宝钢研制的全氢罩式炉控制系统分析

对宝钢研制的全氢罩式炉计算机控制系统的逻辑结构、工作原理及硬件配置进行了分析.该系统与引进的系统相比,在通讯方式、程序结构、操作分析、报警和开放性等方面都有所改进.     

甲醇燃料的研发现状及发展前景

介绍了甲醇燃料的理化性质、作为车用替代燃料的性能及研发现状，分析了甲醇汽油存在的问题及发展前景。     

有粘结预应力在252m地下室顶板中的应用

在总长度 2 5 2m的超长不设缝地下室顶板中 ,采用了预应力、设置后浇带等综合抗裂技术 ,并对有粘结预应力平板的设计理论、施工工艺、锚固体系及超长结构预应力损失控制和抗裂控制作了深入研究。     

Stem cells in prostatic epithelia

The normal prostate is, structurally and functionally, a highly complex glandular tissue in which populations of epithelial and stromal cells interact, one with the other, and are under a constant state of proliferation, differentiation, elimination and selective secondary replenishment so that functional integrity of the tissue is maintained. The ability of normal prostatic tissue to maintain its structure and function is dependent upon retention of cells, generally regarded as 'stem cells', which are able to respond by proliferation and selective differentiation within a wide range of phenotypic alternatives. With respect to cells in the epithelial compartment, replenishment is possible at several levels from within distinct pathways of normal cellular differentiation. It is now appreciated that fully differentiated prostatic epithelial cells retain a far greater degree of phenotypic 'plasticity' than was earlier apparent from morphological examination of the intact tissue. This inherent plasticity, coupled with the ability of the intact tissue to respond to diverse environmental (particularly humoral) stimuli by regenerating a wide and divergent spectrum of functional prostatic epithelial phenotypes is its strength--but also its weakness. Disturbance and distortion of the homeostatic regulatory mechanisms, whether physical or humoral, which control the normal sequence of epithelial proliferation, differentiation and elimination exposes these cells, particularly multipotent 'stem cells', to an increased probability of genetic change, thus resulting in either transient, or permanent, neoplastic transformation.     

Towards a generalized TLM algorithm for solving arbitraryreciprocal and nonreciprocal planar structures

A generalized transmission line matrix (TLM) algorithm is developed in the frequency domain to tackle arbitrary both reciprocal and nonreciprocal anisotropic waveguiding problems. In particular, the modeling issue for arbitrary planar structures is stressed in this work. A new three-dimensional (3-D) condensed node is used to consider the effect of both electric and magnetic constitutive tensors. Various results indicate how the modal dispersive behavior can be manipulated by changing not only the anisotropic characteristics of the substrate, but also the strip/slot geometry as well as the magnitude and orientation of the applied static magnetic field. The present algorithm is useful for CAD and simulation of a large class of gyrotropic waveguide-based microwave and millimeter-wave circuits     

清代皇家园林规划设计控制的量化研究——以圆明三园、清漪园为例

本文通过量化分析探索了清代皇家园林规划设计的控制规律及相关理论。     

大学教学价值取向的生存论反思

在生存论看来，以实存论为基底的大学教学价值取向，遗忘了追问人的生存意义。实际上，生存意义是在欲、技、道的游戏中生成的。大学教学价值向“寻求意义”的转向，实质上是“理智培育”、“技术培训”、“情感培养”三类传统价值取向在当代的共同表现形式．而非彼此对立。     

Synthesis and aqueous solution behaviors of sodium sulfonate‐terminated dendritic poly(ester‐amine)

Sodium sulfonate‐terminated dendritic poly(ester‐amine) (SPEA) was synthesized by sulfonation of acrylic double bond‐terminated dendritic poly(ester‐amine) (APEA) with sodium hydrogen sulfite (NaHSO₃) in mixture of diglycol and 2‐butanone under normal pressure. The structure of SPEA was characterized by IR, ¹H‐NMR, and elemental analysis. SPEA was water‐soluble. 1.0–40.0% (mass) SPEA aqueous solutions appeared as dilatant fluid. When pH value varied from 1.5 to 12.0, the viscosity of 1–5% (mass) SPEA aqueous solutions changed very small, and the electric conductivity almost kept stable within pH 3.0–10.0. The relationship between the viscosity and the concentration of SPEA water solutions was similar to that of NaCl water solutions. The surface tension of SPEA water solutions was lower than that of polyethylene glycol 2000 water solutions with the same concentration. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Green and self-lubricating polyoxymethylene composites filled with low-density polyethylene and rice husk flour

Polyoxymethylene (POM) composites filled with low-density polyethylene (LDPE) and rice husk flour (RHF) were prepared by injection molding. The POM/5 wt % LDPE/7.5 wt % RHF composite exhibited the lowest wear rate, whereas the coefficient of friction remained low, and the POM/5 wt % LDPE/5 wt % RHF composite had the best mechanical properties. X-ray diffraction analysis was carried out, and the worn surfaces were examined with scanning electron microscopy. The results showed that the addition of the filler reduced the crystallinity degree of the POM composites. The main wear mechanism for unfilled POM was adhesion, whereas for the POM composites, wear seemed to occur mainly by fatigue and abrasion. It was experimentally confirmed that the POM composite filled with LDPE and RHF, which is well-performing, low-cost, and environmentally friendly, could be a potential material for tribological applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008