TRANSIENT RESPONSE FUNCTIONS FOR CONJUNCTIVE WATER MANAGEMENT IN THE SNAKE RIVER PLAIN,IDAHO1

ABSTRACT: Increasing demands on western water are causing a mounting need for the conjunctive management of surface water and ground water resources. Under western water law, the senior water rights holder has priority over the junior water rights holder in times of water shortage. Water managers have been reluctant to conjunctively manage surface water and ground water resources because of the difficulty of quantification of the impacts to surface water resources from ground water stresses. Impacts from ground water use can take years to propagate through an aquifer system. Prediction of the degree of impact to surface water resources over time and the spatial distribution of impacts is very difficult. Response functions mathematically describe the relationship between a unit ground water stress applied at a specific location and stream depletion or aquifer water level change elsewhere in the system. Response functions can be used to help quantify the spatial and temporal impacts to surface water resources caused by ground water pumping. This paper describes the theory of response functions and presents an application of transient response functions in the Snake River Plain, Idaho. Transient response functions can be used to facilitate the conjunctive management of surface and ground water not only in the eastern Snake River Plain basin, but also in similar basins throughout the western United States.     

土壤钙的生物有效性及与其它元素的相互作用

根据国内有关土壤钙素的研究文献、总结了土壤钙的生物有效性.土壤钙与其它元素的相互作用,以及钙在土壤中的固定、移动的研究进展,提出了钙肥的施用原则.其施用原则应该是平衡且适量。     

Poisoned plusiines: toxicity of milkweed latex and cardenolides to some generalist caterpillars

Summary. Larvae of Trichoplusia ni Hübner (Lepidoptera: Noctuidae) that ingested latex from Asclepias curassavica L. (Asclepiadaceae) often regurgitated and convulsed with spasms before becoming immobile and unresponsive. Some larvae required over a day to recover sufficiently to feed. Latices from four other plant species in three families were all deterrent, but none caused detectable poisoning. The toxicity of A. curassavica latex was evidently due to cardenolides because pure cardenolides had similar effects when ingested by T. ni. Other species of noctuid caterpillars (Rachiplusia ou Guenée, Anagrapha falcifera Kirby, and Autographa precationis Guenée) sometimes also suffered spasms and temporary immobility when fed A. curassavica latex. A more distantly related noctuid, Spodoptera ornithogalli, was deterred by the latex, but showed no overt physiological responses at the dosage tested. T. ni larvae failed to develop on intact leaves of A. curassavica, on leaves with latex canals deactivated by midrib severance, and on excised leaves. Similarly, larvae reared on excised A. syriaca L. leaves to the final instar died when transferred to A. curassavica leaves with either intact or severed midribs. The final instar larvae sometimes suffered from spasms and immobility even when confined on leaves with depressurized canal systems. Evidently, cardenolides stored outside the latex system suffice to poison larvae. We conclude that cardenolides in A. curassavica have potent physiological effects on some generalist caterpillars and that the presence of these compounds both inside and outside laticifers effectively protects the plant. Received 30 June 1999; accepted 18 October 1999     

Cd、Zn交互作用对三七景天根系形态和重金属吸收积累的影响

采取水培试验,研究了不同Cd、Zn浓度单一胁迫及其交互作用对三七景天生长、根系形态及Cd、Zn吸收和积累的影响.结果表明,三七景天对Cd、Zn单一胁迫均有较强的耐受性,其根、茎、叶各组织中Cd、Zn含量均随胁迫的增加而增加,且对Cd有较强的富集能力,地上部Cd含量可达133.0 mg·kg~(-1).Cd、Zn共同胁迫对三七景天生长的影响大于单一胁迫,而根系对其胁迫更为敏感,在Cd、Zn共同胁迫下其根系长度、表面积、体积和根尖数均显著降低,且对其根尖数的影响最为显著.Zn对三七景天地上部Cd吸收具有"低促高抑"效应,低浓度Zn(10 mg·L~(-1))对三七景天地上部Cd吸收有协同作用,促进Cd由根部向地上部转运.而添加Cd则对三七景天Zn吸收具有拮抗作用.Zn/Cd浓度比值对三七景天Cd吸收有显著影响,Zn/Cd比值较低时促进三七景天地上部Cd的积累,而高Zn/Cd比则抑制其Cd的积累.因此,三七景天具有较强的Cd富集能力,可应用于修复Cd污染土壤,而调节生长介质中Cd、Zn比例可促进三七景天对Cd的吸收效率.     

A new approach to spatial source apportionment of haze pollution in large scale and its application in China

Long-lasting expansion of haze pollution in China has already presented a stern challenge to regional joint prevention and control. There is an urgent need to enlarge and reconstruct the coverage of joint prevention and control of air pollution in key area. Air quality models can identify and quantify the regional contribution of haze pollution and its key components with the help of numerical simulation, but it is difficult to be applied to larger spatial scale due to the complexity of model parameters. The time series analysis can recognize the existence of spatial interaction of haze pollution between cities, but it has not yet been used to further identify the spatial sources of haze pollution in large scale. Using econometric framework of time series analysis, this paper developed a new approach to perform spatial source apportionment. We applied this approach to calculate the contribution from spatial sources of haze pollution in China, using the monitoring data of particulate matter (PM_2.5) across 161 Chinese cities. This approach overcame the limitation of numerical simulation that the model complexity increases at excess with the expansion of sample range, and could effectively deal with severe large-scale haze episodes.     

长江三角洲晚第四纪陆-海交互地层的光释光年代学

长江三角洲地层的年代学研究对探讨晚第四纪以来我国东部沿海地区陆海交互作用历史以及海岸地貌的形成与演化具有重要价值。本研究选择长江三角洲YZ07和EGQD14两支钻孔开展系统光释光（optically stimulated luminescence,OSL）测年研究,总结前期已发表的50个年代数据并收集整理该区域相关钻孔的年代地层资料,探讨在可靠的年代框架约束下晚第四纪长江三角洲沉积地层演变特征,取得了以下几点认识：（1）在长江三角洲地区,常规OSL测年以较细石英颗粒OSL测年效果较为理想;对粗颗粒石英,若存在长石包裹体对石英OSL信号的影响,建议用脉冲释光测年（POSL）技术加以解决。（2）以YZ07孔为例,¹⁴C测年和OSL测年结果对比表明在三角洲海岸地区,¹⁴C测年方法建立的年代地层框架需要谨慎对待,建议在此区域开展年代地层学研究时可以尝试将两种测年方法结合使用,以确保年代地层框架的准确和可靠。（3）针对争议较大的氧同位素3阶段（MIS3）沉积环境问题,EGQD14孔给出了新的年代学证据,认为MIS3阶段（约30?—?50 ka）长江三角洲可能是陆地河流相沉积环境为主导,这也得到了区域相邻的几支钻孔沉积记录的佐证。（4）两支钻孔从年代学角度证实了前人关于末次盛冰期（Last Glacial Maximum,LGM）以来长江三角洲发育下切河谷的沉积学判识和地层学论断。此外,多钻孔的年代地层学特征也验证了全新世时段海平面变化控制下的长江三角洲及海岸演变的时空动态。     

Experimental study on the synergistic inhibition effect of nitrogen and ultrafine water mist on gas explosion in a vented duct

In this study, in order to research the synergistic inhibition effect of nitrogen and ultrafine water mist on gas explosion in a vented duct, a semi-confined transparent chamber was designed with the size of 120 × 120 × 840 mm, and the experiments were carried out with stoichiometric methane/air premixed mixture (fraction of methane: 9.5%), adding different fractions of nitrogen and ultrafine water mist. The experimental results showed the following: The combination of nitrogen and ultrafine water mist had a synergistic inhibiting effect on methane/air explosion, which was preferable to the single use of any kind. With the increase of spraying time of water mist and fraction of nitrogen, the initial shape of the explosion flame became snakelike, and at the same time the peak flame propagation speed and peak overpressure decreased significantly. When the nitrogen fraction was increased to 10% and the mist spraying time was increased to 2min, synergistic inhibiting effect on overpressure was high efficient. However, with the increase of spraying time of water mist and fraction of nitrogen going on, the amount of increase of explosion inhibition efficiency was gradually reduced.     

地方政府土地出让策略互动行为的检验及其影响分析

本文以山东省设区市地方政府土地出让行为作为研究对象,通过构建空间面板模型,从价格和数量两个维度,全面检验了地方政府商服、住宅、工业用地出让的策略互动行为,并利用空间计量工具,分析了地方政府土地出让策略互动行为的影响。研究发现:(1)山东省内地方政府商服、住宅、工业用地出让价格以及工业用地出让量存在显著的策略互动,地方政府的商服、住宅、工业用地出让价格以及工业用地出让量,不仅会受城市自身情况的约束,还会受邻近地区地方政府土地出让行为的影响,外在表现为你涨我跌、你增我减的反向变动格局;(2)由于未考虑策略互动,传统计量经济学非空间面板模型对地方政府土地出让行为影响因素的估计普遍存在偏误。对于商服用地出让价格,第三产业比重、人口密度的影响分别被低估了33.33%、13.08%;对于住宅用地出让价格,人口城镇化率、人均可支配收入的影响分别被低估了20.00%、9.98%,人口密度的影响被高估了32.34%;对于工业用地出让价格,人均外商直接投资的影响被高估了3.68%;对于工业用地出让量,第二产业比重、地均工业产值的影响分别被高估了13.95%、31.36%;(3)地方政府土地出让行为的影响因素普遍存在明显的空间溢出效应。对于商服用地出让价格,具有空间溢出效应的影响因素为人口密度;对于住宅用地出让价格,具有空间溢出效应的影响因素为人口城镇化率、人口密度、人均可支配收入;对于工业用地出让价格,具有空间溢出效应的影响因素为人均外商直接投资、地均固定资产投资;对于工业用地出让量,具有空间溢出效应的影响因素为第二产业比重、地均固定资产投资。     

Biospheric influence on carbon dioxide measurements in Italy

The study concerning carbon dioxide measurements taken during the 1997, 1998 and 1999 summer campaigns at two different altitude stations and biospheric conditions are presented. The higher station (Mt. Cimone, 2165 m a.s.l.) is characterised by 360° free horizon and is located on a rocky mountain while the lower (Ninfa lake, 1550 m a.s.l.) is located inside the red spruce and beech forest. The different behaviour of CO₂ at the two mountain stations has been registered. It shows the strong effect of nighttime soil emission and vegetation respiration on CO₂ mixing ratio increases and of diurnal vegetative activity on CO₂ concentration decreases at the lower measurement site. The baseline character of the higher measurement site has been confirmed by comparison of CO₂ diurnal amplitudes recorded at the two stations.     

植物种类与水力负荷对人工湿地去除污染物的交互作用

人工湿地去污效能不仅受水力负荷(HL)影响,还与植物种类有关。为研究这2种因素对污染物去除的交互作用,根据植物根系长度,分别构建短根型、中根型及长根型植物潜流人工湿地中试系统,在运行稳定后,考察不同植物种类在不同水力负荷(152、230、305和460 mm/d)下的去污效果。结果表明:植物种类对COD去除率的影响差别不显著,对氮磷去除率有显著影响,且去除率符合长根型 > 中根型 > 短根型;水力负荷对COD、TN、NH4+-N和TP的去除均有显著影响,随着水力负荷减小去除率均逐渐升高;植物种类与水力负荷的交互作用对各污染物去除率均有显著影响,且受水力负荷影响较大,TN、NH4+-N的去除在水力负荷较小时交互作用较明显,COD去除的最优HL为230 mm/d。因此,在人工湿地设计时应考虑植物种类与水力负荷的交互作用。