风景园林学:未来的发展前景与责任

<正>"我认为风景园林是一个‘脑、心、手’合一的职业。我们用头脑发现、探究、和理解自然世界,组织并构建事物。我们通过心灵创造艺术、认知、感受和付出。我们用双手组装并感知景观材料,无论是常用的还是少见的材料,都会激发完美制作后的愉悦。因而风景园林全面发挥了人类的才能。"——尼尔·柯克伍德今天的风景园林教育者有责任引领大家直面当今不断变化发展的学科边界,并坚持本领域的追寻拷问和艺术探索。我坚信上述观点,尽管全球环境的不利因素众多,行业内部也有不同声音——景观都市主义的追随者     

Immune responses to Ro60 and its peptides in mice. I. The nature of the immunogen and endogenous autoantigen determine the specificities of the induced autoantibodies

Two fatty acid hydroperoxide lyases (HPO lyase I and II) were purified to apparent homogeneity from etiolated hypocotyls of sunflower (Helianthus annuus L.) by a combination of ion-exchange, hydrophobic interaction, and gel filtration chromatography. The two HPO lyases were separated during the hydrophobic interaction chromatography step, with HPO lyase I more hydrophilic than HPO lyase II. The estimated M(r) of both native HPO lyases was determined by gel filtration to be 200,000 and SDS-PAGE in the presence of 100 mM dithiothreitol showed that the enzyme was composed of a single 53 kDa peptide, suggesting that the enzyme exists as a tetramer in vivo. HPO lyase was also abundant in the cotyledons and green leaves. HPO lyases I and II from hypocotyl metabolized 13-hydroperoxylinoleic acid and 13-hydroperoxylinolenic acid to the same extent, but the green leaf enzyme was more than ten-fold more active with 13-hydroperoxylinolenic acid than 13-hydroperoxylinoleic acid. A difference spectrum between CO-bound and CO-unbound dithionite-reduced HPO lyase I showed an absorbance maximum at 452 nm, indicating that it was a cytochrome P450-type enzyme. The activities of HPO lyase I and II were significantly inhibited by nordihydroguaiaretic acid, sulfhydryl reagents, and piperonylbutoxide, which is a cytochrome P450 inhibitor.     

防恐操作平台:美国对水坝人为破坏的防护策略

美国在遭受“911”恐怖事件袭击后,正发起“反恐全民准备运动”。为避免水坝保安措施的不足及人为的疏失,美国政府开始推动“水坝安全之破坏风险评估”。2002年12月美国总统签署了“水坝安全和保安法案”,正式立法防范水坝人为破坏,确保水坝和公众安全。     

A new heat propagation velocity prevails over Brownian particle velocities in determining the thermal conductivities of nanofluids

An alternative insight is presented concerning heat propagation velocity scales in predicting the effective thermal conductivities of nanofluids. The widely applied Brownian particle velocities in published literature are often found too slow to describe the relatively higher nanofluid conductivities. In contrast, the present model proposes a faster heat transfer velocity at the same order as the speed of sound, rooted in a modified kinetic principle. In addition, this model accounts for both nanoparticle heat dissipation as well as coagulation effects. This novel model of effective thermal conductivities of nanofluids agrees well with an extended range of experimental data.     

A Method for Evaluation of QRS Shape Features Using a Mathematical Model for the ECG

Automated classification of ECG patterns is facilitated by careful selection of waveform features. This paper presents a method for evaluating the properties of features that describe the shape of a QRS complex. By examining the distances in the feature space for a class of nearly similar complexes, shape transitions which are poorly described by the feature under investigation can be readily identified. To obtain a continuous range of waveforms, which is required by the method, a mathematical model is used to simulate the QRS complexes.     

Adaptive QRS Detection Based on Maximum A Posteriori Estimation

A mathematical model for the occurrence of nonoverlapping pulse-shaped waveforms corrupted with colored Gaussian noise is considered for the purpose of QRS detection. The number of waveforms, the arrival times, amplitudes, and widths are regarded as random variables. The joint MAP estimation of all the unknown quantities consists of linear filtering followed by an optimization procedure. A class of filters is introduced which is easy to implement. The mismatching obtained by using this class for detection of model QRS complexes is investigated. The optimization procedure is time-consuming and is modified so that a threshold test is obtained. The model formulation with nonoverlapping waveforms leads to an "eye-closing" procedure covering a segment before as well as after an accepted event. Adaptivity of the detector is gained by utilizing past as well as future signal properties in determining thresholds for QRS acceptance.     

Potassium fertilization in relation to plant water potential of wheat

The water potential of wheat plants increased during the mid-day noon, probably as an adaptation; the rise was greater with less frequent irrigation and was increased by KCl application.     

劳伦斯·哈普林景观实践中的生态智慧及当代启示

从劳伦斯·哈普林（Lawrence HALPRIN）人生经历和实践历程出发,阐述了其生态智慧的来源,并通过对其设计作品过程的解读,梳理、总结出其景观实践中体现出的生态智慧。从结合自然的生态方法与以人为本的生态哲学两方面详述了哈普林在景观实践中体现出的超前的场地意识、科学的调套分析和将自然引八城市的理念;并介绍了生态谱记概念、面向过程和集体创作的RSVP方法．最后讨论了哈普林生态智慧对当代的启示体现在对场地的敏锐观察、科学方法与创新思维自勺统一以及多学科协作的群体智慧。