保定市大水系建设的实践与思考

近年来,由于保定市降水偏少,用水量增加,以及水污染等方面的原因,致使市区严重缺水,地下水环境恶化,白洋淀湿地面积萎缩,出现了"有河皆干,有水皆污"的局面。为进一步改善保定地区水环境,保定市开始实施大水系建设。从建设背景入手,回顾保定市大水系建设的实践历程,思考和总结其中的经验教训,对于今后的水系建设和城市发展具有一定的借鉴意义。

Application of water loop variable refrigerant flow air-conditioning system in large-scale buildings in northern China

A water loop variable refrigerant flow（WLVRF）air-conditioning system is designed to be applied in large-scale buildings in northern China.The system is energy saving and it is an integrated system consisting of a variable refrigerant flow（VRF）air-conditioning unit,a water loop and an air source heat pump.The water loop transports energy among different regions in the buildings instead of refrigerant pipes,decreasing the scale of the VRF air-conditioning unit and improving the performance.Previous models for refrigerants and building loads are cited in this investigation.Mathematical models of major equipment and other elements of the system are established using the lumped parameter method based on the DATAFIT software and the MATLAB software.The performance of the WLVRF system is simulated.The initial investments and the running costs are calculated based on the results of market research.Finally,a contrast is carried out between the WLVRF system and the traditional VRF system.The results show that the WLVRF system has a better working condition and lower running costs than the traditional VRF system.

Effect of Dietary Vitamin E on the Sperm Quality of Turbot(Scophthalmus maximus)

A 3-month feeding experiment was conducted in an in-door seawater system to investigate the effect of dietary vitamin E （Ve） on the sperm quality of turbot （Scophthalmus maximus）. D-α-tocopherol acetate was supplemented to the basal （control） diet （65.14 mg kg-l Ve） to obtain low and high levels of dietary Ve （244.60 mgkg-1, LVe; 721.60 mg kg-1, HVe）. Compared with the con- trol, sperm concentration was significantly increased in Ve-supplemented groups （LVe and HVe）; while relative sperm volume and testis-somatic index were significantly increased in group HVe only. Sperm motility duration was significantly longer in group HVe than in the control, but no significant difference was observed in percent motility among groups. Sperm size, the uniformity of mito- chondrial size, and the integrity of mitochondria cristae and plasma membrane were improved by dietary Ve, especially in HVe. The content of Ve in testis and liver as well as polyunsaturated fatty acids in sperm increased with dietary Ve. These results suggested that dietary Ve, especially at the high level （721.60 mg kgl）, significantly improved sperm concentration and motility duration and main- tained normal sperm morphology of turbot.Abstract A 3-month feeding experiment was conducted in an in-door seawater system to investigate the effect of dietary vitamin E （Ve） on the sperm quality of turbot （Scophthalmus maximus）. D-α-tocopherol acetate was supplemented to the basal （control） diet （65.14 mg kg-l Ve） to obtain low and high levels of dietary Ve （244.60 mgkg-1, LVe; 721.60 mg kg-1, HVe）. Compared with the con- trol, sperm concentration was significantly increased in Ve-supplemented groups （LVe and HVe）; while relative sperm volume and testis-somatic index were significantly increased in group HVe only. Sperm motility duration was significantly longer in group HVe than in the control, but no significant difference was observed in percent motility among groups. Sperm size, the uniformity of mito- chondrial size, and the integrity of mitochondria cristae and plasma membrane were improved by dietary Ve, especially in HVe. The content of Ve in testis and liver as well as polyunsaturated fatty acids in sperm increased with dietary Ve. These results suggested that dietary Ve, especially at the high level （721.60 mg kgl）, significantly improved sperm concentration and motility duration and main- tained normal sperm morphology of turbot.

Optimum Scheduling for the Chilled Water System of an Intelligent Building

The energy saving issue of chilled water system in an intelligent building is analyzed from the systematic point of view, and an optimum scheduling scheme which can save energy of the system facilities and satisfy the constraints of the real time cold loads and system running is also proposed. It can make the minimum cost of the system by optimizing the number of running chillers, running parameters and the distribution of real time loads of running chillers. The improved genetic algorithm is used in the optimum scheduling scheme. The computation results show that the building energy consumption can be decreased by about 10%.

Electroacupuncture alleviates stress-induced visceral hypersensitivity through an opioid system in rats

AIM:To investigate whether stress-induced visceral hypersensitivity could be alleviated by electroacupuncture(EA) and whether EA effect was mediated by endogenous opiates.METHODS:Six to nine week-old male SpragueDawley rats were used in this study.Visceral hypersensitivity was induced by a 9-d heterotypic intermittent stress(HIS) protocol composed of 3 randomly stressors,which included cold restraint stress at 4?℃ for 45 min,water avoidance stress for 60 min,and forced swimming stress for 20 min,in adult male rats.The extent of visceral hypersensitivity was quantified by electromyography or by abdominal withdrawal reflex(AWR) scores of colorectal distension at different distention pressures(20 mmHg,40 mmHg,60 mmHg and 80 mmHg).AWR scores either 0,1,2,3 or 4 were obtained by a blinded observer.EA or sham EA was performed at classical acupoint ST-36(Zu-San-Li) or BL-43(Gao-Huang) in both hindlimbs of rats for 30 min.Naloxone(NLX) or NLX methiodide(m-NLX) was administered intraperitoneally to HIS rats in some experiments.RESULTS:HIS rats displayed an increased sensitivity to colorectal distention,which started from 6 h(the first measurement),maintained for 24 h,and AWR scores returned to basal levels at 48 h and 7 d after HIS compared to pre-HIS baseline at different distention pressures.The AWR scores before HIS were 0.6 ± 0.2,1.3 ± 0.2,1.9 ± 0.2 and 2.3 ± 0.2 for 20 mmHg,40 mmHg,60 mmHg and 80 mmHg distention pressures,respectively.Six hours after termination of the last stressor,the AWR scores were 2.0 ± 0.1,2.5 ± 0.1,2.8 ± 0.2 and 3.5 ± 0.2 for 20 mmHg,40 mmHg,60 mmHg and 80 mmHg distention pressures,respectively.EA given at classical acupoint ST-36 in both hindlimbs for 30 min significantly attenuated the hypersensitive responses to colorectal distention in HIS rats compared with sham EA treatment [AWRs at 20 mmHg:2.0 ± 0.2 vs 0.7 ± 0.1,P = 4.23 711 E-4;AWRs at 40 mmHg:2.6 ± 0.2 vs 1.5 ± 0.2,P = 0.00 163;AWRs at 60 mmHg:3.1 ± 0.2 vs 1.9 ± 0.1,P = 0.003;AWRs at 80 mmHg:3.6 ± 0.1 vs 2.4 ± 0.2,P = 0.0023;electromyographic(EMG) at 20 mmHg:24 ± 4.7 vs 13.8 ± 3.5;EMG at 40 mmHg:60.2 ± 6.6 vs 30 ± 4.9,P = 0.00 523;EMG at 60 mmHg:83 ± 10 vs 39.8 ± 5.9,P = 0.00 029;EMG at 80 mmHg:94.3 ± 10.8 vs 49.6 ± 5.9,P = 0.00 021].In addition,EA at the acupuncture point BL-43 with same parameters did not alleviate visceral hypersensitivity in HIS rats.EA in healthy rats also did not have any effect on AWR scores to colorectal distention at distention pressuresof 20 and 40 mmHg.The EA-mediated analgesic effect was blocked by pretreatment with NLX in HIS rats [AWR scores pretreated with NLX vs normal saline(NS) were 2.0 vs 0.70 ± 0.20,2.80 ± 0.12 vs 1.50 ± 0.27,3 vs 2.00 ± 0.15 and 3.60 ± 0.18 vs 2.60 ± 0.18 for 20 mmHg,40 mmHg,60 mmHg and 80 mmHg;P = 0.0087,0.0104,0.0117 and 0.0188 for 20,40,60 and 80 mmHg,respectively].Furthermore,EA-mediated analgesic effect was completely reversed by administration of m-NLX,a peripherally restricted opioid antagonist(EMG pretreated with m-NLX vs NS were 30.84 ± 4.39 vs 13.33 ± 3.88,74.16 ± 9.04 vs 36.28 ± 8.01,96.45 ± 11.80 vs 50.19 ± 8.28,and 111.59 ± 13.79 vs 56.42 ± 8.43 for 20 mmHg,40 mmHg,60 mmHg and 80 mmHg;P = 0.05 026,0.00 034,0.00 005,0.000 007 for 20 mmHg,40 mmHg,60 mmHg and 80 mmHg,respectively).CONCLUSION:EA given at classical acupoint ST-36 alleviates stress-induced visceral pain,which is most likely mediated by opioid pathways in the periphery.

Effects of spectral composition,photoperiod and light intensity on the gonadal development of Atlantic salmon Salmo salar in recirculating aquaculture systems(RAS)

Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P<0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P>0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m^2;and LD 8:16,8.60 W/m^2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.

Characterization of Bacterial Strains Isolated from a Novel Seawater-based Retting Treatment of Hemp

Cultivable bacteria were isolated from seawater-based retting treatment of hemp, in which three of purified strains (SW- 1, SW- 2, and S-SW1) produced relatively high levels of pectinase activities, and also produced mannanases and xylanases. PCR-based entebacterial repetitive intergenic consensus primers (ERIC-PCR) were employed for fingerprinting DNA of the bacterial strains. The ERIC-PCR fingerprints of stains SW- 1, SW- 2, and S-SW1 were found to be different, and should be further identified for each isolate. Strains SW- 1 and SW- 2 were identified as Stenotrophomnas maltophilia, while strain S-SW1 was assigned to Ochrobactrum anthropi by BIOLOG system. These two species represented rhizosphere bacterial genera, and possibly were introduced by the hemp plants. These organisms seemed potentially capable of producing pectinase and hemicellulase, and thus effectively degrading the gum substances in the seawater retting. This research could be helpful for improving a novel seawater-based retting treatment of hemp.

A Study of the system control model of caisson dewatering of the north anchorage of Taizhou Bridge

A caisson foundation is applied to the north anchorage of Taizhou Yangtze River Highway Bridge of which the initial caisson sinking requires dewatering. Since the caisson foundation is quite close to nearby buildings, a system control model is established with source (sink) distribution and intensity being the object function, minimum requirements of settlement and deformation of surroundings caused by dewatering and dynamic water levels during different working procedures being constraints, and the design parameter of pumping wells being the variable,so as to lower the jeopardizing of surrounding buildings, which provides a new method for active control over settlement during dewatering. Such a method of dewatering based on system control model should be of significance for similar projects involving dewatering.

Quality Evaluation and Its Application to Surface Water Ecosystem Based on Maximum Flux Principle

Based on the maximum flux principle(MFP),a water quality evaluation model for surface water ecosystem is presented by using self-organization map(SOM) neural network simulation algorithm from the aspect of systematic structural evolution.This evaluation model is applied to the case of surface water ecosystem in Xindu District of Chengdu City in China.The values reflecting the water quality of five cross-sections of the system at different developing stages are obtained,with stable values of 1.438,2.952,1.86...

Effects of intercropping systems of trees with soybean on soil physicochemical properties in juvenile plantations

The intercropping system of tree with soybean in juvenile plantations, as a short-term practice, was applied at Lao Shan Experimental Station in Mao＇er Shan Forest of Northeast Forestry University, Harbin, China. The larch （Larix gmelinii）lsoybean （Glycine max.） and ash （Fraxinus mandshurica） intercropping systems were studied in the field to assess the effects of the intercropping on soil physicochemical properties. The results showed that soil physical properties were improved after soybean intercropping with larch and ash in one growing season. The soil bulk density in larch/soybean and ash/soybean systems was 1.112 g·cm^-3 and 1.058 g·cm^ 3, respectively, which was lower than that in the pure larch or ash plantation without intercropping. The total soil porosity also increased after intercropping. The organic matter amount in larch/soybean system was 1.77 times higher than that in the pure larch plantation, and it was 1.09 times higher in ash/soybean system than that in the pure ash plantation. Contents of total nitrogen and hydrolyzable nitrogen in larch/soybean system were 4.2% and 53.0% higher than those in the pure larch stand. Total nitrogen and hydrolyzable nitrogen contents in ash/soybean system were 75.5% and 3.3% higher than those in the pure ash plantation. Total phosphorus content decreased after intercropping, while change of available phosphorus showed an increasing trend. Total potassium and available potassium contents in the larch/soybean system were 0.6% and 17.5% higher than those in the pure larch stand. Total potassium and available potassium contents in the ash/soybean system were 56.4% and 21.8% higher than those in the oure ash plantation.

Potential Impacts of Climate Change on Water and Public Health in Alberta, Canada

A warming climate may affect the well-being through impacts on health and sustainability of its natural resources. Climate change, population growth, and agricultural and industrial development are increasing demand and pressure on Alberta＇s water supplies, and the risk to the health and well-being of Albertanso its economy and its aquatic ecosystems. An analytic framework was developed to help determine the adaptive capacity of the public health sector and its ability to cope with changes in climate and water quality and quantity. The framework includes possibilities for changes in public health processes, management, inputs, outputs, structure, financing, institutions, and policies. Research gaps and priorities related to impacts on the health sector from changed conditions of climate and water supply are offered.

A New Way to Study Water-Vapor Absorption Coefficient

In the visible spectrum, the atmospheric attenuations to sunlight mainly include aerosol scattering, atmospheric molecule Rayleigh scattering and ozone absorption, while in the near-infrared spectrum (from 650 nm to 1 000 nm), we must take water-vapor absorption into account. Based on the atmospheric correction theory, using spectrum irradiance data measured by Instantaneous Ground spectrometer, ozone content measured by Microtops Ⅱozone monitor, water-vapor content and aerosol optical thickness measured by sun photometer, we give a new way to study water-vapor absorption to sunlight, and the result shows that the main peak values of water-vapor absorption coefficients are 0.025 cm-1, 0.073 cm-1, 0.124 cm-1, 0.090 cm-1, 0.141 cm-1 and 0.417 cm-1, which respectively lie at 692 nm, 725 nm, 761 nm, 818 nm, 912 nm and 937 nm.

Research on the system of the performance-based salary in colleges and universities -- Taking M University as an example

The performance-based pay system of M university has been implemented for many years. During the operation process. there are many problems. For example, the performance standards are not timely adjusted, and there are the repeated rewards for a few elites, and the evaluation is a mere formality. Starting from the elements of motivating the knowledge-oriented workers, this paper probes into the reasons affecting the implementation of the performance-based pay system, and puts forward some suggestions for the implementation of the performance-based pay system in M University.

Evaluation of Feed and Feeding Regime on Growth Performance, Flesh Quality and Fecal Viscosity of Atlantic Salmon(Salmo salar L.) in Recirculating Aquaculture Systems

The effects of different feeds and feeding regimes on growth performance, flesh quality and fecal viscosity of Atlantic salmon （Salmo salar L.） in recirculating aquaculture systems （R.AS） were investigated. Fish （initial body weight of 1677 g＋ 157 g） were fed with four commercial feeds （Nosan salmon-NS, Aller gold-AG, Skretting salmon-SS and Hart ye-HY） in two feeding regimes （80% and 100% satiation） for 78 d. The results showed that salmon specific growth ratio （SGR） and weight gain ratio （WGR） were significantly affected by feed type and feeding regime （P〈0.05）. Feed conversion ratio （FCR） varied between 0.93 and 3.40, which was significantly affected by feed type （P〈0.05）, and slightly improved with increased satiation degree. The activities of digestive enzymes including protease, lipase and amylase were also significantly affected by feed type and feeding regime （P〈0.05）, increasing with satiation degree. Flesh qualities for vitamin E, hydroxyproline （HYP）, liquid loss and muscle pH among all groups showed significant differences （P〈0.05）, ranging from 26.67 to 29.67, while no obvious difference was found in flesh color. Fecal viscosity for different treatments showed no significant difference, though improvement was found in 100% satiation group. From present experiment, it was concluded that both feed type and feeding regime can affect the important quality attributes of Atlantic salmon.

Allelopathic eff ects of macroalga Corallina pilulifera on the red-tide forming alga Heterosigma akashiwo under laboratory conditions

Over the past few years, harmful algal blooms （HABs）, such as red tides, have been frequently observed in coastal zones worldwide. The natural allelopathic interactions among macroalgae and red tide microalgae can alter the structure and succession of aquatic ecosystems. We investigated the influence of four environmental factors （temperature, salinity, light, and pH） on the allelopathic effects of the macroalgae Corallina pilulifera on red-tide forming Heterosigma akashiwo under laboratory conditions. Each of the factors had four levels： temperature （15, 20, 25, and 30℃）, salinity （10, 20, 30, and 40）, light （20, 100, 200 and 400 gmol/（m2.s））, and pH （5.5, 7, 8.5, and 10. Two-factor experiments were designed for each two environmental factors, with six combination treatments （temperature-salinity, temperature-light, temperature-pH, salinity-light, salinity-pH, and light-pH）. Results showed that the allelopathic effect was significantly influenced by temperature, salinity, light, and pH. As single factors, the low temperature （15 ℃）, low salinity （10）, high-intensity light （400umol/（m2.s））, and high pH （10） treatments substantially enhanced the allelopathic effect. The strongest allelopathic effect of C. pilulifera on H. akashiwo was observed under the following treatments： 15℃ and salinity of 40, 25℃ and pH 10, 25℃ with medium- to high-intensity light at 200-400 umol/（m2.s）, 400umol/（m2.s） and salinity of 10, 400 gmol/（m2·s） and pH 10, and pH 10 with a salinity of 40.

Runoff and Sediment Load from the Right Bank Valleys of Mosul Dam Reservoir

Mosul Dam is a Multipurpose Project on the River Tigris in Iraq with 11.11 billion m3 storage capacity. It is used to store the water for irrigation, hydropower generation, and flood control. As in other dams in the world, this dam also have sedimentation problem. Sediment accumulation in its reservoir can effect the dam operation （pumping station, hydropower plants, and bottom outlets） and it will definitely shorten the life span of the dam. In this study, the SWAT （soil and water assessment tool） under （]IS （Geographical Information System） was applied to simulate the yearly surface rtmoff and sediment load for the main three valleys on the right bank of Mosul Dam Reservoir. The simulation considered for the twenty one years begin from the dam operation in 1988 to 2008. The resultant values of the average annual sediment load are 35.6~ 103, 4.9 ~ 103, and 2.2~ 103 ton, while the average values of sediment concentration are 1.73, 1.65, and 2.73 kg/m3 for the considered valleys one, two and three respectively. This implies that significant sediment load enters the reservoir from these valleys. To minimize the sediment load entering the reservoir, a check dam is to be constructed in suitable sites especially for valley one. The check dam can store the runoff water and trap the sediment load, and then the flow can be released to the reservoir.

Profile of Methane Concentrations in Soil and Atmosphere in Alpine Steppe Ecosystem on Tibetan Plateau

The methane concentration profile from -1.5m depth in soil to 32m height in air was measured in alpine steppe lo-cated in the permafrost area. Methane concentrations showed widely variations both in air and in soil during the study period. The mean concentrations in atmosphere were all higher than those in soil, and the highest methane concentration was found in air at the height of 16m with the lowest concentration occur-ring at the depth of 1.5m in soil. The variations of atmospheric methane concentrations did not show any clear pattern both temporally and spatially, although they exhibited a more steady-stable state than those in soil. During the seasonal variations, the methane concentrations at different depths in soil were sig-nificantly correlated (R2>0.6) with each other comparing to the weak correlations (R2<0.2) between the atmospheric concentra-tions at different heights. Mean methane concentrations in soil significantly decreased with depth. This was the compositive influence of the decreasing production rates and the increasing methane oxidation rates, which was caused by the descent soil moisture with depth. Although the methane concentrations at all depths varied widely during the growing season, they showed very distinct temporal variations in the non-growing season. It was indicated from the literatures that methane oxidation rates were positively correlated with soil temperature. The higher methane concentrations in soil during the winter were deter-mined by the lower methane oxidation rates with decreasing soil temperatures, whereas methane production rates had no reaction to the lower temperature. Relations between methane contribution and other environmental factors were not discussed in this paper for lacking of data, which impulse us to carry out further and more detailed studies in this unique area.

Development and application of a system for the analysis of atmospheric, water and sediment nitrogen and carbon

Eutrophication and climate change, key environmental concerns, are both linked to the carbon and nitrogen cycles hence the improved understanding of these cycles is essential. Currently, there is no system that simultaneously measures the fluxes of the three key gas phase products of nitrogen and carbon cycling （CO2, CH4 and N2O） in submerged ecosystems with hourly time resolution. A ＂Lake-in-a-box＂ （mesocosm） was developed in the laboratory which allowed the monitoring of key components of the carbon and nitrogen cycles within the air, water and sediments. The approach is automated, simple and time efficient and novel in its ability to examine many different carbon and nitrogen compounds in all three physical component of the ＂lake＂. Dramatic fluctuations in gaseous flux and the concentrations of overlying water and sedimentary carbon and nitrogen compounds were noted over a three week period. These were split into five distinct phases which were linked to changes in sedimentary N and C cycling. The results highlighted the important of links between the two cycles and supported recent studies showing that estuarine sediments can act as both a source and a sink of nitrogen.

Control for Modified University of Cape Town Process Using Oxidation-Reduction Potential in the Second Anoxic Zone

The aim of this work is to evaluate the feasibility of applying the technology of oxidation-reduction potential （ORP） control on the municipal wastewater treatment system for nitrogen and phosphorus removal. Meanwhile the relation between the optimal ORP （ ORPopt ） and influent C/N ratio was evaluated, in which the influent chemical oxygen demand （ COD ） concentration was stabilized at （290 ± 10 ） mg/L, the influent total phosphorus （TP） concentration was stabilized at （7.0 ± 0.5 ） mg/L. The results indicated that： （1） the ORP in the second anoxic zone had effect on nitrogen and phosphorus removal capability, and the average percentages of phosphorus uptake in ANO2 zone （ ηa ） increased with increasing ORP, i. e. , increasing from 12. 0% at - 143 mV to 22.0%,30.0%,37.0%, and45.0% at -123, -111, -105 and -95 mV, respectively; （2） the ORPopt as function of influent C/N ratio could be calculated by the equation： y ffi 252. 73e〈 -x/3.39） _ 131.01 ; the maximum percentage of phosphorus uptake in ANO2 as function of the ORPopt could be calculated by the equation： y ffi -0.49e（x/15.58） ＋ 1. 51. The ORPopt was the important process control parameter that must be optimized for operation of enhanced biological phosphorus removal （ EBPR ） system. Moreover, ORP sensor is very simple, and the industrial applications of this strategy is practical.

Design of motion control of dam safety inspection underwater vehicle

Plenty of dams in China are in danger while there are few effective methods for underwater dam inspections of hidden problems such as conduits,cracks and inanitions.The dam safety inspection remotely operated vehicle(DSIROV) is designed to solve these problems which can be equipped with many advanced sensors such as acoustical,optical and electrical sensors for underwater dam inspection.A least-square parameter estimation method is utilized to estimate the hydrodynamic coefficients of DSIROV,and a four degree-of-freedom(DOF) simulation system is constructed.The architecture of DSIROV's motion control system is introduced,which includes hardware and software structures.The hardware based on PC104 BUS,uses AMD ELAN520 as the controller's embedded CPU and all control modules work in VxWorks real-time operating system.Information flow of the motion system of DSIROV,automatic control of dam scanning and dead-reckoning algorithm for navigation are also discussed.The reliability of DSIROV's control system can be verified and the control system can fulfill the motion control mission because embankment checking can be demonstrated by the lake trials.