冲积河流推移质输沙最优河道形态影响因素理论分析

为从理论上确定水沙动力、阻力和边界条件对冲积河流推移质输沙最优河道形态和最小比降的影响,基于 水力半径分割方法将河床整体糙率划分为河岸糙率和河底糙率;采用河道形态自动调整变分方法,以等腰梯形为 河道过水断面,推导推移质输沙率与河道形态的关系,分析河岸与河底相对糙率、河岸坡角、流量、输沙率、中值 粒径和河底糙率对最优河道形态和最小比降的影响。结果表明：最优河道形态和最小比降随河岸与河底相对糙 率的增大而减小,随河岸坡角的增大而增大。流量或者河底糙率的增加将使最小比降减小,同时造成最优河道形 态趋向窄深。输沙率或者中值粒径的增加将使最小比降增大,但两者对最优河道形态演变的影响不同,输沙率增 大将使最优河道形态向宽浅发展,而中值粒径增加将使最优河道形态向窄深发展。     

中国经济社会消费水量、效率及其未来极值

为客观评估消费环节的真实水量消费和用水效率,在虚拟水分析的基础上研究经济社会消费水量。基于国 家和各省水资源投入产出表,构建虚拟水通量以及综合用水效率评价模型,评估 2007、2012、2017 年我国 31 个省 （自治区、直辖市）虚拟水通量、经济社会消费水量及其综合效率,并对未来经济社会消费水量极值进行预测。结 果表明：国内虚拟水输入区向高收入区域聚集,虚拟水输出区向水资源密集型产品生产地聚集,考虑虚拟水流通 后,各省（自治区、直辖市）综合用水效率具有趋同性特征,人均综合消费水量与经济发展水平呈较好的对数关系, 经济越发达、居民生活水平越高,人均综合消费水量越高;由于国际贸易商品结构变化,2012 年之前我国经济社 会用水量高于经济社会水消费量,之后后者超过前者,预期在 2035—2040 年我国经济社会消费水量将达到 6?907 亿 m 3极值,比经济社会用水量高 427 亿 m 3。经济社会用水量和经济社会消费水量分别反映生产端和消费端用水 规模,随着经济社会生活水平提升以及生产结构和贸易结构的转变,经济社会消费水量超过经济社会用水量规模 将日趋扩大,二者差额主要通过虚拟水解决,需要合理优化商品进出口结构,避免大宗进口引发经济和社会风险。     

南水北调受水区生活用水影响因素与节水潜力

为持续推进水资源节约工作,保障南水北调受水区经济社会可持续发展,开展居民用水习惯问卷调查,分析 南水北调东线和中线受水区各省（直辖市）居民家庭用水现状及差异特点,识别生活用水的主要影响因素,设计节 水情景模拟家庭节水潜力。结果表明,受水区居民用水习惯呈现较明显的地域性差异,其中：天津市和河北省居 民整体节水意识较高,河南省和山东省现状人均日用水量比北京市、安徽省和江苏省低 12%;从用水行为上看,家 庭洗浴日均用水量浮动范围达 30%,是造成用水差异的主要环节。节水情景模拟结果显示,通过进一步提高居民 节水意识、替换高等级节水器具、增强家庭内部废水循环利用等措施,受水区居民人均日用水量可下降 12%～29%。根据受水区各省 (直辖市) 针对其生活用水特点,提出了进一步开展节水器具普及工作、完善节水管 理体制机制、提升居民节水意识以及合理利用废水等节水建议,因地制宜持续推进节水工作。     

水-能源-碳排放复杂关系研究进展及展望

系统梳理水-能-碳复杂关系的概念内涵,认为其本质是水资源、能源以及碳排放在整个产品生命周期过程 中的相互关系。回顾了复杂关系的近今进展,可将评估方法归纳为基于耦合关联视角的评估、基于整体协同视角 的评估、基于风险与韧性视角的评估以及基于土地利用视角的综合评估。在此基础上,建议未来应重点关注 4 个 前沿议题,即基于水-能-碳承载力的国土空间优化研究、水-能-碳视角下资源消耗与经济增长脱钩分析、水-能-碳 复杂关系确定性与不确定性量化分析以及水-能-碳工程措施助力“负排放”,旨在通过水-能-碳系统协同管理推动 绿色高质量发展。     

Bit-level systolic arrays for modular multiplication

This paper presents bit-level cellular arrays implementing Blakley's algorithm for multiplication of twon-bit integers modulo anothern-bit integer. The semi-systolic version uses 3n(n+3) single-bit carry save adders and 2n copies of 3-bit carry look-ahead logic, and computes a pair of binary numbers (C, S) in 3n clock cycles such thatC+S[0, 2N). The carry look-ahead logic is used to estimate the sign of the partial product, which is needed during the reduction process. The final result in the correct range [0,N) can easily be obtained by computingC+S andC+S–N, and selecting the latter if it is positive; otherwise, the former is selected. We construct a localized process dependence graph of this algorithm, and introduce a systolic array containing 3nw simple adder cells. The latency of the systolic array is 6n+w–2, wherew=n/2. The systolic version does not require broadcast and can be used to efficiently compute several modular multiplications in a pipelined fashion, producing a result in every clock cycle.     

Consensus control of multi‑manipulator systems based on disturbance observer under Markov switching topologies

In this paper, to solve the consensus control problem of multi-manipulator systems under Markov switching topologies, we propose a distributed consensus control strategy based on disturbance observer. In multi-manipulator systems, external disturbance described by heterogeneous exogenous systems is considered, and all communication topologies are directed. First, a disturbance observer is presented to suppress the influence of unknown external disturbance, and the equivalent compensation is introduced into the control protocol in multi-manipulator systems. Then, a novel control protocol based on neighbor information is designed, which guarantees that multi-manipulator systems reach consensus under Markov switching topologies. Finally, two simulation examples verify the validity of the theoretical result.     

Der Umgang mit „second victims“ als organisationsethische Aufgabe

Background and purpose

Adverse events and medical errors can have severe consequences for patients (“first victims”), but also for the involved health care professionals (“second victims”). Don Berwick, former director of the Boston Institute for Healthcare Improvement (USA), highlighted the support for “second victims” as an “ethical issue”. But there is no clarity about what “ethical issue” implies. This article aims to clarify this question from the perspective of organizational ethics.

Method

Starting with data from the literature, challenges are described and evaluated from the perspective of organizational ethics.

Results

Evidence suggests that current approaches for supporting “second victims” are not sufficiently effective to help professionals to cope with the psychological consequences of adverse patient events and medical errors. This not only has negative consequences for the involved professionals, but can also put patient safety again at risk. In the light of these data, an organizational ethics approach is needed to comply with Don Berwick’s claim to consider the support of “second victims” as an “ethical issue”. This approach fosters the congruence of the organization’s values that are declared and those that are practiced. Its normative foundation is rooted in the organization’s duty of care both for the patients and for the employees.

Conclusions

Using organizational ethics it is possible to conceptualize and visualize the support for “second victims” as a binding component of the safety culture of the organization. It is translated into the organization’s obligation to raise the awareness for the phenomenon and to provide the resources necessary to deal effectively with it, e.?g., evidence-based ethical guidelines, standardized procedures, staff training, and low-threshold coaching programs.

     

PID auf Aneuploidie des Embryos?

Definition of problem

At least in some cases, testing for aneuploidy as part of preimplantation genetic diagnosis (PGD) can be medically useful for pregnancy care. The current legal situation in Germany seems to not generally exclude PGD to detect a maldistribution of chromosomes in an embryo, but testing would require approval by a PGD ethics committee on a case-by-case basis and a well-reasoned application by the concerned woman. This article examines ethically and legally whether fundamental reasons prevent PGD commissions from admitting requests to perform aneuploidy tests as part of PGD.

Arguments

Three constellations – each with differing ethical implications – can be distinguished in which testing for aneuploidy could be considered or could occur: Testing for aneuploidy can (i) be the main reason for in vitro fertilization (IVF), which in itself is not medically indicated; (ii) IVF is done as infertility treatment in which case PGD and aneuploidy testing could be done additionally; or (iii) PGD with IVF is indicated in order to prevent a congenital disease or chromosomal aberration leading to a diagnosis of aneuploidy as an incidental or additional finding. Ethical arguments which could lead to a general rejection of aneuploidy testing are the prevention of discrimination against people with aneuploidy, as well as the protection of embryos. These concerns oppose constellation (i), but do not apply to (ii) and (iii). Yet there are at least three ethical arguments in favour of an admissibility of a request for aneuploidy testing: the “good practice” of IVF, the duty to the emerging child and the parent’s right to have a voice in the discussion.

Conclusion

Aneuploidy testing as part of PGD is not ruled out by legal or ethical reasons and should be openly discussed by the relevant German ethics commissions.

     

Tod des Körpers oder Tod der Person?

Definition of the problem

Within the current philosophical debate on the adequate definition of human death, death is defined either as the death of the body or the death of the person. However, the application of these notions leads to several practical conflicts, which can be seen first and foremost in the brain-death debate and the discussions on how to increase organ donation.

Arguments

The conflicts are based in both a dualistic and objectivistic notion of the human being which are implied in both definitions of death. In order to solve these conflicts, we are in need of a nondualistic concept of human being which at the same time enables us to elaborate a first- and second-person perspective on death. On the basis of Helmuth Plessner’s philosophical anthropology, such an integrative concept of death can be developed.

Conclusion

Following this concept, it seems reasonable to abandon the brain-death criterion as the criterion for human death and to fundamentally reform the current information campaigns for organ donation.