Heterogeneity in Youth Symptom Trajectories Following Psychiatric Crisis: Predictors and Placement Outcome.

The authors examined heterogeneity in symptom trajectories among youths following psychiatric crises as well as the psychosocial correlates and placement outcomes associated with identified trajectories. Using semiparametric mixture modeling with 156 youths approved for psychiatric hospitalization, the authors identified 5 trajectories based on symptoms over the 16 months following crisis: high improved, high unimproved, borderline improved, borderline unimproved, and subclinical. Membership in unimproved symptom groups was associated with less suicidality, younger age, more youth hopelessness, and more caregiver empowerment. Improved symptom group membership predicted long-term decreases in days in out-of-home placements. More important, and in contrast with general impressions from the existing literature, findings suggest that a substantive proportion of youths with serious emotional disturbance sustain high levels of symptomatology following intensive mental health services. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A robust adaptive pole‐placement controller without strictly positive real condition

This paper considers the adaptive pole‐placement control problem for system (1) with unmodelled dynamics η_n dominated by a small constant ε multiplied by a quantity independent of ε but tending to infinity as the past input, output, and noise grow. Using bounded external excitation and randomly varying truncation techniques, we give a design method of adaptive pole‐placement controller. It is shown that the closed‐loop system is globally stable, the estimation error for the parameter contained in the modelled part is of order ε, and the closed‐loop system under the adaptive pole‐placement control law is suboptimal in the sense of $$\mathop{\lim\sup}\limits_{{n\to\infty }}{1\over n}\mathop{\sum}\limits_{i=0}^n{\left({A^{*}(z)y_{n}‐L(z)C(z)w_{n}‐B(z)R(z)y_{n}^{*}}\right)^{2}{\leq}O({\varepsilon}^{2})+\gamma^{2}\mathop{\sum}\limits_{j=1}^q{b_{j}^{2}}}$$\nopagenumbers\end while the SPR condition used usually in other papers is replaced by a stability condition. Copyright © 2001 John Wiley & Sons, Ltd.     

纤维混凝土在水工建筑工程中的应用(上)

概述改性混凝土垢发展情况，介绍纤维混凝土在国内外水工建筑物上的应用实例，提出钢纤维增强钢筋混凝土水工建筑结构强度计算方法。包括受弯构件正截面强度，斜截面抗剪强度的计算；重点介绍了网状钢纤维增强混凝土（FOC）在水工建筑物上的应用，包括在渡槽，闸门，小型拦河坝，轻型岸型等工程上的应用实例，T新梁正斜截面的强度计算，板材承载力计算的方法。     

对称配筋小偏心受压构件的截面设计

对小偏心受压构件在对称配筋情况下的截面配筋计算，提出用最佳一次逼近多项式简化基本公式，直接按二次方程求解ξ的近似方法，具有精度高，相对误差小，计算方便等优点，可供工程设计人员参考。     

影响混凝土强度的因素及控制措施

分析了水泥强度等级、水灰比和骨料质量等内因,及施工条件、养护温度、湿度、龄期等外因对混凝土强度的影响,并提出了控制混凝土强度的相应措施,以确保混凝土强度符合设计及施工要求,从而保证建筑物结构安全。     

某铁路医院加速器室大体积防射线混凝土施工

结合大同铁路分局中心医院直线加速器室工程实际，介绍了大体积防射线混凝土的特点及施工中应注意的事项，并阐述了具体的施工技术。     

定向爆破拆除框架式水塔

高 2 7m的水塔建于 193 4年 ,其顶部水罐由 12根钢筋混凝土柱支撑。在倒向侧 7根立柱上形成不同高度的爆破切口 ,背向侧倾倒中心线上的一根立柱上形成小爆破切口 ,其余 4根立柱底部打贯通孔 ,使水塔准确定向倾倒。文中讨论了立柱切口高度的计算 ,爆破参数的确定 ,并介绍了所采用的安全措施。     

针梁台车在大花水水电站引水隧洞混凝土衬砌施工中的改进

大花水水电站引水隧洞由于前期开挖工期略有滞后，为加快施工进度，结合全圆断面的施工特点，大部分引水隧洞采用了全圆针梁穿行式钢模台车进行混凝土衬砌。通过各参建单位对针梁台车的运用和改进，有效地提高了引水隧洞混凝土的衬砌速度，并确保了工程质量。     

Effect of specimen size and loading conditions on spalling of concrete

Different qualities of concrete have been fire tested using different geometries of the specimens as well as different load levels and load configurations. The main objective with the study was to examine a test methodology consisting of a full‐scale test and different small scale‐tests for determining the probability of spalling and the amount of spalling of fire exposed concrete structures. A reference specimen was defined as a one‐sided fire exposed slab with the dimensions 1800 × 1200 mm² giving an exposed area of 1500 × 1200 mm². A number of concrete qualities with different probabilities for spalling, were tested using the reference specimen. These tests showed that the reference specimens worked well giving the expected test results. Small specimens were manufactured in different shapes with the same concrete as the one used in the reference tests. These small specimens were tested either at the same time as the reference specimens in the large furnace or afterwards on a small‐scale furnace where the fire exposed surface was 450 × 360 mm². The test results clearly show the increased probability and the increased amount of spalling by using external compressive loading. The results also show that by using pre‐stress through bars or wires the load can be lost due to heating of the bars/wires which results in a decreased amount of spalling. The boundary of the specimen also affects the amount of spalling. The spalling around the edges was in all tests less than the spalling on the central parts of the exposed area. It could also be noted that the spalling did not pass completely through any of the specimens. The reason for this is probably that the water/vapour could migrate out from the unexposed surface of the specimen. Copyright © 2006 John Wiley & Sons, Ltd.     

A limit analysis of nonlinear elastic lateral displacements of thin-walled reinforced and prestressed beams

An incremental iterative process based on direct energy minimization is presented for a limit analysis of nonlinear elastic lateral displacements and twists of reinforced and prestressed beams. Problems encountered with the constitutive relations are discussed and two possible material models are presented.