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1.
2003年在内蒙古西辽河平原灰色草甸土上采用"3414"二次回归最优设计设计试验方案,研究N、P、K肥配施对WL-232HQ紫花苜蓿(Medicago sativa)当年草产量和营养成分的影响,结果表明:施N 27.36kg hm-2,施P2O5 54.71kg hm-2,施K2O 281.33 kg hm-2时可获得鲜草最高产量77976.9kg hm-2.14个处理组合中,初花期以处理4(N2P0K2)和处理12(N2P1K1)粗蛋白的含量高;初花期的粗纤维含量小于25.0%的处理组合是处理8(N2P2K0)和处理10(N2P2K3),均达到国家一级标准[9];初花期粗灰分含量处理1(N0P0K0)和处理9(N2P2K1)较低;并分析了N、P、K肥对WL-232HQ紫花苜蓿营养成分的影响.  相似文献   

2.
本研究采用田间小区的试验方法研究了不同氮、磷、钾用量下玉米各组分的干物质积累及其随时间的动态变化规律。结果表明,不同氮、磷、钾肥用量下玉米的各组分干物质积累随生育期的延续呈现有规律的动态变化:叶片、茎秆、营养体干物质积累自拔节期后呈直线上升,至灌浆期干物质积累达到最大值,之后便呈缓慢下降趋势;籽粒的干物质积累在灌浆期之前缓慢增加,之后呈直线上升;总生物产量在苗期缓慢增长,中期呈直线上升,到了后期由于营养体干物质的下降以及籽粒干物质的显著上升,也稳定增长。营养体、籽粒干物质和总生物产量的积累随时间的动态变化,均可用Logistic方程Y=a/(1 bexp(ct))来描述;在各个氮、磷、钾处理中,以N240、P225、K240处理各组分干物质积累最大速率较大,出现日期较早。籽粒和总生物产量之间的关系可用回归方程Y=exp(a bx)描述。在氮、磷、钾各用量下,氮以N240、磷以P225、钾以K240处理籽粒产量最高,收获系数最大,因此比较适宜的N、P2O5、K2O用量分别为240、150、240 kg hm-2。  相似文献   

3.
在田间试验条件下对覆膜旱作稻体内N、P、K养分浓度、吸收动态及N肥利用率作了研究。结果表明,相同施肥处理条件下不同生育期覆膜旱作稻N、P、K养分浓度及吸收量均高于水作稻,尤以生育中后期较为明显;覆膜旱作稻全生育期N、P、K养分吸收量明显高于水作稻,分布在籽粒中的N、P、K养分含量也有所提高,而在整株中的占有率差异不大,N肥利用率提高12%左右。  相似文献   

4.
大田试验研究结果表明:单施化肥的水稻植株干物质积累和养分吸收主要集中于生长中前期。而有机无机肥配施,特别是化肥与厩肥配合施用有利于水稻植株在中后期,尤其是灌浆期对养分吸收和干物质的积累,其中以植株对磷的吸收比例在各肥料结构间差异最大(p<0.01)。有机无机肥配施还可促进水稻植株养分向籽粒中转移和分配。从而明显增加了水稻结实率和千粒重,进而大大提高了水稻籽粒产量(p<0.05或p<0.01)。  相似文献   

5.
砂姜黑土10年定位试验结果表明:施肥是砂姜黑土小麦增产的关键,N肥增产贡献率为69.4%,P肥增产贡献率为23.3%,K肥为7.3%。P、K肥的肥效随时间的推移逐渐提高。凡施肥处理土壤有机质含量都有所提高,施P处理土壤速效P含量提高幅度较大,每年每公顷施135kg K2O尚不能满足一年两季作物的高产需求,应适当提高K肥用量。  相似文献   

6.
为明确不同腐植酸复混肥施用量,对葡萄生长及土壤养分的影响,采取以二年生葡萄幼树进行盆栽试验。结果表明,与等养分无机化肥相比,腐植酸复合肥明显提高了葡萄植株对N、P、K肥的利用率,使土壤中的N素释放减缓,P的移动性和K的含量有较明显提高,并使土壤中有机质含量有增加的趋势。  相似文献   

7.
在河西走廊旱塬灌漠土上连续11年肥料定位试验结果表明:有机肥料、化学N肥、P肥3种肥料配合施用,对土壤理化性质和小麦产量有良好的影响。其中有机肥料与化学N肥、P肥(MNP)配合施用与化学N肥、P肥(NP)配合施用比较,0~20 cm耕层土壤有机质、碱解N、速效P、速效K分别增加1.40g kg-1、14.01mg kg-1、7.04 mg kg-1、14.80mg kg-1;土壤总孔度、团粒结构、自然含水量、土壤贮水量分别增加4.15%、8.32%、66.85g kg-1、177.15m3hm-2;小麦产量、产值、施肥利润分别增加1.94 t hm-2、0.21×104元hm-2、0.14×104元hm-2;肥料投资效率达1.39元/元。不同处理间的肥效是MNP>MN、MP、NP>M、N、P>CK。  相似文献   

8.
通过对硅藻土结构观察、养分吸附和不同硅藻土与肥料比例肥效试验,结果表明,硅藻土具有多孔质结构,湿润后孔隙明显增大,对N、P有较强吸附作用,能吸附2.5%的N和37.4%的P;施用1∶10硅藻土肥的比施用化学肥料的增产9.8%,比施用化学肥料的多吸收20.4%的N,18.6%的P和12.8%的K,值得在生产上推广应用。  相似文献   

9.
通过自制长效包膜肥与常规施肥在草地早熟禾盆栽上的试验研究表明,在同一施肥量的情况下作基肥一次施入,长效包膜肥在整个试验期间可以满足早熟禾整个试验期对养分的需求,但常规施肥则出现了缺肥症状。包膜肥加工过程及加入缓释剂对N素养分和P、K养分的释放规律有所不同:缓释剂的加入有利于提高N肥效但却加速了肥料中P、K的释放;包膜却对N、P、K均有延缓释放的作用。  相似文献   

10.
本文应用二次通用旋转组合设计,研究了NPK肥用量和配比对辣椒产量的影响,获得了相应的函数模型;通过对模型的优化和解析,得出了辣椒获得最高产量时N的用量为342.5kg/hm2,P2O5用量为112.5kg/hm2,K2O用量为175kg/hm2,此时辣椒产量为23.55t/hm2;试验土壤栽培辣椒适宜的NPK肥用量配比应为N∶P2O5∶K2O=1∶0.33∶0.51。  相似文献   

11.
We describe a computer vision system for observing facial motion by using an optimal estimation optical flow method coupled with geometric, physical and motion-based dynamic models describing the facial structure. Our method produces a reliable parametric representation of the face's independent muscle action groups, as well as an accurate estimate of facial motion. Previous efforts at analysis of facial expression have been based on the facial action coding system (FACS), a representation developed in order to allow human psychologists to code expression from static pictures. To avoid use of this heuristic coding scheme, we have used our computer vision system to probabilistically characterize facial motion and muscle activation in an experimental population, thus deriving a new, more accurate, representation of human facial expressions that we call FACS+. Finally, we show how this method can be used for coding, analysis, interpretation, and recognition of facial expressions  相似文献   

12.
Usually technological innovation and artistic work are seen as very distinctive practices, and innovation of technologies is understood in terms of design and human intention. Moreover, thinking about technological innovation is usually categorized as “technical” and disconnected from thinking about culture and the social. Drawing on work by Dewey, Heidegger, Latour, and Wittgenstein and responding to academic discourses about craft and design, ethics and responsible innovation, transdisciplinarity, and participation, this essay questions these assumptions and examines what kind of knowledge and practices are involved in art and technological innovation. It argues that technological innovation is indeed “technical”, but, if conceptualized as techne, can be understood as art and performance. It is argued that in practice, innovative techne is not only connected to episteme as theoretical knowledge but also has the mode of poiesis: it is not just the outcome of human design and intention but rather involves a performative process in which there is a “dialogue” between form and matter and between creator and environment in which humans and non-humans participate. Moreover, this art is embedded in broader cultural patterns and grammars—ultimately a ‘form of life’—that shape and make possible the innovation. In that sense, there is no gap between science and society—a gap that is often assumed in STS and in, for instance, discourse on responsible innovation. It is concluded that technology and art were only relatively recently and unfortunately divorced, conceptually, but that in practices and performances they were always linked. If we understand technological innovation as a poetic, participative, and performative process, then bringing together technological innovation and artistic practices should not be seen as a marginal or luxury project but instead as one that is central, necessary, and vital for cultural-technological change. This conceptualization supports not only a different approach to innovation but has also social-transformative potential and has implications for ethics of technology and responsible innovation.  相似文献   

13.
Aspect-oriented programming (AOP) is a novel programming paradigm that aims at modularizing complex software. It embraces several mechanisms including (1) pointcuts and advice as well as (2) refinements and collaborations. Though all these mechanisms deal with crosscutting concerns, i.e., a special class of design and implementation problems that challenge traditional programming paradigms, they do so in different ways. In this article we explore their relationship and their impact on modularity, which is an important prerequisite for reliable and maintainable software. Our exploration helps researchers and practitioners to understand their differences and exposes which mechanism is best used for which problem.  相似文献   

14.
P Rabbitt 《Ergonomics》1990,33(10-11):1291-1305
Younger people report more lapses than the elderly on the Broadbent Cognitive Failure Questionnaire, the Harris and Sunderland Memory Failure Questionnaire, and a 'Lost and Found' questionnaire. Lapses are not predicted by IQ or vocabulary test scores (AH 4 parts 1 and 2, and Mill Hill). These paradoxical findings reveal some logical and methodological difficulties in the interpretations of subjective self-ratings. Age and IQ differences in the memorability of errors were illustrated using choice reaction time (CRT) tasks. All age groups were equally efficient at 'automatic' error detection and correction, but older individuals more often omitted controller error-signalling responses. Errors followed by controlled responses were better remembered. It is argued that conscious self-monitoring and the ability to remember errors improves with IQ and declines with age.  相似文献   

15.
《Ergonomics》2012,55(10-11):1291-1305
Younger people report more lapses than the elderly on the Broadbent Cognitive Failure Questionnaire, the Harris and Sunderland Memory Failure Questionnaire, and a ‘Lost and Found’ questionnaire. Lapses are not predicted by IQ or vocabulary test scores (AH 4 parts 1 and 2, and Mill Hill). These paradoxical findings reveal some logical and methodological difficulties in the interpretations of subjective self-ratings. Age and IQ differences in the memorability of errors were illustrated using choice reaction time (CRT) tasks. All age groups were equally efficient at ‘automatic’ error detection and correction, but older individuals more often omitted controller error-signalling responses. Errors followed by controlled responses were better remembered. It is argued that conscious self-monitoring and the ability to remember errors improves with IQ and declines with age.  相似文献   

16.
Quiescence, Fairness, Testing, and the Notion of Implementation   总被引:2,自引:0,他引:2  
Two formalisms for concurrency, the Input/Output automaton model and the theory of testing, are compared and are shown to have common foundations. The relationship between the fair and quiescent preorders of I/O automata is investigated and the two preorders are shown to coincide subject to some restrictions. I/O automata are encoded into the theory of testing and the reversed preorder is shown to be equivalent to the quiescent preorder for strongly convergent, finitely branching I/O automata up to encoding. Conversely, a theory of testing is defined directly on I/O automata, and the new reversed preorder is shown to coincide with the quiescent preorder on strongly convergent, finitely branching I/O automata.  相似文献   

17.
18.
Coupled transformation occurs when multiple software artifacts must be transformed in such a way that they remain consistent with each other. For instance, when a database schema is adapted in the context of system maintenance, the persistent data residing in the system's database needs to be migrated to conform to the adapted schema. Also, queries embedded in the application code and any declared referential constraints must be adapted to take the schema changes into account. As another example, in XML-to-relational data mapping, a hierarchical XML Schema is mapped to a relational SQL schema with appropriate referential constraints, and the XML documents and queries are converted into relational data and relational queries. The 2LT project is aimed at providing a formal basis for coupled transformation. This formal basis is found in data refinement theory, point-free program calculation, and strategic term rewriting. We formalize the coupled transformation of a data type by an algebra of information-preserving data refinement steps, each witnessed by appropriate data conversion functions. Refinement steps are modeled by so-called two-level rewrite rules on type expressions that synthesize conversion functions between redex and reduct while rewriting. Strategy combinators are used to composed two-level rewrite rules into complete rewrite systems. Point-free program calculation is applied to optimized synthesize conversion function, to migrate queries, and to normalize data type constraints. In this paper, we provide an overview of the challenges met by the 2LT project and we give a sketch of the solutions offered.  相似文献   

19.
20.
Outsourcing of IT functions has become so pervasive that IT managers and CIOs cannot ignore it. To complicate the matter, outsourcing to other countries has become increasingly popular. The advantages of this type of outsourcing include cost savings, 24/7 operation, and access to highly specialized skills. Yet a strategic alliance with a geographically and culturally remote partner presents its own unique challenges. Thus, IT professionals should not take the strategic questions of whether or not to outsource lightly, or avoid it. Rather, they can make such a decision by analyzing the responses to the following five key questions, what we call the five Ws: Who should outsource? What is outsourcing? Why outsource? Where should you outsource? When should you outsource? This article emerged from a focus group of CIOs conducted by the CIO Institute, a not-for-profit community of practice for CIOs in the Greater Philadelphia region.  相似文献   

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