渔业企业投资经济效益评估

在市场经济的条件下,渔业企业作为一个独立的投资主体,对任何一项投资,它都会考虑其经济效益.本文通过一个实例,阐述了渔业企业在投资之前,如何从财务上评估该项投资的经济效益.     

测绘科技进步的研究与测算

科技进步是测绘事业发展的动力 ,讨论运用科技进步的评价指标 ,对测绘单位的科技进步速度和对经济增长的贡献等进行测算和分析 ,可以为测绘规划管理及决策提供参考。     

测绘生产计划统计管理应用系统的建立

基于windows软件平台及foxpro工具软件开发的“测绘生产计划统计管理应用系统 (PPCMAS)”是一种较为科学的测绘生产管理模式 ,具有较先进的技术性和通用性 ,并以多媒体方式实现信息查询和综合统计图形显示、文字说明及统计报表 ,解决了规划和管理等问题 ,提供了数据录入、资源查询、统计生成、专家系统壳、显示输出、信息通讯等多方面的功能     

测绘项目管理实施引论

根据我国测绘生产单位的实际情况 ,测绘项目管理的具体实施大致包括对项目的识别、选定、启动与筹集资金、计划、成本估算、执行计划、控制、收尾等主要步骤。当项目确定后 ,需要启动和筹集资金。而计划是项目管理的基本组成部分 ,包括明确项目目标和工作范围。项目成本估算有因素估算法和利用WBS方法的详细估算。项目质量管理规划的依据有质量目标、范围说明、标准和规范等。     

Neoliberalism and natural resource management: Agri-environmental standards and the governing of farming practices

Private standards and certification schemes are widely acknowledged as playing an increasingly important role in agri-environmental governance. While much of the existing research concludes that these mechanisms consolidate the global extension of neoliberalism – enhancing the power of corporate actors to the detriment of smaller producers – we argue that this overlooks the complex ways in which standards are used by governments and farmers in the governing of farming practices. Focusing specifically on a process standard – Environmental Management Systems (EMS) – promoted by the Australian government as a way of verifying the ‘clean and green’ status of agricultural exports, we examine how one regional group of producers has sought to use EMS standards in practice. Our analysis of a case study in the state of Victoria appears to confirm that EMS was a successful instrument for the extension of neoliberal governance, reinforcing the production of neoliberal subjectivities and practices amongst farmer participants and enabling the government to compensate for gaps in environmental provision. However, it would be a mistake to interpret the development of this EMS scheme as an example of naïve farmers manipulated by the state. In practice, farmers used the opportunities provided by government funding to undertake actions which expressed their own agri-environmental values and practices. Establishment of an EMS and associated eco-label enabled producers to demonstrate and extend their capacity to act as good environmental stewards. Our research highlights how the local application of environmental standards negotiates and shapes, rather than simply contributes to, neoliberal rule.     

Depths of Partial Crystallization of H2O-bearing MORB: Phase Equilibria Simulations of Basalts at the MAR near Ascension Island (7 11{degrees}S)

Phase equilibria simulations were performed on naturally quenchedbasaltic glasses to determine crystallization conditions priorto eruption of magmas at the Mid-Atlantic Ridge (MAR) east ofAscension Island (7–11°S). The results indicate thatmid-ocean ridge basalt (MORB) magmas beneath different segmentsof the MAR have crystallized over a wide range of pressures(100–900 MPa). However, each segment seems to have a specificcrystallization history. Nearly isobaric crystallization conditions(100–300 MPa) were obtained for the geochemically enrichedMORB magmas of the central segments, whereas normal (N)-MORBmagmas of the bounding segments are characterized by polybariccrystallization conditions (200–900 MPa). In addition,our results demonstrate close to anhydrous crystallization conditionsof N-MORBs, whereas geochemically enriched MORBs were successfullymodeled in the presence of 0·4–1 wt% H₂O in theparental melts. These estimates are in agreement with direct(Fourier transform IR) measurements of H₂O abundances in basalticglasses and melt inclusions for selected samples. Water contentsdetermined in the parental melts are in the range 0·04–0·09and 0·30–0·55 wt% H₂O for depleted and enrichedMORBs, respectively. Our results are in general agreement (within±200 MPa) with previous approaches used to evaluate pressureestimates in MORB. However, the determination of pre-eruptiveconditions of MORBs, including temperature and water contentin addition to pressure, requires the improvement of magma crystallizationmodels to simulate liquid lines of descent in the presence ofsmall amounts of water. KEY WORDS: MORB; Mid-Atlantic Ridge; depth of crystallization; water abundances; phase equilibria calculations; cotectic crystallization; pressure estimates; polybaric fractionation     

Spatial and temporal variability of crustal magnetization of a slowly spreading ridge: Mid-Atlantic Ridge (20°–24° N)

The results of the two- and three-dimensional magnetic inversions performed on data located between 20°–24° N on the Mid-Atlantic Ridge indicate the crustal magnetization has decayed exponentially for the last 10 Ma, and that this decay has been fairly symmetric about the ridge axis. After removal of the mean temporal decay, the residual field is characterized by more positive magnetizations at the second-order discontinuities, regardless of initial magnetization direction. A model that involves the preferential emplacement of serpentinized lithologies near the discontinuities is proposed to explain this correlation. The temporal detrending method also indicates that several ridge-parallel depressions located on the flanks of the ridge axis are regions of more positive magnetizations. These bathymetric depressions may mark the locations of detachment faulting that occurred during amagmatic periods of extension. The general symmetry of the crustal magnetization about the ridge axis does not support the occurrence of continuous detachment faulting proposed to correspond to the inner and outer corners of ridge axis discontinuities.     

使用简易测试平台检测马哈克扭力仪的性能

本文描述简易测试平台的原理与制作，对马哈克MAIHAK MDS－820型扭力仪检测模拟负载的准确性进行探讨。     

Management of the commons for biodiversity: lessons from the North Pacific

The North Pacific has the world's largest groundfish fisheries, with a value in excess of $1 billion annually. The North Pacific also is home to the largest population of Steller sea lions (SSL), an ancient species that is now endangered. Decline of the western stock of SSL in the 1970–1990s coincided with the US nationalization and exponential growth in the Gulf of Alaska and Bering Sea/Aleutian Islands groundfish fishery.The article treats five aspects of the competition between the fishery and protection of the endangered species. First, we analyze competition of interests in the use, management, and preservation of the North Pacific commons, including offshore and near-shore fisheries, environmental organizations, governments (federal, state, and local), and the scientific community. Second, the article compares and contrasts provisions of the National Environmental Policy Act, the Marine Mammal Protection Act, the Endangered Species Act, and the Magnuson–Stevens Act (as amended in 1996 by the Sustainable Fisheries Act).Third, we examine the regulatory environment with a focus on the National Marine Fisheries Service (NMFS) and its relationship to the North Pacific Fishery Management Council. We illustrate how NMFS establishes fishery management plans and the methods, such as crafting biological opinions and environmental-impact-statements, it uses to resolve conflicts. Fourth, we investigate how the dual pressures on the agency—to increase fisheries production for the benefit of the industry and to preserve endangered marine species—have affected its culture (behavioral norms and operational codes). Then, the article explains agency changes in terms of crises, competition among affected interests, and development of new scientific knowledge.The article concludes by drawing lessons from the SSL controversy in the North Pacific which may pertain to national and global biodiversity conflicts. These concern the role of law in biodiversity protection, the role of science, and agency capacity for change.     

Three-dimensional inversion of marine magnetic anomalies: Implications for crustal accretion along the Mid-Atlantic Ridge (28°–31°30′ N)

We present magnetic field data collected over the Mid-Atlantic Ridge in the vicinity of the Atlantis Fracture Zone and extending out to 10 Ma-old lithosphere. We calculated a magnetization distribution which accounts for the observed magnetic field by performing a three-dimensional inversion in the presence of bathymetry. Our results show the well-developed pattern of magnetic reversals over our study area. We observe a sharp decay in magnetization from the axis out to older lithosphere and we attribute this decay to progressive low temperature oxidation of basalt. In crust which is 10 Ma, we observe an abrupt increase in magnetic field intensity which could be due to an increase in the intensity of magnetization or thickness of the magnetic source layer. We demonstrate that because the reversal epoch was of unusually long duration, a two-layer model comprised of a shallow extrusive layer and a deeper intrusive layer with sloping polarity boundaries can account for the increase in the amplitude of anomaly 5. South of the Atlantis Fracture Zone, high magnetization is correlated with bathymethic troughts at segment end points and lower magnetization is associated with bathymetric highs at segment midpoints. This pattern can be explained by a relative thinning of the magnetic source layer toward the midpoint of the segment. Thickening of the source layer at segment endpoints due to alteration of lower oceanic crust could also cause this pattern. Because we do not observe this pattern north of the fracture zone, we suggest it is a result of the nature of crustal formation process where mantle upwelling is focused. South of the fracture zone, reversals along discontinuity traces only continue to crust 2 Ma old. In crust >2 Ma, we observe bands of high, positive magnetization along discontinuity traces. We suggest that within the discontinuity traces, a high, induced component of magnetization is produced by serpentinized lower crust/upper mantle and this masks the contribution of basalts to the magnetic anomaly signal.