基于遗传算法与Hardy-Cross方法的矿井通风机控制

针对矿井通风机系统控制的复杂问题,提出了一种遗传算法与Hardy-Cross方法相结合的矿井通风控制,强化了其在处理离散变量和非凸搜索空间中寻找全局最优解的能力。通过数学形式化定义问题并结合基尔霍夫定律,确立了通风机网络的优化模型。根据实际用风情况智能调节通风机的供风量,以实现能源节约和安全生产的目标。通过对某煤矿的通风案例深入研究和验证,风扇的配置在优化气流方面表现出了卓越性能。该研究不仅为矿山工程领域提供了新的优化思路和方法,也为通风机系统的管理提供了重要参考。

标准Criss-Cross剖分下线性有限元方程的快速AMG算法

首先对标准Criss -Cross剖分下的线性有限元空间进行能量正交分解 ,通过对正交子空间的双尺度分析 ,获得了一种合适的限制算子 ,进而构造相应的AMG算法 .数值实验结果表明 ,该方法对求解椭圆方程是非常有效和健壮的 ,且与通常的代数多重网格法相比较 。

一个新的线性规划Criss-cross算法(英文)

本文利用重新排列下标的技巧,提出了一个新的criss-cross算法.并证明了其有限性,理论分析及初步的计算实验表明,新算法比最小下标criss-cross算法效率更高.

Gas permeation properties of a metallic ion-cross-linked PIM-1 thin-film composite membrane supported on a UV-cross-linked porous substrate

Metallic ion-cross-linked polymer of intrinsic microporosity(PIM-1) thin-film composite(TFC) membranes supported on an ultraviolet(UV)-cross-linked porous substrate were fabricated. The UV-cross-linked porous substrate was prepared via polymerization-induced phase separation. The PIM-1 TFC membranes were fabricated via a dip-coating procedure. Metallic ion-cross-linked PIM-1 TFC membranes were fabricated by hydrolyzing the PIM-1 TFC membrane in an alkali solution and then cross-linking it in a multivalent metallic ion solution. The pore size and porous structures were evaluated by low-temperature N_2 adsorption–desorption analysis. The membrane structure was investigated by field-emission scanning electron microscopy. The effects of heat treatment and pore-forming additives on the gas permeance of the UV-cross-linked porous substrate are reported. The effects of different pre-coating treatments on the gas permeance of the metallic ion-cross-linked PIM-1 TFC membrane are also discussed. The metallic ion-crosslinked PIM-1 TFC membrane displayed high CO_2/N_2 selectivity(23) and good CO_2 permeance(1058 GPU).

基于Q 90法与R2-Cross法的麻栗坝水库下游河道生态流量研究

针对拟建大型灌区工程从水库引水后可能对水库下游河道造成流量减小及鱼类生态系统破坏等问题,对已建的麻栗坝大型水库下游36.9km的南宛河研究河段采用水文学法的Q 90法与水力学法的R2-Cross法进行生态流量研究。根据两种方法计算结果并取其中最大值作为最终生态流量值,为水利工程建设后生态流量计算和水资源管理提供依据。

Principle and Experimental Verification of Caudal-fin-type Piezoelectric-stack Pump with Variable-cross-section Oscillating Vibrator

In the traditional flow-resistance-differential (FRD) type valve-less piezoelectric pump, the generated outflow and pressure are discontinuous because of the inherent periodicity and fluctuation of the pump. To overcome these drawbacks, utilizing the bending vibration of piezoelectric bimorph to drive fluid was conducted. However, our investigation on the current status of this piezoelectric bimorph pump shows that larger driving force and vibration amplitude are required for fluid pumping; the pumping can be realized through the centrifugal force; and the mechanism of fluid pumping is no longer further studied. Based on these cases, the paper designed a piezoelectric-stack pump with variable-cross-section oscillating (VCSO) vibrator by imitating the swing of the caudal-fin of tuna, and the pump is neither the rotating type nor the volumetric type according to the taxonomy. The interaction between the oscillating vibrator and the fluid parcel is firstly analyzed from the viewpoint of momentum conservation, and the analytical expression of pump flow rate is obtained. Then the modal and harmonic response analyses on the vibrator immerged in water are carried out. From the analyses the first two orders resonance frequencies are 832 Hz and 1 939 Hz, respectively, and the peak value of the tip amplitude is 0.6 mm. Laser Doppler vibrometer is used to measure both the frequency and vibration amplitude, and the determined first two orders resonance frequencies are 617 Hz and 1 356 Hz, respectively. The measured tip amplitude reaches to the peak value of 0.3 mm. At last, experimental measurement for the flow rates with different driving frequencies is conducted. The results show that the flow rate can reach 560 mL/min at 1 370 Hz when the pump runs under the backpressure of 30 mm water column. And the flow rate is as much as 560% of that of experiment results carried out by researchers from Brazil. The proposed pump innovates in both theory and taxonomy; in addition, the pump overcomes the drawbacks such as large flow fluctuation and low flow rate in the traditional FRD type pumps, which will help to broaden the application of the valve-less piezoelectric pump.

基于Tennant和R2-CROSS的滇池流域河流生态需水量计算

滇池流域内河流众多,为研究滇池流域的河流水生态状况,采用Tennant法和R2-CROSS法计算滇池流域河流生态需水量,进行对比分析。研究结果表明:使用Tennant法计算河流生态需水量为16974.59万m^(3),使用R2-CROSS法计算河流生态需水量为16715.49万m^(3)。Tennant法计算灵活、简单,R2-CROSS法综合考虑了研究河段的水力特性、生态特性和河道形态特性,计算结果更全面。研究结果可为滇池流域的水资源开发利用以及生态系统的保护和恢复提供科学依据。

Ultra-wideband circular-polarization converter with micro-split Jerusalem-cross metasurfaces

An ultrathin micro-split Jerusalem-cross metasurface is proposed in this paper, which can efficiently convert the linear polarization of electromagnetic （EM） wave into the circular polarization in ultra-wideband. By symmetrically employing two micro-splits on the horizontal arm （in the x direction） of the Jerusalem-cross structure, the bandwidth of the proposed device is significantly extended. Both simulated and experimental results show that the proposed metasurface is able to convert linearly polarized waves into circularly polarized waves in a frequency range from 12.4 GHz to 21 GHz, with an axis ratio better than 1 dB. The simulated results also show that such a broadband and high-performance are maintained over a wide range of incident angle. The presented polarization converter can be used in a number of areas, such as spectroscopy and wireless communications.

250H-VitD,Totol-P1NP,β-Cross,N-MID血清学水平对骨质疏松诊断价值的研究

目的 探讨血清骨质疏松三项（P1NP,β-Cross,N-MID）和25羟基维生素D水平对骨质疏松症患者的诊断价值。 方法 选取嘉定区中心医院2017全年患者434例，其中确诊骨质疏松患者247例，非骨质疏松患者187例。采用电化学发光免疫分析法检测两组患者血清总I型胶原氨基端延长肽（Total-P1NP）、β-胶原特殊序列（β-CrossLaps）、N端骨钙素片段（N-MID Osteocalcin）和25-羟基维生素D（250H-VitD）水平并统计分析。 结果 骨质疏松患者组血清P1NP、N-MID、25OH-VitD水平均显著低于非骨质疏松组，β-Cross虽然两组间血清水平表达无统计学意义，但骨质疏松组有水平下降的趋势。 结论 P1NP、N-MID、25OH-VitD对骨质疏松诊断有较高的价值，而β-Cross则可能存在一定的参考意义。

Pt Deposition on Anode Enhances the Performance of Dye-Sensitized Solar Cell with Non-Cross-Linked Gel Electrolyte

We fabricated dye-sensitized solar cells with non-cross-linked fluorinated gel electrolyte. The application of fluorinated gel to electrolyte is a challenging issue at present. The gelation of the electrolyte is of importance in order to solve the problem in the durability of the cell. We investigated, in this article, the effect of Pt deposition on the anode of the cell. The Pt was deposited by means of a DC sputtering technique. The studies showed that the deposition time strongly affected both open voltage and short-circuit current of the cell. The adaptive thickness of the Pt layer was determined to be 10 nm for the non-cross-linked fluorinated gel electrolyte cells.

Estimating Out-Crossing Rate of Bg 379-2 Using Morphological Markers and Confirmation by Molecular Markers

Rice is largely self-fertilized and accordingly a field population of rice is completely composed of near homozygotes. Due to the emergence of off-types, homozygosity will be affected. With the time, this will cause the reduction of genetic purity in some rice varieties. One of the reasons has been suspected to be the high out-crossing frequencies of such varieties. Studies were conducted at the Rice Research and Development Institute, Batalagoda, Sri Lanka to estimate the out-crossing rate of Bg 379-2, a variety having the problem of maintaining genetic purity. Bg 379-2 was allowed to out-cross with Bg 450 and the number of out- crossed plants were counted using dominant morphological markers such as short-round grain and purple culm of pollen donor. A molecular confirmation of out-crossing was also performed using sequence tagged site （STS） molecular marker pTA248. The variety Bg 379-2 showed a potential out-crossing rate of 3.41% and an average out-crossing rate of 1.29% using dominant morphological markers. Polymorphism was cleady detected between parents and out-crossed plants as well as selfed plants of Bg 379-2 using their banding patterns. A similar study can be performed to determine the out-crossing rates of other varieties which show high percentage of off-types in the population for the better understanding of the breeding behavior of the varieties.

STATISTICAL PROPERTY OF THRESHOLD-CROSSING FOR ZERO-MEAN-VALUED, NARROW-BANDED GAUSSIAN PROCESSES

Based on a comprehensive discussion of the calculation method for the threshold-crossing statistics of zero mean valued, narrow banded Gaussian processes of various practical engineering problems, including the threshold-crossing probability, average number of crossing events per unit time, mean threshold-crossing duration and amplitude, a new Simple numerical procedure is proposed for the efficient evaluation of mean threshold-crossing duration. A new dimensionless parameter, called the threshold-crossing intensity, is defined as a measure of the threshold-crossing severity, which is equal to the ratio of the product of average number of crossing events per unit time and mean threshold-crossing duration and amplitude over the threshold. It is found, by the calculation results for various combinations of stochastic processes and different thresholds, that the threshold-crossing intensity, irrelevant of the threshold and spectral density of the process, is dependent only on the threshold-crossing probability.

非参数回归的L_1-Cross-Validation最近邻中位数估计的强相合性

考虑非参数回归模型Yi=g（xi）+ei,i≥1,其中g（x）是待估计的连续函数,{xi,i≥1}是非随机的,{ei,i≥1}是iid随机误差,在本文中,我们讨论最近邻中位数估计（x）=m(Y（i（1））,…,Yi（h*）=Yi（1）,…,Yi（h*）之中位数,其中h*利用L1—Cross—Validation方法选择,在一定条件下,建立了L1—Cross—Validation最近邻中位数估计的强相合性。

非参数回归的L_1-cross-validation最近邻估计的强相合性

考虑非参数回归模型:Y_i=g(x_i)+e_i,i≥1,其中g是待估计的连续函数,{x_i,i≥1}是非随机的,{e_i,i≥1)是iid随机误差。在本文中,我们讨论最近邻估计g_(n,h)(x)=1/h∑Y_(R_(i,x)^(n)),其中h利用L_1-cross-validation方法选择,在一定条件下,证明了L_1-cross-validation最近邻估计的强相合性。

Inclined-cross Microstructure of Conch Shell

The microstructures of conch shell were observed with scanning electronic microscope （SEM）, and a kind of inclined-cross microstructure of aragonite sheets was found. The maximal pull-out force of the inclined-cross microstructure was analyzed based on its representative model and compared with that of a conventional 0 °- structure. The experimental result indicates that the maximal pull-out force of the inclined-cross microstructure is markedly larger than that of the 0°- structure.

Vertical deformation of the fault-crossing network around Baotou,observed by GPS

GPS data and precise leveling data of seismic network profiles across the fault in Baotou in 2006, 2009 and 2011 were processed and analyzed to test the feasibility of using GPS technology for fault-crossing vertical deformation monitoring. The results showed that high precision cross-fauh vertical deformation measurements can be obtained using appropriate GPS data processing strategies.

Vegetation Formation in Estuarine Tidal Flats: Influences of Basin Scale and River-Crossing Structures of the Eight Rivers of Ise Bay in Mie and Aichi Prefectures, Japan

In this study, we examined the influences of the differences in basin scale and river-crossing structures of 8 rivers of Ise Bay in Mie and Aichi Prefectures, Japan on the vegetation in the estuarine tidal flats of these rivers. The dominant plant communities of the estuarine tidal flats formed from rivers of large-scale river basins (exceeding 300 km2) were determined. In the Miya River, the dominant plant community was the Suaeda maritima and Artemisia fukudo community. In the Kushida River, the dominant plant community was composed of Phacelurus latifolius, Artemisia fukudo, Phragmites australis, and bamboo. In the Kumozu River, the dominant community was composed of the coastal plants Calystegia soldanella, Lathyrus japonicus, and Carex pumila and the exotic plant of Lolium multiflorum. The plant community of Suzuka River was dominated by the exotic plant of Eragrostis curvula. Among the estuarine tidal flats influenced by a small-scale river basin (50 km2 or less), the plant community of Shinbori River (Fukue tidal flat) was dominated by Suaeda maritima, and the plant communities of the Shio and Harai Rivers were dominated by Phragmites australis. The plant community of Tanaka River was dominated by Phragmites australis and coastal plants. Regarding the relationship between the vegetation and the river environment for each study site, we hypothesised that in a large basin area with few structures crossing the river, the river water catchment in the estuary after heavy rains caused large areas of disturbance and formed bare land, providing suitable habitat for an annual salt marsh plant community. In contrast, in cases with many structures crossing the river, a stable channel, an excavated riverbed and the suppression of runoff and the resulting disturbance of the estuary, flooding did not occur during high tide. Moreover, we hypothesised that in a small basin with many structures crossing the river, disturbance to the estuary was not likely, and the perennial salt marsh plant community of Phragmites australis would be widely distributed, except for a river type such as the Shinbori River, in which tide and river flow were managed by a final closure.

Optimum Combination of Femoral Head Size, Femoral Head Material, and Acetabular Cup Liner’s Highly-Cross-Linked Polyethylene Brand for Hip Implant

Clinical two-dimensional linear wear rate data for acetabular cup liners fabricated using approved brands of highly cross-linked ultra-high-molecular-weight polyethylene, as reported in 39 articles in the literature, were analyzed using a statistical technique called response surface methodology. The output was a series comprising16 acceptable combinations of femoral head diameter (HD), femoral head material (HM), and HXLPE brand (PB), each of which would yield the optimum wear rate (herein taken to be a wear rate of practically zero). An example of such a combination is 28- mm-diameter Oxinium? femoral head articulated against an acetabular cup liner fabricated from ReflectionTM HXLPE. The findings in this work may guide an orthopaedic surgeon’s selection of the combination of HD, HM, and PB to use in a primary total hip joint replacement.

线性规划的无比值检验criss-cross算法

Zionts提出的求解线性规划问题的criss-cross算法实际是一阶段算法,不过与传统一阶段算法不同,它交替进行原始和对偶迭代,而产生的既可以是原始可行解,也可以是对偶可行解。为了提高计算效率,文章提出了一种采用无比值检验规则的新criss-cross算法,基于新算法编制的一个稠密软件在对40个小问题进行的数值试验中,就迭代次数而言,以2.12的比率胜过了传统的两阶段算法。

Preparation and characterization of genipin-cross-linked chitosan microparticles by water-in-oil emulsion solvent diffusion method

Chitosan (CS) microparticles with and without cross-linking were prepared by a water-in-oil emulsion solvent diffusion method without any surfactants. Aqueous CS solution and ethyl ace- tate were used as water and oil phases, respectively. Genipin was used as a cross-linker. Influ- ences of genipin ratios and cross-linking times on CS microparticle characteristics were investigated. Non-cross-linked and cross-linked CS microparticles were spherical in shape and rough in surface. Microparticle matrices showed porous structures. Surface roughness, mean par- ticle sizes and bulk density of CS microparticles increased and their dissolutions in acetic acid solution decreased when genipin ratio and cross- linking time increased.