Based on the analysis of forest inner mechanism, forest benefit in re ducing flood disaster is defined. Through the characteristic analysis of forest benefit in reducing flood disaster, it is suggested that it is imp...Based on the analysis of forest inner mechanism, forest benefit in re ducing flood disaster is defined. Through the characteristic analysis of forest benefit in reducing flood disaster, it is suggested that it is impossible to ado pt the microanalysis method for studying the forest benefit in reducing flood, t he macro analysis is the only method to be adopted. With the special case of dis aster flooding of Changjiang River happened in 1998, the forest benefit in reduc ing flood disaster was scientifically assessed. The estimated results of forest benefit in reducing flood shows that forest vegetation establishment is the radi cal way to control flood, but it only equals to 5 percent of the total benefits of water conservancy facilities.展开更多
This paper reports two newly recorded species, lsohypsibius lunulatus Iharos, 1966 and lsohypsibiusprosostomus Thulin, 1928, of the genus lsohypsibius （Tardigrada; Hypsibiidae） from China. The specimens of lsohysibi...This paper reports two newly recorded species, lsohypsibius lunulatus Iharos, 1966 and lsohypsibiusprosostomus Thulin, 1928, of the genus lsohypsibius （Tardigrada; Hypsibiidae） from China. The specimens of lsohysibius lunulatus were collected from Taibai Mt （34°18′N, 107°42′E） at 2,500 m a.s.1, and those oflsohypsibius prosostomus from Taibai Mt （34°10′N, 107°35′E） at 2,000 m above sea level. All specimens are deposited at the College of Life Sciences, Shaanxi Normal University, China. A key to the Chinese species of lsohypsibius was also given.展开更多
Objective To probe into the function mechanism of penetration therapy with head electrical acupuncture on Parkinson＇s disease. Methods Microinjection of 6-hydroxydopamin （6-OHDA） on the left cor- pus striatum was a...Objective To probe into the function mechanism of penetration therapy with head electrical acupuncture on Parkinson＇s disease. Methods Microinjection of 6-hydroxydopamin （6-OHDA） on the left cor- pus striatum was adopted to prepare rotation model of Parkinson^s disease in rat. Penetration therapy with head electrical acupuncture was administered in treatment. Normal group, sham-operation group, model group and penetration therapy group were set up. （1）lmmunohistochemical （IHC） method was used to test the morphology and count of positive cell of tyrosine hydroxylase （TH）. （2）RT-PCR technology was used to detect the expression of nestin mRNA of neural stem cell （NSC）. Results （1）Compared with model group, in pene- tration therapy group, the expressions of TH-positive neurons in immune response were increased in areal density （AD）, numerical density （ND） and integrating optic density （P〈0.05）. （2）Compared with model group, in penetration therapy group, the expression of nestin mRNA was increased （P〈0. 05）. Conclusion Penetration therapy with head electrical acupuncture promotes the proliferation of endogenous neural stem cells in substantia nigra of rat model of Parkinson＇s disease.展开更多
Boundary extraction of watershed is an important step in forest landscape research. The boundary of the upriver wa-tershed of the Hunhe River in the sub-alpine Qingyuan County of eastern Liaoning Province, China was e...Boundary extraction of watershed is an important step in forest landscape research. The boundary of the upriver wa-tershed of the Hunhe River in the sub-alpine Qingyuan County of eastern Liaoning Province, China was extracted by digital elevation modeling (DEM) data in ArcInfo8.1. Remote sensing image of the corresponding region was applied to help modify its copy according to Enhanced Thematic Mapper (ETM) image抯 profuse geomorphological structure information. Both the DEM-dependent boundary and modified copy were overlapped with county map and drainage network map to visually check the effects of result. Overlap of county map suggested a nice extraction of the boundary line since the two layers matched precisely, which indicated the DEM-dependent boundary by program was effective and precise. Further upload of drainage network showed discrepancies between the boundary and the drainage network. Altogether, there were three sections of the extraction result that needed to correct. Compared with this extraction boundary, the modified boundary had a better match to the drainage network as well as to the county map. Comprehensive analysis demonstrated that the program extraction has generally fine precision in position and excels the digitized result by hand. The errors of the DEM-dependant extraction are due to the fact that it is difficult for program to recognize sections of complex landform especially altered by human activities, but these errors are discernable and adjustable because the spatial resolution of ETM image is less than that of DEM. This study result proved that application of remote sensing information could help obtain better result when DEM method is used in extraction of watershed boundary.展开更多
An exploratory study was conducted on the housing pattern and food habit of the Mro tribe in Bandarban region, Bangladesh, highlighting their indigenous knowledge. The study was carried out with respect to three incom...An exploratory study was conducted on the housing pattern and food habit of the Mro tribe in Bandarban region, Bangladesh, highlighting their indigenous knowledge. The study was carried out with respect to three income groups. A total of 36 households (12 from each income groups) were assessed using different participatory appraisals through semi-structured questionnaires. A special type of indigenous knowledge on housing pattern and food habit was explored in the Mro community, which correspond to the severe dependence on forest resources.展开更多
To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross ...To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross N mineralization rate （GNR） in mineral soils （0-10 cm） from six forest stands located in central Germany were determined and compared with two sampling times： April and November. Additionally, soil density fractionation was conducted for incubated soils （with addition of ^15NH4-N and glucose, 40 days） to observe the sink of added ^15N in different soil fractions. The study showed that Nmic and NNR in most stands differed significantly （P 〈 0.05） between the two sampling times, but not GNR, SAN and SON. In November, no close relationships were found between GNR and other N indices, or between Nrnic, SON, and SAN and forest type. However, in April, GNR was significantly correlated （P 〈 0.05） with Nmic, SAN, and NNR along with Nmlc under beech being significantly higher （P 〈 0.05） than under conifers. Furthermore, density fractionation revealed that the light fraction （LF, 0.063-2 mm, 〉 1.7 gcm^-3） was not correlated with the other N indices. In contrast, results from the incubation study proved that more 15N was incorporated into the heavy fraction （HF 〈 0.063 ram, 〉 1.7 g cm^-3） than into LF, indicaing that more labile N existed in HF than in LF. These findings suggested that attention should be paid to the differences existing in N status between agricultural and forest soils.展开更多
The wear behavior of AZ91 alloy was investigated by considering different parameters,such as load(10−50 N),sliding speed(160−220 mm/s)and sliding distance(250−1000 m).It was found that wear volume loss increased as lo...The wear behavior of AZ91 alloy was investigated by considering different parameters,such as load(10−50 N),sliding speed(160−220 mm/s)and sliding distance(250−1000 m).It was found that wear volume loss increased as load increased for all sliding distances and some sliding speeds.For sliding speed of 220 mm/s and sliding distance of 1000 m,the wear volume losses under loads of 10,20,30,40 and 50 N were calculated to be 15.0,19.0,24.3,33.9 and 37.4 mm3,respectively.Worn surfaces show that abrasion and oxidation were present at a load of 10 N,which changes into delamination at a load of 50 N.ANOVA results show that the contributions of load,sliding distance and sliding speed were 12.99%,83.04%and 3.97%,respectively.The artificial neural networks(ANN),support vector regressor(SVR)and random forest(RF)methods were applied for the prediction of wear volume loss of AZ91 alloy.The correlation coefficient(R2)values of SVR,RF and ANN for the test were 0.9245,0.9800 and 0.9845,respectively.Thus,the ANN model has promising results for the prediction of wear performance of AZ91 alloy.展开更多
基金National Foundation of Ninth Five-Yea r Plan (No. 96-007-04-06-03).
文摘Based on the analysis of forest inner mechanism, forest benefit in re ducing flood disaster is defined. Through the characteristic analysis of forest benefit in reducing flood disaster, it is suggested that it is impossible to ado pt the microanalysis method for studying the forest benefit in reducing flood, t he macro analysis is the only method to be adopted. With the special case of dis aster flooding of Changjiang River happened in 1998, the forest benefit in reduc ing flood disaster was scientifically assessed. The estimated results of forest benefit in reducing flood shows that forest vegetation establishment is the radi cal way to control flood, but it only equals to 5 percent of the total benefits of water conservancy facilities.
基金This study was supported by scientific research foundation project of Shaanxi Institute of Education (No. 07KJ37Q)
文摘This paper reports two newly recorded species, lsohypsibius lunulatus Iharos, 1966 and lsohypsibiusprosostomus Thulin, 1928, of the genus lsohypsibius （Tardigrada; Hypsibiidae） from China. The specimens of lsohysibius lunulatus were collected from Taibai Mt （34°18′N, 107°42′E） at 2,500 m a.s.1, and those oflsohypsibius prosostomus from Taibai Mt （34°10′N, 107°35′E） at 2,000 m above sea level. All specimens are deposited at the College of Life Sciences, Shaanxi Normal University, China. A key to the Chinese species of lsohypsibius was also given.
基金the Excellent Discipline Leadership Fund Project of Harbin Science-Technology Administration :2006RFXYS044
文摘Objective To probe into the function mechanism of penetration therapy with head electrical acupuncture on Parkinson＇s disease. Methods Microinjection of 6-hydroxydopamin （6-OHDA） on the left cor- pus striatum was adopted to prepare rotation model of Parkinson^s disease in rat. Penetration therapy with head electrical acupuncture was administered in treatment. Normal group, sham-operation group, model group and penetration therapy group were set up. （1）lmmunohistochemical （IHC） method was used to test the morphology and count of positive cell of tyrosine hydroxylase （TH）. （2）RT-PCR technology was used to detect the expression of nestin mRNA of neural stem cell （NSC）. Results （1）Compared with model group, in pene- tration therapy group, the expressions of TH-positive neurons in immune response were increased in areal density （AD）, numerical density （ND） and integrating optic density （P〈0.05）. （2）Compared with model group, in penetration therapy group, the expression of nestin mRNA was increased （P〈0. 05）. Conclusion Penetration therapy with head electrical acupuncture promotes the proliferation of endogenous neural stem cells in substantia nigra of rat model of Parkinson＇s disease.
基金This work was supported by Knowledge Innovation Pro-gram Chinese Academy of Sciences (No. KZCX2-SW-320-3 & KZCX3-SW-425).
文摘Boundary extraction of watershed is an important step in forest landscape research. The boundary of the upriver wa-tershed of the Hunhe River in the sub-alpine Qingyuan County of eastern Liaoning Province, China was extracted by digital elevation modeling (DEM) data in ArcInfo8.1. Remote sensing image of the corresponding region was applied to help modify its copy according to Enhanced Thematic Mapper (ETM) image抯 profuse geomorphological structure information. Both the DEM-dependent boundary and modified copy were overlapped with county map and drainage network map to visually check the effects of result. Overlap of county map suggested a nice extraction of the boundary line since the two layers matched precisely, which indicated the DEM-dependent boundary by program was effective and precise. Further upload of drainage network showed discrepancies between the boundary and the drainage network. Altogether, there were three sections of the extraction result that needed to correct. Compared with this extraction boundary, the modified boundary had a better match to the drainage network as well as to the county map. Comprehensive analysis demonstrated that the program extraction has generally fine precision in position and excels the digitized result by hand. The errors of the DEM-dependant extraction are due to the fact that it is difficult for program to recognize sections of complex landform especially altered by human activities, but these errors are discernable and adjustable because the spatial resolution of ETM image is less than that of DEM. This study result proved that application of remote sensing information could help obtain better result when DEM method is used in extraction of watershed boundary.
文摘An exploratory study was conducted on the housing pattern and food habit of the Mro tribe in Bandarban region, Bangladesh, highlighting their indigenous knowledge. The study was carried out with respect to three income groups. A total of 36 households (12 from each income groups) were assessed using different participatory appraisals through semi-structured questionnaires. A special type of indigenous knowledge on housing pattern and food habit was explored in the Mro community, which correspond to the severe dependence on forest resources.
基金Project supported by the German Research Council, Germany (No. DFG Graduiertenkolleg 339).
文摘To evaluate the validity of different indices in estimating soil readily mineralizable N, soil microbial biomass （Nmic）, soil active N （SAN）, soluble organic N （SON）, net N mineralization rate （NNR） and gross N mineralization rate （GNR） in mineral soils （0-10 cm） from six forest stands located in central Germany were determined and compared with two sampling times： April and November. Additionally, soil density fractionation was conducted for incubated soils （with addition of ^15NH4-N and glucose, 40 days） to observe the sink of added ^15N in different soil fractions. The study showed that Nmic and NNR in most stands differed significantly （P 〈 0.05） between the two sampling times, but not GNR, SAN and SON. In November, no close relationships were found between GNR and other N indices, or between Nrnic, SON, and SAN and forest type. However, in April, GNR was significantly correlated （P 〈 0.05） with Nmic, SAN, and NNR along with Nmlc under beech being significantly higher （P 〈 0.05） than under conifers. Furthermore, density fractionation revealed that the light fraction （LF, 0.063-2 mm, 〉 1.7 gcm^-3） was not correlated with the other N indices. In contrast, results from the incubation study proved that more 15N was incorporated into the heavy fraction （HF 〈 0.063 ram, 〉 1.7 g cm^-3） than into LF, indicaing that more labile N existed in HF than in LF. These findings suggested that attention should be paid to the differences existing in N status between agricultural and forest soils.
文摘The wear behavior of AZ91 alloy was investigated by considering different parameters,such as load(10−50 N),sliding speed(160−220 mm/s)and sliding distance(250−1000 m).It was found that wear volume loss increased as load increased for all sliding distances and some sliding speeds.For sliding speed of 220 mm/s and sliding distance of 1000 m,the wear volume losses under loads of 10,20,30,40 and 50 N were calculated to be 15.0,19.0,24.3,33.9 and 37.4 mm3,respectively.Worn surfaces show that abrasion and oxidation were present at a load of 10 N,which changes into delamination at a load of 50 N.ANOVA results show that the contributions of load,sliding distance and sliding speed were 12.99%,83.04%and 3.97%,respectively.The artificial neural networks(ANN),support vector regressor(SVR)and random forest(RF)methods were applied for the prediction of wear volume loss of AZ91 alloy.The correlation coefficient(R2)values of SVR,RF and ANN for the test were 0.9245,0.9800 and 0.9845,respectively.Thus,the ANN model has promising results for the prediction of wear performance of AZ91 alloy.
