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In this paper, we study an extended global routing problem with RLC crosstalk constraints. Considering simultaneous shield insertion and net ordering, we propose a multiphase algorithm to synthesize a global routing solution with track assignment to satisfy the RLC crosstalk constraint at each sink. The key algorithm phase is global routing synthesis with shield reservation and minimization based on prerouting shield estimation. Experiments using large industrial benchmarks show that compared to the best alternative with postrouting shield insertion and net ordering, the proposed algorithm with shield reservation and minimization reduces the congestion by 18.4 % with a smaller runtime. To the best of our knowledge, this is the first in-depth study on global routing synthesis with RLC crosstalk constraints.

Existing layout-optimization methods for both capacitive and inductive (RLC) crosstalk reduction assume a set of interconnects with a priori given crosstalk bounds in a routing region. RLC crosstalk budgeting is critical for effectively applying these methods at the full-chip level. In this paper, we formulate a full-chip routing optimization problem with RLC crosstalk budgeting, and solve this problem with a multiphase algorithm. In phase I, we solve an optimal RLC crosstalk budgeting based on linear programming to partition crosstalk bounds at sinks into bounds for net segments in routing regions. In phase II, we perform simultaneous shield insertion and net ordering to meet the partitioned crosstalk bounds in each region. In phase III, we carry out a local refinement procedure to reduce the total number of shields. Compared with the best alternative approach in experiments, the proposed algorithm reduces the total routing area by up to 5.71% and uses less runtime. To the best of our knowledge, this work is the first in-depth study on full-chip routing optimization with RLC crosstalk budgeting.

Theoretical calculations have been performed to study the effects of piezoelectric fields in superlattice systems. The results show that cubic strained superlattices and quantum wells subjected to variable temperature and pressure exhibit changes in their piezoelectric fields. We consider superlattice systems grown in arbitrary directions, with a thickness smaller and larger than the critical thickness value (undercritical and overcritical systems). In both cases (including the partially relaxed case), theory predicts the existence of a critical temperature Tm and a critical pressure pm, above which the sign of the piezoelectric fields in each layer reverses. As applications to practical systems, we calculated (1) the piezoelectric fields as a function of temperature in GaAs/ZnSe superlattice and (2) the piezoelectric fields as a function of pressure in GaAs/InAs, GaAs/Si, and ZnSe/GaAs superlattice systems. We present here the results of the effects of piezoelectric fields for three different systems (undercritical systems, overcritical systems, and partially relaxed systems), where the piezoelectric field changes under variable temperature, pressure, and thickness of the layers. We also discuss the valence band offset, which is induced by piezoelectric fields, and its dependence on temperature and pressure. In addition, we present data on the valence band offset for some practical undercritical systems. All results and conclusions are valid in a linear region of strain or stress where no phase transitions occur. [ABSTRACT FROM AUTHOR]

This paper seeks to measure and evaluate crack growth behaviors and residual lives of aluminum alloys (AAs) 2524-T3 and 7050-T7452 subjected to fatigue loading at temperatures of 25°C and -70°C. Fatigue crack growth tests were performed on AAs 2524-T3 and 7050-T7452 subjected to constant-amplitude and actual random-spectra loading histories at temperatures of about 25°C and -70°C, respectively, to determine the crack growth behaviors and residual lives. The interaction mechanisms between cryogenic temperature and the fatigue load were deduced on the basis of the results of fractographic analysis. The crack growth behaviors and residual lives were evaluated and compared at both temperatures of 25°C and -70°C. Good correlation was achieved between the predictions and actual experiments. [ABSTRACT FROM AUTHOR]

This article presents a new micromechanical model to predict biaxial tensile moduli of plain weave fabric composites by considering the interaction between the orthogonal interlacing strands. The two orthogonal yarns in micromechanical unit cell were idealized as curved beams with a path depicted using sinusoidal shape functions. The biaxial tensile moduli of plain weave fabric composites were derived by means of the minimum total complementary potential energy principle founded on micromechanics. Biaxial tensile tests were conducted on the resin transfer molding–made EW220/5284 plain weave fabric composites at five biaxial loading ratios of 0, 1, 2, 3 and ∞ to validate the new model. Predictions from the new model were compared with experimental data. Good correlation was achieved between the predictions and actual experiments, demonstrating the practical and effective use of the proposed model. Using the new model, the biaxial tensile moduli of plain weave fabric composites can be predicted based only on the properties of basic woven fabric. [ABSTRACT FROM AUTHOR]

This paper deals with mode II interlaminar delamination properties and failure mechanisms of composite laminates in three-point end-notched flexure (3-ENF) tests under fixed cyclic loading. The results for fracture toughness, fatigue driving force and delamination propagation behaviours of three different types of carbon and E-glass fibre/epoxy resin-reinforced composite laminates are evaluated and compared with each other for providing an insight into fatigue damage development in composites and for constituting a fundamental basis for the development of a characterization model. A new characterization formulation is presented for mode II interlaminar delamination propagation based on controlling fatigue stress. Finally, the model is applied to experimental data, demonstrating the practical and effective use of the proposed model. It is shown that fatigue-driven strength for mode II interlaminar delamination propagation can be obtained realistically from experimental data using the new formulae. [ABSTRACT FROM AUTHOR]

This paper seeks to establish an integrated and practical data treatment system for actual load history reliability analysis. A convergence–divergence counting procedure is presented to extract all load cycles from a load history of divergence–convergence waves. The lowest number of load history sampling is established on the basis of the damage-based prediction criterion. A parameter estimation formula is proposed for hypothesis testing of the load distribution. The examples of its application for the data treatment of actual load history are given. The proposed data treatment system has been shown to have valid and practical characteristics in analysing reliability results. [ABSTRACT FROM AUTHOR]

Objective: To study the risk of malnutrition and related factors of cancer patients in community of Shanghai. Methods: From October 2018 to January 2019, four communities, Pengpu New Village Street, Pengpu Town, Jiangning Road Street, and Caojiadu Street, from 14 communities in Jing 'an District, Shanghai City, were selected by using a random cluster sampling method based on the Shanghai Cancer Registration and reporting system. All cases of malignant tumors and benign tumors of the central nervous system were included. A total of 4 396 questionnaires were distributed. After the exclusion of 9 invalid questionnaires, 3 310 valid questionnaires were included with a rate of 99.73%. A self-designed questionnaire was used to collect data including basic demographic characteristics, history of malignant, physical and psychological pain, nutritional demands and cognitive status. Malnutrition Universal Screening Tools (MUST) was used to analyze the nutritional risk of cancer patients in the community. Multivariate logistic regression model was applied to analyze potential factors. Results: Among the 3 310 cancer patients who completed the survey, the average age of study participants was (64.05±13.02), and 1 467 cases (44.32%) were males. The incidence rate of nutritional risk was 12.84% (425/3 310). The result of logistic regression analysis showed that compared with male, other cancer patients and no physical pain, the risk factors of the occurrence of nutritional included: female ( OR =1.53,95% CI :1.23-1.92), head and neck malignant tumors ( OR =1.42,95% CI :1.07-1.90), bronchus/lung malignant tumors ( OR =1.93,95% CI :1.43-2.61), liver, biliary/pancreatic malignant tumors ( OR =2.11,95% CI :1.21-3.65) and upper gastrointestinal malignant tumors ( OR =6.04,95% CI :4.31-8.46), patients with physical pain ( OR =1.39,95% CI :1.02-1.89). Conclusion: Nutritional risk of cancer patients is higher in community of Shanghai. Gender, location of tumors and physical pain are associated with the occurrence of nutritional risk.

In the Suffolk ewe, seasonal reproductive transitions are due primarily to changes in the responsiveness of the GnRH neurosecretory system to the negative feedback influence of estradiol. As GnRH neurons in the sheep, like those in other mammals, lack estrogen receptors, the influence of estradiol on GnRH neurosecretory activity is probably conveyed via afferents. As a possible structural basis for seasonality, we examined the ultrastructure and synaptic inputs of GnRH neurons in the preoptic area of ewes during the breeding season and seasonal anestrus. GnRH neurons were examined in both ovary-intact ewes and ovariectomized ewes bearing implants that produced constant levels of estradiol to eliminate a changing hormonal milieu as a factor in any seasonal variations. We found that preoptic GnRH neurons in breeding season ewes received more than twice the mean number of synaptic inputs per unit of plasma membrane as GnRH neurons in anestrous animals. Although GnRH dendrites received more synaptic input than GnRH somas, significant seasonal differences were seen in both axodendritic and axosomatic inputs. In contrast, unidentified neurons in the preoptic area showed no significant seasonal changes in their synaptic inputs. Seasonal changes in synaptic inputs onto GnRH neurons were seen in both intact animals and ovariectomized ewes bearing estradiol implants. Consequently, these seasonal alterations are unlikely to be due to changing levels of endogenous sex steroids, but may instead reflect changes in the environmental photoperiod and/or the expression of an endogenous circannual rhythm.

Expression of Fos protein, detected immunocytochemically, was used to assess the relative responses of supraoptic nucleus (SON) oxytocin- (OX) and vasopressin- (VP) containing neurons to the osmotic vs. the osmotic plus stressful components of intraperitoneal hypertonic saline injections. The percentage of SON neurons showing Fos-like immunoreactivity (Fos-ir) was quantified for rats receiving general anesthesia only, anesthesia 1 h prior to either isotonic or hypertonic saline injection or no anesthesia prior to hypertonic injection. Hypertonic saline injection with and without anesthesia induced Fos-ir in 66% and 77% of SON neurons, respectively, whereas isotonic saline with anesthesia and anesthesia alone resulted in 15% and 13%, respectively, of cells showing Fos-ir. Double labeling for Fos-ir and either OX-ir or VP-ir resulted in quantitatively different responses to hypertonic injections with and without anesthesia in OX-ir and VP-ir neurons. The VP-ir neuronal response was similar under the two conditions: 49% and 48% of VP cells displaying Fos-ir with and without prior anesthesia, respectively. By contrast, a higher percentage of OX-ir neurons was found to exhibit Fos-ir without (68%) than with (53%) anesthesia. Thus, a greater percentage of neurons was induced to express Fos-ir when the stressful components of the hypertonic injection were unattenuated by anesthesia, and this difference was entirely due to increased numbers of responding OX neurons. These data indicate that, under these experimental conditions, SON OX neurons respond in larger numbers to the osmotic components of hypertonic saline injections and have a greater responsiveness than do VP neurons to the stressful components.