UIC60kg/m重轨孔型系统优化

用 6个轨形孔代替 5个轨形孔轧制UIC 60kgm钢轨 ,降低了断辊、掰辊环及扭脖子事故 ,同时使轧件轧痕及规格不合格量大大减少 ,提高了UIC 60kgm钢轨的出口合格率。     

Testicular volume of boys after inguinal herniotomy: combined clinical and radiological follow-up

Many nurse managers practice enterprise-wide resource management across networked departments and facilities. Here's help in understanding how automation can ease the process.     

Accelerated growth of melanomas after specific immune destruction of tumor stroma in a mouse model

Destruction of the entire stroma in a tumor could provide a stringent test of the prospects for tumor eradication in a single treatment. This possibility was investigated by experimental immune destruction of the stroma in a mouse melanoma model. Melanomas were first produced by grafting skin from transgenic C57BL/6 females of high-melanoma susceptibility to low-susceptibility transgenic males so that the malignant cells would be genetically female and the stromal cells genetically male. Subcutaneous transplant lines were then established from the melanotic and the amelanotic zones of such a melanoma and were carried in transgenic male hosts to ensure the male composition of the stroma. Thus, the male-specific H-Y histocompatibility antigen, which is ubiquitously expressed on male cells, could provide the target for an immune attack against the stroma. The transplant lines were next passaged once in transgenic females preimmunized against the H-Y antigen by having received and rejected a graft of C57BL/6 nontransgenic male skin. The antistromal immune response of these hosts did not prevent recovery of the tumors, which required a substantially prolonged latency. However, after retransplantation to nonimmunized males and females, the latency was markedly shortened from the original level. Thus, the treatment had indirectly selected for more rapidly growing tumor cells and hastened malignant progression.     

Ultrasonographic evaluation of the anterior recess in the normal hip: a prospective study on 166 asymptomatic children

Bypass graft patency with ultrafast computed tomography (= Electron Beam Tomography, EBT) was examined in 72 bypass grafts (47 saphenous veins, 25 internal mammary arteries) in 30 patients and compared with coronary angiography. Angiography was performed a mean of 4.4 +/- 3.5 months (range 1-13) from the EBT examination. Contrast material (120 ml) was continuously administered via a peripheral vein and 40 axial slices (3 mm slice thickness, 110 ms scan time) without overlap sequences were obtained, ECG triggered with the single slice scanner mode. Imaging of internal mammary artery grafts began at the thoracic inlet, for saphenous vein grafts, at the undersurface of the aorta. Sixty of 63 angiographically patent bypass grafts were determined patent by EBT (sensitivity 95%), 8 bypass grafts could not be detected by EBT, and 9 were angiographically occluded (specificity 89%). Twenty-four of 25 internal mammary artery grafts were patent at EBT and coronary angiography, one was occluded. In 27 of the 30 patients (90%), all of the angiographically patent grafts could be confirmed as open with EBT. Obstructions of 10 grafts could not be visualized with EBT. Graft insertion into native coronary vessels could be visualized in axial slices, although morphologic quantification of graft insertion stenosis (75-90%) in two cases was not possible. Three dimensional reconstruction of the 40 axial slices allowed graft anatomy to be delineated. Visualization of bypass insertion into the native coronary vessel was less successful because of opacification of the left and right ventricle. Electron beam computed tomography is a minimally invasive procedure capable of evaluating the patency of saphenous vein and internal mammary artery grafts. The morphologic quantification of graft obstruction and visualization of the insertion of the bypasses into the native coronary vessels is less successful with present technology and imaging modalities.     

Collaborative techniques for intrusion detection in mobile ad-hoc networks

In this paper, we present two intrusion detection techniques for mobile ad-hoc networks, which use collaborative efforts of nodes in a neighborhood to detect a malicious node in that neighborhood. The first technique is designed for detection of malicious nodes in a neighborhood of nodes in which each pair of nodes in the neighborhood are within radio range of each other. Such a neighborhood of nodes is known as a clique [12]. The second technique is designed for detection of malicious nodes in a neighborhood of nodes, in which each pair of nodes may not be in radio range of each other but where there is a node among them which has all the other nodes in its one-hop vicinity. This neighborhood is identical to a cluster as mentioned in [12]. Both techniques use message passing between the nodes. A node called the monitor node initiates the detection process. Based on the messages that it receives during the detection process, each node determines the nodes it suspects to be malicious and send votes to the monitor node. The monitor node upon inspecting the votes determines the malicious nodes from among the suspected nodes. Our intrusion detection system is independent of any routing protocol. We give the proof of correctness of the first algorithm, which shows that it correctly detects the malicious nodes always when there is no message loss. We also show with the help of simulations that both the algorithms give good performance even when there are message losses arising due to unreliable channel.     

A Novel Nonlinear Constellation Precoding for OFDM Systems with Subcarrier Grouping

This paper proposed a novel nonlinear constellation precoding (NCP) technique based on maximum distance separable (MDS) codes in orthogonal frequency-division multiplexing (OFDM) systems. The proposed method envisage to maximize both the diversity and coding gains for any number of diversity channels and desired diversity orders. The novel NCP technique combined with subcarrier groping in OFDM systems to replace the most existing linear constellation precoding (LCP) scheme. In this scheme, the full set of subcarriers are splitted into smaller groups and the codewords are constructed from $q$ point constellation mapper with MDS encoder. The maximum-likelihood (ML) decoder is used in the most existing signal space diversity technique which is replaced by diversity channel selection (DCS) to reduce the decoding complexity with the cost of marginal performance loss. The effect of the Inter-carrier interference (ICI) introduced by the carrier frequency offsets (CFO) also analyzed in the proposed OFDM system. The superiority of the proposed novel NCP technique over the previously proposed designs is verified by simulation results.     

Analysis of CMOS 0.18 μm UWB low noise amplifier for wireless application

Microsystem Technologies - In this work, a 0.18 μm CMOS LNA is designed which is favorable for a wireless application and the topology used in this design is cascode inductive source...