strength and modulus of PP, while the tensile strength of PP did not change greatly with TATA content.

A detailed kinetic model consisting of 126 reactions and 37 species modelled homogeneous low temperature multi-pollutant oxidation in flue gases by ozone. The kinetic model includes the oxidation and chlorination of key flue-gas components, as well as reactions involving SO. An important and previously unrecognized pathway of homogeneous Hg oxidation mechanism includes Hg reactions involving oxygen-containing compounds and chlorine-containing compounds. Analyses by sensitivity simulations revealed that the pathway Hg+Cl=HgCl and HgCl+Cl₂=HgCl₂+Cl is more significant than some of the key reactions in the kinetic mechanism proposed in the literature except Hg+NO₃=HgO+NO₂, which indicates the possibility to promote the Hg removal by adding HCl in the inlet stream. Studies on the effects of SO show that SO violently prevents NO consumption through the pathway SO+NO₂=NO+SO₂, even the net NO produced under the condition of low O₃ concentration and high SO concentration.

Chemical coagulation was used to remove the compounds present in wastewater from dye manufacturing industry. The character of wastewater was determined. Most compounds found in the wastewater are phenol derivatives, aniline derivatives, organic acid and benzene derivatives, output from dye manufacturing. Various polyferric chloride coagulants were investigated. Results showed that high extent of Fe(III) hydrolysis was not always suited for chemical oxygen demand (COD) removal in our wastewater, that electrostatic interaction between flocs and organic contaminants played an important role in removal of organic contaminants, that copolymers of Al(III), Si(IV) and Fe(III) were helpful for high flocculating effect, that COD removal efficiency of poly-silicate-aluminium-ferric chloride (PSAFC) and polyferric chloride (PFC) coagulant increased with increasing dose of coagulants, and that the performance of PSAFC and PFC coagulants was superior to PAC coagulant. This difference in efficiency may also be attributed to the copolymers of Si(IV), Al(III)and Fe(III). However, compared with PFC, PSAFC can easily reach high COD removal efficiency below coagulant dose 0.3 g/L. Thus, from the economic point of view, PSAFC is more suitable for treatment of wastewater effluent from dye manufacturing.

Monodispersed silica spheres were prepared by hydrolysis of tetraethyl orthosilicate (TEOS) in the presence of water and ammonia in ethanol medium. The net negative charge on the surface of SiO₂ spheres was enhanced after ageing silica spheres under suitable condition. Thus, a novel viscous liquid composed of mono-dispersed silica spheres was obtained. Due to the existing net repulsive forces between particles, the viscous liquid can quickly form a movable 3D periodic ordered structure with vivid color, indicating a high degree of ordering of the particles.

The silkworm Bombyx mori is exploited both as a powerful biological model system and also as a tool to convert leaf protein into silk. Silkworm larvae often suffer from viral infections causing heavy losses to the economy of the silk industry. Insects exhibit both humoral and cellular immune responses that are effective against various pathogens like bacteria, fungi, protozoa, etc., but no insect immune response is effective against viral infections. To date, no satisfactory reports are available on antiviral immunity of the silkworm. Some efforts have been made by very few workers to identify and characterize the antiviral proteins in the silkworm. In the present article the mode of viral infection, and the activity of certain antiviral proteins involved in silkworm immunity and also in some other insects are discussed. The investigation will be helpful in understanding the molecular aspects of antiviral immunity, disease control and may form the basis for potential use of silkworm in other fields such as medicine.

The structure difference of pine nuts was tested on the basis of their acoustical characteristics in order to distinguish whether they were open or closed. In this experimental study, pine nuts were dropped from a certain height onto a ceramic board; the impinging sound was recorded by a microphone. The sound wave graph and frequency spectrum graph were obtained while the impinging sound was analyzed by computer. Fractal dimension was calculated on sound wave graph and frequency spectrum graph of open and closed pine nuts. The result of test and analysis showed that the sound wave fractal dimension of open pine nuts was smaller than that of closed ones. The frequency spectrum fractal dimension of open pine nuts was larger than that of closed pine nuts. Fractal dimension of sound wave and frequency spectrum could be used as important indices to distinguish whether the pine nut was open or not.

Green mold caused by Penicillium digitatum (Pers.:Fr) Sacc. is one of the most important postharvest diseases of citrus fruits. Experiments were conducted to determine the occurrence of resistance of P. digitatum to imazalil in China. Four imazalil-Resistant (R) isolates were identified from 189 isolates of P. digitatum. The highest EC₅₀ of an imazalil-R isolate was 0.578 mg/L, 29 times higher than that of the most imazalil-sensitive (S) isolate, suggesting that imazalil-R biotype of P. digtatum had occurred in China. In vitro assessment indicated that the imazalil-R isolates were not significantly different from imazalil-S isolates in their growth rate and sporulation, indicating that the imazalil-R biotype has competence similar to that of imazalil-S one and could co-exist with it in environment. To determine the mechanism of the resistance, CYP51 gene was amplified from P. digitatum genome and sequenced. The results revealed that a tandem repeat of four extra copies of a unique 126-bp sequence in the upstream promoter region of CYP51 gene present only in imazalil-R isolates, but not in imazalil-S isolates, implying this tandem repeat sequence may regulate the expression of CYP51 positively, and lead to the sensitivity decrease.

Spinosad (spinosyns A and D) is a mixture of secondary metabolites produced by Saccharopolyspora spinosa. It is used in agriculture as a potent insect control agent with exceptional safety to non-target organisms. Spinosyns are macrolides with a 21-carbon, tetracyclic lactone backbone to which the deoxysugars forosamine and tri-O-methylrhamnose are attached. According to the pathway and regulation of spinosad biosynthesis, a rational selection procedure with u.v. mutation was performed to obtain high spinosad producing strain. The spinosad resistant mutants, the rhamnose resistant mutants, the 2-deoxygen-D-glucose resistant mutants were selected, successively. Eventually, a strain S. spinosa 4~6 was obtained, with its production of spinosad reaching 268 mg/L, which is increased by 121% in comparison with that of the parent strain S. spinosa 1~5. The subculture experiments indicated that the hereditary character of high production of S. spinosa 4~6 is stable. The spinosad fermentation with S. spinosa 4~6 was scaled up in a 10 L fermentor, and a production of 458 mg/L was obtained, which was 71% higher than the production with shaking-flask fermentation.

The effects of surfactants on dibenzothiophene (DBT) degradation by Corynebacterium sp. ZD-1 were investigated in hydrocarbon aqueous biphasic (O/W) systems in shake flask. Among Brij-35, Tween-80, Triton-100X and β-cyclodextrin, Tween-80 was a suitable surfactant to improve the desulfurization rate of dibenzothiophene. The amount of 2-hydroxybiphenyl (2-HBP) formed with Tween-80 present was about 50% more than that formed without surfactant. The results demonstrated that Tween-80 could improve the mass transfer of DBT between organic and aqueous phases, and could be used in dibenzothiophene biodesulfurization systems.

Investigation of the characteristics of soil microorganism ecosystem under irrigated rice cropping with different fertilization treatments showed that balanced application of N, P and K promoted microbial biomass and community composition, while unbalanced fertilization reduced microbial N and increased C/N ratio of the microbial biomass and that the fertilizer practice had impact on the community structure of specific microbial groups and the microbe diversity in soils. This research focused on soil microbial biomass and soil microbial community structure in a long-term fertilization experiment on rice based on nutrient balance concepts.