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1.
对应用于宾馆用户的热电冷联产系统进行方案优化,得到在不同建筑面积下所对应的最优设计方案及性能指标。以净现值率为目标函数,对宾馆用户在不同地区优化方案进行对比分析,结论为:在严寒地区的经济效益最好,其净现值率在2.1-4.1范围内变化,其次是夏热冬冷和寒冷地区,其净现值率在1.2-2.6范围内变化,夏热冬暖地区的经济效益最差,其净现值率在1.0-2.4范围内变化。  相似文献   

2.
Inhibition of return (IOR) describes a performance decrement for stimuli appearing at recently cued locations. Both attentional and motor processes have been implicated in the IOR effect. The present data reveal a double dissociation between the attentional and motor components of IOR whereby the motor-based component of IOR is present when the response is oculomotor, and the attention-based component of IOR is present when the response is manual. These 2 distinct components should be considered and studied separately, as well as in relation to each other, if a comprehensive theory of IOR is to be achieved. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

3.
In a previous study by the present 1st author et al, evidence was found that items in several leading stress measures, including a hassles scale developed by A. D. Kanner et al (1981), are confounded with measures of psychological distress. R. S. Lazarus et al (see record 1986-10770-001) disagree with the present authors' conclusions about the hassles scale and present additional data indicating that their measure is not confounded. Lazarus et al also argue in more general terms that the present authors' theoretical and methodological approach is a misguided quest for rigor. In rebuttal, the present authors offer further analyses of their data and compare their theoretical approach to that of Lazarus et al. On the matter of confounding, it is concluded that the hassles scale is even more confounded than originally supposed. With regard to the theoretical issue, it is believed that a rapprochement would be both feasible and useful. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

4.
5.
A new formulation in which the assumed stress field is divided into membrane and bending stress fields is developed. A family of effective shell elements of hybrid/mixed finite element method that accounts for transverse shear deformations is proposed based on a modified Hellinger–Reissner variational principle. In this paper, the present shell elements possess different three-field assumptions, which are described by compatible displacement, incompatible displacement, and stress fields. Several benchmark problems are conducted to test both the accuracy and reliability of the proposed shell elements. Numerical analyses show that the present shell elements pass all the patch tests, do not contain any spurious zero energy modes, and have no lock phenomena even for very thin plate and shell. Further insight into the performance of the present shell elements is gained to demonstrate the high accuracy of the elements by several folded-plate structure problems. The numerical results demonstrate the validity, reliability, and applicability of the present elements. The present elements are valid for thick as well as thin shell structures.  相似文献   

6.
Potassium bromate (KBrO3) is a rodent carcinogen and a nephro- and neurotoxicant in humans. KBrO3 is used in cosmetics and food products and is a by-product of water disinfection by ozonization. KBrO3 is carcinogenic in the rat kidney, thyroid, and mesothelium and is a renal carcinogen in the male mouse. The present study was designed to investigate the relationship of time and dose to bromate-induced tumors in male Fischer 344 (F344) rats and to provide some insight into the development of these tumors. KBrO3 was dissolved in drinking water at nominal concentrations of 0, 0.02, 0.1, 0.2, and 0.4 g/L and administered to male F344 rats as the sole water source for 12, 26, 52, 78, or 100 wk. Renal cell tumors were present after 52 wk of treatment only in the high-dose group. Mesotheliomas developed after 52 wk of treatment on the tunica vaginalis. Mesotheliomas were present at sites other than the testicle after 78 wk of treatment, indicating that their origin was the testicular tunic. Thyroid follicular tumors were present as early as 26 wk in 1 rat each from the 0.1- and 0.2-g/L groups. The present study can be used as a basis for the determination of dose-time relationships of tumor development for a better understanding of KBrO3-induced cancer.  相似文献   

7.
The Sertoli cells of many species produce an androgen binding protein (ABP) which carries testicular androgens to the epididymis and is thought to play a role in sperm maturation. In the present report we analyzed the morphological modifications present in Leydig, Sertoli, and peritubular cells of the testis of young adult male mice transgenic for ABP gene, which overproduce ABP in testis. By in situ hybridization we demonstrated that ABP is specifically produced by Sertoli cells. Using light and electron microscopy, we detected scattered alterations of the seminiferous tubule cells which include cell degeneration and vacuolization. Leydig and Sertoli cells present morphological signs of hyperfunctioning compensatory mechanisms which include increased amounts of lipid droplets probably due to the existence of a stimulated steroid synthesis that in turn could be a consequence of the decreased unbound testosterone and/or a direct paracrine effect of ABP. Peritubular cells also present numerous signs of hyperstimulation.  相似文献   

8.
论述了BEe30-1-1冷凝管生产工艺的优点及主要问题,对现行工艺提出了改进方案。  相似文献   

9.
The accessory soleus muscle is a rare anatomic variant that may present as a mass in the posterior-medial aspect of the ankle in young adults. The presence of such a mass may result in pain and difficulty with running. We present a case of accessory soleus muscle in a 21-year-old soldier and review the literature. We present the first magnetic resonance imaging studies in the American literature, to our knowledge, of this unusual anomaly.  相似文献   

10.
The purpose of this presentation of pathological data is to demonstrate how our ideas have developed from a chronological point of view to our present interest in elementary cognitive processes. The present relative rarity of significant data in brain imagery, compared with what is observed in other fields of neuro-psychology, is probably due to the complexity of this cognitive processes.  相似文献   

11.
The interslice force function f(x) is a major assumption of the limit equilibrium method, which is important but has not been adequately considered in the past. In this paper, f(x) is taken as the control variable, and the upper and lower limits of the factor of safety for a general slope will be determined by a global optimization analysis. Based on this approach, f(x) will be determined and investigated. We demonstrate that f(x) cannot be arbitrarily assigned if a set of acceptable internal forces is required. The present approach can be presented practically as a lower bound approach with the advantage that failure to converge is virtually eliminated, which is not possible with all other existing “rigorous” methods. The “present proposal” attempts to answer several important questions in the basic theory of slope stability analysis, and provides a f(x) based on the lower bound approach statically admissible forces throughout the whole failure zone. Currently, different assumptions will give different factors of safety to the same problem, and this situation will be overcome by the use of the present proposal. The present proposal is also proven to give a result equal to the slip line solution for a simple footing on clay which is not possible for other classical slope stability methods, which has demonstrated that the applicability of the “present proposal” for general difficult problems.  相似文献   

12.
We have shown that ecto-apyrase protein is expressed in primary neurons and astrocytes in cell culture (T.-F. Wang, P.A. Rosenberg, G. Guidotti, 1997. Mol. Brain Res. 1997, 47: 295-302). Here we present immunohistochemical studies showing that ecto-apyrase protein is widely distributed in rat brain, as it is present in neurons of the cerebral cortex, hippocampus and cerebellum as well as in glial cells and endothelial cells. Ecto-apyrase is enriched in brain postsynaptic density membrane fractions and is localized in proximity to synaptophysin, the marker of synaptic vesicles. These results together with the observation that P2 purinergic receptors are present throughout the brain suggest that ecto-apyrase is involved in regulating synaptic transmission mediated by extracellular ATP.  相似文献   

13.
The chaperonin GroEL binds nonnative proteins in its central channel through hydrophobic interactions and initiates productive folding in this space underneath bound co-chaperone, GroES, in the presence of ATP. The questions of where along the folding pathway a protein is recognized by GroEL, and how much structure is present in a bound substrate have remained subjects of discussion, with some experiments suggesting that bound forms are fully unfolded and others suggesting that bound species are partially structured. Here we have studied a substrate protein, human dihydrofolate reductase (DHFR), observing in stopped-flow fluorescence experiments that it can rapidly bind to GroEL at various stages of folding. We have also analyzed the structure of the GroEL-bound protein using hydrogen-deuterium exchange and NMR spectroscopy. The pattern and magnitude of amide proton protection indicate that the central parallel beta-sheet found in native DHFR is present in a moderately stable state in GroEL-bound DHFR. Considering that the strands are derived from distant parts of the primary structure, this suggests that a native-like global topology is also present. We conclude that significant native-like structure is present in protein-folding intermediates bound to GroEL.  相似文献   

14.
Dermatologic nondisease is a relatively common problem presenting to dermatologists with rich symptomatology in important body image areas such as the face, scalp, and genital area. There is no objective dermatologic change present on examination. The most common psychiatric disease present is depression. Suicide is common, especially in women with perceived facial problems.  相似文献   

15.
Using an immunoadsorbent prepared with a monoclonal antibody specific for the high molecular mass isoform of human tenascin-C, we purified tenascin-C molecules containing at least one large subunit from the extracellular matrix of cultured normal human fibroblasts. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis and immunoblotting analyses have shown that both high and low molecular mass subunits are present in these tenascin-C preparations. Because the monoclonal antibody used is able to bind only the high molecular mass isoform, the present data show that part of the tenascin-C present in the fibroblast extracellular matrix is made up of heterohexameric molecules.  相似文献   

16.
OBJECTIVE: We intended to characterize the CT patterns of hemorrhage associated with ruptured posterior inferior cerebellar artery (PICA) aneurysms. MATERIALS AND METHODS: CT scans of 44 cases of angiographically confirmed ruptured saccular PICA aneurysms (4) aneurysms at the junction of the vertebral artery and the PICA and three distal PICA aneurysms) were retrospectively reviewed. All scans had been obtained within 2 days of the subarachnoid hemorrhage (SAH) (day 0 [less than 24 hr], 35 patients; day 1, eight patients; day 2, one patient). Presence or absence of hemorrhage in specific subarachnoid, intraventricular, and intraparenchymal locations was noted, as were the presence and degree of hydrocephalus. RESULTS: Posterior fossa SAH was present in 95% of cases. Isolated posterior fossa SAH was present in 30% of cases, but in no case was isolated supratentorial SAH present. Supratentorial SAH was present in 70% of cases. SAH involving the sylvian fissure or the interhemispheric region was present in 25% and 23% of cases, respectively. SAH along the convexity was present in 2% of cases. Intraventricular hemorrhage (IVH) with or without associated SAH was seen in 95% of cases, whereas isolated IVH was seen in 5% of cases. Hydrocephalus was present in 95% of cases and was moderate to marked in 70%. Both IVH and hydrocephalus were present in 93% of cases. CONCLUSION: Ruptured PICA aneurysms almost always coexist with hydrocephalus and IVH, as seen in 93% of cases, and almost never coexist with SAH along the convexity. The most common pattern of hemorrhage associated with such aneurysms includes IVH and posterior fossa hemorrhage. Extensive supratentorial SAH, in conjunction with posterior fossa SAH, is a common finding in patients with ruptured PICA aneurysms. SAH isolated to the posterior fossa is present in a sizeable minority of cases.  相似文献   

17.
目前我国对矿产资源的重视程度越来越高,可以说金矿资源与我国的经济发展是具有非常重要的关系的,但是目前我国采矿的手段仍然比较落后状态。基于此,本文主要讨论了绿色开采技术在采矿工程当中的使用策略。  相似文献   

18.
Previous studies have demonstrated that endothelin is present in the ovine endometrium and increases at around the expected time of implantation. To characterize further uterine endothelin at the time of establishment of pregnancy in sheep, endothelin was measured by radioimmunoassay in uterine flushings obtained during the oestrous cycle and in pregnant ewes up to the time of implantation (day 16). During the oestrous cycle, the highest amounts of endothelin were present in uterine flushings on day 14 (1.1 +/- 0.2 ng endothelin/uterus). During early pregnancy, basal levels of endothelin (0.5-0.6 ng endothelin/uterus) were present in uterine flushings for the first 10 days and then increased on day 14 to levels similar to those found at the equivalent stage of the oestrous cycle. On days 15 and 16 of pregnancy, endothelin content in the uterine lumen increased to significantly (P < 0.05) higher concentrations (2.9 +/- 0.4 ng endothelin/uterus) when compared with the non-fertile cycle. The principal isoform present in flushings at the time of implantation was endothelin-1, as determined by reverse-phase HPLC. Endothelin was released principally by purified endometrial epithelial cells in culture, with barely detectable amounts released by endometrial stromal cells or conceptus tissue, which is consistent with the epithelium being the principal source of endothelin in the uterine lumen. Endothelin binding sites were present in endometrium and myometrium, as demonstrated by specific binding of 125I-labelled endothelin-1, which was saturable and displaced by endothelin-1. Both endothelinA and B sub-types of receptors were present as demonstrated by the biphasic displacement of 125I-labelled endothelin-1 binding by the specific endothelinB agonist BQ3020. These were localised principally on luminal and glandular epithelium and in the vasculature of the endometrium and myometrium as shown by autoradiography. Endothelin receptors were also present on the conceptus obtained at the time of implantation. In the day 20 conceptus, endothelin immunostaining was localised principally in the heart, in trophoblast in uninucleate but not in binucleate cells, and in fetal membranes. This immunostaining of the conceptus may represent binding to receptor sites. It is concluded that endothelin-1 is present in the uterine lumen and may play an important role in the paracrine regulation of the conceptus and endometrium at the time of rapid embryo development, implantation and early placentation.  相似文献   

19.
李首山  王小明 《炼钢》1995,11(5):50-53
简介EOF炉的发展和炼钢工艺特点,分析和对比EOF炉与电炉、转炉的优点,从我国国情出发,指出在国内中小钢铁企业中采用EOF炉可解决自身存在的难题,对中小钢铁企业贯彻执行产业政策非常有利。  相似文献   

20.
A new case of eosinophilic esophagitis is reported in a young male with a 10-year history of dysphagia who did not present manifestations of allergy, reflux or other involvement of the digestive tract by eosinophilic infiltration. A review of the literature up to the present is provided with emphasis on the fact that this is an entity to take into account in the differential diagnosis of dysphagia, especially in young people and that this disease is probably underdiagnosed.  相似文献   

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