螺旋升流反应器氧传递性能的试验研究

本文主要针对螺旋升流反应器技术特性，对工艺的好氧反应器进行了氧传递性能的试验研究，考察了反应器水深、曝气量等对螺旋升流反应器氧转移过程的影响；并对试验数据进行回归，得到了氧传质总系数与螺旋升流反应器内表现气速的数学关系。试验结果表明，螺旋升流反应器具有良好的氧传递特性，是一种新型的高效、节能的污水处理反应技术。     

Sperm bundle and reproductive organs of carabid beetles tribe Pterostichini (Coleoptera: Carabidae)

The morphological characteristics of sperm and reproductive organs may offer clues as to how reproductive systems have evolved. In this paper, the morphologies of the sperm and male reproductive organs of carabid beetles in the tribe Pterostichini (Coleoptera: Carabidae) are described, and the morphological associations among characters are examined. All species form sperm bundles in which the head of the sperm was embedded in a rod-shaped structure, i.e., spermatodesm. The spermatodesm shape (left-handed spiral, right-handed spiral, or without conspicuous spiral structure) and the condition of the sperm on the spermatodesm surface (with the tail free-moving or forming a thin, sheetlike structure) vary among species. In all species, the spiral directions of the convoluted seminal vesicles and vasa deferentia are the same on both sides of the body; that is, they show an asymmetric structure. The species in which the sperm bundle and the seminal vesicles both have a spiral structure could be classified into two types, with significant differences in sperm-bundle length between the two types. The species with a sperm-bundle spiral and seminal-vesicle spiral of almost the same diameter have longer sperm bundles than the species with a sperm-bundle spiral and seminal-vesicle tube of almost the same diameter. In the former type, the spiral directions of the sperm bundles and seminal vesicles are inevitably the same, whereas they differ in some species with the later type. Therefore, increased sperm bundle length appears to have been facilitated by the concordance of the sperm bundle’s coiling direction with the coiling direction of the seminal vesicle.     

螺旋钢管盘制成形的一种新方法

对如何在三辊卷板机上进行盘制螺旋钢管、盘管所用模具及成形工艺作了介绍.     

Experimental investigation of the pressure gradient of a new spiral mesh foam generator

Foam is used as part of an effective dust suppression method in underground coal mines, but conventional foaming devices severely restrict its popularization and application due to the high cost of foam preparation, poor applicability and high pressure loss. Therefore, a new spiral mesh foam generator is designed, and its performance is investigated and evaluated experimentally. The results show that the pressure gradient of the spiral mesh foam generator increases with the increase of foam concentration in water. There is a large pressure gradient gap between the top and bottom at both ends of the foam generator. However, the gap disappears and uniform foam is generated in the middle section of the foam generator. When the pressure gradient is higher than minimum pressure gradient, the foam production quantity will increase sharply. Based on the length of spiral mesh and operating conditions determined, the new foam generator is applied to produce foam for dust suppression in the heading face of coal mines. A good foaming effect, less pressure loss and high dust suppression efficiency suggest that the new foam generator will greatly promote the large-scale application of foam technology used to suppress dust in underground coal mines.     

Pattern formation of a predator-prey system with Ivlev-type functional response

In this paper, we investigate the spatial pattern formation of a predator-prey system with prey-dependent functional response Ivlev-type and reaction-diffusion. The Hopf bifurcation of the model is discussed, and the sufficient conditions for the Turing instability with zero-flux boundary conditions are obtained. Based on this, we perform the spiral and the chaotic spiral patterns via numerical simulation, i.e., the evolution process of the system with the initial conditions which was small amplitude random perturbation around the steady state. For the sake of learning the pattern formation of the model further, we perform three categories of unsymmetric initial condition, and find that with these special initial conditions the system can emerge not only spiral pattern but also target pattern and so on, and the effect of these special conditions on the formation of spatial patterns is less and less with more and more iterations but the effect does not decay forever. This indicates that for prey-dependent type predator-prey system, pattern formations do depend on the initial conditions, while for predator-dependent type they do not.     

SUFR系统在低温影响下处理效果的试验分析

全面分析低温(8—20℃)对螺旋升流式反应器(spiral Up-Flow Reactor,SUFR)系统处理效果的影响．低温时利用SUFR系统进行试验研究的结果表明,该系统耗氧有机物(以COD计)和TN处理效果虽然随着温度的降低有所下降,但是耗氧有机物(以COD计)及TN去除率仍分别达到86％、70％以上．TP的去除率一直在92％以上．低温时该系统的活性污泥一时难于压缩、沉降．然而在未采取任何措施的情况下,污泥沉降性能可以在较短时间内自行恢复．这说明,接近活塞流特征的SUFR系统可以减轻低温对污水处理的负影响．该系统具有更宽的温度适宜范围．     

新型反应器(SUFR)去除城市污水中氮和磷的试验研究

开发了一种新的污水生物处理反应器——螺旋升流式反应器（Spiral Up-Flow Reactor,SUFR）,与传统的“池型反应器”（如氧化沟）相比,既提高了反应器中稳定的活塞流流态的容积利用率,又便于工程应用。运用SUFR对生物脱氮除磷进行了研究,系统连续稳定运行6个月的结果表明,该系统能保证出水平均质量浓度COD小于31mg/L,总氮小于10mg/L,总磷小于0.50mg/L,对COD、TN和TP的去除率分别达94%、86%和96%以上。对去除性能的分析结果表明,（1）SUFR系统厌氧反应器、缺氧反应器和好氧反应器对COD的去除量分别占去除总量的51.2%、12.5%和36.3%;（2）在去除总氮时,好氧反应器表现出了同步硝化反硝化功能,其对总氮的去除量约占SUFR系统去除总量的10%～20%;（3）去除总磷时,缺氧反应器表现出了反硝化吸磷现象,吸磷的量与进水COD质量浓度有关。     

Patchy Distribution Fields: Sampling Distance Unit of a Spiral Survey and Reconstruction Adequacy

A mathematical model is used to examine the effects of choosing various units of sampling distance of a spiral acoustic survey on the adequacy of reconstructing patchy distribution fields. The model simulates fish or plankton patches (or gaps) of different shapes and spatial orientations, and an acoustic survey by a spiral of Archimedes along which a unit of sampling distance is set. For comparison, surveys are imitated by parallel transects along which the same unit of sampling distance is set. Adequacy of the reconstructed fields to those originally generated is evaluated by calculating their correlations (r). In the case of a spiral survey, the mathematical experiments conducted show that an immovable field can be reconstructed properly (r ² > 0.70) if the ratio of the units of sampling distance to the autocorrelation radius for the field averaged in various directions d/R _av < 1.0–1.5. Regarding immovable fields, the spiral surveys ensure, practically speaking, the same adequacy of the field reconstruction as do surveys by parallel transects with the same unit of sampling distance. In regard to movable fields, a comparison of the results of spiral surveys with those of surveys by parallel transects indicates that the former may ensure even higher adequacy of the field reconstruction than do the latter, provided that the units of sampling distances in these surveys are equal to each other.     

Patchy distribution fields: A spiral survey design and reconstruction adequacy

A mathematical model was used to examine the effects of a spiral survey design on the adequacy of reconstructing patchy distribution fields. The model simulates fish or plankton patches (or gaps) of different shapes and spatial orientations, and acoustic surveys by a spiral of Archimedes; for comparison, surveys by parallel or zigzag transects are imitated. Adequacy of the reconstructed fields to those originally generated was evaluated by calculating their correlations (r). The mathematical experiments conducted showed that spiral surveys ensure, practically speaking, the same adequacy of field reconstruction (both in cases of immovable or movable patches) as do surveys by parallel or zigzag transects with greater sampling effort (overall path). In the case of a spiral survey, a patchy field can be reconstructed properly (r² = 0.70) if the overall survey path is not less than S/R_av = 20–30, where R_av is the autocorrelation radius averaged for various directions. Thus, the results obtained allow us to conclude that a spiral survey design is expedient in cases that the minimal duration of a survey is a decisive factor for its conduction and there is a priori information that no onshore-offshore gradients of fish density exist in a region under study.     

ERIC-PCR指纹图谱技术对低温下SUFR反应器中菌群结构分析

使用ERIC-PCR指纹图谱技术对螺旋升流式反应器(Spiral Up-Flow Reactor,SUFR)在低温下的微生物群落结构进行了分析.结果表明,低温下反应器中微生物菌群呈多样性分布,优势菌群突出;在遭受约5℃低温条件冲击后,反应器中菌群多样性和反应器脱氮除磷效率都有所降低,但TN去除率和TP去除率仍然达到了72.35%和93.28%,维持了反应器的正常功能.不同温度下对比分析可以看出,在低温和常温下反应器中优势菌群发生了一定变化,常温条件下的优势菌群比低温条件下更丰富多样.总体看来,SUFR反应器良好的螺旋升流特质有利于不同菌群在不同温度下的功能发挥,特别是低温下脱氮除磷功能的维持.