期刊文献+
共找到5,105篇文章
< 1 2 250 >
每页显示 20 50 100
Changes in Land Use and Agricultural Production Structure Before and After the Implementation of Grain for Green Program in Western China–Taking Two Typical Counties as Examples 被引量:6
1
作者 ZHOU Ping WEN An-bang +4 位作者 YAN Dong-chun SHI Zhong-lin GUO Jin JU Zhan-sheng ZHANG Yi-lan 《Journal of Mountain Science》 SCIE CSCD 2014年第2期526-534,共9页
Soil erosion becomes a serious environmental problem in the world, especially in western China. An effective management practice called the Grain for Green Program(GGP), which was launched in 1999, aims to reduce soil... Soil erosion becomes a serious environmental problem in the world, especially in western China. An effective management practice called the Grain for Green Program(GGP), which was launched in 1999, aims to reduce soil and water loss and alleviate the ecological environment problem in western China. Two typical counties in western China, the Zhongxian(in Chongqing Municipality) and Ansai(in Shaanxi Province) were chosen to evaluate the dynamic changes of land use and agricultural production structure before and after the implementation of the Program in this paper. The results showed that the cultivated land area was reduced by 7.08% from 1989 to 2003. The cultivated land per person was decreased by 8.42% during 1999-2003. Moreover, the stability index of the secondary sector of the economy was increased from 0.91 in the period 1990-1999 to 0.94 in the following ten years. In addition, the stability index of tertiary economic sector increased from 0.88 to 0.92 in Zhongxian county. Meanwhile, the cultivated land area was reduced by 15.48% from 1990 to 1999. The soil erosion modulus was decreased by 33.33% from 1999 to 2006. Also, the stability index of secondary and tertiary economic sectors was 0.86 in the period 1998-2002. However, it decreased by 77% during 2002 to 2007 in Ansai County. These results imply that the Grain for Green Program had different impact on the two regions. Several effective strategies of soil and water conservation have been carried out to ameliorate the sustainable development of ecological environment and economy in these two counties of western China. 展开更多
关键词 Cultivated land Stability index Agricultural production structure Grain for Green program (GGP) Three Gorges Reservoir region Loess Plateau
原文传递
Source Rock Classification and the Basic Structure of Coal and Kerogen 被引量:1
2
作者 金奎励 杨陆武 《Journal of China University of Mining and Technology》 2002年第1期1-5,共5页
In accordance with the confusion on classification of source rocks, the authors raised a source rock classification for its enriched and dispersed organic matter types based on both Alpern’s idea and maceral genesis/... In accordance with the confusion on classification of source rocks, the authors raised a source rock classification for its enriched and dispersed organic matter types based on both Alpern’s idea and maceral genesis/composition. The determined rock type is roughly similar to palynofacies of Combaz , whereas it is "rock maceral facies (for coal viz. coal facies)" in strictly speaking. Therefore, it is necessary to use the organic ingredients classification proposed by the authors so that it can be used for both maceral analysis and environment research . This source rock classification not only shows sedimentology and diagenetic changes but also acquires organic matter type even if hydrocarbon potential derived from maceral’s geochemical parameters. So, it is considered as genetic classification. The "rock maceral facies" may be transformed to sedimentary organic facies , which is used as quantitative evaluation means if research being perfect.Now, there are many models in terms of structure either for coal or for kerogen. In our opinion, whatever coal or kerogen ought be polymer, then we follow Combaz’s thought and study structure of amorphous kerogens which are accordance with genetic mechanism showing biochemical and geochemical process perfectly. Here, we use the time of flight secondary ion mass spectrometry (TOFSIMS) to expand Combaz’s models from three to five. They are also models for coal. 展开更多
关键词 Source rock classification organic ingredient classification basic structure for coal/kerogen time of flight secondary ion mass spectrometry (TofSIMS)
在线阅读 下载PDF
STATISTICAL TESTS FOR THE COMPARISON OF THE INCIDENCE OR MORTALITY RATES IN CANCER REGISTRY AND DESCRIPTIVE EPIDEMIOLOGY──A MICROCOMPUTER PROGRAM IN BASIC
3
作者 项永兵 金凡 高玉堂 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1997年第1期68-75,共8页
This paper describes the statistical methods of the comparison of the incidence or mortality rates in cancer registry and descriptive epidemiology, and the features of microcomputer program (CANTEST) which was designe... This paper describes the statistical methods of the comparison of the incidence or mortality rates in cancer registry and descriptive epidemiology, and the features of microcomputer program (CANTEST) which was designed to perform the methods. The program was written in IBM BASIC language. Using the program CANTEST we presented here the user can do several statistical tests or estimations as follow: 1. the comparison of the adjusted rates which were calculated by directly or indirectly standardized methods, 2. the calculation of the slope of regression line for testing the linear trends of the adjusted rates, 3. the estimation of the 95% or 99%conndence intervals of the directly adjusted rates, of the cumulative rates (0-64 and 0-74), and of the cumulative risk. Several examples are presented for testing the performances of the program. 展开更多
关键词 Cancer registry basic Microcomputer program INCIDENCE MORTALITY Descriptive epidemiology Statistical tests
暂未订购
Synthesis of a Weak Basic uPA Inhibitor and Crystal Structure of a Complex with uPA
4
作者 于海洋 高丹 +6 位作者 张旭 江龙光 洪泽斌 方昕 袁彩 王俊东 黄明东 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第7期961-968,共8页
As a trypsin-like serine protease, Urokinase-type plasminogen activator (uPA) plays a key role in a range of biological processes including plasminogen activation, angiogenesis, wound healing, tissue remodeling, tum... As a trypsin-like serine protease, Urokinase-type plasminogen activator (uPA) plays a key role in a range of biological processes including plasminogen activation, angiogenesis, wound healing, tissue remodeling, tumor growth and tumor metastasis, uPA is shown as the most validated marker for prognosis of breast cancer. Inhibitors of uPA may then be useful in the treatment of cancer by retarding tumor growth and metastasis. Most current uPA inhibitors employ a highly basic group (amidine or guanidine group) to target the primary specific pocket of uPA active site, which leads to poor oral bioavailability. Here, a uPA inhibitor with weak basic P1 group, 2-(2-amino- benzothiazole-6-carboxamido)acetic acid (ABTCA), was synthesized and reported here. In addition, we also determined the crystal structure of ABTCA in complex with uPA. The structural information will be useful for further improvements of potency and selectivity of this promising new type ofuPA inhibitors. 展开更多
关键词 UPA basic inhibitor SYNtheSIS crystal structure
在线阅读 下载PDF
Control of Melt Structures on Cu-Au Mineralization in Basic-Ultrabasic Complexes of Northern China
5
作者 YUAN Wanming Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100080and MO Xuanxue China University of Geoscienses, Beijing 100083 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2000年第4期786-794,共9页
Based on systematic analyses of 72 samples of different basic-ultrabasic rocks, the present paper discusses the relationship between melt structure and Cu and Au mineralization. It is found that if the NBO/T, NBO, M2+... Based on systematic analyses of 72 samples of different basic-ultrabasic rocks, the present paper discusses the relationship between melt structure and Cu and Au mineralization. It is found that if the NBO/T, NBO, M2+, FeO and MgO values are relatively high and the T, M3+, Fe2O3 and CaO values are low the basic-ultrabasic melt will be favourable to Cu (Ni) mineralization, but if the former are low and the latter are high it is favourable to Au metallization. Cu ions occupy dominantly octahedra in basic-ultrabasic melt and the higher the NBO/T, NBO and M2+ values, the more the octahedra in the melt. Au element mainly takes the form of Au+ ions in basic-ultrabasic melt and the Au+ ions constitute tetrahedral sites together with Fe3+ ions. Therefore, low M2+ and high Fe3+, i.e. high oxygen fu-gacity, can promote the enrichment of Au+ ions and Au mineralization. Components NT (other than Au+), Al2O3 and SiO2 in basic-ultrabasic melt have no effect on metallogenetic species. As mentioned above, in relevant diagrams distribution areas of the characteristic values of ore-free melt and those of ore-forming melt are overlapped in different degrees, which possibly indicates that not all the magmas have mineralizing ability. It can be well distinguished whether basic-ultrabasic rocks are favourable to Cu or Au mineralization or they are just ore-free rocks by analysing integrated diagrams of the characteristic values of the magmatic melt structure. 展开更多
关键词 melt structure Cu-Au mineralization basic-ultrabasic complex
在线阅读 下载PDF
Gender Equality:Now a Basic State Strategy——On the Salient Features of the National Program on the Development of Chinese Women(2011-2020)
6
作者 LI MINGSHUN China Women’s University the China Society for the Study of Human Rights 《The Journal of Human Rights》 2012年第1期22-25,共4页
The National Program on the Development of Chinese Women (2011-2020), herein- after referred to as the "NewProgram," was published in August 2011. This is an important document designed to ensure implementation of... The National Program on the Development of Chinese Women (2011-2020), herein- after referred to as the "NewProgram," was published in August 2011. This is an important document designed to ensure implementation of the basic state strategy of gender equal- ity and the all-round development of Chinese women. The New Program is a part of China's policy program for the protection of human rights. It sets 57 major targets to be attained over the decade. The targets cover seven fields, namely, health, education, economy, 展开更多
关键词 Gender Equality On the Salient Features of the National program on the Development of Chinese Women basic
原文传递
On the compiling principles of Vocational English series--Basic English
7
作者 王勃然 《Sino-US English Teaching》 2009年第4期23-25,共3页
This paper briefly introduces the systemic structure of Vocational English series--Basic English, and puts forwards the four key compiling principles, namely, system, cognition, practicality and interest.
关键词 basic English systemic structure compiling principle
在线阅读 下载PDF
Coupling between the Grain for Green Program and a household level-based agricultural eco-economic system in Ansai,Shaanxi Province of China 被引量:2
8
作者 LI Yue WANG Jijun +4 位作者 HAN Xiaojia GUO Mancai CHENG Simin QIAO Mei ZHAO Xiaocui 《Journal of Arid Land》 SCIE CSCD 2020年第2期199-214,共16页
The implementation of the Grain for Green Program(GGP)has changed the development track of the agricultural eco-economic system in China.In response to the results of a lag study that investigated the coupling between... The implementation of the Grain for Green Program(GGP)has changed the development track of the agricultural eco-economic system in China.In response to the results of a lag study that investigated the coupling between the GGP and the agricultural eco-economic system in a loess hilly region,we used a structural equation model to analyze the survey data from 494 households in Ansai,a district of Yan’an City in Shaanxi Province of China in 2015.The model clarified the direction and intensity of the coupling between the GGP and the agricultural eco-economic system.The coupling benefits were derived through linkages between the program and various chains in the agricultural eco-economic system.The GGP,the agroecosystem of Ansai and their potential coupling effects were in a state of general coordination.The agroecosystem directly affected the coupling effect,with the standardized path coefficient of 0.87,indicating that the agroecosystem in Ansai at this stage provided basic material support for the coupling between the GGP and the agricultural eco-economic system.The direct path coefficient of agroeconomic system impacted on the coupling effect was-0.76,indicating that partial contradictions occurred between the agroeconomic system and the coupling effect.Therefore,although the current agroecosystem in Ansai should be provided sufficient agroecological resources for the benign coupling between the program and the agricultural eco-economic system,agricultural development failed to effectively transform agroecological resources into agricultural economic advantages in this region,which resulted in a relative lag in the development of the agricultural economic system.Thus,the coupling between the GGP and the agricultural eco-economic system was poor.To improve the coupling and the sustainable development of the agricultural eco-economic system in cropland retirement areas,the industrial structure needs to be diversified,the agricultural resources(including agroecological resources,agricultural economic resources and agricultural social resources)need to be rationally allocated,and the chain structure of the agricultural eco-economic system needs to be continuously improved. 展开更多
关键词 GRAIN for Green program AGROECOSYSTEM agroeconomic SYSTEM agrosocial SYSTEM COUPLING effect HOUSEHOLD structural equation model
在线阅读 下载PDF
Static response analysis of structures with interval parameters using the second-order Taylor series expansion and the DCA for QB 被引量:3
9
作者 Qi Li Zhiping Qiu Xudong Zhang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2015年第6期845-854,共10页
In this paper, based on the second-order Taylor series expansion and the difference of convex functions algo- rithm for quadratic problems with box constraints (the DCA for QB), a new method is proposed to solve the... In this paper, based on the second-order Taylor series expansion and the difference of convex functions algo- rithm for quadratic problems with box constraints (the DCA for QB), a new method is proposed to solve the static response problem of structures with fairly large uncertainties in interval parameters. Although current methods are effective for solving the static response problem of structures with interval parameters with small uncertainties, these methods may fail to estimate the region of the static response of uncertain structures if the uncertainties in the parameters are fairly large. To resolve this problem, first, the general expression of the static response of structures in terms of structural parameters is derived based on the second-order Taylor series expansion. Then the problem of determining the bounds of the static response of uncertain structures is transformed into a series of quadratic problems with box constraints. These quadratic problems with box constraints can be solved using the DCA approach effectively. The numerical examples are given to illustrate the accuracy and the efficiency of the proposed method when comparing with other existing methods. 展开更多
关键词 Interval parameters · Second-order Taylorseries expansion · Static response of uncertain structures Quadratic programming problems · DCA
在线阅读 下载PDF
THE DYNAMIC CHARACTERISTICS OF LONG SPAN ARCH STRUCTURE
10
作者 颜玉玲 张建周 《Journal of Southeast University(English Edition)》 EI CAS 1989年第1期1-8,共8页
This paper presents a method for isolatedly solving the normal mode of vi-bration according to the uncoupling condition of vibrations inside and outside the archplane.The finite element method for curved beam elements... This paper presents a method for isolatedly solving the normal mode of vi-bration according to the uncoupling condition of vibrations inside and outside the archplane.The finite element method for curved beam elements is adopted to analyse the dy-namic characteristics of arch structures and the calculating program is made.The resultsobtained from Apple II microcomputer are compared with those from SAP5 program byan example,and are in good agreement. 展开更多
关键词 ARCH structure DYNAMIC characteristics program FREQUENCY MODES of VIBRATION
在线阅读 下载PDF
Comparative Survey of Object Serialization Techniques and the Programming Supports 被引量:1
11
作者 Kazuaki Maeda 《通讯和计算机(中英文版)》 2012年第8期920-928,共9页
关键词 对象序列化 编程语言 二进制文件 技术 APACHE ASCII Java 检查模式
在线阅读 下载PDF
The New Detection and the Basic Characteristics of the Structural System of Taiwan Region of China—Using the Earth Satellite's Remote-sensing Images to Explain the Structural System of Taiwan Region of China
12
作者 Hu Dongsheng Zhang Huajing 《工程科学(英文版)》 2006年第3期29-36,共8页
This text uses the regional geological investigation data and the remote sensing image data of earth-satellite remote sensing to synthetically analyze the structural system of Taiwan region of China. Authors detection... This text uses the regional geological investigation data and the remote sensing image data of earth-satellite remote sensing to synthetically analyze the structural system of Taiwan region of China. Authors detection-marked and assurance-marked and divided 5 kinds of structural system of the Taiwan region: (1) the wreath-shaped structural system, (2) the N-N-E oriented structural system, (3) the S-N oriented structural system, (4) the N-E oriented structural system, (5) the arc-shaped structural system. Combination of the texture faces and associated method were adopted to recover and reconstruct the structural evolution sequences and the formation periods. In this paper, problems such as the development process in geology etc. are also discussed, contributing new information to research the structural field of the East Asia and its tectonic plate movements and structural actions inside the land plate . 展开更多
关键词 中国 台湾省 区域地质特征 基本格局 构造演化 构造系统 遥感图象 地球卫星
在线阅读 下载PDF
Effect of the CaO/SiO2 mass ratio and FeO content on the viscosity of CaO–SiO2–“FeO”–12wt%ZnO–3wt%Al2O3 slags 被引量:8
13
作者 Jian-fang Lü Zhe-nan Jin +3 位作者 Hong-ying Yang Lin-lin Tong Guo-bao Chen Fa-xin Xiao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2017年第7期756-767,共12页
An effective process for recycling lead from hazardous waste cathode ray tubes(CRTs) funnel glass through traditional lead smelting has been presented previously. The viscous behavior of the molten high lead slag, w... An effective process for recycling lead from hazardous waste cathode ray tubes(CRTs) funnel glass through traditional lead smelting has been presented previously. The viscous behavior of the molten high lead slag, which is affected by the addition of funnel glass, plays a critical role in determining the production efficiency. Therefore, the viscosities of the CaO–SiO_2–"FeO"–12wt%ZnO–3wt%Al_2O_3 slags were measured in the current study using the rotating spindle method. The slag viscosity decreases as the CaO/SiO_2 mass ratio is increased from 0.8 to 1.2 and also as the FeO content is increased from 8wt% to 20wt%. The breaking temperature of the slag is lowered substantially by the addition of FeO, whereas the influence of the CaO/SiO_2 mass ratio on the breaking temperature is complex. The structural analysis of quenched slags using Fourier transform infrared(FTIR) spectroscopy and Raman spectroscopy reveals that the silicate network structure is depolymerized with increasing CaO/SiO_2 mass ratio or increasing FeO content. The [FeO_6]-octahedra in the slag melt increase as the CaO/SiO_2 mass ratio or the FeO content increases. This increase can further decrease the degree of polymerization(DOP) of the slag. Furthermore, the activation energy for viscous flow decreases both with increasing CaO/SiO_2 mass ratio and increasing FeO content. 展开更多
关键词 lead smelting slag viscosity basicity ferrous oxide slag structure
在线阅读 下载PDF
Industrial structure optimization in central China under the energy constraint 被引量:1
14
作者 孙威 李文会 +1 位作者 唐志鹏 樊杰 《Journal of Geographical Sciences》 SCIE CSCD 2016年第9期1377-1388,共12页
Optimizing industrial structure is an important research object of human-economic geography, and it is also the object of government departments to strengthen macro-control. This has become even greater problem that C... Optimizing industrial structure is an important research object of human-economic geography, and it is also the object of government departments to strengthen macro-control. This has become even greater problem that China has entered the "new normal" in recent years. The study uses a multi-regional input-output model, with linear programming to build an optimal model of industrial structure as well as a model of optimization degree under the energy constraint. The results of the study revealed that:(1) the degree of optimization of industrial structure in Anhui Province is optimal(0.763), while that of Shanxi Province is the lowest(0.662);(2) the degree of optimization of industrial structure is negatively related to energy consumption per unit output value and the proportion of heavy industry; and(3) overall, central China should maintain or moderately increase the proportions of resource-based industry, greatly increase the proportions of manufacturing, including transport and telecommunications equipment, computers and other electronic equipment, and moderately reduce the proportions of smelting and pressing of metals and non-metal mineral products. In terms of service industries, the region should greatly increase the proportions of the production and supply of natural gas and tap water, moderately reduce or maintain the proportions of transport and storage as well as tourism, and maintain or moderately reduce the proportions of wholesale trade, retail trade and catering services. 展开更多
关键词 central China multi-regional input-output model linear programming industrial structure energyconsumption
原文传递
Design and Movement Simulation to the Cam of the Testing Device for Capacitor Encapsulation Equipment 被引量:1
15
作者 Hongwei Fang Guoquan Zhang Jiaqing Jian 《Open Journal of Modelling and Simulation》 2014年第4期138-143,共6页
In this paper, in order to design a cam mechanism be up to the mustard, a set of methods are put forward that using the Visual Basic programming language based on solidworks to draw cam contour line and then get its 3... In this paper, in order to design a cam mechanism be up to the mustard, a set of methods are put forward that using the Visual Basic programming language based on solidworks to draw cam contour line and then get its 3D models and generate the cam motion simulation by the solidworks motion. In the end, it’s proved that the cam designed though this method met the requirement. 展开更多
关键词 Visual basic programMING LANGUAGE CAM CONTOUR Line Motion Simulation
在线阅读 下载PDF
A New Version of Unified Field Theory—Stochastic Quantum Space Theory on Particle Physics and Cosmology 被引量:3
16
作者 Zhi-Yuan Shen 《Journal of Modern Physics》 2013年第10期1213-1380,共168页
Stochastic Quantum Space (SQS) theory is a new version of unified field theory based on three fundamental postulations: Gaussian Probability Postulation, Prime Numbers Postulation, Vacuon Postulation. It build a frame... Stochastic Quantum Space (SQS) theory is a new version of unified field theory based on three fundamental postulations: Gaussian Probability Postulation, Prime Numbers Postulation, Vacuon Postulation. It build a framework with theoretical results agree with many experimental data well. For more information, please refer to the PDF. 展开更多
关键词 Unified Field theORY SPACE structure Elementary Particles Gaussian Probability Prime Numbers SPORADIC Groups GUT DARK Matter DARK Energy Cosmos INFLATON MULTIVERSE Anthropic Principle General Relativity Primary basic Equations
在线阅读 下载PDF
The Interpretation of The Intruder in the Dust under the Theory of Initiation Story
17
作者 方立 《海外英语》 2016年第11期198-201,共4页
Initiation is an ever- lasting literary theme. This novel has long been typically assumed as a detective story by many readers as well as critics, but when we delve further into its essence and its major characters, i... Initiation is an ever- lasting literary theme. This novel has long been typically assumed as a detective story by many readers as well as critics, but when we delve further into its essence and its major characters, it is not difficult to find that this novel is not only about an case of racial conflict in American South as it may appears, but more about the process of growing into maturity of a white American Southern boy amidst the raging noise of racial discrimination. This paper, proceeding from the theory of initiation story, aims to provide a new interpretation of William Faulkner's novel Intruder in the Dust. Based on the indepth textual analysis and the effective implementation of the theory of initiation story, the paper will explore the theme of initiation in the novel from two aspects, namely, the four basic elements of initiation story and the narrative structure of the initiation story. Therefore, a new point of view can be adopted to a better understanding of this novel. 展开更多
关键词 INITIATION INTRUDER in the DUST four basic elements NARRATIVE structure
在线阅读 下载PDF
Cloning and bioinformatical analysis of the N-terminus of the sonic hedgehog gene
18
作者 Yi Zhang Shu Zhao +6 位作者 Weiren Dong Suifen He Haihong Wang Lihua Zhang Yinjuan Tang Jiasong Guo Suiqun Guo 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第3期258-263,共6页
The sonic hedgehog protein not only plays a key role in early embryonic development, but also has essential effects on the adult nervous system, including neural stem cell proliferation, differentiation migration and ... The sonic hedgehog protein not only plays a key role in early embryonic development, but also has essential effects on the adult nervous system, including neural stem cell proliferation, differentiation migration and neuronal axon guidance. The N-terminal fragment of sonic hedgehog is the key functional element in this process. Therefore, this study aimed to clone and analyze the N-terminal fragment of the sonic hedgehog gene. Total RNA was extracted from the notochord of a Sprague-Dawley rat at embryonic day 9 and the N-terminal fragment of sonic hedgehog was amplified by nested reverse transcription-PCR. The N-terminal fragment of the sonic hedgehog gene was successfully cloned. The secondary and tertiary structures of the N-terminal fragment of the sonic hedgehog protein were predicted using Jpred and Phyre online. 展开更多
关键词 neural regeneration basic research sonic hedgehog protein CLONING nested reversetranscription-PCR secondary structure tertiary structure central nervous system developmentalneurobiology rats grants-supported paper photographs-containing paper neuroregeneration
暂未订购
National Swine Genetic Improvement: An overview of essential program components and organizational structure needed for success
19
作者 John MABRY 《华南农业大学学报》 CAS CSCD 北大核心 2005年第S1期20-27,共8页
The swine industry in China is a thriving and evolving industry that has shown phenomenal growth over the past 10 years. To insure long term success and viability in a worldwide competitive industry such as pork, ther... The swine industry in China is a thriving and evolving industry that has shown phenomenal growth over the past 10 years. To insure long term success and viability in a worldwide competitive industry such as pork, there is need for a National Swine Genetic Improvement Program. This program needs to draw on expertise and technology from across the world for its development, but it should be based on the structure of the pig industry in China and be led by Chinese scientists, administrators and producers. National Genetic Improvement requires more than just technology. A successful program of national genetic improvement will require cooperation from the industry and the government. The support for the university system is essential for the success of the pig industry. The university system has a vital role on education (of students, faculty, producers and consumers) as well as research and technology transfer. The government could also have a role in supporting the central test stations and AI stations across the country. An accurate and comprehensive pedigree maintenance system is essential to genetic improvement. And it will be vitally important to be active in the importation of new genetics to sample other populations. 展开更多
关键词 SWINE National Genetic Improvement program organizational structure
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部