The dynamics of soil seed banks and seed movement was investigated in three bare alkali-saline patches in Songnen grassland, Northeast China, for exploring their potential role in the vegetation restoration of bare al...The dynamics of soil seed banks and seed movement was investigated in three bare alkali-saline patches in Songnen grassland, Northeast China, for exploring their potential role in the vegetation restoration of bare alkali-saline patches. The results showed that the seed banks and the seed movement in these patches were very similar to each other, and to some extent the seed movement was related to patch-side vegetation there. Seed movement across the soil surface of these bare alkali-saline patches was abundant and dominated by the seeds of pioneer species, such as Chloris virgata and Suaeda corniculata, which accounted for over 96% of these trapped seeds. In the contrast, soil seed banks of bare patches were extremely small, in different seasons, especially in May and June, even no any seed have been found, mainly due to lowest retaining capacity of surface soil to those abundant seed movement. Both soil seed banks and seed movement showed seasonal variation, and usually reached the maximum in October. Soil seed banks of bare alkali-saline patches, which were extremely small and difficult to recruit naturally, may inhibit speed of vegetation restoration. It is suggested that seed movement would be the potential seed source and play a potentially important role in the process of vegetation restoration of bare alkali-saline patches by enhancing the soft retaining capacity to seed movement.展开更多
Objectives To evaluate the very long-term safety and effectiveness of drug-eluting stents （DES） compared to bare-metal stents （BMS） for patients with large coronary vessels. Methods From April 2004 to October 2006...Objectives To evaluate the very long-term safety and effectiveness of drug-eluting stents （DES） compared to bare-metal stents （BMS） for patients with large coronary vessels. Methods From April 2004 to October 2006, 2407 consecutive patients undergoing de novo lesion percutaneous coronary intervention with reference vessel diameter greater than or equal to 3.5 mm at Fu Wai Hospital in Beijing, China, were prospectively enrolled into this study. We obtained 9-year clinical outcomes including death, myocardial infarction （MI）, thrombosis, target lesion revascularization （TLR）, target vessel revascularization （TVR）, and major adverse cardiac events （MACE, the composite of death, MI, and TVR）. We performed Cox＇s proportional-hazards models to assess relative risks of all the outcome measures after propensity match. Results After propensity scoring, 514 DES-treated patients were matched to 514 BMS-treated patients. The patients treated with BMS were associated with higher risk ofTLR （HR： 2.55, 95%CI： 1.520-4.277, P = 0.0004） and TVR （HR： 1.889, 95%CI： 1.185-3.011, P = 0.0075）, but the rates of death/MI and MACE were not statistically different. All Academic Research Consortium definition stent thrombosis at 9-year were comparable in the two groups. Conclusions During long-term follow-up through nine years, use of DES in patients with large coronary arteries was still associated with significant reductions in the risks of TLR and TVR.展开更多
Munitions contain casings that consume explosive energy.The blast load(e.g.,peak overpressure and maximum impulse)intensity generated by ammunition explosion will be lower than that generated by a bare charge with equ...Munitions contain casings that consume explosive energy.The blast load(e.g.,peak overpressure and maximum impulse)intensity generated by ammunition explosion will be lower than that generated by a bare charge with equal mass.To evaluate the blast load of a cased charge under different conditions,the equivalent bare mass needs to be calculated.However,the accuracy of existing correlations strongly depends on the empirical determination of relevant controlling parameters and lacks theoretical clarification.In this paper,new correlations are proposed based on a more rigorous theoretical derivation,considering both the mechanical behaviors of the casing’s material and the change of the polytropic exponent during the expansion process of the explosion products.The controlling parameters are attributed to the rupture radius ratio and the polytropic exponent of detonation products expansion to casing rupture state.The reasonability is validated by both comprehensive numerical simulations with dynamic mechanical constitutive model and theoretical derivations.The results calculated by the new correlation show better agreement with the experimental results than those calculated by previous correlations,and the results difference is explained in more consistency with the thermos-physical properties of the charge and mechanical behaviors of casing material.Furthermore,the correlation of the cased-to-bare impulse ratio is also theoretically improved,providing a more accurate theoretical basis for both the equivalent bare mass and impulse evaluation for a cased charge.展开更多
bare 一词在《大学英语》教材中经常出现。由于其含义较多,很多同学无法准确把握该词在具体句子中的意思。这里拟将该词含义归纳如下:1.裸的,光秃的如:fight the enemy with bare hands 赤手空拳同敌人肉搏,withone’s head bare 光着头...bare 一词在《大学英语》教材中经常出现。由于其含义较多,很多同学无法准确把握该词在具体句子中的意思。这里拟将该词含义归纳如下:1.裸的,光秃的如:fight the enemy with bare hands 赤手空拳同敌人肉搏,withone’s head bare 光着头,be bare to the waist 赤膊,trees that are alreadybare 叶已落光的树木bare 与 naked 比较:1)bare 指身体局部的裸,如:bare knees展开更多
Infinitives which consist of bare infinitive and infinitival to are imperative in linguistic studies.And both of the two kinds of infinitives do not indicate person,tense and number.This research aims to analyze the p...Infinitives which consist of bare infinitive and infinitival to are imperative in linguistic studies.And both of the two kinds of infinitives do not indicate person,tense and number.This research aims to analyze the properties,similarities and differences between bare infinitive and infinitival to from the perspective of syntax.Thus,it enables us to attain a uniform characterization of the infinitival to and bare infinitive on the syntactic level and help us to understand these two kinds of infinitives better.展开更多
Since Carlson(1977), bare noun phrases(which willbe referred to as BNPs afterwards) have been a focus of linguistics in English. Gradually, the studies of bare noun phrase has also caught much attention in China. Desp...Since Carlson(1977), bare noun phrases(which willbe referred to as BNPs afterwards) have been a focus of linguistics in English. Gradually, the studies of bare noun phrase has also caught much attention in China. Despite of the extensive studies of BNPs in English and Chinese respectively, a systematic comparison between English and Chinese BNPs in semantic readings is still less developed. More detailed studies and comparisons are obviously desirable. Most linguists agree that the semantics of the predicates, syntactic distribution and pragmatic factors all have a role to play in determining the interpretation of BNPs. Thus the paper has systematically made a semantic comparison between English BNPs and Chinese BNPs in terms of different predicate types and different syntactic distributions following the four semantic readings of BNPs of Shen(2005), namely, generic reading, existential reading,definite reading and non-referential reading.展开更多
基金The study was supported by the State Basic Research and Development Plan of China (G2000018602)
文摘The dynamics of soil seed banks and seed movement was investigated in three bare alkali-saline patches in Songnen grassland, Northeast China, for exploring their potential role in the vegetation restoration of bare alkali-saline patches. The results showed that the seed banks and the seed movement in these patches were very similar to each other, and to some extent the seed movement was related to patch-side vegetation there. Seed movement across the soil surface of these bare alkali-saline patches was abundant and dominated by the seeds of pioneer species, such as Chloris virgata and Suaeda corniculata, which accounted for over 96% of these trapped seeds. In the contrast, soil seed banks of bare patches were extremely small, in different seasons, especially in May and June, even no any seed have been found, mainly due to lowest retaining capacity of surface soil to those abundant seed movement. Both soil seed banks and seed movement showed seasonal variation, and usually reached the maximum in October. Soil seed banks of bare alkali-saline patches, which were extremely small and difficult to recruit naturally, may inhibit speed of vegetation restoration. It is suggested that seed movement would be the potential seed source and play a potentially important role in the process of vegetation restoration of bare alkali-saline patches by enhancing the soft retaining capacity to seed movement.
文摘Objectives To evaluate the very long-term safety and effectiveness of drug-eluting stents （DES） compared to bare-metal stents （BMS） for patients with large coronary vessels. Methods From April 2004 to October 2006, 2407 consecutive patients undergoing de novo lesion percutaneous coronary intervention with reference vessel diameter greater than or equal to 3.5 mm at Fu Wai Hospital in Beijing, China, were prospectively enrolled into this study. We obtained 9-year clinical outcomes including death, myocardial infarction （MI）, thrombosis, target lesion revascularization （TLR）, target vessel revascularization （TVR）, and major adverse cardiac events （MACE, the composite of death, MI, and TVR）. We performed Cox＇s proportional-hazards models to assess relative risks of all the outcome measures after propensity match. Results After propensity scoring, 514 DES-treated patients were matched to 514 BMS-treated patients. The patients treated with BMS were associated with higher risk ofTLR （HR： 2.55, 95%CI： 1.520-4.277, P = 0.0004） and TVR （HR： 1.889, 95%CI： 1.185-3.011, P = 0.0075）, but the rates of death/MI and MACE were not statistically different. All Academic Research Consortium definition stent thrombosis at 9-year were comparable in the two groups. Conclusions During long-term follow-up through nine years, use of DES in patients with large coronary arteries was still associated with significant reductions in the risks of TLR and TVR.
文摘Munitions contain casings that consume explosive energy.The blast load(e.g.,peak overpressure and maximum impulse)intensity generated by ammunition explosion will be lower than that generated by a bare charge with equal mass.To evaluate the blast load of a cased charge under different conditions,the equivalent bare mass needs to be calculated.However,the accuracy of existing correlations strongly depends on the empirical determination of relevant controlling parameters and lacks theoretical clarification.In this paper,new correlations are proposed based on a more rigorous theoretical derivation,considering both the mechanical behaviors of the casing’s material and the change of the polytropic exponent during the expansion process of the explosion products.The controlling parameters are attributed to the rupture radius ratio and the polytropic exponent of detonation products expansion to casing rupture state.The reasonability is validated by both comprehensive numerical simulations with dynamic mechanical constitutive model and theoretical derivations.The results calculated by the new correlation show better agreement with the experimental results than those calculated by previous correlations,and the results difference is explained in more consistency with the thermos-physical properties of the charge and mechanical behaviors of casing material.Furthermore,the correlation of the cased-to-bare impulse ratio is also theoretically improved,providing a more accurate theoretical basis for both the equivalent bare mass and impulse evaluation for a cased charge.
文摘bare 一词在《大学英语》教材中经常出现。由于其含义较多,很多同学无法准确把握该词在具体句子中的意思。这里拟将该词含义归纳如下:1.裸的,光秃的如:fight the enemy with bare hands 赤手空拳同敌人肉搏,withone’s head bare 光着头,be bare to the waist 赤膊,trees that are alreadybare 叶已落光的树木bare 与 naked 比较:1)bare 指身体局部的裸,如:bare knees
文摘Infinitives which consist of bare infinitive and infinitival to are imperative in linguistic studies.And both of the two kinds of infinitives do not indicate person,tense and number.This research aims to analyze the properties,similarities and differences between bare infinitive and infinitival to from the perspective of syntax.Thus,it enables us to attain a uniform characterization of the infinitival to and bare infinitive on the syntactic level and help us to understand these two kinds of infinitives better.
文摘Since Carlson(1977), bare noun phrases(which willbe referred to as BNPs afterwards) have been a focus of linguistics in English. Gradually, the studies of bare noun phrase has also caught much attention in China. Despite of the extensive studies of BNPs in English and Chinese respectively, a systematic comparison between English and Chinese BNPs in semantic readings is still less developed. More detailed studies and comparisons are obviously desirable. Most linguists agree that the semantics of the predicates, syntactic distribution and pragmatic factors all have a role to play in determining the interpretation of BNPs. Thus the paper has systematically made a semantic comparison between English BNPs and Chinese BNPs in terms of different predicate types and different syntactic distributions following the four semantic readings of BNPs of Shen(2005), namely, generic reading, existential reading,definite reading and non-referential reading.
