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1.
Urban particulate matter 2.5(PM_(2.5)) pollution and public health are closely related, and concerns regarding PM_(2.5) are widespread. Of the underlying factors, the urban morphology is the most manageable. Therefore, investigations of the impact of urban three-dimensional(3D) morphology on PM_(2.5) concentration have important scientific significance. In this paper, 39 PM_(2.5) monitoring sites of Beijing in China were selected with PM_(2.5) automatic monitoring data that were collected in 2013. This data set was used to analyze the impacts of the meteorological condition and public transportation on PM_(2.5) concentrations. Based on the elimination of the meteorological conditions and public transportation factors, the relationships between urban 3D morphology and PM_(2.5) concentrations are highlighted. Ten urban 3D morphology indices were established to explore the spatial-temporal correlations between the indices and PM_(2.5) concentrations and analyze the impact of urban 3D morphology on the PM_(2.5) concentrations. Results demonstrated that road length density(RLD), road area density(RAD), construction area density(CAD), construction height density(CHD), construction volume density(CVD), construction otherness(CO), and vegetation area density(VAD) have positive impacts on the PM_(2.5) concentrations, whereas water area density(WAD), water fragmentation(WF), and vegetation fragmentation(VF)(except for the 500 m buffer) have negative impacts on the PM_(2.5) concentrations. Moreover, the correlations between the morphology indices and PM_(2.5) concentrations varied with the buffer scale. The findings could lay a foundation for the high-precision spatial-temporal modelling of PM_(2.5) concentrations and the scientific planning of urban 3D spaces by authorities responsible for controlling PM_(2.5) concentrations.  相似文献   

2.
In order to approach the characteristics of nitrogen and phosphorus pollution caused by cage culture and the balance of nitrogen and phosphorus during the process of cage culture, a monitoring was conducted in Daya Bay of Guangdong Province, China from April 2002 to Jane 2003. The results show that the concentrations of total nitrogen (TN) in the waters at the sites with five and ten years of cage culture history are 1.8 and 2.3 times of that at control site respectively. Ammonium (NH3-N) is the main form of nitrogen in spring while nitrate ( NO3 -) in winter. The concentrations of TN, total dissolved nitrogen (TDN) and dissolved organic nitrogen (DON) are highest in autumn. The concentration of phosphorus increases with the increasing of the culturing time, among which phosphate ( PO 34-) increases most obviously. The concentrations of total phosphorus (TP) and total dissolved phosphorus (TDP) are highest in autumn. The nitrogen and phosphorus are accumulated significantly in the sediment of cage culture area. The model of N balance in the cage culture area: bait (70.62%) fry (0.28%) input by tide (14.8%) release from sediment (14.3%) = harvest of adult fish (12.07%) deposition into sediment (28.75%) output by tide (56.18%) others (3.00%). The model of P balance: bait (83.11%) fry (0.17%) input by tide (12.23%) release from sediment (4.49%) = harvest of adult fish (8.43%) deposition into sediment (48.59%) output by tide (41.94%) others (1.04%). In one fish growth year, the contents of nitrogen and phosphorus in harvest of adult fish are only 17.0% and 10.1% of the contents of nitrogen and phosphorus in fish bait and fry, wherein 83% of nitrogen and more than 89% of phosphorus in fish bait became marine pollutants.  相似文献   

3.
THEINVESTMENTCIRCUMSTANCESANDITSCLASSIFICATIONAPPRAISALOFCHANGJIANGRIVERDELTAXuGang(许刚)SheZhixiang(佘之祥)NanjingInstituteofGeog...  相似文献   

4.
本文报道1992~1993年在湛江沿海收集的口足类标本,经整理鉴定共20种,隶属3个上科,6个科,13个属。对每种的外部形态作了描述。  相似文献   

5.
This study investigated the difference of nutrient composition in Caulerpa lentillifera collected from different regions.The nutrient compositions of C.lentillifera from China's Hainan and Shandong provinces were determined and compared with those from Semporna(Malaysia),Sabah(Malaysia),Petchburi(Thailand),and two other species of seaweeds(Malaysia).The results showed that the polysaccharide and protein contents of C.lentillifera from Hainan(44.82%±0.98%and 12.5%±0.70%),Shandong(43.22%±1.42%and 14.7%±0.72%),Petchburi(59.27%±2.31%and 12.49%±0.30%),and Sabah(44.02%±2.01%and 19.38%±1.48%)were higher than those of Eucheuma cottonii(26.49%±3.01%and 9.76%±1.33%)and Sargassum polycystum(33.49%±1.70%and 5.40%±0.07%),respectively.The polyunsaturated fatty acid contents in C.lentillifera from Hainan(29.98%)and Shandong(22.11%)were higher than that in Semporna(16.76%±0.27%),Sabah(9.49%),and S.polycystum(20.34%±0.43%),but lower than that in E.cottonii(51.55%±0.57%).In Caulerpa lentillifera of Hainan and Shandong provinces,the essential amino acid(EAA)/total amino acid(TAA)ratios were 35.22%and 38.78%,respectively;and the EAA/ETAA ratios were 54.36%and 63.35%,respectively.The EAA composition of C.lentillifera was close to the ideal model of Food and Agriculture Organization/World Health Organization.C.lentillifera was rich in mineral elements,including calcium((3315.85±127.55)mg(100 g)^-1 and(3728.35±92.38)mg(100 g)^-1),magnesium((6715.74±82.58)mg(100 g)^-1 and(8128.59±242.72)mg(100 g)^-1),and trace elements,including iron((510.65±5.47)mg(100 g)^-1 and(1972.97±183.35)mg(100 g)^-1),selenium((1.04±0.08)mg(100 g)^-1 and(0.83±0.15)mg(100 g)^-1),and zinc((33.90±0.13)mg(100 g)^-1 and(11.75±2.05)mg(100 g)^-1).These results showed that C.lentillifera was more nutritious than S.polycystum or E.cottonii in terms of polysaccharide,protein,and fatty acid contents.Furthermore,both C.lentillifera species collected from Hainan and Shandong provinces show more basic nutrients.Therefore,C.lentillifera has important development and application prospects.  相似文献   

6.
This paper explains the meaning of investment circumstance, and analyses the overall feature of investment circumstances of the Changjiang River Delta zone and clears about its targets’ system. Then the authors use “polytarget comprehensive value evaluation rule” to make comprehensive classification appraisal of the investment circumstance of the five regions including Shanghai, Ning (Nanjing)-Zhen (Zhenjiang)-Yang(Yangzhou), Su(Suzhou)-Xi(Wuxi)-Chang(Changzhou)-Tong(Nantong), Hang(Hangzhou)-Jia(Jiaxing)-Hu(Huzhou), Ning(Ningbo)-Shao(Shaoxing)-Zhou(Zhoushan)etc., which have similar region feature and district join together due to the long-term development of society and economy among these regions.  相似文献   

7.
罗非鱼4个选育群体遗传结构SSR分析   总被引:2,自引:0,他引:2  
采用SSR分子标记分析了吉富品系罗非鱼的两个家系(GF1和GF2)以及奥利亚罗非鱼(Fo)和奥本尼罗罗非鱼(Fn)群体的遗传结构。结果显示,扩增后等位基因数为3~8个,随引物不同而异,14对引物共扩增60个等位基因,扩增片断大小在102~267 bp之间。微卫星分析表明,奥本尼罗罗非鱼(Fn)的平均观测杂合度(0.764 3)和平均期望杂合度(0.519 6)均最高,吉富尼罗罗非鱼(GF1)平均多态信息含量(0.419 5)最高;吉富尼罗罗非鱼(GF2)平均观测杂合度(0.614 2),奥利亚罗非鱼(Fo)的平均期望观测度(0.446 6)、平均多态信息含量(0.359 2)最低;因此,吉富鱼(GF1)的遗传多样性最高,奥利亚的遗传多样性最低。Hardy-Weinberg平衡遗传偏离指数(D)奥利亚(Fo)和尼罗(Fn)(0.463 4和0.478 9)明显高于吉富的两家系(0.234 1和0.250 0)。Fo与GF2间遗传距离(0.477 0)最大;而GF1和GF2间的遗传距离(0.302 7)最小,遗传相似系数(0.607 3)最大,可推断新一代吉富罗非鱼与本地选育群体有相对较远的亲缘关系,更具杂种优势。  相似文献   

8.
??????????С????????о???????(??)??????????????????????????????????????????????????????????????????????????????ü???λ??????????????(??)????????????С???????????????????????????????????м???в??????????????????????????м???????????????????????????????????????????????????С??????????????????????????????????????????????????????С???????????С?????????????????????????????????С????????о???????????????????Ч???  相似文献   

9.
Surface sediments and bivalves were collected from the Changjiang Estuary in December 2003 and November 2004, respectively. Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in these samples were measured with high-resolution chromatography (HRGC)/High Resolution Mass Spectrometer (HRMS). The concentrations of total PCDD/Fs and toxic equivalent (TEQ) were 169.83±119.63 and 0.81±0.36 pg/g dry weight (dw) in sediments, and 580.33±240.17 and 7.24±3.65 pg/g dw in bivalves. The homolog compositions of PCDD/Fs were similar among samples, the most abundant congener was octa-chlorinated dibenzo-p-dioxin (OCDD) and then octa-chlorinated dibenzofuran (OCDF) and 1,2,3,4,6,7,8-hepta-chlorinated dibenzo-p-dioxin (HpCDD). The herbicide pentachlorophenol (PCP) and sodium pentachlorophenol (Na-PCP) were proved the main source of PCDD/Fs in this area.  相似文献   

10.
为了进一步认识北极涛动与行星波之间的关系,利用NCEP/NCAR再分析资料并借助谐波分析、相关分析等方法讨论了北极涛动异常下行星波的活动情况。结果表明:在北极涛动指数强(弱)值年,纬向平均风场在中纬度明显减小(增大),在中高纬度明显增大(减小);行星波1波振幅在低纬度对流层中层和中纬度平流层明显增大(减小),在高纬度平流层明显减小(增大);2波振幅在中纬度对流层明显减小(增大),在高纬度平流层有所增大(减小)。E-P通量反映出在北极涛动强(弱)值年,行星波1波在中高纬度从地面向上传播显著增强(减弱),低纬度波导显著增强(减弱),极地波导显著减弱(增强);2波在中高纬度从地面向上传播显著减弱(增强),低纬度波导和极地波导变化不明显。  相似文献   

11.
Lancelets (subphylum Cephalochordata) are a transitional species between invertebrates and vertebrates. They are currently listed in the Second Order of Protected Animals in China. Lancelets were first documented in the waters around the city of Weihai (Shandong, China) in 2002. However, little is known about the phylogeny of this population. We analyzed the sequences of cytochrome b (Cyt b) and cytochrome oxidase c subunit I (CO I) genes from samples collected from coastal waters in the cities of Weihai and Qingdao (~150 km to the south). We analyzed 176 sequences, of which 150 were novel sequences and 26 were obtained from GenBank. Our results suggest that (1) lancelets in the two cities belong to the species Branchiostoma japonicus and have a high level of genetic diversity; (2) there is a high level of gene flow and low level of genetic differentiation between lancelets from the two cities; (3) demographic expansion occurred an estimated 1.1 million years (Ma) ago (mid Pleistocene) for lancelets in Weihai-Qingdao; and (4) the divergence between B. belcheri and B. japonicus was estimated at between 37.75 Ma (early Oligocene)-46.5 Ma (late Eocene).  相似文献   

12.
Isopentnyladenosine(i~6Ado) was identified, and trans-zeatin (trans-Z) and trans-zeatin riboside(trans-ZR) were detected by high pressure liquld chrmoatoguphy (HPLC) but not verified withchromatography - mass spectrometry (GC - M S ) analysis of cytokinin from the extracts of green algae (Ulvapertusa (Kjellm), Enteromopha compressa and Monostma sp). This indicated that the green algae mixturecontained cytokinin -like substances.  相似文献   

13.
本文证明,其中,f(z)为超越亚纯函数,ψ(z)为非零亚纯函数,使得T(r,ψ)=S(r,f),其中,S(r,f)表示O{T(r,f)}(r→+∞),至多除去一个线性测度有限的r集。  相似文献   

14.
Specimens of Clarias gariepinus were treated with lethal(70,75,80,85,90,and 95 mg/L) and sub-lethal concentrations(8,12 and 16 mg/L) of uranyl acetate,a low-radiotoxicity uranium salt. The LC 50 value was registered as 81.45 mg/L. The protein and glycogen concentrations in liver and muscles were decreased in the fish exposed to sub-lethal concentrations. The red blood cell(RBC) and white blood cell(WBC) counts,haemoglobin(Hb) concentration and haematocrit(Hct) values were decreased. Different blood indices like mean corpuscular volume(MCV),mean corpuscular haemoglobin(MCH) and mean corpuscular haemoglobin concentration(MCHC) were negatively affected. Level of plasma glucose was elevated whereas protein was decreased. The level of calcium concentration(Ca) was declined in the blood of exposed fish whereas magnesium(Mg) remains unchanged. The activity level of glutamic-oxaloacetic transaminase(GOT) and glutamic-pyruvic transaminase(GPT) was elevated in exposed fish. These effects were more pronounced in the last period of exposure and in higher concentrations. Results of the present study indicate that uranyl acetate has adverse effects on C larias gariepinus and causes changes in the biochemical and hematological parameters of the fish.  相似文献   

15.
Long chain alkyl diols have shown important potential for the reconstruction of sea surface temperature,productivities and upwelling conditions in marine or lacustrine environments.However,little is known about the distribution and sources of the diols in eastern China marginal seas(CMS),which are areas of important organic carbon sink.Here the contents of C_(30) and C_(32)1,15-diols were analyzed in 181 surface sediments from eastern CMS.The similar distribution pattern and strong linear correlation between C_(30) and C_(32) diols indicated that they had similar biological source,with a dominance of C_(30) diol.Their contents ranged from 7-2726 ng g~(-1) for C_(30) diol and 5-669 ng g~(-1) for C_(32) diol,and both showed higher values mainly in the mud area of the Yellow Sea,while the TOC normalized contents showed a more obvious seaward increasing trend.The similar distribution pattern and significant positive correlation between diols and the other marine biomarkers(brassicasterol,dinosterol,C_(37) alkenones) indicated C_(30) and C_(32) diols in eastern CMS were mainly from marine algae.This conclusion was also supported by principal component analysis(PCA).Our results also showed that sediment diol contents were generally related to marine productivity,suggesting that diols could be applied for marine productivity reconstruction in eastern CMS.  相似文献   

16.
????GM(1,1)?????????????????????????????????????????GM(1,1)?????????????????????????GM(1,1) ??????GM(1,1)??PGM(1,1)?????GM(1,1)????????????б???????????????????????GM(1,1)????????????  相似文献   

17.
This paper introduces the experiences and models of land resources use in China. They are: (1) to protect farmland is as the basic state policy; (2) to carry out land resources survey and land use planning; (3) establishing a resource-saving agricultural production system with land saving as its priority; (4) to develop agriculture in the whole territory and explore food resources; (5) improving eco-environment and protecting land resources; (6) population control'and moderate consumption to release the pressure on land resources; (7) the integrated development and experiment of the typical regions.  相似文献   

18.
With the implementation of the GEOTRACES program, the biogeochemical cycle and distribution of tellurium (Te) in marine environments are becoming increasing environmental concerns. In this study, the concentration of dissolved Te in the Changjiang (Yangtze) River estuary and nearby waters was determined in May 2009 by hydride-generation atomic fluorescence spectrometry to elucidate the abundance, dominant species, distribution, and relationship with environmental factors. Results show that: (1) dissolved Te was low owing to its low abundance in the Earth's crust, high insolubility in water, and strong affinity to particulate matter; (2) Te(IV) and Te(VI) predominated in surface water. Te(VI) was the dominant species in bottom water, and Te(IV) was the minor species; (3) Horizontally, resulting from low phytoplankton metabolism and the weak reduction from Te(VI) to Te(IV) in the shore, Te(IV) was concentrated in the central zone instead of the coastal region. However, Te(VI) was abundant near the mouth of the Changjiang River where the Changjiang water is diluted and in the area to the south where the Taiwan Warm Current invaded. In the adsorption-desorption process, Te(IV) was negatively related to suspended paniculate matter (SPM), indicating that it was adsorbed by particulate matter. While for Te(VI), the positive correlation with SPM suggested that it was desorbed from the solid phase. In the estuary, dissolved Te had a negative correlation to salinity. However, it deviated from the dilution line in high-salinity regions due to the invasion of the Taiwan Warm Current and the mineralization of organic matter. The relationship between Te(IV) and SPM nutrients indicated that it was more bioavailable and more related to phosphorus than to nitrogen. Progress in the field is slow and more research is needed to quantify the input of Te to the estuary and evaluate the biochemical role of organisms.  相似文献   

19.
The serum thyroid hormone and plasma catecholamine were examined in 18 male and 2 female members of the Chinese Antarctic Expedition (who spent the 2000 or 2001 austral winter at the Great Wall Station) . The changes of serum thyroid hormone i. e. total thyroxine (TT4) and free T4 (FT4) , total triodothyronine (TT3) and freeT3 ( FT3 ) , thyroid stimulating hormone ( TSH ) and plasma catecholamine, including norepinephrine (NE) , epinephrine ( E) and dopamine ( DA ) , were investigated by Chemoluminescence Immunoassay (CLIA) and High Performance Liquid Chromatography with electrochemical detection (HPLC-ECD) . Samples were taken at different time; (1)1 day before departure to Antarctica (16th expedition 1999/12/ 09; 17th expedition 2000/12/06). (2) 1 day after returned to China after living 54 weeks in Antarctica ( 16th expedition 2000/12/25 ; 17th expedition 2001/12/25 ). Comparing the data of before departure and returned, results showed that there was a significant decrease in the contents of TT4 (P <  相似文献   

20.
应用CNDO/2量子化学方法计算了12个氯苯类化合物(包括苯分子)的电子结构,并结合相关分析和逐步回归分析方法,探讨了氯苯类化合物电子结构与其对花鳉鱼(Guppy)和发光细菌(MicrotoX)半致死量负对数(DLC50、EC50)之间的定量关系,分别获得氯苯化合物最低空轨道(LUMO)与最高占据轨道(HOMO)的能量差(DELH)与DLC50和EC50之间的线性方程(相关系数分别为0.969和0.937)。结果表明:DELH值越小,即化合物接受电子的能力越强,则氯苯化合物对Guppy和Microtox的毒性就越大,据此可预测氯苯化合物的毒性。  相似文献   

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